X-Git-Url: http://git.sourceforge.jp/view?p=pf3gnuchains%2Fgcc-fork.git;a=blobdiff_plain;f=gcc%2Ftree-data-ref.c;h=40f7a4407c7a74d100778fbdef9815eb84888789;hp=57b1ac0092122270b4c0d5a9a3dc98e24382b59c;hb=5b7cd9a5b3895e38d03c8fe09dcb371be4e4a1f3;hpb=df71b940580bce9853600f078093d225fc4f9c02 diff --git a/gcc/tree-data-ref.c b/gcc/tree-data-ref.c index 57b1ac00921..40f7a4407c7 100644 --- a/gcc/tree-data-ref.c +++ b/gcc/tree-data-ref.c @@ -1,12 +1,13 @@ /* Data references and dependences detectors. - Copyright (C) 2003, 2004, 2005, 2006 Free Software Foundation, Inc. + Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 + Free Software Foundation, Inc. Contributed by Sebastian Pop This file is part of GCC. GCC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free -Software Foundation; either version 2, or (at your option) any later +Software Foundation; either version 3, or (at your option) any later version. GCC is distributed in the hope that it will be useful, but WITHOUT ANY @@ -15,63 +16,62 @@ FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License -along with GCC; see the file COPYING. If not, write to the Free -Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA -02110-1301, USA. */ +along with GCC; see the file COPYING3. If not see +. */ /* This pass walks a given loop structure searching for array references. The information about the array accesses is recorded - in DATA_REFERENCE structures. - - The basic test for determining the dependences is: - given two access functions chrec1 and chrec2 to a same array, and - x and y two vectors from the iteration domain, the same element of + in DATA_REFERENCE structures. + + The basic test for determining the dependences is: + given two access functions chrec1 and chrec2 to a same array, and + x and y two vectors from the iteration domain, the same element of the array is accessed twice at iterations x and y if and only if: | chrec1 (x) == chrec2 (y). - + The goals of this analysis are: - + - to determine the independence: the relation between two independent accesses is qualified with the chrec_known (this information allows a loop parallelization), - + - when two data references access the same data, to qualify the dependence relation with classic dependence representations: - + - distance vectors - direction vectors - loop carried level dependence - polyhedron dependence or with the chains of recurrences based representation, - - - to define a knowledge base for storing the data dependence + + - to define a knowledge base for storing the data dependence information, - + - to define an interface to access this data. - - + + Definitions: - + - subscript: given two array accesses a subscript is the tuple composed of the access functions for a given dimension. Example: Given A[f1][f2][f3] and B[g1][g2][g3], there are three subscripts: (f1, g1), (f2, g2), (f3, g3). - Diophantine equation: an equation whose coefficients and - solutions are integer constants, for example the equation + solutions are integer constants, for example the equation | 3*x + 2*y = 1 has an integer solution x = 1 and y = -1. - + References: - + - "Advanced Compilation for High Performance Computing" by Randy Allen and Ken Kennedy. - http://citeseer.ist.psu.edu/goff91practical.html - - - "Loop Transformations for Restructuring Compilers - The Foundations" + http://citeseer.ist.psu.edu/goff91practical.html + + - "Loop Transformations for Restructuring Compilers - The Foundations" by Utpal Banerjee. - + */ #include "config.h" @@ -79,20 +79,22 @@ Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA #include "coretypes.h" #include "tm.h" #include "ggc.h" +#include "flags.h" #include "tree.h" /* These RTL headers are needed for basic-block.h. */ -#include "rtl.h" #include "basic-block.h" #include "diagnostic.h" +#include "tree-pretty-print.h" +#include "gimple-pretty-print.h" #include "tree-flow.h" #include "tree-dump.h" #include "timevar.h" #include "cfgloop.h" -#include "tree-chrec.h" #include "tree-data-ref.h" #include "tree-scalar-evolution.h" #include "tree-pass.h" +#include "langhooks.h" static struct datadep_stats { @@ -121,401 +123,23 @@ static struct datadep_stats int num_miv_unimplemented; } dependence_stats; -static tree object_analysis (tree, tree, bool, struct data_reference **, - tree *, tree *, tree *, tree *, tree *, - struct ptr_info_def **, subvar_t *); -static struct data_reference * init_data_ref (tree, tree, tree, tree, bool, - tree, tree, tree, tree, tree, - struct ptr_info_def *, - enum data_ref_type); static bool subscript_dependence_tester_1 (struct data_dependence_relation *, struct data_reference *, - struct data_reference *); - -/* Determine if PTR and DECL may alias, the result is put in ALIASED. - Return FALSE if there is no symbol memory tag for PTR. */ - -static bool -ptr_decl_may_alias_p (tree ptr, tree decl, - struct data_reference *ptr_dr, - bool *aliased) -{ - tree tag; - - gcc_assert (TREE_CODE (ptr) == SSA_NAME && DECL_P (decl)); - - tag = get_var_ann (SSA_NAME_VAR (ptr))->symbol_mem_tag; - if (!tag) - tag = DR_MEMTAG (ptr_dr); - if (!tag) - return false; - - *aliased = is_aliased_with (tag, decl); - return true; -} - - -/* Determine if two pointers may alias, the result is put in ALIASED. - Return FALSE if there is no symbol memory tag for one of the pointers. */ - -static bool -ptr_ptr_may_alias_p (tree ptr_a, tree ptr_b, - struct data_reference *dra, - struct data_reference *drb, - bool *aliased) -{ - tree tag_a, tag_b; - - tag_a = get_var_ann (SSA_NAME_VAR (ptr_a))->symbol_mem_tag; - if (!tag_a) - tag_a = DR_MEMTAG (dra); - if (!tag_a) - return false; - tag_b = get_var_ann (SSA_NAME_VAR (ptr_b))->symbol_mem_tag; - if (!tag_b) - tag_b = DR_MEMTAG (drb); - if (!tag_b) - return false; - *aliased = (tag_a == tag_b); - return true; -} - - -/* Determine if BASE_A and BASE_B may alias, the result is put in ALIASED. - Return FALSE if there is no symbol memory tag for one of the symbols. */ - -static bool -may_alias_p (tree base_a, tree base_b, - struct data_reference *dra, - struct data_reference *drb, - bool *aliased) -{ - if (TREE_CODE (base_a) == ADDR_EXPR || TREE_CODE (base_b) == ADDR_EXPR) - { - if (TREE_CODE (base_a) == ADDR_EXPR && TREE_CODE (base_b) == ADDR_EXPR) - { - *aliased = (TREE_OPERAND (base_a, 0) == TREE_OPERAND (base_b, 0)); - return true; - } - if (TREE_CODE (base_a) == ADDR_EXPR) - return ptr_decl_may_alias_p (base_b, TREE_OPERAND (base_a, 0), drb, - aliased); - else - return ptr_decl_may_alias_p (base_a, TREE_OPERAND (base_b, 0), dra, - aliased); - } - - return ptr_ptr_may_alias_p (base_a, base_b, dra, drb, aliased); -} - - -/* Determine if a pointer (BASE_A) and a record/union access (BASE_B) - are not aliased. Return TRUE if they differ. */ -static bool -record_ptr_differ_p (struct data_reference *dra, - struct data_reference *drb) -{ - bool aliased; - tree base_a = DR_BASE_OBJECT (dra); - tree base_b = DR_BASE_OBJECT (drb); - - if (TREE_CODE (base_b) != COMPONENT_REF) - return false; - - /* Peel COMPONENT_REFs to get to the base. Do not peel INDIRECT_REFs. - For a.b.c.d[i] we will get a, and for a.b->c.d[i] we will get a.b. - Probably will be unnecessary with struct alias analysis. */ - while (TREE_CODE (base_b) == COMPONENT_REF) - base_b = TREE_OPERAND (base_b, 0); - /* Compare a record/union access (b.c[i] or p->c[i]) and a pointer - ((*q)[i]). */ - if (TREE_CODE (base_a) == INDIRECT_REF - && ((TREE_CODE (base_b) == VAR_DECL - && (ptr_decl_may_alias_p (TREE_OPERAND (base_a, 0), base_b, dra, - &aliased) - && !aliased)) - || (TREE_CODE (base_b) == INDIRECT_REF - && (ptr_ptr_may_alias_p (TREE_OPERAND (base_a, 0), - TREE_OPERAND (base_b, 0), dra, drb, - &aliased) - && !aliased)))) - return true; - else - return false; -} - - -/* Determine if an array access (BASE_A) and a record/union access (BASE_B) - are not aliased. Return TRUE if they differ. */ -static bool -record_array_differ_p (struct data_reference *dra, - struct data_reference *drb) -{ - bool aliased; - tree base_a = DR_BASE_OBJECT (dra); - tree base_b = DR_BASE_OBJECT (drb); - - if (TREE_CODE (base_b) != COMPONENT_REF) - return false; - - /* Peel COMPONENT_REFs to get to the base. Do not peel INDIRECT_REFs. - For a.b.c.d[i] we will get a, and for a.b->c.d[i] we will get a.b. - Probably will be unnecessary with struct alias analysis. */ - while (TREE_CODE (base_b) == COMPONENT_REF) - base_b = TREE_OPERAND (base_b, 0); - - /* Compare a record/union access (b.c[i] or p->c[i]) and an array access - (a[i]). In case of p->c[i] use alias analysis to verify that p is not - pointing to a. */ - if (TREE_CODE (base_a) == VAR_DECL - && (TREE_CODE (base_b) == VAR_DECL - || (TREE_CODE (base_b) == INDIRECT_REF - && (ptr_decl_may_alias_p (TREE_OPERAND (base_b, 0), base_a, drb, - &aliased) - && !aliased)))) - return true; - else - return false; -} - - -/* Determine if an array access (BASE_A) and a pointer (BASE_B) - are not aliased. Return TRUE if they differ. */ -static bool -array_ptr_differ_p (tree base_a, tree base_b, - struct data_reference *drb) -{ - bool aliased; - - /* In case one of the bases is a pointer (a[i] and (*p)[i]), we check with the - help of alias analysis that p is not pointing to a. */ - if (TREE_CODE (base_a) == VAR_DECL && TREE_CODE (base_b) == INDIRECT_REF - && (ptr_decl_may_alias_p (TREE_OPERAND (base_b, 0), base_a, drb, &aliased) - && !aliased)) - return true; - else - return false; -} - - -/* This is the simplest data dependence test: determines whether the - data references A and B access the same array/region. Returns - false when the property is not computable at compile time. - Otherwise return true, and DIFFER_P will record the result. This - utility will not be necessary when alias_sets_conflict_p will be - less conservative. */ - -static bool -base_object_differ_p (struct data_reference *a, - struct data_reference *b, - bool *differ_p) -{ - tree base_a = DR_BASE_OBJECT (a); - tree base_b = DR_BASE_OBJECT (b); - bool aliased; - - if (!base_a || !base_b) - return false; - - /* Determine if same base. Example: for the array accesses - a[i], b[i] or pointer accesses *a, *b, bases are a, b. */ - if (base_a == base_b) - { - *differ_p = false; - return true; - } - - /* For pointer based accesses, (*p)[i], (*q)[j], the bases are (*p) - and (*q) */ - if (TREE_CODE (base_a) == INDIRECT_REF && TREE_CODE (base_b) == INDIRECT_REF - && TREE_OPERAND (base_a, 0) == TREE_OPERAND (base_b, 0)) - { - *differ_p = false; - return true; - } - - /* Record/union based accesses - s.a[i], t.b[j]. bases are s.a,t.b. */ - if (TREE_CODE (base_a) == COMPONENT_REF && TREE_CODE (base_b) == COMPONENT_REF - && TREE_OPERAND (base_a, 0) == TREE_OPERAND (base_b, 0) - && TREE_OPERAND (base_a, 1) == TREE_OPERAND (base_b, 1)) - { - *differ_p = false; - return true; - } - - - /* Determine if different bases. */ - - /* At this point we know that base_a != base_b. However, pointer - accesses of the form x=(*p) and y=(*q), whose bases are p and q, - may still be pointing to the same base. In SSAed GIMPLE p and q will - be SSA_NAMES in this case. Therefore, here we check if they are - really two different declarations. */ - if (TREE_CODE (base_a) == VAR_DECL && TREE_CODE (base_b) == VAR_DECL) - { - *differ_p = true; - return true; - } - - /* In case one of the bases is a pointer (a[i] and (*p)[i]), we check with the - help of alias analysis that p is not pointing to a. */ - if (array_ptr_differ_p (base_a, base_b, b) - || array_ptr_differ_p (base_b, base_a, a)) - { - *differ_p = true; - return true; - } - - /* If the bases are pointers ((*q)[i] and (*p)[i]), we check with the - help of alias analysis they don't point to the same bases. */ - if (TREE_CODE (base_a) == INDIRECT_REF && TREE_CODE (base_b) == INDIRECT_REF - && (may_alias_p (TREE_OPERAND (base_a, 0), TREE_OPERAND (base_b, 0), a, b, - &aliased) - && !aliased)) - { - *differ_p = true; - return true; - } - - /* Compare two record/union bases s.a and t.b: s != t or (a != b and - s and t are not unions). */ - if (TREE_CODE (base_a) == COMPONENT_REF && TREE_CODE (base_b) == COMPONENT_REF - && ((TREE_CODE (TREE_OPERAND (base_a, 0)) == VAR_DECL - && TREE_CODE (TREE_OPERAND (base_b, 0)) == VAR_DECL - && TREE_OPERAND (base_a, 0) != TREE_OPERAND (base_b, 0)) - || (TREE_CODE (TREE_TYPE (TREE_OPERAND (base_a, 0))) == RECORD_TYPE - && TREE_CODE (TREE_TYPE (TREE_OPERAND (base_b, 0))) == RECORD_TYPE - && TREE_OPERAND (base_a, 1) != TREE_OPERAND (base_b, 1)))) - { - *differ_p = true; - return true; - } - - /* Compare a record/union access (b.c[i] or p->c[i]) and a pointer - ((*q)[i]). */ - if (record_ptr_differ_p (a, b) || record_ptr_differ_p (b, a)) - { - *differ_p = true; - return true; - } - - /* Compare a record/union access (b.c[i] or p->c[i]) and an array access - (a[i]). In case of p->c[i] use alias analysis to verify that p is not - pointing to a. */ - if (record_array_differ_p (a, b) || record_array_differ_p (b, a)) - { - *differ_p = true; - return true; - } - - return false; -} - -/* Function base_addr_differ_p. - - This is the simplest data dependence test: determines whether the - data references DRA and DRB access the same array/region. Returns - false when the property is not computable at compile time. - Otherwise return true, and DIFFER_P will record the result. - - The algorithm: - 1. if (both DRA and DRB are represented as arrays) - compare DRA.BASE_OBJECT and DRB.BASE_OBJECT - 2. else if (both DRA and DRB are represented as pointers) - try to prove that DRA.FIRST_LOCATION == DRB.FIRST_LOCATION - 3. else if (DRA and DRB are represented differently or 2. fails) - only try to prove that the bases are surely different -*/ - -static bool -base_addr_differ_p (struct data_reference *dra, - struct data_reference *drb, - bool *differ_p) -{ - tree addr_a = DR_BASE_ADDRESS (dra); - tree addr_b = DR_BASE_ADDRESS (drb); - tree type_a, type_b; - bool aliased; - - if (!addr_a || !addr_b) - return false; - - type_a = TREE_TYPE (addr_a); - type_b = TREE_TYPE (addr_b); - - gcc_assert (POINTER_TYPE_P (type_a) && POINTER_TYPE_P (type_b)); - - /* 1. if (both DRA and DRB are represented as arrays) - compare DRA.BASE_OBJECT and DRB.BASE_OBJECT. */ - if (DR_TYPE (dra) == ARRAY_REF_TYPE && DR_TYPE (drb) == ARRAY_REF_TYPE) - return base_object_differ_p (dra, drb, differ_p); - - /* 2. else if (both DRA and DRB are represented as pointers) - try to prove that DRA.FIRST_LOCATION == DRB.FIRST_LOCATION. */ - /* If base addresses are the same, we check the offsets, since the access of - the data-ref is described by {base addr + offset} and its access function, - i.e., in order to decide whether the bases of data-refs are the same we - compare both base addresses and offsets. */ - if (DR_TYPE (dra) == POINTER_REF_TYPE && DR_TYPE (drb) == POINTER_REF_TYPE - && (addr_a == addr_b - || (TREE_CODE (addr_a) == ADDR_EXPR && TREE_CODE (addr_b) == ADDR_EXPR - && TREE_OPERAND (addr_a, 0) == TREE_OPERAND (addr_b, 0)))) - { - /* Compare offsets. */ - tree offset_a = DR_OFFSET (dra); - tree offset_b = DR_OFFSET (drb); - - STRIP_NOPS (offset_a); - STRIP_NOPS (offset_b); - - /* FORNOW: we only compare offsets that are MULT_EXPR, i.e., we don't handle - PLUS_EXPR. */ - if (offset_a == offset_b - || (TREE_CODE (offset_a) == MULT_EXPR - && TREE_CODE (offset_b) == MULT_EXPR - && TREE_OPERAND (offset_a, 0) == TREE_OPERAND (offset_b, 0) - && TREE_OPERAND (offset_a, 1) == TREE_OPERAND (offset_b, 1))) - { - *differ_p = false; - return true; - } - } - - /* 3. else if (DRA and DRB are represented differently or 2. fails) - only try to prove that the bases are surely different. */ - - /* Apply alias analysis. */ - if (may_alias_p (addr_a, addr_b, dra, drb, &aliased) && !aliased) - { - *differ_p = true; - return true; - } - - /* An instruction writing through a restricted pointer is "independent" of any - instruction reading or writing through a different pointer, in the same - block/scope. */ - else if ((TYPE_RESTRICT (type_a) && !DR_IS_READ (dra)) - || (TYPE_RESTRICT (type_b) && !DR_IS_READ (drb))) - { - *differ_p = true; - return true; - } - return false; -} - + struct data_reference *, + struct loop *); /* Returns true iff A divides B. */ -static inline bool -tree_fold_divides_p (tree a, - tree b) +static inline bool +tree_fold_divides_p (const_tree a, const_tree b) { - /* Determines whether (A == gcd (A, B)). */ - return tree_int_cst_equal (a, tree_fold_gcd (a, b)); + gcc_assert (TREE_CODE (a) == INTEGER_CST); + gcc_assert (TREE_CODE (b) == INTEGER_CST); + return integer_zerop (int_const_binop (TRUNC_MOD_EXPR, b, a, 0)); } /* Returns true iff A divides B. */ -static inline bool +static inline bool int_divides_p (int a, int b) { return ((b % a) == 0); @@ -523,9 +147,9 @@ int_divides_p (int a, int b) -/* Dump into FILE all the data references from DATAREFS. */ +/* Dump into FILE all the data references from DATAREFS. */ -void +void dump_data_references (FILE *file, VEC (data_reference_p, heap) *datarefs) { unsigned int i; @@ -535,10 +159,26 @@ dump_data_references (FILE *file, VEC (data_reference_p, heap) *datarefs) dump_data_reference (file, dr); } -/* Dump into FILE all the dependence relations from DDRS. */ +/* Dump into STDERR all the data references from DATAREFS. */ + +void +debug_data_references (VEC (data_reference_p, heap) *datarefs) +{ + dump_data_references (stderr, datarefs); +} + +/* Dump to STDERR all the dependence relations from DDRS. */ + +void +debug_data_dependence_relations (VEC (ddr_p, heap) *ddrs) +{ + dump_data_dependence_relations (stderr, ddrs); +} + +/* Dump into FILE all the dependence relations from DDRS. */ -void -dump_data_dependence_relations (FILE *file, +void +dump_data_dependence_relations (FILE *file, VEC (ddr_p, heap) *ddrs) { unsigned int i; @@ -548,58 +188,97 @@ dump_data_dependence_relations (FILE *file, dump_data_dependence_relation (file, ddr); } +/* Print to STDERR the data_reference DR. */ + +void +debug_data_reference (struct data_reference *dr) +{ + dump_data_reference (stderr, dr); +} + /* Dump function for a DATA_REFERENCE structure. */ -void -dump_data_reference (FILE *outf, +void +dump_data_reference (FILE *outf, struct data_reference *dr) { unsigned int i; - - fprintf (outf, "(Data Ref: \n stmt: "); - print_generic_stmt (outf, DR_STMT (dr), 0); - fprintf (outf, " ref: "); + + fprintf (outf, "#(Data Ref: \n# stmt: "); + print_gimple_stmt (outf, DR_STMT (dr), 0, 0); + fprintf (outf, "# ref: "); print_generic_stmt (outf, DR_REF (dr), 0); - fprintf (outf, " base_object: "); + fprintf (outf, "# base_object: "); print_generic_stmt (outf, DR_BASE_OBJECT (dr), 0); - + for (i = 0; i < DR_NUM_DIMENSIONS (dr); i++) { - fprintf (outf, " Access function %d: ", i); + fprintf (outf, "# Access function %d: ", i); print_generic_stmt (outf, DR_ACCESS_FN (dr, i), 0); } - fprintf (outf, ")\n"); + fprintf (outf, "#)\n"); +} + +/* Dumps the affine function described by FN to the file OUTF. */ + +static void +dump_affine_function (FILE *outf, affine_fn fn) +{ + unsigned i; + tree coef; + + print_generic_expr (outf, VEC_index (tree, fn, 0), TDF_SLIM); + for (i = 1; VEC_iterate (tree, fn, i, coef); i++) + { + fprintf (outf, " + "); + print_generic_expr (outf, coef, TDF_SLIM); + fprintf (outf, " * x_%u", i); + } +} + +/* Dumps the conflict function CF to the file OUTF. */ + +static void +dump_conflict_function (FILE *outf, conflict_function *cf) +{ + unsigned i; + + if (cf->n == NO_DEPENDENCE) + fprintf (outf, "no dependence\n"); + else if (cf->n == NOT_KNOWN) + fprintf (outf, "not known\n"); + else + { + for (i = 0; i < cf->n; i++) + { + fprintf (outf, "["); + dump_affine_function (outf, cf->fns[i]); + fprintf (outf, "]\n"); + } + } } /* Dump function for a SUBSCRIPT structure. */ -void +void dump_subscript (FILE *outf, struct subscript *subscript) { - tree chrec = SUB_CONFLICTS_IN_A (subscript); + conflict_function *cf = SUB_CONFLICTS_IN_A (subscript); fprintf (outf, "\n (subscript \n"); fprintf (outf, " iterations_that_access_an_element_twice_in_A: "); - print_generic_stmt (outf, chrec, 0); - if (chrec == chrec_known) - fprintf (outf, " (no dependence)\n"); - else if (chrec_contains_undetermined (chrec)) - fprintf (outf, " (don't know)\n"); - else + dump_conflict_function (outf, cf); + if (CF_NONTRIVIAL_P (cf)) { tree last_iteration = SUB_LAST_CONFLICT (subscript); fprintf (outf, " last_conflict: "); print_generic_stmt (outf, last_iteration, 0); } - - chrec = SUB_CONFLICTS_IN_B (subscript); + + cf = SUB_CONFLICTS_IN_B (subscript); fprintf (outf, " iterations_that_access_an_element_twice_in_B: "); - print_generic_stmt (outf, chrec, 0); - if (chrec == chrec_known) - fprintf (outf, " (no dependence)\n"); - else if (chrec_contains_undetermined (chrec)) - fprintf (outf, " (don't know)\n"); - else + dump_conflict_function (outf, cf); + if (CF_NONTRIVIAL_P (cf)) { tree last_iteration = SUB_LAST_CONFLICT (subscript); fprintf (outf, " last_conflict: "); @@ -623,7 +302,8 @@ print_direction_vector (FILE *outf, for (eq = 0; eq < length; eq++) { - enum data_dependence_direction dir = dirv[eq]; + enum data_dependence_direction dir = ((enum data_dependence_direction) + dirv[eq]); switch (dir) { @@ -684,7 +364,7 @@ print_dist_vectors (FILE *outf, VEC (lambda_vector, heap) *dist_vects, /* Debug version. */ -void +void debug_data_dependence_relation (struct data_dependence_relation *ddr) { dump_data_dependence_relation (stderr, ddr); @@ -692,21 +372,41 @@ debug_data_dependence_relation (struct data_dependence_relation *ddr) /* Dump function for a DATA_DEPENDENCE_RELATION structure. */ -void -dump_data_dependence_relation (FILE *outf, +void +dump_data_dependence_relation (FILE *outf, struct data_dependence_relation *ddr) { struct data_reference *dra, *drb; + fprintf (outf, "(Data Dep: \n"); + + if (!ddr || DDR_ARE_DEPENDENT (ddr) == chrec_dont_know) + { + if (ddr) + { + dra = DDR_A (ddr); + drb = DDR_B (ddr); + if (dra) + dump_data_reference (outf, dra); + else + fprintf (outf, " (nil)\n"); + if (drb) + dump_data_reference (outf, drb); + else + fprintf (outf, " (nil)\n"); + } + fprintf (outf, " (don't know)\n)\n"); + return; + } + dra = DDR_A (ddr); drb = DDR_B (ddr); - fprintf (outf, "(Data Dep: \n"); - if (DDR_ARE_DEPENDENT (ddr) == chrec_dont_know) - fprintf (outf, " (don't know)\n"); - - else if (DDR_ARE_DEPENDENT (ddr) == chrec_known) + dump_data_reference (outf, dra); + dump_data_reference (outf, drb); + + if (DDR_ARE_DEPENDENT (ddr) == chrec_known) fprintf (outf, " (no dependence)\n"); - + else if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE) { unsigned int i; @@ -721,6 +421,7 @@ dump_data_dependence_relation (FILE *outf, dump_subscript (outf, DDR_SUBSCRIPT (ddr, i)); } + fprintf (outf, " inner loop index: %d\n", DDR_INNER_LOOP (ddr)); fprintf (outf, " loop nest: ("); for (i = 0; VEC_iterate (loop_p, DDR_LOOP_NEST (ddr), i, loopi); i++) fprintf (outf, "%d ", loopi->num); @@ -747,40 +448,40 @@ dump_data_dependence_relation (FILE *outf, /* Dump function for a DATA_DEPENDENCE_DIRECTION structure. */ void -dump_data_dependence_direction (FILE *file, +dump_data_dependence_direction (FILE *file, enum data_dependence_direction dir) { switch (dir) { - case dir_positive: + case dir_positive: fprintf (file, "+"); break; - + case dir_negative: fprintf (file, "-"); break; - + case dir_equal: fprintf (file, "="); break; - + case dir_positive_or_negative: fprintf (file, "+-"); break; - - case dir_positive_or_equal: + + case dir_positive_or_equal: fprintf (file, "+="); break; - - case dir_negative_or_equal: + + case dir_negative_or_equal: fprintf (file, "-="); break; - - case dir_star: - fprintf (file, "*"); + + case dir_star: + fprintf (file, "*"); break; - - default: + + default: break; } } @@ -790,7 +491,7 @@ dump_data_dependence_direction (FILE *file, dependence vectors, or in other words the number of loops in the considered nest. */ -void +void dump_dist_dir_vectors (FILE *file, VEC (ddr_p, heap) *ddrs) { unsigned int i, j; @@ -820,7 +521,7 @@ dump_dist_dir_vectors (FILE *file, VEC (ddr_p, heap) *ddrs) /* Dumps the data dependence relations DDRS in FILE. */ -void +void dump_ddrs (FILE *file, VEC (ddr_p, heap) *ddrs) { unsigned int i; @@ -832,1316 +533,906 @@ dump_ddrs (FILE *file, VEC (ddr_p, heap) *ddrs) fprintf (file, "\n\n"); } - - -/* Estimate the number of iterations from the size of the data and the - access functions. */ +/* Helper function for split_constant_offset. Expresses OP0 CODE OP1 + (the type of the result is TYPE) as VAR + OFF, where OFF is a nonzero + constant of type ssizetype, and returns true. If we cannot do this + with OFF nonzero, OFF and VAR are set to NULL_TREE instead and false + is returned. */ -static void -estimate_niter_from_size_of_data (struct loop *loop, - tree opnd0, - tree access_fn, - tree stmt) -{ - tree estimation = NULL_TREE; - tree array_size, data_size, element_size; - tree init, step; - - init = initial_condition (access_fn); - step = evolution_part_in_loop_num (access_fn, loop->num); - - array_size = TYPE_SIZE (TREE_TYPE (opnd0)); - element_size = TYPE_SIZE (TREE_TYPE (TREE_TYPE (opnd0))); - if (array_size == NULL_TREE - || TREE_CODE (array_size) != INTEGER_CST - || TREE_CODE (element_size) != INTEGER_CST) - return; +static bool +split_constant_offset_1 (tree type, tree op0, enum tree_code code, tree op1, + tree *var, tree *off) +{ + tree var0, var1; + tree off0, off1; + enum tree_code ocode = code; - data_size = fold_build2 (EXACT_DIV_EXPR, integer_type_node, - array_size, element_size); + *var = NULL_TREE; + *off = NULL_TREE; - if (init != NULL_TREE - && step != NULL_TREE - && TREE_CODE (init) == INTEGER_CST - && TREE_CODE (step) == INTEGER_CST) + switch (code) { - tree i_plus_s = fold_build2 (PLUS_EXPR, integer_type_node, init, step); - tree sign = fold_binary (GT_EXPR, boolean_type_node, i_plus_s, init); - - if (sign == boolean_true_node) - estimation = fold_build2 (CEIL_DIV_EXPR, integer_type_node, - fold_build2 (MINUS_EXPR, integer_type_node, - data_size, init), step); - - /* When the step is negative, as in PR23386: (init = 3, step = - 0ffffffff, data_size = 100), we have to compute the - estimation as ceil_div (init, 0 - step) + 1. */ - else if (sign == boolean_false_node) - estimation = - fold_build2 (PLUS_EXPR, integer_type_node, - fold_build2 (CEIL_DIV_EXPR, integer_type_node, - init, - fold_build2 (MINUS_EXPR, unsigned_type_node, - integer_zero_node, step)), - integer_one_node); - - if (estimation) - record_estimate (loop, estimation, boolean_true_node, stmt); - } -} - -/* Given an ARRAY_REF node REF, records its access functions. - Example: given A[i][3], record in ACCESS_FNS the opnd1 function, - i.e. the constant "3", then recursively call the function on opnd0, - i.e. the ARRAY_REF "A[i]". - If ESTIMATE_ONLY is true, we just set the estimated number of loop - iterations, we don't store the access function. - The function returns the base name: "A". */ + case INTEGER_CST: + *var = build_int_cst (type, 0); + *off = fold_convert (ssizetype, op0); + return true; -static tree -analyze_array_indexes (struct loop *loop, - VEC(tree,heap) **access_fns, - tree ref, tree stmt, - bool estimate_only) -{ - tree opnd0, opnd1; - tree access_fn; - - opnd0 = TREE_OPERAND (ref, 0); - opnd1 = TREE_OPERAND (ref, 1); - - /* The detection of the evolution function for this data access is - postponed until the dependence test. This lazy strategy avoids - the computation of access functions that are of no interest for - the optimizers. */ - access_fn = instantiate_parameters - (loop, analyze_scalar_evolution (loop, opnd1)); - - if (estimate_only - && chrec_contains_undetermined (loop->estimated_nb_iterations)) - estimate_niter_from_size_of_data (loop, opnd0, access_fn, stmt); - - if (!estimate_only) - VEC_safe_push (tree, heap, *access_fns, access_fn); - - /* Recursively record other array access functions. */ - if (TREE_CODE (opnd0) == ARRAY_REF) - return analyze_array_indexes (loop, access_fns, opnd0, stmt, estimate_only); - - /* Return the base name of the data access. */ - else - return opnd0; -} + case POINTER_PLUS_EXPR: + ocode = PLUS_EXPR; + /* FALLTHROUGH */ + case PLUS_EXPR: + case MINUS_EXPR: + split_constant_offset (op0, &var0, &off0); + split_constant_offset (op1, &var1, &off1); + *var = fold_build2 (code, type, var0, var1); + *off = size_binop (ocode, off0, off1); + return true; -/* For an array reference REF contained in STMT, attempt to bound the - number of iterations in the loop containing STMT */ + case MULT_EXPR: + if (TREE_CODE (op1) != INTEGER_CST) + return false; -void -estimate_iters_using_array (tree stmt, tree ref) -{ - analyze_array_indexes (loop_containing_stmt (stmt), NULL, ref, stmt, - true); -} - -/* For a data reference REF contained in the statement STMT, initialize - a DATA_REFERENCE structure, and return it. IS_READ flag has to be - set to true when REF is in the right hand side of an - assignment. */ + split_constant_offset (op0, &var0, &off0); + *var = fold_build2 (MULT_EXPR, type, var0, op1); + *off = size_binop (MULT_EXPR, off0, fold_convert (ssizetype, op1)); + return true; -struct data_reference * -analyze_array (tree stmt, tree ref, bool is_read) -{ - struct data_reference *res; - VEC(tree,heap) *acc_fns; + case ADDR_EXPR: + { + tree base, poffset; + HOST_WIDE_INT pbitsize, pbitpos; + enum machine_mode pmode; + int punsignedp, pvolatilep; - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, "(analyze_array \n"); - fprintf (dump_file, " (ref = "); - print_generic_stmt (dump_file, ref, 0); - fprintf (dump_file, ")\n"); - } + op0 = TREE_OPERAND (op0, 0); + if (!handled_component_p (op0)) + return false; - res = XNEW (struct data_reference); - - DR_STMT (res) = stmt; - DR_REF (res) = ref; - acc_fns = VEC_alloc (tree, heap, 3); - DR_BASE_OBJECT (res) = analyze_array_indexes - (loop_containing_stmt (stmt), &acc_fns, ref, stmt, false); - DR_TYPE (res) = ARRAY_REF_TYPE; - DR_SET_ACCESS_FNS (res, acc_fns); - DR_IS_READ (res) = is_read; - DR_BASE_ADDRESS (res) = NULL_TREE; - DR_OFFSET (res) = NULL_TREE; - DR_INIT (res) = NULL_TREE; - DR_STEP (res) = NULL_TREE; - DR_OFFSET_MISALIGNMENT (res) = NULL_TREE; - DR_MEMTAG (res) = NULL_TREE; - DR_PTR_INFO (res) = NULL; + base = get_inner_reference (op0, &pbitsize, &pbitpos, &poffset, + &pmode, &punsignedp, &pvolatilep, false); - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, ")\n"); + if (pbitpos % BITS_PER_UNIT != 0) + return false; + base = build_fold_addr_expr (base); + off0 = ssize_int (pbitpos / BITS_PER_UNIT); - return res; + if (poffset) + { + split_constant_offset (poffset, &poffset, &off1); + off0 = size_binop (PLUS_EXPR, off0, off1); + if (POINTER_TYPE_P (TREE_TYPE (base))) + base = fold_build2 (POINTER_PLUS_EXPR, TREE_TYPE (base), + base, fold_convert (sizetype, poffset)); + else + base = fold_build2 (PLUS_EXPR, TREE_TYPE (base), base, + fold_convert (TREE_TYPE (base), poffset)); + } + + var0 = fold_convert (type, base); + + /* If variable length types are involved, punt, otherwise casts + might be converted into ARRAY_REFs in gimplify_conversion. + To compute that ARRAY_REF's element size TYPE_SIZE_UNIT, which + possibly no longer appears in current GIMPLE, might resurface. + This perhaps could run + if (CONVERT_EXPR_P (var0)) + { + gimplify_conversion (&var0); + // Attempt to fill in any within var0 found ARRAY_REF's + // element size from corresponding op embedded ARRAY_REF, + // if unsuccessful, just punt. + } */ + while (POINTER_TYPE_P (type)) + type = TREE_TYPE (type); + if (int_size_in_bytes (type) < 0) + return false; + + *var = var0; + *off = off0; + return true; + } + + case SSA_NAME: + { + gimple def_stmt = SSA_NAME_DEF_STMT (op0); + enum tree_code subcode; + + if (gimple_code (def_stmt) != GIMPLE_ASSIGN) + return false; + + var0 = gimple_assign_rhs1 (def_stmt); + subcode = gimple_assign_rhs_code (def_stmt); + var1 = gimple_assign_rhs2 (def_stmt); + + return split_constant_offset_1 (type, var0, subcode, var1, var, off); + } + CASE_CONVERT: + { + /* We must not introduce undefined overflow, and we must not change the value. + Hence we're okay if the inner type doesn't overflow to start with + (pointer or signed), the outer type also is an integer or pointer + and the outer precision is at least as large as the inner. */ + tree itype = TREE_TYPE (op0); + if ((POINTER_TYPE_P (itype) + || (INTEGRAL_TYPE_P (itype) && TYPE_OVERFLOW_UNDEFINED (itype))) + && TYPE_PRECISION (type) >= TYPE_PRECISION (itype) + && (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))) + { + split_constant_offset (op0, &var0, off); + *var = fold_convert (type, var0); + return true; + } + return false; + } + + default: + return false; + } +} + +/* Expresses EXP as VAR + OFF, where off is a constant. The type of OFF + will be ssizetype. */ + +void +split_constant_offset (tree exp, tree *var, tree *off) +{ + tree type = TREE_TYPE (exp), otype, op0, op1, e, o; + enum tree_code code; + + *var = exp; + *off = ssize_int (0); + STRIP_NOPS (exp); + + if (automatically_generated_chrec_p (exp)) + return; + + otype = TREE_TYPE (exp); + code = TREE_CODE (exp); + extract_ops_from_tree (exp, &code, &op0, &op1); + if (split_constant_offset_1 (otype, op0, code, op1, &e, &o)) + { + *var = fold_convert (type, e); + *off = o; + } +} + +/* Returns the address ADDR of an object in a canonical shape (without nop + casts, and with type of pointer to the object). */ + +static tree +canonicalize_base_object_address (tree addr) +{ + tree orig = addr; + + STRIP_NOPS (addr); + + /* The base address may be obtained by casting from integer, in that case + keep the cast. */ + if (!POINTER_TYPE_P (TREE_TYPE (addr))) + return orig; + + if (TREE_CODE (addr) != ADDR_EXPR) + return addr; + + return build_fold_addr_expr (TREE_OPERAND (addr, 0)); } -/* Analyze an indirect memory reference, REF, that comes from STMT. - IS_READ is true if this is an indirect load, and false if it is - an indirect store. - Return a new data reference structure representing the indirect_ref, or - NULL if we cannot describe the access function. */ +/* Analyzes the behavior of the memory reference DR in the innermost loop or + basic block that contains it. Returns true if analysis succeed or false + otherwise. */ -static struct data_reference * -analyze_indirect_ref (tree stmt, tree ref, bool is_read) +bool +dr_analyze_innermost (struct data_reference *dr) { + gimple stmt = DR_STMT (dr); struct loop *loop = loop_containing_stmt (stmt); - tree ptr_ref = TREE_OPERAND (ref, 0); - tree access_fn = analyze_scalar_evolution (loop, ptr_ref); - tree init = initial_condition_in_loop_num (access_fn, loop->num); - tree base_address = NULL_TREE, evolution, step = NULL_TREE; - struct ptr_info_def *ptr_info = NULL; + tree ref = DR_REF (dr); + HOST_WIDE_INT pbitsize, pbitpos; + tree base, poffset; + enum machine_mode pmode; + int punsignedp, pvolatilep; + affine_iv base_iv, offset_iv; + tree init, dinit, step; + bool in_loop = (loop && loop->num); - if (TREE_CODE (ptr_ref) == SSA_NAME) - ptr_info = SSA_NAME_PTR_INFO (ptr_ref); + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, "analyze_innermost: "); + + base = get_inner_reference (ref, &pbitsize, &pbitpos, &poffset, + &pmode, &punsignedp, &pvolatilep, false); + gcc_assert (base != NULL_TREE); - STRIP_NOPS (init); - if (access_fn == chrec_dont_know || !init || init == chrec_dont_know) + if (pbitpos % BITS_PER_UNIT != 0) { if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, "\nBad access function of ptr: "); - print_generic_expr (dump_file, ref, TDF_SLIM); - fprintf (dump_file, "\n"); - } - return NULL; + fprintf (dump_file, "failed: bit offset alignment.\n"); + return false; } - if (dump_file && (dump_flags & TDF_DETAILS)) + base = build_fold_addr_expr (base); + if (in_loop) { - fprintf (dump_file, "\nAccess function of ptr: "); - print_generic_expr (dump_file, access_fn, TDF_SLIM); - fprintf (dump_file, "\n"); + if (!simple_iv (loop, loop_containing_stmt (stmt), base, &base_iv, + false)) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, "failed: evolution of base is not affine.\n"); + return false; + } + } + else + { + base_iv.base = base; + base_iv.step = ssize_int (0); + base_iv.no_overflow = true; } - if (!expr_invariant_in_loop_p (loop, init)) + if (!poffset) { - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, "\ninitial condition is not loop invariant.\n"); + offset_iv.base = ssize_int (0); + offset_iv.step = ssize_int (0); } else { - base_address = init; - evolution = evolution_part_in_loop_num (access_fn, loop->num); - if (evolution != chrec_dont_know) - { - if (!evolution) - step = ssize_int (0); - else + if (!in_loop) + { + offset_iv.base = poffset; + offset_iv.step = ssize_int (0); + } + else if (!simple_iv (loop, loop_containing_stmt (stmt), + poffset, &offset_iv, false)) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, "failed: evolution of offset is not" + " affine.\n"); + return false; + } + } + + init = ssize_int (pbitpos / BITS_PER_UNIT); + split_constant_offset (base_iv.base, &base_iv.base, &dinit); + init = size_binop (PLUS_EXPR, init, dinit); + split_constant_offset (offset_iv.base, &offset_iv.base, &dinit); + init = size_binop (PLUS_EXPR, init, dinit); + + step = size_binop (PLUS_EXPR, + fold_convert (ssizetype, base_iv.step), + fold_convert (ssizetype, offset_iv.step)); + + DR_BASE_ADDRESS (dr) = canonicalize_base_object_address (base_iv.base); + + DR_OFFSET (dr) = fold_convert (ssizetype, offset_iv.base); + DR_INIT (dr) = init; + DR_STEP (dr) = step; + + DR_ALIGNED_TO (dr) = size_int (highest_pow2_factor (offset_iv.base)); + + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, "success.\n"); + + return true; +} + +/* Determines the base object and the list of indices of memory reference + DR, analyzed in loop nest NEST. */ + +static void +dr_analyze_indices (struct data_reference *dr, struct loop *nest) +{ + gimple stmt = DR_STMT (dr); + struct loop *loop = loop_containing_stmt (stmt); + VEC (tree, heap) *access_fns = NULL; + tree ref = unshare_expr (DR_REF (dr)), aref = ref, op; + tree base, off, access_fn = NULL_TREE; + basic_block before_loop = NULL; + + if (nest) + before_loop = block_before_loop (nest); + + while (handled_component_p (aref)) + { + if (TREE_CODE (aref) == ARRAY_REF) + { + op = TREE_OPERAND (aref, 1); + if (nest) { - if (TREE_CODE (evolution) == INTEGER_CST) - step = fold_convert (ssizetype, evolution); - else - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, "\nnon constant step for ptr access.\n"); + access_fn = analyze_scalar_evolution (loop, op); + access_fn = instantiate_scev (before_loop, loop, access_fn); + VEC_safe_push (tree, heap, access_fns, access_fn); } + + TREE_OPERAND (aref, 1) = build_int_cst (TREE_TYPE (op), 0); } - else - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, "\nunknown evolution of ptr.\n"); + + aref = TREE_OPERAND (aref, 0); + } + + if (nest && INDIRECT_REF_P (aref)) + { + op = TREE_OPERAND (aref, 0); + access_fn = analyze_scalar_evolution (loop, op); + access_fn = instantiate_scev (before_loop, loop, access_fn); + base = initial_condition (access_fn); + split_constant_offset (base, &base, &off); + access_fn = chrec_replace_initial_condition (access_fn, + fold_convert (TREE_TYPE (base), off)); + + TREE_OPERAND (aref, 0) = base; + VEC_safe_push (tree, heap, access_fns, access_fn); } - return init_data_ref (stmt, ref, NULL_TREE, access_fn, is_read, base_address, - NULL_TREE, step, NULL_TREE, NULL_TREE, - ptr_info, POINTER_REF_TYPE); + + DR_BASE_OBJECT (dr) = ref; + DR_ACCESS_FNS (dr) = access_fns; } -/* For a data reference REF contained in the statement STMT, initialize - a DATA_REFERENCE structure, and return it. */ +/* Extracts the alias analysis information from the memory reference DR. */ -struct data_reference * -init_data_ref (tree stmt, - tree ref, - tree base, - tree access_fn, - bool is_read, - tree base_address, - tree init_offset, - tree step, - tree misalign, - tree memtag, - struct ptr_info_def *ptr_info, - enum data_ref_type type) -{ - struct data_reference *res; - VEC(tree,heap) *acc_fns; +static void +dr_analyze_alias (struct data_reference *dr) +{ + tree ref = DR_REF (dr); + tree base = get_base_address (ref), addr; - if (dump_file && (dump_flags & TDF_DETAILS)) + if (INDIRECT_REF_P (base)) { - fprintf (dump_file, "(init_data_ref \n"); - fprintf (dump_file, " (ref = "); - print_generic_stmt (dump_file, ref, 0); - fprintf (dump_file, ")\n"); + addr = TREE_OPERAND (base, 0); + if (TREE_CODE (addr) == SSA_NAME) + DR_PTR_INFO (dr) = SSA_NAME_PTR_INFO (addr); } +} - res = XNEW (struct data_reference); - - DR_STMT (res) = stmt; - DR_REF (res) = ref; - DR_BASE_OBJECT (res) = base; - DR_TYPE (res) = type; - acc_fns = VEC_alloc (tree, heap, 3); - DR_SET_ACCESS_FNS (res, acc_fns); - VEC_quick_push (tree, DR_ACCESS_FNS (res), access_fn); - DR_IS_READ (res) = is_read; - DR_BASE_ADDRESS (res) = base_address; - DR_OFFSET (res) = init_offset; - DR_INIT (res) = NULL_TREE; - DR_STEP (res) = step; - DR_OFFSET_MISALIGNMENT (res) = misalign; - DR_MEMTAG (res) = memtag; - DR_PTR_INFO (res) = ptr_info; +/* Returns true if the address of DR is invariant. */ - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, ")\n"); +static bool +dr_address_invariant_p (struct data_reference *dr) +{ + unsigned i; + tree idx; - return res; -} + for (i = 0; VEC_iterate (tree, DR_ACCESS_FNS (dr), i, idx); i++) + if (tree_contains_chrecs (idx, NULL)) + return false; -/* Function strip_conversions + return true; +} - Strip conversions that don't narrow the mode. */ +/* Frees data reference DR. */ -static tree -strip_conversion (tree expr) +void +free_data_ref (data_reference_p dr) { - tree to, ti, oprnd0; - - while (TREE_CODE (expr) == NOP_EXPR || TREE_CODE (expr) == CONVERT_EXPR) - { - to = TREE_TYPE (expr); - oprnd0 = TREE_OPERAND (expr, 0); - ti = TREE_TYPE (oprnd0); - - if (!INTEGRAL_TYPE_P (to) || !INTEGRAL_TYPE_P (ti)) - return NULL_TREE; - if (GET_MODE_SIZE (TYPE_MODE (to)) < GET_MODE_SIZE (TYPE_MODE (ti))) - return NULL_TREE; - - expr = oprnd0; - } - return expr; + VEC_free (tree, heap, DR_ACCESS_FNS (dr)); + free (dr); } - -/* Function analyze_offset_expr - - Given an offset expression EXPR received from get_inner_reference, analyze - it and create an expression for INITIAL_OFFSET by substituting the variables - of EXPR with initial_condition of the corresponding access_fn in the loop. - E.g., - for i - for (j = 3; j < N; j++) - a[j].b[i][j] = 0; - - For a[j].b[i][j], EXPR will be 'i * C_i + j * C_j + C'. 'i' cannot be - substituted, since its access_fn in the inner loop is i. 'j' will be - substituted with 3. An INITIAL_OFFSET will be 'i * C_i + C`', where - C` = 3 * C_j + C. - - Compute MISALIGN (the misalignment of the data reference initial access from - its base). Misalignment can be calculated only if all the variables can be - substituted with constants, otherwise, we record maximum possible alignment - in ALIGNED_TO. In the above example, since 'i' cannot be substituted, MISALIGN - will be NULL_TREE, and the biggest divider of C_i (a power of 2) will be - recorded in ALIGNED_TO. - - STEP is an evolution of the data reference in this loop in bytes. - In the above example, STEP is C_j. - - Return FALSE, if the analysis fails, e.g., there is no access_fn for a - variable. In this case, all the outputs (INITIAL_OFFSET, MISALIGN, ALIGNED_TO - and STEP) are NULL_TREEs. Otherwise, return TRUE. +/* Analyzes memory reference MEMREF accessed in STMT. The reference + is read if IS_READ is true, write otherwise. Returns the + data_reference description of MEMREF. NEST is the outermost loop of the + loop nest in that the reference should be analyzed. */ -*/ +struct data_reference * +create_data_ref (struct loop *nest, tree memref, gimple stmt, bool is_read) +{ + struct data_reference *dr; -static bool -analyze_offset_expr (tree expr, - struct loop *loop, - tree *initial_offset, - tree *misalign, - tree *aligned_to, - tree *step) -{ - tree oprnd0; - tree oprnd1; - tree left_offset = ssize_int (0); - tree right_offset = ssize_int (0); - tree left_misalign = ssize_int (0); - tree right_misalign = ssize_int (0); - tree left_step = ssize_int (0); - tree right_step = ssize_int (0); - enum tree_code code; - tree init, evolution; - tree left_aligned_to = NULL_TREE, right_aligned_to = NULL_TREE; + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "Creating dr for "); + print_generic_expr (dump_file, memref, TDF_SLIM); + fprintf (dump_file, "\n"); + } - *step = NULL_TREE; - *misalign = NULL_TREE; - *aligned_to = NULL_TREE; - *initial_offset = NULL_TREE; + dr = XCNEW (struct data_reference); + DR_STMT (dr) = stmt; + DR_REF (dr) = memref; + DR_IS_READ (dr) = is_read; - /* Strip conversions that don't narrow the mode. */ - expr = strip_conversion (expr); - if (!expr) - return false; + dr_analyze_innermost (dr); + dr_analyze_indices (dr, nest); + dr_analyze_alias (dr); - /* Stop conditions: - 1. Constant. */ - if (TREE_CODE (expr) == INTEGER_CST) + if (dump_file && (dump_flags & TDF_DETAILS)) { - *initial_offset = fold_convert (ssizetype, expr); - *misalign = fold_convert (ssizetype, expr); - *step = ssize_int (0); - return true; + fprintf (dump_file, "\tbase_address: "); + print_generic_expr (dump_file, DR_BASE_ADDRESS (dr), TDF_SLIM); + fprintf (dump_file, "\n\toffset from base address: "); + print_generic_expr (dump_file, DR_OFFSET (dr), TDF_SLIM); + fprintf (dump_file, "\n\tconstant offset from base address: "); + print_generic_expr (dump_file, DR_INIT (dr), TDF_SLIM); + fprintf (dump_file, "\n\tstep: "); + print_generic_expr (dump_file, DR_STEP (dr), TDF_SLIM); + fprintf (dump_file, "\n\taligned to: "); + print_generic_expr (dump_file, DR_ALIGNED_TO (dr), TDF_SLIM); + fprintf (dump_file, "\n\tbase_object: "); + print_generic_expr (dump_file, DR_BASE_OBJECT (dr), TDF_SLIM); + fprintf (dump_file, "\n"); } - /* 2. Variable. Try to substitute with initial_condition of the corresponding - access_fn in the current loop. */ - if (SSA_VAR_P (expr)) - { - tree access_fn = analyze_scalar_evolution (loop, expr); + return dr; +} - if (access_fn == chrec_dont_know) - /* No access_fn. */ - return false; +/* Returns true if FNA == FNB. */ - init = initial_condition_in_loop_num (access_fn, loop->num); - if (!expr_invariant_in_loop_p (loop, init)) - /* Not enough information: may be not loop invariant. - E.g., for a[b[i]], we get a[D], where D=b[i]. EXPR is D, its - initial_condition is D, but it depends on i - loop's induction - variable. */ - return false; +static bool +affine_function_equal_p (affine_fn fna, affine_fn fnb) +{ + unsigned i, n = VEC_length (tree, fna); - evolution = evolution_part_in_loop_num (access_fn, loop->num); - if (evolution && TREE_CODE (evolution) != INTEGER_CST) - /* Evolution is not constant. */ - return false; + if (n != VEC_length (tree, fnb)) + return false; - if (TREE_CODE (init) == INTEGER_CST) - *misalign = fold_convert (ssizetype, init); - else - /* Not constant, misalignment cannot be calculated. */ - *misalign = NULL_TREE; + for (i = 0; i < n; i++) + if (!operand_equal_p (VEC_index (tree, fna, i), + VEC_index (tree, fnb, i), 0)) + return false; - *initial_offset = fold_convert (ssizetype, init); + return true; +} - *step = evolution ? fold_convert (ssizetype, evolution) : ssize_int (0); - return true; - } +/* If all the functions in CF are the same, returns one of them, + otherwise returns NULL. */ - /* Recursive computation. */ - if (!BINARY_CLASS_P (expr)) - { - /* We expect to get binary expressions (PLUS/MINUS and MULT). */ - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, "\nNot binary expression "); - print_generic_expr (dump_file, expr, TDF_SLIM); - fprintf (dump_file, "\n"); - } - return false; - } - oprnd0 = TREE_OPERAND (expr, 0); - oprnd1 = TREE_OPERAND (expr, 1); +static affine_fn +common_affine_function (conflict_function *cf) +{ + unsigned i; + affine_fn comm; - if (!analyze_offset_expr (oprnd0, loop, &left_offset, &left_misalign, - &left_aligned_to, &left_step) - || !analyze_offset_expr (oprnd1, loop, &right_offset, &right_misalign, - &right_aligned_to, &right_step)) - return false; + if (!CF_NONTRIVIAL_P (cf)) + return NULL; - /* The type of the operation: plus, minus or mult. */ - code = TREE_CODE (expr); - switch (code) - { - case MULT_EXPR: - if (TREE_CODE (right_offset) != INTEGER_CST) - /* RIGHT_OFFSET can be not constant. For example, for arrays of variable - sized types. - FORNOW: We don't support such cases. */ - return false; + comm = cf->fns[0]; - /* Strip conversions that don't narrow the mode. */ - left_offset = strip_conversion (left_offset); - if (!left_offset) - return false; - /* Misalignment computation. */ - if (SSA_VAR_P (left_offset)) - { - /* If the left side contains variables that can't be substituted with - constants, the misalignment is unknown. However, if the right side - is a multiple of some alignment, we know that the expression is - aligned to it. Therefore, we record such maximum possible value. - */ - *misalign = NULL_TREE; - *aligned_to = ssize_int (highest_pow2_factor (right_offset)); - } - else - { - /* The left operand was successfully substituted with constant. */ - if (left_misalign) - { - /* In case of EXPR '(i * C1 + j) * C2', LEFT_MISALIGN is - NULL_TREE. */ - *misalign = size_binop (code, left_misalign, right_misalign); - if (left_aligned_to && right_aligned_to) - *aligned_to = size_binop (MIN_EXPR, left_aligned_to, - right_aligned_to); - else - *aligned_to = left_aligned_to ? - left_aligned_to : right_aligned_to; - } - else - *misalign = NULL_TREE; - } + for (i = 1; i < cf->n; i++) + if (!affine_function_equal_p (comm, cf->fns[i])) + return NULL; - /* Step calculation. */ - /* Multiply the step by the right operand. */ - *step = size_binop (MULT_EXPR, left_step, right_offset); - break; - - case PLUS_EXPR: - case MINUS_EXPR: - /* Combine the recursive calculations for step and misalignment. */ - *step = size_binop (code, left_step, right_step); + return comm; +} - /* Unknown alignment. */ - if ((!left_misalign && !left_aligned_to) - || (!right_misalign && !right_aligned_to)) - { - *misalign = NULL_TREE; - *aligned_to = NULL_TREE; - break; - } +/* Returns the base of the affine function FN. */ - if (left_misalign && right_misalign) - *misalign = size_binop (code, left_misalign, right_misalign); - else - *misalign = left_misalign ? left_misalign : right_misalign; +static tree +affine_function_base (affine_fn fn) +{ + return VEC_index (tree, fn, 0); +} - if (left_aligned_to && right_aligned_to) - *aligned_to = size_binop (MIN_EXPR, left_aligned_to, right_aligned_to); - else - *aligned_to = left_aligned_to ? left_aligned_to : right_aligned_to; +/* Returns true if FN is a constant. */ - break; +static bool +affine_function_constant_p (affine_fn fn) +{ + unsigned i; + tree coef; - default: - gcc_unreachable (); - } + for (i = 1; VEC_iterate (tree, fn, i, coef); i++) + if (!integer_zerop (coef)) + return false; - /* Compute offset. */ - *initial_offset = fold_convert (ssizetype, - fold_build2 (code, TREE_TYPE (left_offset), - left_offset, - right_offset)); return true; } -/* Function address_analysis +/* Returns true if FN is the zero constant function. */ - Return the BASE of the address expression EXPR. - Also compute the OFFSET from BASE, MISALIGN and STEP. - - Input: - EXPR - the address expression that is being analyzed - STMT - the statement that contains EXPR or its original memory reference - IS_READ - TRUE if STMT reads from EXPR, FALSE if writes to EXPR - DR - data_reference struct for the original memory reference +static bool +affine_function_zero_p (affine_fn fn) +{ + return (integer_zerop (affine_function_base (fn)) + && affine_function_constant_p (fn)); +} - Output: - BASE (returned value) - the base of the data reference EXPR. - INITIAL_OFFSET - initial offset of EXPR from BASE (an expression) - MISALIGN - offset of EXPR from BASE in bytes (a constant) or NULL_TREE if the - computation is impossible - ALIGNED_TO - maximum alignment of EXPR or NULL_TREE if MISALIGN can be - calculated (doesn't depend on variables) - STEP - evolution of EXPR in the loop - - If something unexpected is encountered (an unsupported form of data-ref), - then NULL_TREE is returned. - */ +/* Returns a signed integer type with the largest precision from TA + and TB. */ static tree -address_analysis (tree expr, tree stmt, bool is_read, struct data_reference *dr, - tree *offset, tree *misalign, tree *aligned_to, tree *step) +signed_type_for_types (tree ta, tree tb) { - tree oprnd0, oprnd1, base_address, offset_expr, base_addr0, base_addr1; - tree address_offset = ssize_int (0), address_misalign = ssize_int (0); - tree dummy, address_aligned_to = NULL_TREE; - struct ptr_info_def *dummy1; - subvar_t dummy2; + if (TYPE_PRECISION (ta) > TYPE_PRECISION (tb)) + return signed_type_for (ta); + else + return signed_type_for (tb); +} - switch (TREE_CODE (expr)) - { - case PLUS_EXPR: - case MINUS_EXPR: - /* EXPR is of form {base +/- offset} (or {offset +/- base}). */ - oprnd0 = TREE_OPERAND (expr, 0); - oprnd1 = TREE_OPERAND (expr, 1); - - STRIP_NOPS (oprnd0); - STRIP_NOPS (oprnd1); - - /* Recursively try to find the base of the address contained in EXPR. - For offset, the returned base will be NULL. */ - base_addr0 = address_analysis (oprnd0, stmt, is_read, dr, &address_offset, - &address_misalign, &address_aligned_to, - step); - - base_addr1 = address_analysis (oprnd1, stmt, is_read, dr, &address_offset, - &address_misalign, &address_aligned_to, - step); - - /* We support cases where only one of the operands contains an - address. */ - if ((base_addr0 && base_addr1) || (!base_addr0 && !base_addr1)) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, - "\neither more than one address or no addresses in expr "); - print_generic_expr (dump_file, expr, TDF_SLIM); - fprintf (dump_file, "\n"); - } - return NULL_TREE; - } +/* Applies operation OP on affine functions FNA and FNB, and returns the + result. */ - /* To revert STRIP_NOPS. */ - oprnd0 = TREE_OPERAND (expr, 0); - oprnd1 = TREE_OPERAND (expr, 1); - - offset_expr = base_addr0 ? - fold_convert (ssizetype, oprnd1) : fold_convert (ssizetype, oprnd0); - - /* EXPR is of form {base +/- offset} (or {offset +/- base}). If offset is - a number, we can add it to the misalignment value calculated for base, - otherwise, misalignment is NULL. */ - if (TREE_CODE (offset_expr) == INTEGER_CST && address_misalign) - { - *misalign = size_binop (TREE_CODE (expr), address_misalign, - offset_expr); - *aligned_to = address_aligned_to; - } - else - { - *misalign = NULL_TREE; - *aligned_to = NULL_TREE; - } +static affine_fn +affine_fn_op (enum tree_code op, affine_fn fna, affine_fn fnb) +{ + unsigned i, n, m; + affine_fn ret; + tree coef; - /* Combine offset (from EXPR {base + offset}) with the offset calculated - for base. */ - *offset = size_binop (TREE_CODE (expr), address_offset, offset_expr); - return base_addr0 ? base_addr0 : base_addr1; + if (VEC_length (tree, fnb) > VEC_length (tree, fna)) + { + n = VEC_length (tree, fna); + m = VEC_length (tree, fnb); + } + else + { + n = VEC_length (tree, fnb); + m = VEC_length (tree, fna); + } - case ADDR_EXPR: - base_address = object_analysis (TREE_OPERAND (expr, 0), stmt, is_read, - &dr, offset, misalign, aligned_to, step, - &dummy, &dummy1, &dummy2); - return base_address; + ret = VEC_alloc (tree, heap, m); + for (i = 0; i < n; i++) + { + tree type = signed_type_for_types (TREE_TYPE (VEC_index (tree, fna, i)), + TREE_TYPE (VEC_index (tree, fnb, i))); - case SSA_NAME: - if (!POINTER_TYPE_P (TREE_TYPE (expr))) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, "\nnot pointer SSA_NAME "); - print_generic_expr (dump_file, expr, TDF_SLIM); - fprintf (dump_file, "\n"); - } - return NULL_TREE; - } - *aligned_to = ssize_int (TYPE_ALIGN_UNIT (TREE_TYPE (TREE_TYPE (expr)))); - *misalign = ssize_int (0); - *offset = ssize_int (0); - *step = ssize_int (0); - return expr; - - default: - return NULL_TREE; + VEC_quick_push (tree, ret, + fold_build2 (op, type, + VEC_index (tree, fna, i), + VEC_index (tree, fnb, i))); } -} + for (; VEC_iterate (tree, fna, i, coef); i++) + VEC_quick_push (tree, ret, + fold_build2 (op, signed_type_for (TREE_TYPE (coef)), + coef, integer_zero_node)); + for (; VEC_iterate (tree, fnb, i, coef); i++) + VEC_quick_push (tree, ret, + fold_build2 (op, signed_type_for (TREE_TYPE (coef)), + integer_zero_node, coef)); -/* Function object_analysis - - Create a data-reference structure DR for MEMREF. - Return the BASE of the data reference MEMREF if the analysis is possible. - Also compute the INITIAL_OFFSET from BASE, MISALIGN and STEP. - E.g., for EXPR a.b[i] + 4B, BASE is a, and OFFSET is the overall offset - 'a.b[i] + 4B' from a (can be an expression), MISALIGN is an OFFSET - instantiated with initial_conditions of access_functions of variables, - and STEP is the evolution of the DR_REF in this loop. - - Function get_inner_reference is used for the above in case of ARRAY_REF and - COMPONENT_REF. - - The structure of the function is as follows: - Part 1: - Case 1. For handled_component_p refs - 1.1 build data-reference structure for MEMREF - 1.2 call get_inner_reference - 1.2.1 analyze offset expr received from get_inner_reference - (fall through with BASE) - Case 2. For declarations - 2.1 set MEMTAG - Case 3. For INDIRECT_REFs - 3.1 build data-reference structure for MEMREF - 3.2 analyze evolution and initial condition of MEMREF - 3.3 set data-reference structure for MEMREF - 3.4 call address_analysis to analyze INIT of the access function - 3.5 extract memory tag - - Part 2: - Combine the results of object and address analysis to calculate - INITIAL_OFFSET, STEP and misalignment info. - - Input: - MEMREF - the memory reference that is being analyzed - STMT - the statement that contains MEMREF - IS_READ - TRUE if STMT reads from MEMREF, FALSE if writes to MEMREF - - Output: - BASE_ADDRESS (returned value) - the base address of the data reference MEMREF - E.g, if MEMREF is a.b[k].c[i][j] the returned - base is &a. - DR - data_reference struct for MEMREF - INITIAL_OFFSET - initial offset of MEMREF from BASE (an expression) - MISALIGN - offset of MEMREF from BASE in bytes (a constant) modulo alignment of - ALIGNMENT or NULL_TREE if the computation is impossible - ALIGNED_TO - maximum alignment of EXPR or NULL_TREE if MISALIGN can be - calculated (doesn't depend on variables) - STEP - evolution of the DR_REF in the loop - MEMTAG - memory tag for aliasing purposes - PTR_INFO - NULL or points-to aliasing info from a pointer SSA_NAME - SUBVARS - Sub-variables of the variable - - If the analysis of MEMREF evolution in the loop fails, NULL_TREE is returned, - but DR can be created anyway. - -*/ - -static tree -object_analysis (tree memref, tree stmt, bool is_read, - struct data_reference **dr, tree *offset, tree *misalign, - tree *aligned_to, tree *step, tree *memtag, - struct ptr_info_def **ptr_info, subvar_t *subvars) -{ - tree base = NULL_TREE, base_address = NULL_TREE; - tree object_offset = ssize_int (0), object_misalign = ssize_int (0); - tree object_step = ssize_int (0), address_step = ssize_int (0); - tree address_offset = ssize_int (0), address_misalign = ssize_int (0); - HOST_WIDE_INT pbitsize, pbitpos; - tree poffset, bit_pos_in_bytes; - enum machine_mode pmode; - int punsignedp, pvolatilep; - tree ptr_step = ssize_int (0), ptr_init = NULL_TREE; - struct loop *loop = loop_containing_stmt (stmt); - struct data_reference *ptr_dr = NULL; - tree object_aligned_to = NULL_TREE, address_aligned_to = NULL_TREE; - tree comp_ref = NULL_TREE; + return ret; +} - *ptr_info = NULL; +/* Returns the sum of affine functions FNA and FNB. */ - /* Part 1: */ - /* Case 1. handled_component_p refs. */ - if (handled_component_p (memref)) - { - /* 1.1 build data-reference structure for MEMREF. */ - if (!(*dr)) - { - if (TREE_CODE (memref) == ARRAY_REF) - *dr = analyze_array (stmt, memref, is_read); - else if (TREE_CODE (memref) == COMPONENT_REF) - comp_ref = memref; - else - { - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, "\ndata-ref of unsupported type "); - print_generic_expr (dump_file, memref, TDF_SLIM); - fprintf (dump_file, "\n"); - } - return NULL_TREE; - } - } +static affine_fn +affine_fn_plus (affine_fn fna, affine_fn fnb) +{ + return affine_fn_op (PLUS_EXPR, fna, fnb); +} - /* 1.2 call get_inner_reference. */ - /* Find the base and the offset from it. */ - base = get_inner_reference (memref, &pbitsize, &pbitpos, &poffset, - &pmode, &punsignedp, &pvolatilep, false); - if (!base) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, "\nfailed to get inner ref for "); - print_generic_expr (dump_file, memref, TDF_SLIM); - fprintf (dump_file, "\n"); - } - return NULL_TREE; - } +/* Returns the difference of affine functions FNA and FNB. */ - /* 1.2.1 analyze offset expr received from get_inner_reference. */ - if (poffset - && !analyze_offset_expr (poffset, loop, &object_offset, - &object_misalign, &object_aligned_to, - &object_step)) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, "\nfailed to compute offset or step for "); - print_generic_expr (dump_file, memref, TDF_SLIM); - fprintf (dump_file, "\n"); - } - return NULL_TREE; - } +static affine_fn +affine_fn_minus (affine_fn fna, affine_fn fnb) +{ + return affine_fn_op (MINUS_EXPR, fna, fnb); +} - /* Add bit position to OFFSET and MISALIGN. */ +/* Frees affine function FN. */ - bit_pos_in_bytes = ssize_int (pbitpos/BITS_PER_UNIT); - /* Check that there is no remainder in bits. */ - if (pbitpos%BITS_PER_UNIT) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, "\nbit offset alignment.\n"); - return NULL_TREE; - } - object_offset = size_binop (PLUS_EXPR, bit_pos_in_bytes, object_offset); - if (object_misalign) - object_misalign = size_binop (PLUS_EXPR, object_misalign, - bit_pos_in_bytes); - - memref = base; /* To continue analysis of BASE. */ - /* fall through */ - } - - /* Part 1: Case 2. Declarations. */ - if (DECL_P (memref)) - { - /* We expect to get a decl only if we already have a DR, or with - COMPONENT_REFs of type 'a[i].b'. */ - if (!(*dr)) - { - if (comp_ref && TREE_CODE (TREE_OPERAND (comp_ref, 0)) == ARRAY_REF) - { - *dr = analyze_array (stmt, TREE_OPERAND (comp_ref, 0), is_read); - if (DR_NUM_DIMENSIONS (*dr) != 1) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, "\n multidimensional component ref "); - print_generic_expr (dump_file, comp_ref, TDF_SLIM); - fprintf (dump_file, "\n"); - } - return NULL_TREE; - } - } - else - { - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, "\nunhandled decl "); - print_generic_expr (dump_file, memref, TDF_SLIM); - fprintf (dump_file, "\n"); - } - return NULL_TREE; - } - } +static void +affine_fn_free (affine_fn fn) +{ + VEC_free (tree, heap, fn); +} - /* TODO: if during the analysis of INDIRECT_REF we get to an object, put - the object in BASE_OBJECT field if we can prove that this is O.K., - i.e., the data-ref access is bounded by the bounds of the BASE_OBJECT. - (e.g., if the object is an array base 'a', where 'a[N]', we must prove - that every access with 'p' (the original INDIRECT_REF based on '&a') - in the loop is within the array boundaries - from a[0] to a[N-1]). - Otherwise, our alias analysis can be incorrect. - Even if an access function based on BASE_OBJECT can't be build, update - BASE_OBJECT field to enable us to prove that two data-refs are - different (without access function, distance analysis is impossible). - */ - if (SSA_VAR_P (memref) && var_can_have_subvars (memref)) - *subvars = get_subvars_for_var (memref); - base_address = build_fold_addr_expr (memref); - /* 2.1 set MEMTAG. */ - *memtag = memref; - } +/* Determine for each subscript in the data dependence relation DDR + the distance. */ + +static void +compute_subscript_distance (struct data_dependence_relation *ddr) +{ + conflict_function *cf_a, *cf_b; + affine_fn fn_a, fn_b, diff; - /* Part 1: Case 3. INDIRECT_REFs. */ - else if (TREE_CODE (memref) == INDIRECT_REF) + if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE) { - tree ptr_ref = TREE_OPERAND (memref, 0); - if (TREE_CODE (ptr_ref) == SSA_NAME) - *ptr_info = SSA_NAME_PTR_INFO (ptr_ref); + unsigned int i; - /* 3.1 build data-reference structure for MEMREF. */ - ptr_dr = analyze_indirect_ref (stmt, memref, is_read); - if (!ptr_dr) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, "\nfailed to create dr for "); - print_generic_expr (dump_file, memref, TDF_SLIM); - fprintf (dump_file, "\n"); - } - return NULL_TREE; - } + for (i = 0; i < DDR_NUM_SUBSCRIPTS (ddr); i++) + { + struct subscript *subscript; - /* 3.2 analyze evolution and initial condition of MEMREF. */ - ptr_step = DR_STEP (ptr_dr); - ptr_init = DR_BASE_ADDRESS (ptr_dr); - if (!ptr_init || !ptr_step || !POINTER_TYPE_P (TREE_TYPE (ptr_init))) - { - *dr = (*dr) ? *dr : ptr_dr; - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, "\nbad pointer access "); - print_generic_expr (dump_file, memref, TDF_SLIM); - fprintf (dump_file, "\n"); - } - return NULL_TREE; - } + subscript = DDR_SUBSCRIPT (ddr, i); + cf_a = SUB_CONFLICTS_IN_A (subscript); + cf_b = SUB_CONFLICTS_IN_B (subscript); - if (integer_zerop (ptr_step) && !(*dr)) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, "\nptr is loop invariant.\n"); - *dr = ptr_dr; - return NULL_TREE; - - /* If there exists DR for MEMREF, we are analyzing the base of - handled component (PTR_INIT), which not necessary has evolution in - the loop. */ - } - object_step = size_binop (PLUS_EXPR, object_step, ptr_step); - - /* 3.3 set data-reference structure for MEMREF. */ - if (!*dr) - *dr = ptr_dr; - - /* 3.4 call address_analysis to analyze INIT of the access - function. */ - base_address = address_analysis (ptr_init, stmt, is_read, *dr, - &address_offset, &address_misalign, - &address_aligned_to, &address_step); - if (!base_address) - { - if (dump_file && (dump_flags & TDF_DETAILS)) + fn_a = common_affine_function (cf_a); + fn_b = common_affine_function (cf_b); + if (!fn_a || !fn_b) { - fprintf (dump_file, "\nfailed to analyze address "); - print_generic_expr (dump_file, ptr_init, TDF_SLIM); - fprintf (dump_file, "\n"); + SUB_DISTANCE (subscript) = chrec_dont_know; + return; } - return NULL_TREE; - } + diff = affine_fn_minus (fn_a, fn_b); - /* 3.5 extract memory tag. */ - switch (TREE_CODE (base_address)) - { - case SSA_NAME: - *memtag = get_var_ann (SSA_NAME_VAR (base_address))->symbol_mem_tag; - if (!(*memtag) && TREE_CODE (TREE_OPERAND (memref, 0)) == SSA_NAME) - *memtag = get_var_ann ( - SSA_NAME_VAR (TREE_OPERAND (memref, 0)))->symbol_mem_tag; - break; - case ADDR_EXPR: - *memtag = TREE_OPERAND (base_address, 0); - break; - default: - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, "\nno memtag for "); - print_generic_expr (dump_file, memref, TDF_SLIM); - fprintf (dump_file, "\n"); - } - *memtag = NULL_TREE; - break; - } - } - - if (!base_address) - { - /* MEMREF cannot be analyzed. */ - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, "\ndata-ref of unsupported type "); - print_generic_expr (dump_file, memref, TDF_SLIM); - fprintf (dump_file, "\n"); - } - return NULL_TREE; - } + if (affine_function_constant_p (diff)) + SUB_DISTANCE (subscript) = affine_function_base (diff); + else + SUB_DISTANCE (subscript) = chrec_dont_know; - if (comp_ref) - DR_REF (*dr) = comp_ref; + affine_fn_free (diff); + } + } +} - if (SSA_VAR_P (*memtag) && var_can_have_subvars (*memtag)) - *subvars = get_subvars_for_var (*memtag); - - /* Part 2: Combine the results of object and address analysis to calculate - INITIAL_OFFSET, STEP and misalignment info. */ - *offset = size_binop (PLUS_EXPR, object_offset, address_offset); +/* Returns the conflict function for "unknown". */ - if ((!object_misalign && !object_aligned_to) - || (!address_misalign && !address_aligned_to)) - { - *misalign = NULL_TREE; - *aligned_to = NULL_TREE; - } - else - { - if (object_misalign && address_misalign) - *misalign = size_binop (PLUS_EXPR, object_misalign, address_misalign); - else - *misalign = object_misalign ? object_misalign : address_misalign; - if (object_aligned_to && address_aligned_to) - *aligned_to = size_binop (MIN_EXPR, object_aligned_to, - address_aligned_to); - else - *aligned_to = object_aligned_to ? - object_aligned_to : address_aligned_to; - } - *step = size_binop (PLUS_EXPR, object_step, address_step); +static conflict_function * +conflict_fn_not_known (void) +{ + conflict_function *fn = XCNEW (conflict_function); + fn->n = NOT_KNOWN; - return base_address; + return fn; } -/* Function analyze_offset. - - Extract INVARIANT and CONSTANT parts from OFFSET. +/* Returns the conflict function for "independent". */ -*/ -static void -analyze_offset (tree offset, tree *invariant, tree *constant) +static conflict_function * +conflict_fn_no_dependence (void) { - tree op0, op1, constant_0, constant_1, invariant_0, invariant_1; - enum tree_code code = TREE_CODE (offset); + conflict_function *fn = XCNEW (conflict_function); + fn->n = NO_DEPENDENCE; - *invariant = NULL_TREE; - *constant = NULL_TREE; + return fn; +} + +/* Returns true if the address of OBJ is invariant in LOOP. */ - /* Not PLUS/MINUS expression - recursion stop condition. */ - if (code != PLUS_EXPR && code != MINUS_EXPR) +static bool +object_address_invariant_in_loop_p (const struct loop *loop, const_tree obj) +{ + while (handled_component_p (obj)) { - if (TREE_CODE (offset) == INTEGER_CST) - *constant = offset; - else - *invariant = offset; - return; + if (TREE_CODE (obj) == ARRAY_REF) + { + /* Index of the ARRAY_REF was zeroed in analyze_indices, thus we only + need to check the stride and the lower bound of the reference. */ + if (chrec_contains_symbols_defined_in_loop (TREE_OPERAND (obj, 2), + loop->num) + || chrec_contains_symbols_defined_in_loop (TREE_OPERAND (obj, 3), + loop->num)) + return false; + } + else if (TREE_CODE (obj) == COMPONENT_REF) + { + if (chrec_contains_symbols_defined_in_loop (TREE_OPERAND (obj, 2), + loop->num)) + return false; + } + obj = TREE_OPERAND (obj, 0); } - op0 = TREE_OPERAND (offset, 0); - op1 = TREE_OPERAND (offset, 1); - - /* Recursive call with the operands. */ - analyze_offset (op0, &invariant_0, &constant_0); - analyze_offset (op1, &invariant_1, &constant_1); + if (!INDIRECT_REF_P (obj)) + return true; - /* Combine the results. */ - *constant = constant_0 ? constant_0 : constant_1; - if (invariant_0 && invariant_1) - *invariant = - fold_build2 (code, TREE_TYPE (invariant_0), invariant_0, invariant_1); - else - *invariant = invariant_0 ? invariant_0 : invariant_1; + return !chrec_contains_symbols_defined_in_loop (TREE_OPERAND (obj, 0), + loop->num); } +/* Returns true if A and B are accesses to different objects, or to different + fields of the same object. */ -/* Function create_data_ref. - - Create a data-reference structure for MEMREF. Set its DR_BASE_ADDRESS, - DR_OFFSET, DR_INIT, DR_STEP, DR_OFFSET_MISALIGNMENT, DR_ALIGNED_TO, - DR_MEMTAG, and DR_POINTSTO_INFO fields. - - Input: - MEMREF - the memory reference that is being analyzed - STMT - the statement that contains MEMREF - IS_READ - TRUE if STMT reads from MEMREF, FALSE if writes to MEMREF +static bool +disjoint_objects_p (tree a, tree b) +{ + tree base_a, base_b; + VEC (tree, heap) *comp_a = NULL, *comp_b = NULL; + bool ret; - Output: - DR (returned value) - data_reference struct for MEMREF -*/ + base_a = get_base_address (a); + base_b = get_base_address (b); -static struct data_reference * -create_data_ref (tree memref, tree stmt, bool is_read) -{ - struct data_reference *dr = NULL; - tree base_address, offset, step, misalign, memtag; - struct loop *loop = loop_containing_stmt (stmt); - tree invariant = NULL_TREE, constant = NULL_TREE; - tree type_size, init_cond; - struct ptr_info_def *ptr_info; - subvar_t subvars = NULL; - tree aligned_to, type = NULL_TREE, orig_offset; + if (DECL_P (base_a) + && DECL_P (base_b) + && base_a != base_b) + return true; - if (!memref) - return NULL; + if (!operand_equal_p (base_a, base_b, 0)) + return false; - base_address = object_analysis (memref, stmt, is_read, &dr, &offset, - &misalign, &aligned_to, &step, &memtag, - &ptr_info, &subvars); - if (!dr || !base_address) + /* Compare the component references of A and B. We must start from the inner + ones, so record them to the vector first. */ + while (handled_component_p (a)) { - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, "\ncreate_data_ref: failed to create a dr for "); - print_generic_expr (dump_file, memref, TDF_SLIM); - fprintf (dump_file, "\n"); - } - return NULL; + VEC_safe_push (tree, heap, comp_a, a); + a = TREE_OPERAND (a, 0); } - - DR_BASE_ADDRESS (dr) = base_address; - DR_OFFSET (dr) = offset; - DR_INIT (dr) = ssize_int (0); - DR_STEP (dr) = step; - DR_OFFSET_MISALIGNMENT (dr) = misalign; - DR_ALIGNED_TO (dr) = aligned_to; - DR_MEMTAG (dr) = memtag; - DR_PTR_INFO (dr) = ptr_info; - DR_SUBVARS (dr) = subvars; - - type_size = fold_convert (ssizetype, TYPE_SIZE_UNIT (TREE_TYPE (DR_REF (dr)))); - - /* Extract CONSTANT and INVARIANT from OFFSET. */ - /* Remove cast from OFFSET and restore it for INVARIANT part. */ - orig_offset = offset; - STRIP_NOPS (offset); - if (offset != orig_offset) - type = TREE_TYPE (orig_offset); - analyze_offset (offset, &invariant, &constant); - if (type && invariant) - invariant = fold_convert (type, invariant); - - /* Put CONSTANT part of OFFSET in DR_INIT and INVARIANT in DR_OFFSET field - of DR. */ - if (constant) + while (handled_component_p (b)) { - DR_INIT (dr) = fold_convert (ssizetype, constant); - init_cond = fold_build2 (TRUNC_DIV_EXPR, TREE_TYPE (constant), - constant, type_size); + VEC_safe_push (tree, heap, comp_b, b); + b = TREE_OPERAND (b, 0); } - else - DR_INIT (dr) = init_cond = ssize_int (0); - if (invariant) - DR_OFFSET (dr) = invariant; - else - DR_OFFSET (dr) = ssize_int (0); - - /* Change the access function for INIDIRECT_REFs, according to - DR_BASE_ADDRESS. Analyze OFFSET calculated in object_analysis. OFFSET is - an expression that can contain loop invariant expressions and constants. - We put the constant part in the initial condition of the access function - (for data dependence tests), and in DR_INIT of the data-ref. The loop - invariant part is put in DR_OFFSET. - The evolution part of the access function is STEP calculated in - object_analysis divided by the size of data type. - */ - if (!DR_BASE_OBJECT (dr) - || (TREE_CODE (memref) == COMPONENT_REF && DR_NUM_DIMENSIONS (dr) == 1)) + ret = false; + while (1) { - tree access_fn; - tree new_step; + if (VEC_length (tree, comp_a) == 0 + || VEC_length (tree, comp_b) == 0) + break; + + a = VEC_pop (tree, comp_a); + b = VEC_pop (tree, comp_b); + + /* Real and imaginary part of a variable do not alias. */ + if ((TREE_CODE (a) == REALPART_EXPR + && TREE_CODE (b) == IMAGPART_EXPR) + || (TREE_CODE (a) == IMAGPART_EXPR + && TREE_CODE (b) == REALPART_EXPR)) + { + ret = true; + break; + } - /* Update access function. */ - access_fn = DR_ACCESS_FN (dr, 0); - new_step = size_binop (TRUNC_DIV_EXPR, - fold_convert (ssizetype, step), type_size); + if (TREE_CODE (a) != TREE_CODE (b)) + break; + + /* Nothing to do for ARRAY_REFs, as the indices of array_refs in + DR_BASE_OBJECT are always zero. */ + if (TREE_CODE (a) == ARRAY_REF) + continue; + else if (TREE_CODE (a) == COMPONENT_REF) + { + if (operand_equal_p (TREE_OPERAND (a, 1), TREE_OPERAND (b, 1), 0)) + continue; - init_cond = chrec_convert (chrec_type (access_fn), init_cond, stmt); - new_step = chrec_convert (chrec_type (access_fn), new_step, stmt); - access_fn = chrec_replace_initial_condition (access_fn, init_cond); - access_fn = reset_evolution_in_loop (loop->num, access_fn, new_step); + /* Different fields of unions may overlap. */ + base_a = TREE_OPERAND (a, 0); + if (TREE_CODE (TREE_TYPE (base_a)) == UNION_TYPE) + break; - VEC_replace (tree, DR_ACCESS_FNS (dr), 0, access_fn); + /* Different fields of structures cannot. */ + ret = true; + break; + } + else + break; } - if (dump_file && (dump_flags & TDF_DETAILS)) - { - struct ptr_info_def *pi = DR_PTR_INFO (dr); + VEC_free (tree, heap, comp_a); + VEC_free (tree, heap, comp_b); - fprintf (dump_file, "\nCreated dr for "); - print_generic_expr (dump_file, memref, TDF_SLIM); - fprintf (dump_file, "\n\tbase_address: "); - print_generic_expr (dump_file, DR_BASE_ADDRESS (dr), TDF_SLIM); - fprintf (dump_file, "\n\toffset from base address: "); - print_generic_expr (dump_file, DR_OFFSET (dr), TDF_SLIM); - fprintf (dump_file, "\n\tconstant offset from base address: "); - print_generic_expr (dump_file, DR_INIT (dr), TDF_SLIM); - fprintf (dump_file, "\n\tbase_object: "); - print_generic_expr (dump_file, DR_BASE_OBJECT (dr), TDF_SLIM); - fprintf (dump_file, "\n\tstep: "); - print_generic_expr (dump_file, DR_STEP (dr), TDF_SLIM); - fprintf (dump_file, "B\n\tmisalignment from base: "); - print_generic_expr (dump_file, DR_OFFSET_MISALIGNMENT (dr), TDF_SLIM); - if (DR_OFFSET_MISALIGNMENT (dr)) - fprintf (dump_file, "B"); - if (DR_ALIGNED_TO (dr)) - { - fprintf (dump_file, "\n\taligned to: "); - print_generic_expr (dump_file, DR_ALIGNED_TO (dr), TDF_SLIM); - } - fprintf (dump_file, "\n\tmemtag: "); - print_generic_expr (dump_file, DR_MEMTAG (dr), TDF_SLIM); - fprintf (dump_file, "\n"); - if (pi && pi->name_mem_tag) - { - fprintf (dump_file, "\n\tnametag: "); - print_generic_expr (dump_file, pi->name_mem_tag, TDF_SLIM); - fprintf (dump_file, "\n"); - } - } - return dr; + return ret; } +/* Returns false if we can prove that data references A and B do not alias, + true otherwise. */ -/* Returns true when all the functions of a tree_vec CHREC are the - same. */ - -static bool -all_chrecs_equal_p (tree chrec) +bool +dr_may_alias_p (const struct data_reference *a, const struct data_reference *b) { - int j; - - for (j = 0; j < TREE_VEC_LENGTH (chrec) - 1; j++) - if (!eq_evolutions_p (TREE_VEC_ELT (chrec, j), - TREE_VEC_ELT (chrec, j + 1))) - return false; + const_tree addr_a = DR_BASE_ADDRESS (a); + const_tree addr_b = DR_BASE_ADDRESS (b); + const_tree type_a, type_b; + const_tree decl_a = NULL_TREE, decl_b = NULL_TREE; + + /* If the accessed objects are disjoint, the memory references do not + alias. */ + if (disjoint_objects_p (DR_BASE_OBJECT (a), DR_BASE_OBJECT (b))) + return false; - return true; -} + /* Query the alias oracle. */ + if (!DR_IS_READ (a) && !DR_IS_READ (b)) + { + if (!refs_output_dependent_p (DR_REF (a), DR_REF (b))) + return false; + } + else if (DR_IS_READ (a) && !DR_IS_READ (b)) + { + if (!refs_anti_dependent_p (DR_REF (a), DR_REF (b))) + return false; + } + else if (!refs_may_alias_p (DR_REF (a), DR_REF (b))) + return false; -/* Determine for each subscript in the data dependence relation DDR - the distance. */ + if (!addr_a || !addr_b) + return true; -static void -compute_subscript_distance (struct data_dependence_relation *ddr) -{ - if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE) - { - unsigned int i; - - for (i = 0; i < DDR_NUM_SUBSCRIPTS (ddr); i++) - { - tree conflicts_a, conflicts_b, difference; - struct subscript *subscript; - - subscript = DDR_SUBSCRIPT (ddr, i); - conflicts_a = SUB_CONFLICTS_IN_A (subscript); - conflicts_b = SUB_CONFLICTS_IN_B (subscript); + /* If the references are based on different static objects, they cannot + alias (PTA should be able to disambiguate such accesses, but often + it fails to). */ + if (TREE_CODE (addr_a) == ADDR_EXPR + && TREE_CODE (addr_b) == ADDR_EXPR) + return TREE_OPERAND (addr_a, 0) == TREE_OPERAND (addr_b, 0); - if (TREE_CODE (conflicts_a) == TREE_VEC) - { - if (!all_chrecs_equal_p (conflicts_a)) - { - SUB_DISTANCE (subscript) = chrec_dont_know; - return; - } - else - conflicts_a = TREE_VEC_ELT (conflicts_a, 0); - } + /* An instruction writing through a restricted pointer is "independent" of any + instruction reading or writing through a different restricted pointer, + in the same block/scope. */ - if (TREE_CODE (conflicts_b) == TREE_VEC) - { - if (!all_chrecs_equal_p (conflicts_b)) - { - SUB_DISTANCE (subscript) = chrec_dont_know; - return; - } - else - conflicts_b = TREE_VEC_ELT (conflicts_b, 0); - } + type_a = TREE_TYPE (addr_a); + type_b = TREE_TYPE (addr_b); + gcc_assert (POINTER_TYPE_P (type_a) && POINTER_TYPE_P (type_b)); + + if (TREE_CODE (addr_a) == SSA_NAME) + decl_a = SSA_NAME_VAR (addr_a); + if (TREE_CODE (addr_b) == SSA_NAME) + decl_b = SSA_NAME_VAR (addr_b); + + if (TYPE_RESTRICT (type_a) && TYPE_RESTRICT (type_b) + && (!DR_IS_READ (a) || !DR_IS_READ (b)) + && decl_a && DECL_P (decl_a) + && decl_b && DECL_P (decl_b) + && decl_a != decl_b + && TREE_CODE (DECL_CONTEXT (decl_a)) == FUNCTION_DECL + && DECL_CONTEXT (decl_a) == DECL_CONTEXT (decl_b)) + return false; - conflicts_b = chrec_convert (integer_type_node, conflicts_b, - NULL_TREE); - conflicts_a = chrec_convert (integer_type_node, conflicts_a, - NULL_TREE); - difference = chrec_fold_minus - (integer_type_node, conflicts_b, conflicts_a); - - if (evolution_function_is_constant_p (difference)) - SUB_DISTANCE (subscript) = difference; - - else - SUB_DISTANCE (subscript) = chrec_dont_know; - } - } + return true; } +static void compute_self_dependence (struct data_dependence_relation *); + /* Initialize a data dependence relation between data accesses A and B. NB_LOOPS is the number of loops surrounding the references: the size of the classic distance/direction vectors. */ static struct data_dependence_relation * -initialize_data_dependence_relation (struct data_reference *a, +initialize_data_dependence_relation (struct data_reference *a, struct data_reference *b, VEC (loop_p, heap) *loop_nest) { struct data_dependence_relation *res; - bool differ_p, known_dependence; unsigned int i; - + res = XNEW (struct data_dependence_relation); DDR_A (res) = a; DDR_B (res) = b; + DDR_LOOP_NEST (res) = NULL; + DDR_REVERSED_P (res) = false; + DDR_SUBSCRIPTS (res) = NULL; + DDR_DIR_VECTS (res) = NULL; + DDR_DIST_VECTS (res) = NULL; if (a == NULL || b == NULL) { - DDR_ARE_DEPENDENT (res) = chrec_dont_know; + DDR_ARE_DEPENDENT (res) = chrec_dont_know; return res; - } + } - /* When A and B are arrays and their dimensions differ, we directly - initialize the relation to "there is no dependence": chrec_known. */ - if (DR_BASE_OBJECT (a) && DR_BASE_OBJECT (b) - && DR_NUM_DIMENSIONS (a) != DR_NUM_DIMENSIONS (b)) + /* If the data references do not alias, then they are independent. */ + if (!dr_may_alias_p (a, b)) { DDR_ARE_DEPENDENT (res) = chrec_known; return res; } - if (DR_BASE_ADDRESS (a) && DR_BASE_ADDRESS (b)) - known_dependence = base_addr_differ_p (a, b, &differ_p); - else - known_dependence = base_object_differ_p (a, b, &differ_p); + /* When the references are exactly the same, don't spend time doing + the data dependence tests, just initialize the ddr and return. */ + if (operand_equal_p (DR_REF (a), DR_REF (b), 0)) + { + DDR_AFFINE_P (res) = true; + DDR_ARE_DEPENDENT (res) = NULL_TREE; + DDR_SUBSCRIPTS (res) = VEC_alloc (subscript_p, heap, DR_NUM_DIMENSIONS (a)); + DDR_LOOP_NEST (res) = loop_nest; + DDR_INNER_LOOP (res) = 0; + DDR_SELF_REFERENCE (res) = true; + compute_self_dependence (res); + return res; + } - if (!known_dependence) + /* If the references do not access the same object, we do not know + whether they alias or not. */ + if (!operand_equal_p (DR_BASE_OBJECT (a), DR_BASE_OBJECT (b), 0)) { - /* Can't determine whether the data-refs access the same memory - region. */ - DDR_ARE_DEPENDENT (res) = chrec_dont_know; + DDR_ARE_DEPENDENT (res) = chrec_dont_know; return res; } - if (differ_p) + /* If the base of the object is not invariant in the loop nest, we cannot + analyze it. TODO -- in fact, it would suffice to record that there may + be arbitrary dependences in the loops where the base object varies. */ + if (loop_nest + && !object_address_invariant_in_loop_p (VEC_index (loop_p, loop_nest, 0), + DR_BASE_OBJECT (a))) { - DDR_ARE_DEPENDENT (res) = chrec_known; + DDR_ARE_DEPENDENT (res) = chrec_dont_know; return res; } - + + gcc_assert (DR_NUM_DIMENSIONS (a) == DR_NUM_DIMENSIONS (b)); + DDR_AFFINE_P (res) = true; DDR_ARE_DEPENDENT (res) = NULL_TREE; DDR_SUBSCRIPTS (res) = VEC_alloc (subscript_p, heap, DR_NUM_DIMENSIONS (a)); DDR_LOOP_NEST (res) = loop_nest; - DDR_DIR_VECTS (res) = NULL; - DDR_DIST_VECTS (res) = NULL; + DDR_INNER_LOOP (res) = 0; + DDR_SELF_REFERENCE (res) = false; for (i = 0; i < DR_NUM_DIMENSIONS (a); i++) { struct subscript *subscript; - + subscript = XNEW (struct subscript); - SUB_CONFLICTS_IN_A (subscript) = chrec_dont_know; - SUB_CONFLICTS_IN_B (subscript) = chrec_dont_know; + SUB_CONFLICTS_IN_A (subscript) = conflict_fn_not_known (); + SUB_CONFLICTS_IN_B (subscript) = conflict_fn_not_known (); SUB_LAST_CONFLICT (subscript) = chrec_dont_know; SUB_DISTANCE (subscript) = chrec_dont_know; VEC_safe_push (subscript_p, heap, DDR_SUBSCRIPTS (res), subscript); @@ -2150,11 +1441,43 @@ initialize_data_dependence_relation (struct data_reference *a, return res; } +/* Frees memory used by the conflict function F. */ + +static void +free_conflict_function (conflict_function *f) +{ + unsigned i; + + if (CF_NONTRIVIAL_P (f)) + { + for (i = 0; i < f->n; i++) + affine_fn_free (f->fns[i]); + } + free (f); +} + +/* Frees memory used by SUBSCRIPTS. */ + +static void +free_subscripts (VEC (subscript_p, heap) *subscripts) +{ + unsigned i; + subscript_p s; + + for (i = 0; VEC_iterate (subscript_p, subscripts, i, s); i++) + { + free_conflict_function (s->conflicting_iterations_in_a); + free_conflict_function (s->conflicting_iterations_in_b); + free (s); + } + VEC_free (subscript_p, heap, subscripts); +} + /* Set DDR_ARE_DEPENDENT to CHREC and finalize the subscript overlap description. */ static inline void -finalize_ddr_dependent (struct data_dependence_relation *ddr, +finalize_ddr_dependent (struct data_dependence_relation *ddr, tree chrec) { if (dump_file && (dump_flags & TDF_DETAILS)) @@ -2164,8 +1487,9 @@ finalize_ddr_dependent (struct data_dependence_relation *ddr, fprintf (dump_file, ")\n"); } - DDR_ARE_DEPENDENT (ddr) = chrec; - VEC_free (subscript_p, heap, DDR_SUBSCRIPTS (ddr)); + DDR_ARE_DEPENDENT (ddr) = chrec; + free_subscripts (DDR_SUBSCRIPTS (ddr)); + DDR_SUBSCRIPTS (ddr) = NULL; } /* The dependence relation DDR cannot be represented by a distance @@ -2188,8 +1512,7 @@ non_affine_dependence_relation (struct data_dependence_relation *ddr) variables, i.e., if the ZIV (Zero Index Variable) test is true. */ static inline bool -ziv_subscript_p (tree chrec_a, - tree chrec_b) +ziv_subscript_p (const_tree chrec_a, const_tree chrec_b) { return (evolution_function_is_constant_p (chrec_a) && evolution_function_is_constant_p (chrec_b)); @@ -2199,15 +1522,14 @@ ziv_subscript_p (tree chrec_a, variable, i.e., if the SIV (Single Index Variable) test is true. */ static bool -siv_subscript_p (tree chrec_a, - tree chrec_b) +siv_subscript_p (const_tree chrec_a, const_tree chrec_b) { if ((evolution_function_is_constant_p (chrec_a) && evolution_function_is_univariate_p (chrec_b)) || (evolution_function_is_constant_p (chrec_b) && evolution_function_is_univariate_p (chrec_a))) return true; - + if (evolution_function_is_univariate_p (chrec_a) && evolution_function_is_univariate_p (chrec_b)) { @@ -2219,19 +1541,66 @@ siv_subscript_p (tree chrec_a, case POLYNOMIAL_CHREC: if (CHREC_VARIABLE (chrec_a) != CHREC_VARIABLE (chrec_b)) return false; - + default: return true; } - + default: return true; } } - + return false; } +/* Creates a conflict function with N dimensions. The affine functions + in each dimension follow. */ + +static conflict_function * +conflict_fn (unsigned n, ...) +{ + unsigned i; + conflict_function *ret = XCNEW (conflict_function); + va_list ap; + + gcc_assert (0 < n && n <= MAX_DIM); + va_start(ap, n); + + ret->n = n; + for (i = 0; i < n; i++) + ret->fns[i] = va_arg (ap, affine_fn); + va_end(ap); + + return ret; +} + +/* Returns constant affine function with value CST. */ + +static affine_fn +affine_fn_cst (tree cst) +{ + affine_fn fn = VEC_alloc (tree, heap, 1); + VEC_quick_push (tree, fn, cst); + return fn; +} + +/* Returns affine function with single variable, CST + COEF * x_DIM. */ + +static affine_fn +affine_fn_univar (tree cst, unsigned dim, tree coef) +{ + affine_fn fn = VEC_alloc (tree, heap, dim + 1); + unsigned i; + + gcc_assert (dim > 0); + VEC_quick_push (tree, fn, cst); + for (i = 1; i < dim; i++) + VEC_quick_push (tree, fn, integer_zero_node); + VEC_quick_push (tree, fn, coef); + return fn; +} + /* Analyze a ZIV (Zero Index Variable) subscript. *OVERLAPS_A and *OVERLAPS_B are initialized to the functions that describe the relation between the elements accessed twice by CHREC_A and @@ -2239,23 +1608,24 @@ siv_subscript_p (tree chrec_a, CHREC_A (*OVERLAPS_A (k)) = CHREC_B (*OVERLAPS_B (k)). */ -static void -analyze_ziv_subscript (tree chrec_a, - tree chrec_b, - tree *overlaps_a, - tree *overlaps_b, +static void +analyze_ziv_subscript (tree chrec_a, + tree chrec_b, + conflict_function **overlaps_a, + conflict_function **overlaps_b, tree *last_conflicts) { - tree difference; + tree type, difference; dependence_stats.num_ziv++; - + if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, "(analyze_ziv_subscript \n"); - - chrec_a = chrec_convert (integer_type_node, chrec_a, NULL_TREE); - chrec_b = chrec_convert (integer_type_node, chrec_b, NULL_TREE); - difference = chrec_fold_minus (integer_type_node, chrec_a, chrec_b); - + + type = signed_type_for_types (TREE_TYPE (chrec_a), TREE_TYPE (chrec_b)); + chrec_a = chrec_convert (type, chrec_a, NULL); + chrec_b = chrec_convert (type, chrec_b, NULL); + difference = chrec_fold_minus (type, chrec_a, chrec_b); + switch (TREE_CODE (difference)) { case INTEGER_CST: @@ -2263,85 +1633,138 @@ analyze_ziv_subscript (tree chrec_a, { /* The difference is equal to zero: the accessed index overlaps for each iteration in the loop. */ - *overlaps_a = integer_zero_node; - *overlaps_b = integer_zero_node; + *overlaps_a = conflict_fn (1, affine_fn_cst (integer_zero_node)); + *overlaps_b = conflict_fn (1, affine_fn_cst (integer_zero_node)); *last_conflicts = chrec_dont_know; dependence_stats.num_ziv_dependent++; } else { /* The accesses do not overlap. */ - *overlaps_a = chrec_known; - *overlaps_b = chrec_known; + *overlaps_a = conflict_fn_no_dependence (); + *overlaps_b = conflict_fn_no_dependence (); *last_conflicts = integer_zero_node; dependence_stats.num_ziv_independent++; } break; - + default: - /* We're not sure whether the indexes overlap. For the moment, + /* We're not sure whether the indexes overlap. For the moment, conservatively answer "don't know". */ if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, "ziv test failed: difference is non-integer.\n"); - *overlaps_a = chrec_dont_know; - *overlaps_b = chrec_dont_know; + *overlaps_a = conflict_fn_not_known (); + *overlaps_b = conflict_fn_not_known (); *last_conflicts = chrec_dont_know; dependence_stats.num_ziv_unimplemented++; break; } - + if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, ")\n"); } -/* Get the real or estimated number of iterations for LOOPNUM, whichever is - available. Return the number of iterations as a tree, or NULL_TREE if - we don't know. */ +/* Sets NIT to the estimated number of executions of the statements in + LOOP. If CONSERVATIVE is true, we must be sure that NIT is at least as + large as the number of iterations. If we have no reliable estimate, + the function returns false, otherwise returns true. */ -static tree -get_number_of_iters_for_loop (int loopnum) +bool +estimated_loop_iterations (struct loop *loop, bool conservative, + double_int *nit) { - tree numiter = number_of_iterations_in_loop (current_loops->parray[loopnum]); + estimate_numbers_of_iterations_loop (loop); + if (conservative) + { + if (!loop->any_upper_bound) + return false; - if (TREE_CODE (numiter) != INTEGER_CST) - numiter = current_loops->parray[loopnum]->estimated_nb_iterations; - if (chrec_contains_undetermined (numiter)) - return NULL_TREE; - return numiter; -} - -/* Analyze a SIV (Single Index Variable) subscript where CHREC_A is a - constant, and CHREC_B is an affine function. *OVERLAPS_A and - *OVERLAPS_B are initialized to the functions that describe the - relation between the elements accessed twice by CHREC_A and - CHREC_B. For k >= 0, the following property is verified: + *nit = loop->nb_iterations_upper_bound; + } + else + { + if (!loop->any_estimate) + return false; - CHREC_A (*OVERLAPS_A (k)) = CHREC_B (*OVERLAPS_B (k)). */ + *nit = loop->nb_iterations_estimate; + } -static void -analyze_siv_subscript_cst_affine (tree chrec_a, + return true; +} + +/* Similar to estimated_loop_iterations, but returns the estimate only + if it fits to HOST_WIDE_INT. If this is not the case, or the estimate + on the number of iterations of LOOP could not be derived, returns -1. */ + +HOST_WIDE_INT +estimated_loop_iterations_int (struct loop *loop, bool conservative) +{ + double_int nit; + HOST_WIDE_INT hwi_nit; + + if (!estimated_loop_iterations (loop, conservative, &nit)) + return -1; + + if (!double_int_fits_in_shwi_p (nit)) + return -1; + hwi_nit = double_int_to_shwi (nit); + + return hwi_nit < 0 ? -1 : hwi_nit; +} + +/* Similar to estimated_loop_iterations, but returns the estimate as a tree, + and only if it fits to the int type. If this is not the case, or the + estimate on the number of iterations of LOOP could not be derived, returns + chrec_dont_know. */ + +static tree +estimated_loop_iterations_tree (struct loop *loop, bool conservative) +{ + double_int nit; + tree type; + + if (!estimated_loop_iterations (loop, conservative, &nit)) + return chrec_dont_know; + + type = lang_hooks.types.type_for_size (INT_TYPE_SIZE, true); + if (!double_int_fits_to_tree_p (type, nit)) + return chrec_dont_know; + + return double_int_to_tree (type, nit); +} + +/* Analyze a SIV (Single Index Variable) subscript where CHREC_A is a + constant, and CHREC_B is an affine function. *OVERLAPS_A and + *OVERLAPS_B are initialized to the functions that describe the + relation between the elements accessed twice by CHREC_A and + CHREC_B. For k >= 0, the following property is verified: + + CHREC_A (*OVERLAPS_A (k)) = CHREC_B (*OVERLAPS_B (k)). */ + +static void +analyze_siv_subscript_cst_affine (tree chrec_a, tree chrec_b, - tree *overlaps_a, - tree *overlaps_b, + conflict_function **overlaps_a, + conflict_function **overlaps_b, tree *last_conflicts) { bool value0, value1, value2; - tree difference; + tree type, difference, tmp; + + type = signed_type_for_types (TREE_TYPE (chrec_a), TREE_TYPE (chrec_b)); + chrec_a = chrec_convert (type, chrec_a, NULL); + chrec_b = chrec_convert (type, chrec_b, NULL); + difference = chrec_fold_minus (type, initial_condition (chrec_b), chrec_a); - chrec_a = chrec_convert (integer_type_node, chrec_a, NULL_TREE); - chrec_b = chrec_convert (integer_type_node, chrec_b, NULL_TREE); - difference = chrec_fold_minus - (integer_type_node, initial_condition (chrec_b), chrec_a); - if (!chrec_is_positive (initial_condition (difference), &value0)) { if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, "siv test failed: chrec is not positive.\n"); + fprintf (dump_file, "siv test failed: chrec is not positive.\n"); dependence_stats.num_siv_unimplemented++; - *overlaps_a = chrec_dont_know; - *overlaps_b = chrec_dont_know; + *overlaps_a = conflict_fn_not_known (); + *overlaps_b = conflict_fn_not_known (); *last_conflicts = chrec_dont_know; return; } @@ -2354,8 +1777,8 @@ analyze_siv_subscript_cst_affine (tree chrec_a, if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, "siv test failed: chrec not positive.\n"); - *overlaps_a = chrec_dont_know; - *overlaps_b = chrec_dont_know; + *overlaps_a = conflict_fn_not_known (); + *overlaps_b = conflict_fn_not_known (); *last_conflicts = chrec_dont_know; dependence_stats.num_siv_unimplemented++; return; @@ -2364,79 +1787,79 @@ analyze_siv_subscript_cst_affine (tree chrec_a, { if (value1 == true) { - /* Example: + /* Example: chrec_a = 12 chrec_b = {10, +, 1} */ - + if (tree_fold_divides_p (CHREC_RIGHT (chrec_b), difference)) { - tree numiter; - int loopnum = CHREC_VARIABLE (chrec_b); - - *overlaps_a = integer_zero_node; - *overlaps_b = fold_build2 (EXACT_DIV_EXPR, integer_type_node, - fold_build1 (ABS_EXPR, - integer_type_node, - difference), - CHREC_RIGHT (chrec_b)); + HOST_WIDE_INT numiter; + struct loop *loop = get_chrec_loop (chrec_b); + + *overlaps_a = conflict_fn (1, affine_fn_cst (integer_zero_node)); + tmp = fold_build2 (EXACT_DIV_EXPR, type, + fold_build1 (ABS_EXPR, type, difference), + CHREC_RIGHT (chrec_b)); + *overlaps_b = conflict_fn (1, affine_fn_cst (tmp)); *last_conflicts = integer_one_node; - + /* Perform weak-zero siv test to see if overlap is outside the loop bounds. */ - numiter = get_number_of_iters_for_loop (loopnum); + numiter = estimated_loop_iterations_int (loop, false); - if (numiter != NULL_TREE - && TREE_CODE (*overlaps_b) == INTEGER_CST - && tree_int_cst_lt (numiter, *overlaps_b)) + if (numiter >= 0 + && compare_tree_int (tmp, numiter) > 0) { - *overlaps_a = chrec_known; - *overlaps_b = chrec_known; + free_conflict_function (*overlaps_a); + free_conflict_function (*overlaps_b); + *overlaps_a = conflict_fn_no_dependence (); + *overlaps_b = conflict_fn_no_dependence (); *last_conflicts = integer_zero_node; dependence_stats.num_siv_independent++; return; - } + } dependence_stats.num_siv_dependent++; return; } - + /* When the step does not divide the difference, there are no overlaps. */ else { - *overlaps_a = chrec_known; - *overlaps_b = chrec_known; + *overlaps_a = conflict_fn_no_dependence (); + *overlaps_b = conflict_fn_no_dependence (); *last_conflicts = integer_zero_node; dependence_stats.num_siv_independent++; return; } } - + else { - /* Example: + /* Example: chrec_a = 12 chrec_b = {10, +, -1} - + In this case, chrec_a will not overlap with chrec_b. */ - *overlaps_a = chrec_known; - *overlaps_b = chrec_known; + *overlaps_a = conflict_fn_no_dependence (); + *overlaps_b = conflict_fn_no_dependence (); *last_conflicts = integer_zero_node; dependence_stats.num_siv_independent++; return; } } } - else + else { if (!chrec_is_positive (CHREC_RIGHT (chrec_b), &value2)) { if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, "siv test failed: chrec not positive.\n"); - *overlaps_a = chrec_dont_know; - *overlaps_b = chrec_dont_know; + *overlaps_a = conflict_fn_not_known (); + *overlaps_b = conflict_fn_not_known (); *last_conflicts = chrec_dont_know; dependence_stats.num_siv_unimplemented++; return; @@ -2445,45 +1868,46 @@ analyze_siv_subscript_cst_affine (tree chrec_a, { if (value2 == false) { - /* Example: + /* Example: chrec_a = 3 chrec_b = {10, +, -1} */ if (tree_fold_divides_p (CHREC_RIGHT (chrec_b), difference)) { - tree numiter; - int loopnum = CHREC_VARIABLE (chrec_b); + HOST_WIDE_INT numiter; + struct loop *loop = get_chrec_loop (chrec_b); - *overlaps_a = integer_zero_node; - *overlaps_b = fold_build2 (EXACT_DIV_EXPR, - integer_type_node, difference, - CHREC_RIGHT (chrec_b)); + *overlaps_a = conflict_fn (1, affine_fn_cst (integer_zero_node)); + tmp = fold_build2 (EXACT_DIV_EXPR, type, difference, + CHREC_RIGHT (chrec_b)); + *overlaps_b = conflict_fn (1, affine_fn_cst (tmp)); *last_conflicts = integer_one_node; /* Perform weak-zero siv test to see if overlap is outside the loop bounds. */ - numiter = get_number_of_iters_for_loop (loopnum); + numiter = estimated_loop_iterations_int (loop, false); - if (numiter != NULL_TREE - && TREE_CODE (*overlaps_b) == INTEGER_CST - && tree_int_cst_lt (numiter, *overlaps_b)) + if (numiter >= 0 + && compare_tree_int (tmp, numiter) > 0) { - *overlaps_a = chrec_known; - *overlaps_b = chrec_known; + free_conflict_function (*overlaps_a); + free_conflict_function (*overlaps_b); + *overlaps_a = conflict_fn_no_dependence (); + *overlaps_b = conflict_fn_no_dependence (); *last_conflicts = integer_zero_node; dependence_stats.num_siv_independent++; return; - } + } dependence_stats.num_siv_dependent++; return; } - + /* When the step does not divide the difference, there are no overlaps. */ else { - *overlaps_a = chrec_known; - *overlaps_b = chrec_known; + *overlaps_a = conflict_fn_no_dependence (); + *overlaps_b = conflict_fn_no_dependence (); *last_conflicts = integer_zero_node; dependence_stats.num_siv_independent++; return; @@ -2491,13 +1915,13 @@ analyze_siv_subscript_cst_affine (tree chrec_a, } else { - /* Example: - chrec_a = 3 + /* Example: + chrec_a = 3 chrec_b = {4, +, 1} - + In this case, chrec_a will not overlap with chrec_b. */ - *overlaps_a = chrec_known; - *overlaps_b = chrec_known; + *overlaps_a = conflict_fn_no_dependence (); + *overlaps_b = conflict_fn_no_dependence (); *last_conflicts = integer_zero_node; dependence_stats.num_siv_independent++; return; @@ -2510,21 +1934,55 @@ analyze_siv_subscript_cst_affine (tree chrec_a, /* Helper recursive function for initializing the matrix A. Returns the initial value of CHREC. */ -static int +static tree initialize_matrix_A (lambda_matrix A, tree chrec, unsigned index, int mult) { gcc_assert (chrec); - if (TREE_CODE (chrec) != POLYNOMIAL_CHREC) - return int_cst_value (chrec); + switch (TREE_CODE (chrec)) + { + case POLYNOMIAL_CHREC: + gcc_assert (TREE_CODE (CHREC_RIGHT (chrec)) == INTEGER_CST); + + A[index][0] = mult * int_cst_value (CHREC_RIGHT (chrec)); + return initialize_matrix_A (A, CHREC_LEFT (chrec), index + 1, mult); + + case PLUS_EXPR: + case MULT_EXPR: + case MINUS_EXPR: + { + tree op0 = initialize_matrix_A (A, TREE_OPERAND (chrec, 0), index, mult); + tree op1 = initialize_matrix_A (A, TREE_OPERAND (chrec, 1), index, mult); + + return chrec_fold_op (TREE_CODE (chrec), chrec_type (chrec), op0, op1); + } + + case NOP_EXPR: + { + tree op = initialize_matrix_A (A, TREE_OPERAND (chrec, 0), index, mult); + return chrec_convert (chrec_type (chrec), op, NULL); + } + + case BIT_NOT_EXPR: + { + /* Handle ~X as -1 - X. */ + tree op = initialize_matrix_A (A, TREE_OPERAND (chrec, 0), index, mult); + return chrec_fold_op (MINUS_EXPR, chrec_type (chrec), + build_int_cst (TREE_TYPE (chrec), -1), op); + } + + case INTEGER_CST: + return chrec; - A[index][0] = mult * int_cst_value (CHREC_RIGHT (chrec)); - return initialize_matrix_A (A, CHREC_LEFT (chrec), index + 1, mult); + default: + gcc_unreachable (); + return NULL_TREE; + } } #define FLOOR_DIV(x,y) ((x) / (y)) -/* Solves the special case of the Diophantine equation: +/* Solves the special case of the Diophantine equation: | {0, +, STEP_A}_x (OVERLAPS_A) = {0, +, STEP_B}_y (OVERLAPS_B) Computes the descriptions OVERLAPS_A and OVERLAPS_B. NITER is the @@ -2532,8 +1990,9 @@ initialize_matrix_A (lambda_matrix A, tree chrec, unsigned index, int mult) constructed as evolutions in dimension DIM. */ static void -compute_overlap_steps_for_affine_univar (int niter, int step_a, int step_b, - tree *overlaps_a, tree *overlaps_b, +compute_overlap_steps_for_affine_univar (int niter, int step_a, int step_b, + affine_fn *overlaps_a, + affine_fn *overlaps_b, tree *last_conflicts, int dim) { if (((step_a > 0 && step_b > 0) @@ -2546,35 +2005,39 @@ compute_overlap_steps_for_affine_univar (int niter, int step_a, int step_b, step_overlaps_a = step_b / gcd_steps_a_b; step_overlaps_b = step_a / gcd_steps_a_b; - tau2 = FLOOR_DIV (niter, step_overlaps_a); - tau2 = MIN (tau2, FLOOR_DIV (niter, step_overlaps_b)); - last_conflict = tau2; - - *overlaps_a = build_polynomial_chrec - (dim, integer_zero_node, - build_int_cst (NULL_TREE, step_overlaps_a)); - *overlaps_b = build_polynomial_chrec - (dim, integer_zero_node, - build_int_cst (NULL_TREE, step_overlaps_b)); - *last_conflicts = build_int_cst (NULL_TREE, last_conflict); + if (niter > 0) + { + tau2 = FLOOR_DIV (niter, step_overlaps_a); + tau2 = MIN (tau2, FLOOR_DIV (niter, step_overlaps_b)); + last_conflict = tau2; + *last_conflicts = build_int_cst (NULL_TREE, last_conflict); + } + else + *last_conflicts = chrec_dont_know; + + *overlaps_a = affine_fn_univar (integer_zero_node, dim, + build_int_cst (NULL_TREE, + step_overlaps_a)); + *overlaps_b = affine_fn_univar (integer_zero_node, dim, + build_int_cst (NULL_TREE, + step_overlaps_b)); } else { - *overlaps_a = integer_zero_node; - *overlaps_b = integer_zero_node; + *overlaps_a = affine_fn_cst (integer_zero_node); + *overlaps_b = affine_fn_cst (integer_zero_node); *last_conflicts = integer_zero_node; } } - /* Solves the special case of a Diophantine equation where CHREC_A is an affine bivariate function, and CHREC_B is an affine univariate - function. For example, + function. For example, | {{0, +, 1}_x, +, 1335}_y = {0, +, 1336}_z - - has the following overlapping functions: + + has the following overlapping functions: | x (t, u, v) = {{0, +, 1336}_t, +, 1}_v | y (t, u, v) = {{0, +, 1336}_u, +, 1}_v @@ -2584,42 +2047,41 @@ compute_overlap_steps_for_affine_univar (int niter, int step_a, int step_b, a common benchmark. Implement the general algorithm. */ static void -compute_overlap_steps_for_affine_1_2 (tree chrec_a, tree chrec_b, - tree *overlaps_a, tree *overlaps_b, +compute_overlap_steps_for_affine_1_2 (tree chrec_a, tree chrec_b, + conflict_function **overlaps_a, + conflict_function **overlaps_b, tree *last_conflicts) { bool xz_p, yz_p, xyz_p; int step_x, step_y, step_z; - int niter_x, niter_y, niter_z, niter; - tree numiter_x, numiter_y, numiter_z; - tree overlaps_a_xz, overlaps_b_xz, last_conflicts_xz; - tree overlaps_a_yz, overlaps_b_yz, last_conflicts_yz; - tree overlaps_a_xyz, overlaps_b_xyz, last_conflicts_xyz; + HOST_WIDE_INT niter_x, niter_y, niter_z, niter; + affine_fn overlaps_a_xz, overlaps_b_xz; + affine_fn overlaps_a_yz, overlaps_b_yz; + affine_fn overlaps_a_xyz, overlaps_b_xyz; + affine_fn ova1, ova2, ovb; + tree last_conflicts_xz, last_conflicts_yz, last_conflicts_xyz; step_x = int_cst_value (CHREC_RIGHT (CHREC_LEFT (chrec_a))); step_y = int_cst_value (CHREC_RIGHT (chrec_a)); step_z = int_cst_value (CHREC_RIGHT (chrec_b)); - numiter_x = get_number_of_iters_for_loop (CHREC_VARIABLE (CHREC_LEFT (chrec_a))); - numiter_y = get_number_of_iters_for_loop (CHREC_VARIABLE (chrec_a)); - numiter_z = get_number_of_iters_for_loop (CHREC_VARIABLE (chrec_b)); - - if (numiter_x == NULL_TREE || numiter_y == NULL_TREE - || numiter_z == NULL_TREE) + niter_x = + estimated_loop_iterations_int (get_chrec_loop (CHREC_LEFT (chrec_a)), + false); + niter_y = estimated_loop_iterations_int (get_chrec_loop (chrec_a), false); + niter_z = estimated_loop_iterations_int (get_chrec_loop (chrec_b), false); + + if (niter_x < 0 || niter_y < 0 || niter_z < 0) { if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, "overlap steps test failed: no iteration counts.\n"); - - *overlaps_a = chrec_dont_know; - *overlaps_b = chrec_dont_know; + + *overlaps_a = conflict_fn_not_known (); + *overlaps_b = conflict_fn_not_known (); *last_conflicts = chrec_dont_know; return; } - niter_x = int_cst_value (numiter_x); - niter_y = int_cst_value (numiter_y); - niter_z = int_cst_value (numiter_z); - niter = MIN (niter_x, niter_z); compute_overlap_steps_for_affine_univar (niter, step_x, step_z, &overlaps_a_xz, @@ -2643,67 +2105,61 @@ compute_overlap_steps_for_affine_1_2 (tree chrec_a, tree chrec_b, if (xz_p || yz_p || xyz_p) { - *overlaps_a = make_tree_vec (2); - TREE_VEC_ELT (*overlaps_a, 0) = integer_zero_node; - TREE_VEC_ELT (*overlaps_a, 1) = integer_zero_node; - *overlaps_b = integer_zero_node; + ova1 = affine_fn_cst (integer_zero_node); + ova2 = affine_fn_cst (integer_zero_node); + ovb = affine_fn_cst (integer_zero_node); if (xz_p) { - tree t0 = chrec_convert (integer_type_node, - TREE_VEC_ELT (*overlaps_a, 0), NULL_TREE); - tree t1 = chrec_convert (integer_type_node, overlaps_a_xz, - NULL_TREE); - tree t2 = chrec_convert (integer_type_node, *overlaps_b, - NULL_TREE); - tree t3 = chrec_convert (integer_type_node, overlaps_b_xz, - NULL_TREE); - - TREE_VEC_ELT (*overlaps_a, 0) = chrec_fold_plus (integer_type_node, - t0, t1); - *overlaps_b = chrec_fold_plus (integer_type_node, t2, t3); + affine_fn t0 = ova1; + affine_fn t2 = ovb; + + ova1 = affine_fn_plus (ova1, overlaps_a_xz); + ovb = affine_fn_plus (ovb, overlaps_b_xz); + affine_fn_free (t0); + affine_fn_free (t2); *last_conflicts = last_conflicts_xz; } if (yz_p) { - tree t0 = chrec_convert (integer_type_node, - TREE_VEC_ELT (*overlaps_a, 1), NULL_TREE); - tree t1 = chrec_convert (integer_type_node, overlaps_a_yz, NULL_TREE); - tree t2 = chrec_convert (integer_type_node, *overlaps_b, NULL_TREE); - tree t3 = chrec_convert (integer_type_node, overlaps_b_yz, NULL_TREE); - - TREE_VEC_ELT (*overlaps_a, 1) = chrec_fold_plus (integer_type_node, - t0, t1); - *overlaps_b = chrec_fold_plus (integer_type_node, t2, t3); + affine_fn t0 = ova2; + affine_fn t2 = ovb; + + ova2 = affine_fn_plus (ova2, overlaps_a_yz); + ovb = affine_fn_plus (ovb, overlaps_b_yz); + affine_fn_free (t0); + affine_fn_free (t2); *last_conflicts = last_conflicts_yz; } if (xyz_p) { - tree t0 = chrec_convert (integer_type_node, - TREE_VEC_ELT (*overlaps_a, 0), NULL_TREE); - tree t1 = chrec_convert (integer_type_node, overlaps_a_xyz, - NULL_TREE); - tree t2 = chrec_convert (integer_type_node, - TREE_VEC_ELT (*overlaps_a, 1), NULL_TREE); - tree t3 = chrec_convert (integer_type_node, overlaps_a_xyz, - NULL_TREE); - tree t4 = chrec_convert (integer_type_node, *overlaps_b, NULL_TREE); - tree t5 = chrec_convert (integer_type_node, overlaps_b_xyz, - NULL_TREE); - - TREE_VEC_ELT (*overlaps_a, 0) = chrec_fold_plus (integer_type_node, - t0, t1); - TREE_VEC_ELT (*overlaps_a, 1) = chrec_fold_plus (integer_type_node, - t2, t3); - *overlaps_b = chrec_fold_plus (integer_type_node, t4, t5); + affine_fn t0 = ova1; + affine_fn t2 = ova2; + affine_fn t4 = ovb; + + ova1 = affine_fn_plus (ova1, overlaps_a_xyz); + ova2 = affine_fn_plus (ova2, overlaps_a_xyz); + ovb = affine_fn_plus (ovb, overlaps_b_xyz); + affine_fn_free (t0); + affine_fn_free (t2); + affine_fn_free (t4); *last_conflicts = last_conflicts_xyz; } + *overlaps_a = conflict_fn (2, ova1, ova2); + *overlaps_b = conflict_fn (1, ovb); } else { - *overlaps_a = integer_zero_node; - *overlaps_b = integer_zero_node; + *overlaps_a = conflict_fn (1, affine_fn_cst (integer_zero_node)); + *overlaps_b = conflict_fn (1, affine_fn_cst (integer_zero_node)); *last_conflicts = integer_zero_node; } + + affine_fn_free (overlaps_a_xz); + affine_fn_free (overlaps_b_xz); + affine_fn_free (overlaps_a_yz); + affine_fn_free (overlaps_b_yz); + affine_fn_free (overlaps_a_xyz); + affine_fn_free (overlaps_b_xyz); } /* Determines the overlapping elements due to accesses CHREC_A and @@ -2712,32 +2168,32 @@ compute_overlap_steps_for_affine_1_2 (tree chrec_a, tree chrec_b, parameters, because it uses lambda matrices of integers. */ static void -analyze_subscript_affine_affine (tree chrec_a, +analyze_subscript_affine_affine (tree chrec_a, tree chrec_b, - tree *overlaps_a, - tree *overlaps_b, + conflict_function **overlaps_a, + conflict_function **overlaps_b, tree *last_conflicts) { unsigned nb_vars_a, nb_vars_b, dim; - int init_a, init_b, gamma, gcd_alpha_beta; - int tau1, tau2; + HOST_WIDE_INT init_a, init_b, gamma, gcd_alpha_beta; lambda_matrix A, U, S; + struct obstack scratch_obstack; if (eq_evolutions_p (chrec_a, chrec_b)) { /* The accessed index overlaps for each iteration in the loop. */ - *overlaps_a = integer_zero_node; - *overlaps_b = integer_zero_node; + *overlaps_a = conflict_fn (1, affine_fn_cst (integer_zero_node)); + *overlaps_b = conflict_fn (1, affine_fn_cst (integer_zero_node)); *last_conflicts = chrec_dont_know; return; } if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, "(analyze_subscript_affine_affine \n"); - + /* For determining the initial intersection, we have to solve a Diophantine equation. This is the most time consuming part. - + For answering to the question: "Is there a dependence?" we have to prove that there exists a solution to the Diophantine equation, and that the solution is in the iteration domain, @@ -2749,53 +2205,46 @@ analyze_subscript_affine_affine (tree chrec_a, nb_vars_a = nb_vars_in_chrec (chrec_a); nb_vars_b = nb_vars_in_chrec (chrec_b); + gcc_obstack_init (&scratch_obstack); + dim = nb_vars_a + nb_vars_b; - U = lambda_matrix_new (dim, dim); - A = lambda_matrix_new (dim, 1); - S = lambda_matrix_new (dim, 1); + U = lambda_matrix_new (dim, dim, &scratch_obstack); + A = lambda_matrix_new (dim, 1, &scratch_obstack); + S = lambda_matrix_new (dim, 1, &scratch_obstack); - init_a = initialize_matrix_A (A, chrec_a, 0, 1); - init_b = initialize_matrix_A (A, chrec_b, nb_vars_a, -1); + init_a = int_cst_value (initialize_matrix_A (A, chrec_a, 0, 1)); + init_b = int_cst_value (initialize_matrix_A (A, chrec_b, nb_vars_a, -1)); gamma = init_b - init_a; /* Don't do all the hard work of solving the Diophantine equation - when we already know the solution: for example, + when we already know the solution: for example, | {3, +, 1}_1 | {3, +, 4}_2 | gamma = 3 - 3 = 0. - Then the first overlap occurs during the first iterations: + Then the first overlap occurs during the first iterations: | {3, +, 1}_1 ({0, +, 4}_x) = {3, +, 4}_2 ({0, +, 1}_x) */ if (gamma == 0) { if (nb_vars_a == 1 && nb_vars_b == 1) { - int step_a, step_b; - int niter, niter_a, niter_b; - tree numiter_a, numiter_b; - - numiter_a = get_number_of_iters_for_loop (CHREC_VARIABLE (chrec_a)); - numiter_b = get_number_of_iters_for_loop (CHREC_VARIABLE (chrec_b)); - if (numiter_a == NULL_TREE || numiter_b == NULL_TREE) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, "affine-affine test failed: missing iteration counts.\n"); - *overlaps_a = chrec_dont_know; - *overlaps_b = chrec_dont_know; - *last_conflicts = chrec_dont_know; - goto end_analyze_subs_aa; - } - - niter_a = int_cst_value (numiter_a); - niter_b = int_cst_value (numiter_b); + HOST_WIDE_INT step_a, step_b; + HOST_WIDE_INT niter, niter_a, niter_b; + affine_fn ova, ovb; + + niter_a = estimated_loop_iterations_int (get_chrec_loop (chrec_a), + false); + niter_b = estimated_loop_iterations_int (get_chrec_loop (chrec_b), + false); niter = MIN (niter_a, niter_b); - step_a = int_cst_value (CHREC_RIGHT (chrec_a)); step_b = int_cst_value (CHREC_RIGHT (chrec_b)); - compute_overlap_steps_for_affine_univar (niter, step_a, step_b, - overlaps_a, overlaps_b, + compute_overlap_steps_for_affine_univar (niter, step_a, step_b, + &ova, &ovb, last_conflicts, 1); + *overlaps_a = conflict_fn (1, ova); + *overlaps_b = conflict_fn (1, ovb); } else if (nb_vars_a == 2 && nb_vars_b == 1) @@ -2810,8 +2259,8 @@ analyze_subscript_affine_affine (tree chrec_a, { if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, "affine-affine test failed: too many variables.\n"); - *overlaps_a = chrec_dont_know; - *overlaps_b = chrec_dont_know; + *overlaps_a = conflict_fn_not_known (); + *overlaps_b = conflict_fn_not_known (); *last_conflicts = chrec_dont_know; } goto end_analyze_subs_aa; @@ -2832,8 +2281,8 @@ analyze_subscript_affine_affine (tree chrec_a, don't know. */ if (gcd_alpha_beta == 0) { - *overlaps_a = chrec_dont_know; - *overlaps_b = chrec_dont_know; + *overlaps_a = conflict_fn_not_known (); + *overlaps_b = conflict_fn_not_known (); *last_conflicts = chrec_dont_know; goto end_analyze_subs_aa; } @@ -2843,8 +2292,8 @@ analyze_subscript_affine_affine (tree chrec_a, { /* The "gcd-test" has determined that there is no integer solution, i.e. there is no dependence. */ - *overlaps_a = chrec_known; - *overlaps_b = chrec_known; + *overlaps_a = conflict_fn_no_dependence (); + *overlaps_b = conflict_fn_no_dependence (); *last_conflicts = integer_zero_node; } @@ -2856,47 +2305,22 @@ analyze_subscript_affine_affine (tree chrec_a, || (A[0][0] < 0 && -A[1][0] < 0))) { /* The solutions are given by: - | + | | [GAMMA/GCD_ALPHA_BETA t].[u11 u12] = [x0] | [u21 u22] [y0] - + For a given integer t. Using the following variables, - + | i0 = u11 * gamma / gcd_alpha_beta | j0 = u12 * gamma / gcd_alpha_beta | i1 = u21 | j1 = u22 - - the solutions are: - - | x0 = i0 + i1 * t, - | y0 = j0 + j1 * t. */ - - int i0, j0, i1, j1; - - /* X0 and Y0 are the first iterations for which there is a - dependence. X0, Y0 are two solutions of the Diophantine - equation: chrec_a (X0) = chrec_b (Y0). */ - int x0, y0; - int niter, niter_a, niter_b; - tree numiter_a, numiter_b; - - numiter_a = get_number_of_iters_for_loop (CHREC_VARIABLE (chrec_a)); - numiter_b = get_number_of_iters_for_loop (CHREC_VARIABLE (chrec_b)); - if (numiter_a == NULL_TREE || numiter_b == NULL_TREE) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, "affine-affine test failed: missing iteration counts.\n"); - *overlaps_a = chrec_dont_know; - *overlaps_b = chrec_dont_know; - *last_conflicts = chrec_dont_know; - goto end_analyze_subs_aa; - } + the solutions are: - niter_a = int_cst_value (numiter_a); - niter_b = int_cst_value (numiter_b); - niter = MIN (niter_a, niter_b); + | x0 = i0 + i1 * t, + | y0 = j0 + j1 * t. */ + HOST_WIDE_INT i0, j0, i1, j1; i0 = U[0][0] * gamma / gcd_alpha_beta; j0 = U[0][1] * gamma / gcd_alpha_beta; @@ -2906,113 +2330,107 @@ analyze_subscript_affine_affine (tree chrec_a, if ((i1 == 0 && i0 < 0) || (j1 == 0 && j0 < 0)) { - /* There is no solution. - FIXME: The case "i0 > nb_iterations, j0 > nb_iterations" - falls in here, but for the moment we don't look at the + /* There is no solution. + FIXME: The case "i0 > nb_iterations, j0 > nb_iterations" + falls in here, but for the moment we don't look at the upper bound of the iteration domain. */ - *overlaps_a = chrec_known; - *overlaps_b = chrec_known; + *overlaps_a = conflict_fn_no_dependence (); + *overlaps_b = conflict_fn_no_dependence (); *last_conflicts = integer_zero_node; + goto end_analyze_subs_aa; } - else + if (i1 > 0 && j1 > 0) { - if (i1 > 0) + HOST_WIDE_INT niter_a = estimated_loop_iterations_int + (get_chrec_loop (chrec_a), false); + HOST_WIDE_INT niter_b = estimated_loop_iterations_int + (get_chrec_loop (chrec_b), false); + HOST_WIDE_INT niter = MIN (niter_a, niter_b); + + /* (X0, Y0) is a solution of the Diophantine equation: + "chrec_a (X0) = chrec_b (Y0)". */ + HOST_WIDE_INT tau1 = MAX (CEIL (-i0, i1), + CEIL (-j0, j1)); + HOST_WIDE_INT x0 = i1 * tau1 + i0; + HOST_WIDE_INT y0 = j1 * tau1 + j0; + + /* (X1, Y1) is the smallest positive solution of the eq + "chrec_a (X1) = chrec_b (Y1)", i.e. this is where the + first conflict occurs. */ + HOST_WIDE_INT min_multiple = MIN (x0 / i1, y0 / j1); + HOST_WIDE_INT x1 = x0 - i1 * min_multiple; + HOST_WIDE_INT y1 = y0 - j1 * min_multiple; + + if (niter > 0) { - tau1 = CEIL (-i0, i1); - tau2 = FLOOR_DIV (niter - i0, i1); + HOST_WIDE_INT tau2 = MIN (FLOOR_DIV (niter - i0, i1), + FLOOR_DIV (niter - j0, j1)); + HOST_WIDE_INT last_conflict = tau2 - (x1 - i0)/i1; - if (j1 > 0) + /* If the overlap occurs outside of the bounds of the + loop, there is no dependence. */ + if (x1 >= niter || y1 >= niter) { - int last_conflict, min_multiple; - tau1 = MAX (tau1, CEIL (-j0, j1)); - tau2 = MIN (tau2, FLOOR_DIV (niter - j0, j1)); - - x0 = i1 * tau1 + i0; - y0 = j1 * tau1 + j0; - - /* At this point (x0, y0) is one of the - solutions to the Diophantine equation. The - next step has to compute the smallest - positive solution: the first conflicts. */ - min_multiple = MIN (x0 / i1, y0 / j1); - x0 -= i1 * min_multiple; - y0 -= j1 * min_multiple; - - tau1 = (x0 - i0)/i1; - last_conflict = tau2 - tau1; - - /* If the overlap occurs outside of the bounds of the - loop, there is no dependence. */ - if (x0 > niter || y0 > niter) - { - *overlaps_a = chrec_known; - *overlaps_b = chrec_known; - *last_conflicts = integer_zero_node; - } - else - { - *overlaps_a = build_polynomial_chrec - (1, - build_int_cst (NULL_TREE, x0), - build_int_cst (NULL_TREE, i1)); - *overlaps_b = build_polynomial_chrec - (1, - build_int_cst (NULL_TREE, y0), - build_int_cst (NULL_TREE, j1)); - *last_conflicts = build_int_cst (NULL_TREE, last_conflict); - } + *overlaps_a = conflict_fn_no_dependence (); + *overlaps_b = conflict_fn_no_dependence (); + *last_conflicts = integer_zero_node; + goto end_analyze_subs_aa; } else - { - /* FIXME: For the moment, the upper bound of the - iteration domain for j is not checked. */ - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, "affine-affine test failed: unimplemented.\n"); - *overlaps_a = chrec_dont_know; - *overlaps_b = chrec_dont_know; - *last_conflicts = chrec_dont_know; - } + *last_conflicts = build_int_cst (NULL_TREE, last_conflict); } - else - { - /* FIXME: For the moment, the upper bound of the - iteration domain for i is not checked. */ - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, "affine-affine test failed: unimplemented.\n"); - *overlaps_a = chrec_dont_know; - *overlaps_b = chrec_dont_know; - *last_conflicts = chrec_dont_know; - } + *last_conflicts = chrec_dont_know; + + *overlaps_a + = conflict_fn (1, + affine_fn_univar (build_int_cst (NULL_TREE, x1), + 1, + build_int_cst (NULL_TREE, i1))); + *overlaps_b + = conflict_fn (1, + affine_fn_univar (build_int_cst (NULL_TREE, y1), + 1, + build_int_cst (NULL_TREE, j1))); + } + else + { + /* FIXME: For the moment, the upper bound of the + iteration domain for i and j is not checked. */ + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, "affine-affine test failed: unimplemented.\n"); + *overlaps_a = conflict_fn_not_known (); + *overlaps_b = conflict_fn_not_known (); + *last_conflicts = chrec_dont_know; } } else { if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, "affine-affine test failed: unimplemented.\n"); - *overlaps_a = chrec_dont_know; - *overlaps_b = chrec_dont_know; + *overlaps_a = conflict_fn_not_known (); + *overlaps_b = conflict_fn_not_known (); *last_conflicts = chrec_dont_know; } } - else { if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, "affine-affine test failed: unimplemented.\n"); - *overlaps_a = chrec_dont_know; - *overlaps_b = chrec_dont_know; + *overlaps_a = conflict_fn_not_known (); + *overlaps_b = conflict_fn_not_known (); *last_conflicts = chrec_dont_know; } -end_analyze_subs_aa: +end_analyze_subs_aa: + obstack_free (&scratch_obstack, NULL); if (dump_file && (dump_flags & TDF_DETAILS)) { fprintf (dump_file, " (overlaps_a = "); - print_generic_expr (dump_file, *overlaps_a, 0); + dump_conflict_function (dump_file, *overlaps_a); fprintf (dump_file, ")\n (overlaps_b = "); - print_generic_expr (dump_file, *overlaps_b, 0); + dump_conflict_function (dump_file, *overlaps_b); fprintf (dump_file, ")\n"); fprintf (dump_file, ")\n"); } @@ -3022,12 +2440,12 @@ end_analyze_subs_aa: determining the dependence relation between chrec_a and chrec_b, that contain symbols. This function modifies chrec_a and chrec_b such that the analysis result is the same, and such that they don't - contain symbols, and then can safely be passed to the analyzer. + contain symbols, and then can safely be passed to the analyzer. Example: The analysis of the following tuples of evolutions produce the same results: {x+1, +, 1}_1 vs. {x+3, +, 1}_1, and {-2, +, 1}_1 vs. {0, +, 1}_1 - + {x+1, +, 1}_1 ({2, +, 1}_1) = {x+3, +, 1}_1 ({0, +, 1}_1) {-2, +, 1}_1 ({2, +, 1}_1) = {0, +, 1}_1 ({0, +, 1}_1) */ @@ -3044,7 +2462,7 @@ can_use_analyze_subscript_affine_affine (tree *chrec_a, tree *chrec_b) type = chrec_type (*chrec_a); left_a = CHREC_LEFT (*chrec_a); - left_b = chrec_convert (type, CHREC_LEFT (*chrec_b), NULL_TREE); + left_b = chrec_convert (type, CHREC_LEFT (*chrec_b), NULL); diff = chrec_fold_minus (type, left_a, left_b); if (!evolution_function_is_constant_p (diff)) @@ -3053,9 +2471,9 @@ can_use_analyze_subscript_affine_affine (tree *chrec_a, tree *chrec_b) if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, "can_use_subscript_aff_aff_for_symbolic \n"); - *chrec_a = build_polynomial_chrec (CHREC_VARIABLE (*chrec_a), + *chrec_a = build_polynomial_chrec (CHREC_VARIABLE (*chrec_a), diff, CHREC_RIGHT (*chrec_a)); - right_b = chrec_convert (type, CHREC_RIGHT (*chrec_b), NULL_TREE); + right_b = chrec_convert (type, CHREC_RIGHT (*chrec_b), NULL); *chrec_b = build_polynomial_chrec (CHREC_VARIABLE (*chrec_b), build_int_cst (type, 0), right_b); @@ -3070,61 +2488,59 @@ can_use_analyze_subscript_affine_affine (tree *chrec_a, tree *chrec_b) CHREC_A (*OVERLAPS_A (k)) = CHREC_B (*OVERLAPS_B (k)). */ static void -analyze_siv_subscript (tree chrec_a, +analyze_siv_subscript (tree chrec_a, tree chrec_b, - tree *overlaps_a, - tree *overlaps_b, - tree *last_conflicts) + conflict_function **overlaps_a, + conflict_function **overlaps_b, + tree *last_conflicts, + int loop_nest_num) { dependence_stats.num_siv++; - + if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, "(analyze_siv_subscript \n"); - + if (evolution_function_is_constant_p (chrec_a) - && evolution_function_is_affine_p (chrec_b)) - analyze_siv_subscript_cst_affine (chrec_a, chrec_b, + && evolution_function_is_affine_in_loop (chrec_b, loop_nest_num)) + analyze_siv_subscript_cst_affine (chrec_a, chrec_b, overlaps_a, overlaps_b, last_conflicts); - - else if (evolution_function_is_affine_p (chrec_a) + + else if (evolution_function_is_affine_in_loop (chrec_a, loop_nest_num) && evolution_function_is_constant_p (chrec_b)) - analyze_siv_subscript_cst_affine (chrec_b, chrec_a, + analyze_siv_subscript_cst_affine (chrec_b, chrec_a, overlaps_b, overlaps_a, last_conflicts); - - else if (evolution_function_is_affine_p (chrec_a) - && evolution_function_is_affine_p (chrec_b)) + + else if (evolution_function_is_affine_in_loop (chrec_a, loop_nest_num) + && evolution_function_is_affine_in_loop (chrec_b, loop_nest_num)) { if (!chrec_contains_symbols (chrec_a) && !chrec_contains_symbols (chrec_b)) { - analyze_subscript_affine_affine (chrec_a, chrec_b, - overlaps_a, overlaps_b, + analyze_subscript_affine_affine (chrec_a, chrec_b, + overlaps_a, overlaps_b, last_conflicts); - if (*overlaps_a == chrec_dont_know - || *overlaps_b == chrec_dont_know) + if (CF_NOT_KNOWN_P (*overlaps_a) + || CF_NOT_KNOWN_P (*overlaps_b)) dependence_stats.num_siv_unimplemented++; - else if (*overlaps_a == chrec_known - || *overlaps_b == chrec_known) + else if (CF_NO_DEPENDENCE_P (*overlaps_a) + || CF_NO_DEPENDENCE_P (*overlaps_b)) dependence_stats.num_siv_independent++; else dependence_stats.num_siv_dependent++; } - else if (can_use_analyze_subscript_affine_affine (&chrec_a, + else if (can_use_analyze_subscript_affine_affine (&chrec_a, &chrec_b)) { - analyze_subscript_affine_affine (chrec_a, chrec_b, - overlaps_a, overlaps_b, + analyze_subscript_affine_affine (chrec_a, chrec_b, + overlaps_a, overlaps_b, last_conflicts); - /* FIXME: The number of iterations is a symbolic expression. - Compute it properly. */ - *last_conflicts = chrec_dont_know; - if (*overlaps_a == chrec_dont_know - || *overlaps_b == chrec_dont_know) + if (CF_NOT_KNOWN_P (*overlaps_a) + || CF_NOT_KNOWN_P (*overlaps_b)) dependence_stats.num_siv_unimplemented++; - else if (*overlaps_a == chrec_known - || *overlaps_b == chrec_known) + else if (CF_NO_DEPENDENCE_P (*overlaps_a) + || CF_NO_DEPENDENCE_P (*overlaps_b)) dependence_stats.num_siv_independent++; else dependence_stats.num_siv_dependent++; @@ -3138,174 +2554,173 @@ analyze_siv_subscript (tree chrec_a, siv_subscript_dontknow:; if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, "siv test failed: unimplemented.\n"); - *overlaps_a = chrec_dont_know; - *overlaps_b = chrec_dont_know; + *overlaps_a = conflict_fn_not_known (); + *overlaps_b = conflict_fn_not_known (); *last_conflicts = chrec_dont_know; dependence_stats.num_siv_unimplemented++; } - + if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, ")\n"); } -/* Return true when the property can be computed. RES should contain - true when calling the first time this function, then it is set to - false when one of the evolution steps of an affine CHREC does not - divide the constant CST. */ +/* Returns false if we can prove that the greatest common divisor of the steps + of CHREC does not divide CST, false otherwise. */ static bool -chrec_steps_divide_constant_p (tree chrec, - tree cst, - bool *res) +gcd_of_steps_may_divide_p (const_tree chrec, const_tree cst) { - switch (TREE_CODE (chrec)) - { - case POLYNOMIAL_CHREC: - if (evolution_function_is_constant_p (CHREC_RIGHT (chrec))) - { - if (tree_fold_divides_p (CHREC_RIGHT (chrec), cst)) - /* Keep RES to true, and iterate on other dimensions. */ - return chrec_steps_divide_constant_p (CHREC_LEFT (chrec), cst, res); - - *res = false; - return true; - } - else - /* When the step is a parameter the result is undetermined. */ - return false; + HOST_WIDE_INT cd = 0, val; + tree step; - default: - /* On the initial condition, return true. */ - return true; + if (!host_integerp (cst, 0)) + return true; + val = tree_low_cst (cst, 0); + + while (TREE_CODE (chrec) == POLYNOMIAL_CHREC) + { + step = CHREC_RIGHT (chrec); + if (!host_integerp (step, 0)) + return true; + cd = gcd (cd, tree_low_cst (step, 0)); + chrec = CHREC_LEFT (chrec); } + + return val % cd == 0; } -/* Analyze a MIV (Multiple Index Variable) subscript. *OVERLAPS_A and - *OVERLAPS_B are initialized to the functions that describe the - relation between the elements accessed twice by CHREC_A and - CHREC_B. For k >= 0, the following property is verified: +/* Analyze a MIV (Multiple Index Variable) subscript with respect to + LOOP_NEST. *OVERLAPS_A and *OVERLAPS_B are initialized to the + functions that describe the relation between the elements accessed + twice by CHREC_A and CHREC_B. For k >= 0, the following property + is verified: CHREC_A (*OVERLAPS_A (k)) = CHREC_B (*OVERLAPS_B (k)). */ static void -analyze_miv_subscript (tree chrec_a, - tree chrec_b, - tree *overlaps_a, - tree *overlaps_b, - tree *last_conflicts) +analyze_miv_subscript (tree chrec_a, + tree chrec_b, + conflict_function **overlaps_a, + conflict_function **overlaps_b, + tree *last_conflicts, + struct loop *loop_nest) { /* FIXME: This is a MIV subscript, not yet handled. - Example: (A[{1, +, 1}_1] vs. A[{1, +, 1}_2]) that comes from - (A[i] vs. A[j]). - + Example: (A[{1, +, 1}_1] vs. A[{1, +, 1}_2]) that comes from + (A[i] vs. A[j]). + In the SIV test we had to solve a Diophantine equation with two variables. In the MIV case we have to solve a Diophantine equation with 2*n variables (if the subscript uses n IVs). */ - bool divide_p = true; - tree difference; + tree type, difference; + dependence_stats.num_miv++; if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, "(analyze_miv_subscript \n"); - chrec_a = chrec_convert (integer_type_node, chrec_a, NULL_TREE); - chrec_b = chrec_convert (integer_type_node, chrec_b, NULL_TREE); - difference = chrec_fold_minus (integer_type_node, chrec_a, chrec_b); - + type = signed_type_for_types (TREE_TYPE (chrec_a), TREE_TYPE (chrec_b)); + chrec_a = chrec_convert (type, chrec_a, NULL); + chrec_b = chrec_convert (type, chrec_b, NULL); + difference = chrec_fold_minus (type, chrec_a, chrec_b); + if (eq_evolutions_p (chrec_a, chrec_b)) { /* Access functions are the same: all the elements are accessed in the same order. */ - *overlaps_a = integer_zero_node; - *overlaps_b = integer_zero_node; - *last_conflicts = get_number_of_iters_for_loop (CHREC_VARIABLE (chrec_a)); + *overlaps_a = conflict_fn (1, affine_fn_cst (integer_zero_node)); + *overlaps_b = conflict_fn (1, affine_fn_cst (integer_zero_node)); + *last_conflicts = estimated_loop_iterations_tree + (get_chrec_loop (chrec_a), true); dependence_stats.num_miv_dependent++; } - + else if (evolution_function_is_constant_p (difference) /* For the moment, the following is verified: - evolution_function_is_affine_multivariate_p (chrec_a) */ - && chrec_steps_divide_constant_p (chrec_a, difference, ÷_p) - && !divide_p) + evolution_function_is_affine_multivariate_p (chrec_a, + loop_nest->num) */ + && !gcd_of_steps_may_divide_p (chrec_a, difference)) { /* testsuite/.../ssa-chrec-33.c - {{21, +, 2}_1, +, -2}_2 vs. {{20, +, 2}_1, +, -2}_2 - - The difference is 1, and the evolution steps are equal to 2, - consequently there are no overlapping elements. */ - *overlaps_a = chrec_known; - *overlaps_b = chrec_known; + {{21, +, 2}_1, +, -2}_2 vs. {{20, +, 2}_1, +, -2}_2 + + The difference is 1, and all the evolution steps are multiples + of 2, consequently there are no overlapping elements. */ + *overlaps_a = conflict_fn_no_dependence (); + *overlaps_b = conflict_fn_no_dependence (); *last_conflicts = integer_zero_node; dependence_stats.num_miv_independent++; } - - else if (evolution_function_is_affine_multivariate_p (chrec_a) + + else if (evolution_function_is_affine_multivariate_p (chrec_a, loop_nest->num) && !chrec_contains_symbols (chrec_a) - && evolution_function_is_affine_multivariate_p (chrec_b) + && evolution_function_is_affine_multivariate_p (chrec_b, loop_nest->num) && !chrec_contains_symbols (chrec_b)) { /* testsuite/.../ssa-chrec-35.c {0, +, 1}_2 vs. {0, +, 1}_3 the overlapping elements are respectively located at iterations: - {0, +, 1}_x and {0, +, 1}_x, - in other words, we have the equality: + {0, +, 1}_x and {0, +, 1}_x, + in other words, we have the equality: {0, +, 1}_2 ({0, +, 1}_x) = {0, +, 1}_3 ({0, +, 1}_x) - - Other examples: - {{0, +, 1}_1, +, 2}_2 ({0, +, 1}_x, {0, +, 1}_y) = + + Other examples: + {{0, +, 1}_1, +, 2}_2 ({0, +, 1}_x, {0, +, 1}_y) = {0, +, 1}_1 ({{0, +, 1}_x, +, 2}_y) - {{0, +, 2}_1, +, 3}_2 ({0, +, 1}_y, {0, +, 1}_x) = + {{0, +, 2}_1, +, 3}_2 ({0, +, 1}_y, {0, +, 1}_x) = {{0, +, 3}_1, +, 2}_2 ({0, +, 1}_x, {0, +, 1}_y) */ - analyze_subscript_affine_affine (chrec_a, chrec_b, + analyze_subscript_affine_affine (chrec_a, chrec_b, overlaps_a, overlaps_b, last_conflicts); - if (*overlaps_a == chrec_dont_know - || *overlaps_b == chrec_dont_know) + if (CF_NOT_KNOWN_P (*overlaps_a) + || CF_NOT_KNOWN_P (*overlaps_b)) dependence_stats.num_miv_unimplemented++; - else if (*overlaps_a == chrec_known - || *overlaps_b == chrec_known) + else if (CF_NO_DEPENDENCE_P (*overlaps_a) + || CF_NO_DEPENDENCE_P (*overlaps_b)) dependence_stats.num_miv_independent++; else dependence_stats.num_miv_dependent++; } - + else { /* When the analysis is too difficult, answer "don't know". */ if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, "analyze_miv_subscript test failed: unimplemented.\n"); - *overlaps_a = chrec_dont_know; - *overlaps_b = chrec_dont_know; + *overlaps_a = conflict_fn_not_known (); + *overlaps_b = conflict_fn_not_known (); *last_conflicts = chrec_dont_know; dependence_stats.num_miv_unimplemented++; } - + if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, ")\n"); } -/* Determines the iterations for which CHREC_A is equal to CHREC_B. - OVERLAP_ITERATIONS_A and OVERLAP_ITERATIONS_B are initialized with - two functions that describe the iterations that contain conflicting - elements. - +/* Determines the iterations for which CHREC_A is equal to CHREC_B in + with respect to LOOP_NEST. OVERLAP_ITERATIONS_A and + OVERLAP_ITERATIONS_B are initialized with two functions that + describe the iterations that contain conflicting elements. + Remark: For an integer k >= 0, the following equality is true: - + CHREC_A (OVERLAP_ITERATIONS_A (k)) == CHREC_B (OVERLAP_ITERATIONS_B (k)). */ -static void -analyze_overlapping_iterations (tree chrec_a, - tree chrec_b, - tree *overlap_iterations_a, - tree *overlap_iterations_b, - tree *last_conflicts) +static void +analyze_overlapping_iterations (tree chrec_a, + tree chrec_b, + conflict_function **overlap_iterations_a, + conflict_function **overlap_iterations_b, + tree *last_conflicts, struct loop *loop_nest) { + unsigned int lnn = loop_nest->num; + dependence_stats.num_subscript_tests++; - + if (dump_file && (dump_flags & TDF_DETAILS)) { fprintf (dump_file, "(analyze_overlapping_iterations \n"); @@ -3322,55 +2737,55 @@ analyze_overlapping_iterations (tree chrec_a, || chrec_contains_undetermined (chrec_b)) { dependence_stats.num_subscript_undetermined++; - - *overlap_iterations_a = chrec_dont_know; - *overlap_iterations_b = chrec_dont_know; + + *overlap_iterations_a = conflict_fn_not_known (); + *overlap_iterations_b = conflict_fn_not_known (); } - /* If they are the same chrec, and are affine, they overlap + /* If they are the same chrec, and are affine, they overlap on every iteration. */ else if (eq_evolutions_p (chrec_a, chrec_b) - && evolution_function_is_affine_multivariate_p (chrec_a)) + && evolution_function_is_affine_multivariate_p (chrec_a, lnn)) { dependence_stats.num_same_subscript_function++; - *overlap_iterations_a = integer_zero_node; - *overlap_iterations_b = integer_zero_node; + *overlap_iterations_a = conflict_fn (1, affine_fn_cst (integer_zero_node)); + *overlap_iterations_b = conflict_fn (1, affine_fn_cst (integer_zero_node)); *last_conflicts = chrec_dont_know; } /* If they aren't the same, and aren't affine, we can't do anything yet. */ - else if ((chrec_contains_symbols (chrec_a) + else if ((chrec_contains_symbols (chrec_a) || chrec_contains_symbols (chrec_b)) - && (!evolution_function_is_affine_multivariate_p (chrec_a) - || !evolution_function_is_affine_multivariate_p (chrec_b))) + && (!evolution_function_is_affine_multivariate_p (chrec_a, lnn) + || !evolution_function_is_affine_multivariate_p (chrec_b, lnn))) { dependence_stats.num_subscript_undetermined++; - *overlap_iterations_a = chrec_dont_know; - *overlap_iterations_b = chrec_dont_know; + *overlap_iterations_a = conflict_fn_not_known (); + *overlap_iterations_b = conflict_fn_not_known (); } else if (ziv_subscript_p (chrec_a, chrec_b)) - analyze_ziv_subscript (chrec_a, chrec_b, + analyze_ziv_subscript (chrec_a, chrec_b, overlap_iterations_a, overlap_iterations_b, last_conflicts); - + else if (siv_subscript_p (chrec_a, chrec_b)) - analyze_siv_subscript (chrec_a, chrec_b, - overlap_iterations_a, overlap_iterations_b, - last_conflicts); - + analyze_siv_subscript (chrec_a, chrec_b, + overlap_iterations_a, overlap_iterations_b, + last_conflicts, lnn); + else - analyze_miv_subscript (chrec_a, chrec_b, + analyze_miv_subscript (chrec_a, chrec_b, overlap_iterations_a, overlap_iterations_b, - last_conflicts); - + last_conflicts, loop_nest); + if (dump_file && (dump_flags & TDF_DETAILS)) { fprintf (dump_file, " (overlap_iterations_a = "); - print_generic_expr (dump_file, *overlap_iterations_a, 0); + dump_conflict_function (dump_file, *overlap_iterations_a); fprintf (dump_file, ")\n (overlap_iterations_b = "); - print_generic_expr (dump_file, *overlap_iterations_b, 0); + dump_conflict_function (dump_file, *overlap_iterations_b); fprintf (dump_file, ")\n"); fprintf (dump_file, ")\n"); } @@ -3464,7 +2879,7 @@ build_classic_dist_vector_1 (struct data_dependence_relation *ddr, access_fn_a = DR_ACCESS_FN (ddr_a, i); access_fn_b = DR_ACCESS_FN (ddr_b, i); - if (TREE_CODE (access_fn_a) == POLYNOMIAL_CHREC + if (TREE_CODE (access_fn_a) == POLYNOMIAL_CHREC && TREE_CODE (access_fn_b) == POLYNOMIAL_CHREC) { int dist, index; @@ -3489,7 +2904,7 @@ build_classic_dist_vector_1 (struct data_dependence_relation *ddr, non_affine_dependence_relation (ddr); return false; } - + dist = int_cst_value (SUB_DISTANCE (subscript)); /* This is the subscript coupling test. If we have already @@ -3512,7 +2927,7 @@ build_classic_dist_vector_1 (struct data_dependence_relation *ddr, init_v[index] = 1; *init_b = true; } - else + else if (!operand_equal_p (access_fn_a, access_fn_b, 0)) { /* This can be for example an affine vs. constant dependence (T[i] vs. T[3]) that is not an affine dependence and is @@ -3525,24 +2940,24 @@ build_classic_dist_vector_1 (struct data_dependence_relation *ddr, return true; } -/* Return true when the DDR contains two data references that have the - same access functions. */ +/* Return true when the DDR contains only constant access functions. */ static bool -same_access_functions (struct data_dependence_relation *ddr) +constant_access_functions (const struct data_dependence_relation *ddr) { unsigned i; for (i = 0; i < DDR_NUM_SUBSCRIPTS (ddr); i++) - if (!eq_evolutions_p (DR_ACCESS_FN (DDR_A (ddr), i), - DR_ACCESS_FN (DDR_B (ddr), i))) + if (!evolution_function_is_constant_p (DR_ACCESS_FN (DDR_A (ddr), i)) + || !evolution_function_is_constant_p (DR_ACCESS_FN (DDR_B (ddr), i))) return false; return true; } /* Helper function for the case where DDR_A and DDR_B are the same - multivariate access function. */ + multivariate access function with a constant step. For an example + see pr34635-1.c. */ static void add_multivariate_self_dist (struct data_dependence_relation *ddr, tree c_2) @@ -3551,11 +2966,16 @@ add_multivariate_self_dist (struct data_dependence_relation *ddr, tree c_2) tree c_1 = CHREC_LEFT (c_2); tree c_0 = CHREC_LEFT (c_1); lambda_vector dist_v; - - /* Polynomials with more than 2 variables are not handled yet. */ - if (TREE_CODE (c_0) != INTEGER_CST) + int v1, v2, cd; + + /* Polynomials with more than 2 variables are not handled yet. When + the evolution steps are parameters, it is not possible to + represent the dependence using classical distance vectors. */ + if (TREE_CODE (c_0) != INTEGER_CST + || TREE_CODE (CHREC_RIGHT (c_1)) != INTEGER_CST + || TREE_CODE (CHREC_RIGHT (c_2)) != INTEGER_CST) { - DDR_ARE_DEPENDENT (ddr) = chrec_dont_know; + DDR_AFFINE_P (ddr) = false; return; } @@ -3564,8 +2984,20 @@ add_multivariate_self_dist (struct data_dependence_relation *ddr, tree c_2) /* For "{{0, +, 2}_1, +, 3}_2" the distance vector is (3, -2). */ dist_v = lambda_vector_new (DDR_NB_LOOPS (ddr)); - dist_v[x_1] = int_cst_value (CHREC_RIGHT (c_2)); - dist_v[x_2] = -int_cst_value (CHREC_RIGHT (c_1)); + v1 = int_cst_value (CHREC_RIGHT (c_1)); + v2 = int_cst_value (CHREC_RIGHT (c_2)); + cd = gcd (v1, v2); + v1 /= cd; + v2 /= cd; + + if (v2 < 0) + { + v2 = -v2; + v1 = -v1; + } + + dist_v[x_1] = v2; + dist_v[x_2] = -v1; save_dist_v (ddr, dist_v); add_outer_distances (ddr, dist_v, x_1); @@ -3595,7 +3027,17 @@ add_other_self_distances (struct data_dependence_relation *ddr) return; } - add_multivariate_self_dist (ddr, DR_ACCESS_FN (DDR_A (ddr), 0)); + access_fun = DR_ACCESS_FN (DDR_A (ddr), 0); + + if (TREE_CODE (CHREC_LEFT (access_fun)) == POLYNOMIAL_CHREC) + add_multivariate_self_dist (ddr, access_fun); + else + /* The evolution step is not constant: it varies in + the outer loop, so this cannot be represented by a + distance vector. For example in pr34635.c the + evolution is {0, +, {0, +, 4}_1}_2. */ + DDR_AFFINE_P (ddr) = false; + return; } @@ -3609,19 +3051,67 @@ add_other_self_distances (struct data_dependence_relation *ddr) add_outer_distances (ddr, dist_v, index_carry); } +static void +insert_innermost_unit_dist_vector (struct data_dependence_relation *ddr) +{ + lambda_vector dist_v = lambda_vector_new (DDR_NB_LOOPS (ddr)); + + dist_v[DDR_INNER_LOOP (ddr)] = 1; + save_dist_v (ddr, dist_v); +} + +/* Adds a unit distance vector to DDR when there is a 0 overlap. This + is the case for example when access functions are the same and + equal to a constant, as in: + + | loop_1 + | A[3] = ... + | ... = A[3] + | endloop_1 + + in which case the distance vectors are (0) and (1). */ + +static void +add_distance_for_zero_overlaps (struct data_dependence_relation *ddr) +{ + unsigned i, j; + + for (i = 0; i < DDR_NUM_SUBSCRIPTS (ddr); i++) + { + subscript_p sub = DDR_SUBSCRIPT (ddr, i); + conflict_function *ca = SUB_CONFLICTS_IN_A (sub); + conflict_function *cb = SUB_CONFLICTS_IN_B (sub); + + for (j = 0; j < ca->n; j++) + if (affine_function_zero_p (ca->fns[j])) + { + insert_innermost_unit_dist_vector (ddr); + return; + } + + for (j = 0; j < cb->n; j++) + if (affine_function_zero_p (cb->fns[j])) + { + insert_innermost_unit_dist_vector (ddr); + return; + } + } +} + /* Compute the classic per loop distance vector. DDR is the data dependence relation to build a vector from. Return false when fail to represent the data dependence as a distance vector. */ static bool -build_classic_dist_vector (struct data_dependence_relation *ddr) +build_classic_dist_vector (struct data_dependence_relation *ddr, + struct loop *loop_nest) { bool init_b = false; int index_carry = DDR_NB_LOOPS (ddr); lambda_vector dist_v; if (DDR_ARE_DEPENDENT (ddr) != NULL_TREE) - return true; + return false; if (same_access_functions (ddr)) { @@ -3629,6 +3119,9 @@ build_classic_dist_vector (struct data_dependence_relation *ddr) dist_v = lambda_vector_new (DDR_NB_LOOPS (ddr)); save_dist_v (ddr, dist_v); + if (constant_access_functions (ddr)) + add_distance_for_zero_overlaps (ddr); + if (DDR_NB_LOOPS (ddr) > 1) add_other_self_distances (ddr); @@ -3670,11 +3163,15 @@ build_classic_dist_vector (struct data_dependence_relation *ddr) if (!lambda_vector_lexico_pos (dist_v, DDR_NB_LOOPS (ddr))) { lambda_vector save_v = lambda_vector_new (DDR_NB_LOOPS (ddr)); - subscript_dependence_tester_1 (ddr, DDR_B (ddr), DDR_A (ddr)); + if (!subscript_dependence_tester_1 (ddr, DDR_B (ddr), DDR_A (ddr), + loop_nest)) + return false; compute_subscript_distance (ddr); - build_classic_dist_vector_1 (ddr, DDR_B (ddr), DDR_A (ddr), - save_v, &init_b, &index_carry); + if (!build_classic_dist_vector_1 (ddr, DDR_B (ddr), DDR_A (ddr), + save_v, &init_b, &index_carry)) + return false; save_dist_v (ddr, save_v); + DDR_REVERSED_P (ddr) = true; /* In this case there is a dependence forward for all the outer loops: @@ -3687,7 +3184,7 @@ build_classic_dist_vector (struct data_dependence_relation *ddr) | T[j][i] = t + 2; // B | } - the vectors are: + the vectors are: (0, 1, -1) (1, 1, -1) (1, -1, 1) @@ -3702,20 +3199,26 @@ build_classic_dist_vector (struct data_dependence_relation *ddr) { lambda_vector save_v = lambda_vector_new (DDR_NB_LOOPS (ddr)); lambda_vector_copy (dist_v, save_v, DDR_NB_LOOPS (ddr)); - save_dist_v (ddr, save_v); if (DDR_NB_LOOPS (ddr) > 1) { lambda_vector opposite_v = lambda_vector_new (DDR_NB_LOOPS (ddr)); - subscript_dependence_tester_1 (ddr, DDR_B (ddr), DDR_A (ddr)); + if (!subscript_dependence_tester_1 (ddr, DDR_B (ddr), + DDR_A (ddr), loop_nest)) + return false; compute_subscript_distance (ddr); - build_classic_dist_vector_1 (ddr, DDR_B (ddr), DDR_A (ddr), - opposite_v, &init_b, &index_carry); + if (!build_classic_dist_vector_1 (ddr, DDR_B (ddr), DDR_A (ddr), + opposite_v, &init_b, + &index_carry)) + return false; + save_dist_v (ddr, save_v); add_outer_distances (ddr, dist_v, index_carry); add_outer_distances (ddr, opposite_v, index_carry); } + else + save_dist_v (ddr, save_v); } } else @@ -3791,7 +3294,8 @@ build_classic_dir_vector (struct data_dependence_relation *ddr) static bool subscript_dependence_tester_1 (struct data_dependence_relation *ddr, struct data_reference *dra, - struct data_reference *drb) + struct data_reference *drb, + struct loop *loop_nest) { unsigned int i; tree last_conflicts; @@ -3800,31 +3304,40 @@ subscript_dependence_tester_1 (struct data_dependence_relation *ddr, for (i = 0; VEC_iterate (subscript_p, DDR_SUBSCRIPTS (ddr), i, subscript); i++) { - tree overlaps_a, overlaps_b; + conflict_function *overlaps_a, *overlaps_b; - analyze_overlapping_iterations (DR_ACCESS_FN (dra, i), + analyze_overlapping_iterations (DR_ACCESS_FN (dra, i), DR_ACCESS_FN (drb, i), - &overlaps_a, &overlaps_b, - &last_conflicts); + &overlaps_a, &overlaps_b, + &last_conflicts, loop_nest); - if (chrec_contains_undetermined (overlaps_a) - || chrec_contains_undetermined (overlaps_b)) + if (CF_NOT_KNOWN_P (overlaps_a) + || CF_NOT_KNOWN_P (overlaps_b)) { finalize_ddr_dependent (ddr, chrec_dont_know); dependence_stats.num_dependence_undetermined++; + free_conflict_function (overlaps_a); + free_conflict_function (overlaps_b); return false; } - else if (overlaps_a == chrec_known - || overlaps_b == chrec_known) + else if (CF_NO_DEPENDENCE_P (overlaps_a) + || CF_NO_DEPENDENCE_P (overlaps_b)) { finalize_ddr_dependent (ddr, chrec_known); dependence_stats.num_dependence_independent++; + free_conflict_function (overlaps_a); + free_conflict_function (overlaps_b); return false; } else { + if (SUB_CONFLICTS_IN_A (subscript)) + free_conflict_function (SUB_CONFLICTS_IN_A (subscript)); + if (SUB_CONFLICTS_IN_B (subscript)) + free_conflict_function (SUB_CONFLICTS_IN_B (subscript)); + SUB_CONFLICTS_IN_A (subscript) = overlaps_a; SUB_CONFLICTS_IN_B (subscript) = overlaps_b; SUB_LAST_CONFLICT (subscript) = last_conflicts; @@ -3834,20 +3347,21 @@ subscript_dependence_tester_1 (struct data_dependence_relation *ddr, return true; } -/* Computes the conflicting iterations, and initialize DDR. */ +/* Computes the conflicting iterations in LOOP_NEST, and initialize DDR. */ static void -subscript_dependence_tester (struct data_dependence_relation *ddr) +subscript_dependence_tester (struct data_dependence_relation *ddr, + struct loop *loop_nest) { - + if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, "(subscript_dependence_tester \n"); - - if (subscript_dependence_tester_1 (ddr, DDR_A (ddr), DDR_B (ddr))) + + if (subscript_dependence_tester_1 (ddr, DDR_A (ddr), DDR_B (ddr), loop_nest)) dependence_stats.num_dependence_dependent++; compute_subscript_distance (ddr); - if (build_classic_dist_vector (ddr)) + if (build_classic_dist_vector (ddr, loop_nest)) build_classic_dir_vector (ddr); if (dump_file && (dump_flags & TDF_DETAILS)) @@ -3855,79 +3369,651 @@ subscript_dependence_tester (struct data_dependence_relation *ddr) } /* Returns true when all the access functions of A are affine or - constant. */ + constant with respect to LOOP_NEST. */ -static bool -access_functions_are_affine_or_constant_p (struct data_reference *a) +static bool +access_functions_are_affine_or_constant_p (const struct data_reference *a, + const struct loop *loop_nest) { unsigned int i; - VEC(tree,heap) **fns = DR_ACCESS_FNS_ADDR (a); + VEC(tree,heap) *fns = DR_ACCESS_FNS (a); tree t; - - for (i = 0; VEC_iterate (tree, *fns, i, t); i++) - if (!evolution_function_is_constant_p (t) - && !evolution_function_is_affine_multivariate_p (t)) + + for (i = 0; VEC_iterate (tree, fns, i, t); i++) + if (!evolution_function_is_invariant_p (t, loop_nest->num) + && !evolution_function_is_affine_multivariate_p (t, loop_nest->num)) return false; - + return true; } -/* This computes the affine dependence relation between A and B. - CHREC_KNOWN is used for representing the independence between two - accesses, while CHREC_DONT_KNOW is used for representing the unknown - relation. - - Note that it is possible to stop the computation of the dependence - relation the first time we detect a CHREC_KNOWN element for a given - subscript. */ +/* Initializes an equation for an OMEGA problem using the information + contained in the ACCESS_FUN. Returns true when the operation + succeeded. -static void -compute_affine_dependence (struct data_dependence_relation *ddr) + PB is the omega constraint system. + EQ is the number of the equation to be initialized. + OFFSET is used for shifting the variables names in the constraints: + a constrain is composed of 2 * the number of variables surrounding + dependence accesses. OFFSET is set either to 0 for the first n variables, + then it is set to n. + ACCESS_FUN is expected to be an affine chrec. */ + +static bool +init_omega_eq_with_af (omega_pb pb, unsigned eq, + unsigned int offset, tree access_fun, + struct data_dependence_relation *ddr) { - struct data_reference *dra = DDR_A (ddr); - struct data_reference *drb = DDR_B (ddr); - - if (dump_file && (dump_flags & TDF_DETAILS)) + switch (TREE_CODE (access_fun)) { - fprintf (dump_file, "(compute_affine_dependence\n"); - fprintf (dump_file, " (stmt_a = \n"); - print_generic_expr (dump_file, DR_STMT (dra), 0); - fprintf (dump_file, ")\n (stmt_b = \n"); - print_generic_expr (dump_file, DR_STMT (drb), 0); - fprintf (dump_file, ")\n"); - } + case POLYNOMIAL_CHREC: + { + tree left = CHREC_LEFT (access_fun); + tree right = CHREC_RIGHT (access_fun); + int var = CHREC_VARIABLE (access_fun); + unsigned var_idx; - /* Analyze only when the dependence relation is not yet known. */ - if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE) - { - dependence_stats.num_dependence_tests++; + if (TREE_CODE (right) != INTEGER_CST) + return false; - if (access_functions_are_affine_or_constant_p (dra) - && access_functions_are_affine_or_constant_p (drb)) - subscript_dependence_tester (ddr); - - /* As a last case, if the dependence cannot be determined, or if - the dependence is considered too difficult to determine, answer - "don't know". */ - else - { - dependence_stats.num_dependence_undetermined++; + var_idx = index_in_loop_nest (var, DDR_LOOP_NEST (ddr)); + pb->eqs[eq].coef[offset + var_idx + 1] = int_cst_value (right); - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, "Data ref a:\n"); - dump_data_reference (dump_file, dra); - fprintf (dump_file, "Data ref b:\n"); - dump_data_reference (dump_file, drb); - fprintf (dump_file, "affine dependence test not usable: access function not affine or constant.\n"); - } - finalize_ddr_dependent (ddr, chrec_dont_know); - } - } - - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, ")\n"); -} + /* Compute the innermost loop index. */ + DDR_INNER_LOOP (ddr) = MAX (DDR_INNER_LOOP (ddr), var_idx); + + if (offset == 0) + pb->eqs[eq].coef[var_idx + DDR_NB_LOOPS (ddr) + 1] + += int_cst_value (right); + + switch (TREE_CODE (left)) + { + case POLYNOMIAL_CHREC: + return init_omega_eq_with_af (pb, eq, offset, left, ddr); + + case INTEGER_CST: + pb->eqs[eq].coef[0] += int_cst_value (left); + return true; + + default: + return false; + } + } + + case INTEGER_CST: + pb->eqs[eq].coef[0] += int_cst_value (access_fun); + return true; + + default: + return false; + } +} + +/* As explained in the comments preceding init_omega_for_ddr, we have + to set up a system for each loop level, setting outer loops + variation to zero, and current loop variation to positive or zero. + Save each lexico positive distance vector. */ + +static void +omega_extract_distance_vectors (omega_pb pb, + struct data_dependence_relation *ddr) +{ + int eq, geq; + unsigned i, j; + struct loop *loopi, *loopj; + enum omega_result res; + + /* Set a new problem for each loop in the nest. The basis is the + problem that we have initialized until now. On top of this we + add new constraints. */ + for (i = 0; i <= DDR_INNER_LOOP (ddr) + && VEC_iterate (loop_p, DDR_LOOP_NEST (ddr), i, loopi); i++) + { + int dist = 0; + omega_pb copy = omega_alloc_problem (2 * DDR_NB_LOOPS (ddr), + DDR_NB_LOOPS (ddr)); + + omega_copy_problem (copy, pb); + + /* For all the outer loops "loop_j", add "dj = 0". */ + for (j = 0; + j < i && VEC_iterate (loop_p, DDR_LOOP_NEST (ddr), j, loopj); j++) + { + eq = omega_add_zero_eq (copy, omega_black); + copy->eqs[eq].coef[j + 1] = 1; + } + + /* For "loop_i", add "0 <= di". */ + geq = omega_add_zero_geq (copy, omega_black); + copy->geqs[geq].coef[i + 1] = 1; + + /* Reduce the constraint system, and test that the current + problem is feasible. */ + res = omega_simplify_problem (copy); + if (res == omega_false + || res == omega_unknown + || copy->num_geqs > (int) DDR_NB_LOOPS (ddr)) + goto next_problem; + + for (eq = 0; eq < copy->num_subs; eq++) + if (copy->subs[eq].key == (int) i + 1) + { + dist = copy->subs[eq].coef[0]; + goto found_dist; + } + + if (dist == 0) + { + /* Reinitialize problem... */ + omega_copy_problem (copy, pb); + for (j = 0; + j < i && VEC_iterate (loop_p, DDR_LOOP_NEST (ddr), j, loopj); j++) + { + eq = omega_add_zero_eq (copy, omega_black); + copy->eqs[eq].coef[j + 1] = 1; + } + + /* ..., but this time "di = 1". */ + eq = omega_add_zero_eq (copy, omega_black); + copy->eqs[eq].coef[i + 1] = 1; + copy->eqs[eq].coef[0] = -1; + + res = omega_simplify_problem (copy); + if (res == omega_false + || res == omega_unknown + || copy->num_geqs > (int) DDR_NB_LOOPS (ddr)) + goto next_problem; + + for (eq = 0; eq < copy->num_subs; eq++) + if (copy->subs[eq].key == (int) i + 1) + { + dist = copy->subs[eq].coef[0]; + goto found_dist; + } + } + + found_dist:; + /* Save the lexicographically positive distance vector. */ + if (dist >= 0) + { + lambda_vector dist_v = lambda_vector_new (DDR_NB_LOOPS (ddr)); + lambda_vector dir_v = lambda_vector_new (DDR_NB_LOOPS (ddr)); + + dist_v[i] = dist; + + for (eq = 0; eq < copy->num_subs; eq++) + if (copy->subs[eq].key > 0) + { + dist = copy->subs[eq].coef[0]; + dist_v[copy->subs[eq].key - 1] = dist; + } + + for (j = 0; j < DDR_NB_LOOPS (ddr); j++) + dir_v[j] = dir_from_dist (dist_v[j]); + + save_dist_v (ddr, dist_v); + save_dir_v (ddr, dir_v); + } + + next_problem:; + omega_free_problem (copy); + } +} + +/* This is called for each subscript of a tuple of data references: + insert an equality for representing the conflicts. */ + +static bool +omega_setup_subscript (tree access_fun_a, tree access_fun_b, + struct data_dependence_relation *ddr, + omega_pb pb, bool *maybe_dependent) +{ + int eq; + tree type = signed_type_for_types (TREE_TYPE (access_fun_a), + TREE_TYPE (access_fun_b)); + tree fun_a = chrec_convert (type, access_fun_a, NULL); + tree fun_b = chrec_convert (type, access_fun_b, NULL); + tree difference = chrec_fold_minus (type, fun_a, fun_b); + + /* When the fun_a - fun_b is not constant, the dependence is not + captured by the classic distance vector representation. */ + if (TREE_CODE (difference) != INTEGER_CST) + return false; + + /* ZIV test. */ + if (ziv_subscript_p (fun_a, fun_b) && !integer_zerop (difference)) + { + /* There is no dependence. */ + *maybe_dependent = false; + return true; + } + + fun_b = chrec_fold_multiply (type, fun_b, integer_minus_one_node); + + eq = omega_add_zero_eq (pb, omega_black); + if (!init_omega_eq_with_af (pb, eq, DDR_NB_LOOPS (ddr), fun_a, ddr) + || !init_omega_eq_with_af (pb, eq, 0, fun_b, ddr)) + /* There is probably a dependence, but the system of + constraints cannot be built: answer "don't know". */ + return false; + + /* GCD test. */ + if (DDR_NB_LOOPS (ddr) != 0 && pb->eqs[eq].coef[0] + && !int_divides_p (lambda_vector_gcd + ((lambda_vector) &(pb->eqs[eq].coef[1]), + 2 * DDR_NB_LOOPS (ddr)), + pb->eqs[eq].coef[0])) + { + /* There is no dependence. */ + *maybe_dependent = false; + return true; + } + + return true; +} + +/* Helper function, same as init_omega_for_ddr but specialized for + data references A and B. */ + +static bool +init_omega_for_ddr_1 (struct data_reference *dra, struct data_reference *drb, + struct data_dependence_relation *ddr, + omega_pb pb, bool *maybe_dependent) +{ + unsigned i; + int ineq; + struct loop *loopi; + unsigned nb_loops = DDR_NB_LOOPS (ddr); + + /* Insert an equality per subscript. */ + for (i = 0; i < DDR_NUM_SUBSCRIPTS (ddr); i++) + { + if (!omega_setup_subscript (DR_ACCESS_FN (dra, i), DR_ACCESS_FN (drb, i), + ddr, pb, maybe_dependent)) + return false; + else if (*maybe_dependent == false) + { + /* There is no dependence. */ + DDR_ARE_DEPENDENT (ddr) = chrec_known; + return true; + } + } + + /* Insert inequalities: constraints corresponding to the iteration + domain, i.e. the loops surrounding the references "loop_x" and + the distance variables "dx". The layout of the OMEGA + representation is as follows: + - coef[0] is the constant + - coef[1..nb_loops] are the protected variables that will not be + removed by the solver: the "dx" + - coef[nb_loops + 1, 2*nb_loops] are the loop variables: "loop_x". + */ + for (i = 0; i <= DDR_INNER_LOOP (ddr) + && VEC_iterate (loop_p, DDR_LOOP_NEST (ddr), i, loopi); i++) + { + HOST_WIDE_INT nbi = estimated_loop_iterations_int (loopi, false); + + /* 0 <= loop_x */ + ineq = omega_add_zero_geq (pb, omega_black); + pb->geqs[ineq].coef[i + nb_loops + 1] = 1; + + /* 0 <= loop_x + dx */ + ineq = omega_add_zero_geq (pb, omega_black); + pb->geqs[ineq].coef[i + nb_loops + 1] = 1; + pb->geqs[ineq].coef[i + 1] = 1; + + if (nbi != -1) + { + /* loop_x <= nb_iters */ + ineq = omega_add_zero_geq (pb, omega_black); + pb->geqs[ineq].coef[i + nb_loops + 1] = -1; + pb->geqs[ineq].coef[0] = nbi; + + /* loop_x + dx <= nb_iters */ + ineq = omega_add_zero_geq (pb, omega_black); + pb->geqs[ineq].coef[i + nb_loops + 1] = -1; + pb->geqs[ineq].coef[i + 1] = -1; + pb->geqs[ineq].coef[0] = nbi; + + /* A step "dx" bigger than nb_iters is not feasible, so + add "0 <= nb_iters + dx", */ + ineq = omega_add_zero_geq (pb, omega_black); + pb->geqs[ineq].coef[i + 1] = 1; + pb->geqs[ineq].coef[0] = nbi; + /* and "dx <= nb_iters". */ + ineq = omega_add_zero_geq (pb, omega_black); + pb->geqs[ineq].coef[i + 1] = -1; + pb->geqs[ineq].coef[0] = nbi; + } + } + + omega_extract_distance_vectors (pb, ddr); + + return true; +} + +/* Sets up the Omega dependence problem for the data dependence + relation DDR. Returns false when the constraint system cannot be + built, ie. when the test answers "don't know". Returns true + otherwise, and when independence has been proved (using one of the + trivial dependence test), set MAYBE_DEPENDENT to false, otherwise + set MAYBE_DEPENDENT to true. + + Example: for setting up the dependence system corresponding to the + conflicting accesses + + | loop_i + | loop_j + | A[i, i+1] = ... + | ... A[2*j, 2*(i + j)] + | endloop_j + | endloop_i + + the following constraints come from the iteration domain: + + 0 <= i <= Ni + 0 <= i + di <= Ni + 0 <= j <= Nj + 0 <= j + dj <= Nj + + where di, dj are the distance variables. The constraints + representing the conflicting elements are: + + i = 2 * (j + dj) + i + 1 = 2 * (i + di + j + dj) + + For asking that the resulting distance vector (di, dj) be + lexicographically positive, we insert the constraint "di >= 0". If + "di = 0" in the solution, we fix that component to zero, and we + look at the inner loops: we set a new problem where all the outer + loop distances are zero, and fix this inner component to be + positive. When one of the components is positive, we save that + distance, and set a new problem where the distance on this loop is + zero, searching for other distances in the inner loops. Here is + the classic example that illustrates that we have to set for each + inner loop a new problem: + + | loop_1 + | loop_2 + | A[10] + | endloop_2 + | endloop_1 + + we have to save two distances (1, 0) and (0, 1). + + Given two array references, refA and refB, we have to set the + dependence problem twice, refA vs. refB and refB vs. refA, and we + cannot do a single test, as refB might occur before refA in the + inner loops, and the contrary when considering outer loops: ex. + + | loop_0 + | loop_1 + | loop_2 + | T[{1,+,1}_2][{1,+,1}_1] // refA + | T[{2,+,1}_2][{0,+,1}_1] // refB + | endloop_2 + | endloop_1 + | endloop_0 + + refB touches the elements in T before refA, and thus for the same + loop_0 refB precedes refA: ie. the distance vector (0, 1, -1) + but for successive loop_0 iterations, we have (1, -1, 1) + + The Omega solver expects the distance variables ("di" in the + previous example) to come first in the constraint system (as + variables to be protected, or "safe" variables), the constraint + system is built using the following layout: + + "cst | distance vars | index vars". +*/ + +static bool +init_omega_for_ddr (struct data_dependence_relation *ddr, + bool *maybe_dependent) +{ + omega_pb pb; + bool res = false; + + *maybe_dependent = true; + + if (same_access_functions (ddr)) + { + unsigned j; + lambda_vector dir_v; + + /* Save the 0 vector. */ + save_dist_v (ddr, lambda_vector_new (DDR_NB_LOOPS (ddr))); + dir_v = lambda_vector_new (DDR_NB_LOOPS (ddr)); + for (j = 0; j < DDR_NB_LOOPS (ddr); j++) + dir_v[j] = dir_equal; + save_dir_v (ddr, dir_v); + + /* Save the dependences carried by outer loops. */ + pb = omega_alloc_problem (2 * DDR_NB_LOOPS (ddr), DDR_NB_LOOPS (ddr)); + res = init_omega_for_ddr_1 (DDR_A (ddr), DDR_B (ddr), ddr, pb, + maybe_dependent); + omega_free_problem (pb); + return res; + } + + /* Omega expects the protected variables (those that have to be kept + after elimination) to appear first in the constraint system. + These variables are the distance variables. In the following + initialization we declare NB_LOOPS safe variables, and the total + number of variables for the constraint system is 2*NB_LOOPS. */ + pb = omega_alloc_problem (2 * DDR_NB_LOOPS (ddr), DDR_NB_LOOPS (ddr)); + res = init_omega_for_ddr_1 (DDR_A (ddr), DDR_B (ddr), ddr, pb, + maybe_dependent); + omega_free_problem (pb); + + /* Stop computation if not decidable, or no dependence. */ + if (res == false || *maybe_dependent == false) + return res; + + pb = omega_alloc_problem (2 * DDR_NB_LOOPS (ddr), DDR_NB_LOOPS (ddr)); + res = init_omega_for_ddr_1 (DDR_B (ddr), DDR_A (ddr), ddr, pb, + maybe_dependent); + omega_free_problem (pb); + + return res; +} + +/* Return true when DDR contains the same information as that stored + in DIR_VECTS and in DIST_VECTS, return false otherwise. */ + +static bool +ddr_consistent_p (FILE *file, + struct data_dependence_relation *ddr, + VEC (lambda_vector, heap) *dist_vects, + VEC (lambda_vector, heap) *dir_vects) +{ + unsigned int i, j; + + /* If dump_file is set, output there. */ + if (dump_file && (dump_flags & TDF_DETAILS)) + file = dump_file; + + if (VEC_length (lambda_vector, dist_vects) != DDR_NUM_DIST_VECTS (ddr)) + { + lambda_vector b_dist_v; + fprintf (file, "\n(Number of distance vectors differ: Banerjee has %d, Omega has %d.\n", + VEC_length (lambda_vector, dist_vects), + DDR_NUM_DIST_VECTS (ddr)); + + fprintf (file, "Banerjee dist vectors:\n"); + for (i = 0; VEC_iterate (lambda_vector, dist_vects, i, b_dist_v); i++) + print_lambda_vector (file, b_dist_v, DDR_NB_LOOPS (ddr)); + + fprintf (file, "Omega dist vectors:\n"); + for (i = 0; i < DDR_NUM_DIST_VECTS (ddr); i++) + print_lambda_vector (file, DDR_DIST_VECT (ddr, i), DDR_NB_LOOPS (ddr)); + + fprintf (file, "data dependence relation:\n"); + dump_data_dependence_relation (file, ddr); + + fprintf (file, ")\n"); + return false; + } + + if (VEC_length (lambda_vector, dir_vects) != DDR_NUM_DIR_VECTS (ddr)) + { + fprintf (file, "\n(Number of direction vectors differ: Banerjee has %d, Omega has %d.)\n", + VEC_length (lambda_vector, dir_vects), + DDR_NUM_DIR_VECTS (ddr)); + return false; + } + + for (i = 0; i < DDR_NUM_DIST_VECTS (ddr); i++) + { + lambda_vector a_dist_v; + lambda_vector b_dist_v = DDR_DIST_VECT (ddr, i); + + /* Distance vectors are not ordered in the same way in the DDR + and in the DIST_VECTS: search for a matching vector. */ + for (j = 0; VEC_iterate (lambda_vector, dist_vects, j, a_dist_v); j++) + if (lambda_vector_equal (a_dist_v, b_dist_v, DDR_NB_LOOPS (ddr))) + break; + + if (j == VEC_length (lambda_vector, dist_vects)) + { + fprintf (file, "\n(Dist vectors from the first dependence analyzer:\n"); + print_dist_vectors (file, dist_vects, DDR_NB_LOOPS (ddr)); + fprintf (file, "not found in Omega dist vectors:\n"); + print_dist_vectors (file, DDR_DIST_VECTS (ddr), DDR_NB_LOOPS (ddr)); + fprintf (file, "data dependence relation:\n"); + dump_data_dependence_relation (file, ddr); + fprintf (file, ")\n"); + } + } + + for (i = 0; i < DDR_NUM_DIR_VECTS (ddr); i++) + { + lambda_vector a_dir_v; + lambda_vector b_dir_v = DDR_DIR_VECT (ddr, i); + + /* Direction vectors are not ordered in the same way in the DDR + and in the DIR_VECTS: search for a matching vector. */ + for (j = 0; VEC_iterate (lambda_vector, dir_vects, j, a_dir_v); j++) + if (lambda_vector_equal (a_dir_v, b_dir_v, DDR_NB_LOOPS (ddr))) + break; + + if (j == VEC_length (lambda_vector, dist_vects)) + { + fprintf (file, "\n(Dir vectors from the first dependence analyzer:\n"); + print_dir_vectors (file, dir_vects, DDR_NB_LOOPS (ddr)); + fprintf (file, "not found in Omega dir vectors:\n"); + print_dir_vectors (file, DDR_DIR_VECTS (ddr), DDR_NB_LOOPS (ddr)); + fprintf (file, "data dependence relation:\n"); + dump_data_dependence_relation (file, ddr); + fprintf (file, ")\n"); + } + } + + return true; +} + +/* This computes the affine dependence relation between A and B with + respect to LOOP_NEST. CHREC_KNOWN is used for representing the + independence between two accesses, while CHREC_DONT_KNOW is used + for representing the unknown relation. + + Note that it is possible to stop the computation of the dependence + relation the first time we detect a CHREC_KNOWN element for a given + subscript. */ + +static void +compute_affine_dependence (struct data_dependence_relation *ddr, + struct loop *loop_nest) +{ + struct data_reference *dra = DDR_A (ddr); + struct data_reference *drb = DDR_B (ddr); + + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "(compute_affine_dependence\n"); + fprintf (dump_file, " (stmt_a = \n"); + print_gimple_stmt (dump_file, DR_STMT (dra), 0, 0); + fprintf (dump_file, ")\n (stmt_b = \n"); + print_gimple_stmt (dump_file, DR_STMT (drb), 0, 0); + fprintf (dump_file, ")\n"); + } + + /* Analyze only when the dependence relation is not yet known. */ + if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE + && !DDR_SELF_REFERENCE (ddr)) + { + dependence_stats.num_dependence_tests++; + + if (access_functions_are_affine_or_constant_p (dra, loop_nest) + && access_functions_are_affine_or_constant_p (drb, loop_nest)) + { + if (flag_check_data_deps) + { + /* Compute the dependences using the first algorithm. */ + subscript_dependence_tester (ddr, loop_nest); + + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "\n\nBanerjee Analyzer\n"); + dump_data_dependence_relation (dump_file, ddr); + } + + if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE) + { + bool maybe_dependent; + VEC (lambda_vector, heap) *dir_vects, *dist_vects; + + /* Save the result of the first DD analyzer. */ + dist_vects = DDR_DIST_VECTS (ddr); + dir_vects = DDR_DIR_VECTS (ddr); + + /* Reset the information. */ + DDR_DIST_VECTS (ddr) = NULL; + DDR_DIR_VECTS (ddr) = NULL; + + /* Compute the same information using Omega. */ + if (!init_omega_for_ddr (ddr, &maybe_dependent)) + goto csys_dont_know; + + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "Omega Analyzer\n"); + dump_data_dependence_relation (dump_file, ddr); + } + + /* Check that we get the same information. */ + if (maybe_dependent) + gcc_assert (ddr_consistent_p (stderr, ddr, dist_vects, + dir_vects)); + } + } + else + subscript_dependence_tester (ddr, loop_nest); + } + + /* As a last case, if the dependence cannot be determined, or if + the dependence is considered too difficult to determine, answer + "don't know". */ + else + { + csys_dont_know:; + dependence_stats.num_dependence_undetermined++; + + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "Data ref a:\n"); + dump_data_reference (dump_file, dra); + fprintf (dump_file, "Data ref b:\n"); + dump_data_reference (dump_file, drb); + fprintf (dump_file, "affine dependence test not usable: access function not affine or constant.\n"); + } + finalize_ddr_dependent (ddr, chrec_dont_know); + } + } + + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, ")\n"); +} /* This computes the dependence relation for the same data reference into DDR. */ @@ -3938,12 +4024,22 @@ compute_self_dependence (struct data_dependence_relation *ddr) unsigned int i; struct subscript *subscript; + if (DDR_ARE_DEPENDENT (ddr) != NULL_TREE) + return; + for (i = 0; VEC_iterate (subscript_p, DDR_SUBSCRIPTS (ddr), i, subscript); i++) { + if (SUB_CONFLICTS_IN_A (subscript)) + free_conflict_function (SUB_CONFLICTS_IN_A (subscript)); + if (SUB_CONFLICTS_IN_B (subscript)) + free_conflict_function (SUB_CONFLICTS_IN_B (subscript)); + /* The accessed index overlaps for each iteration. */ - SUB_CONFLICTS_IN_A (subscript) = integer_zero_node; - SUB_CONFLICTS_IN_B (subscript) = integer_zero_node; + SUB_CONFLICTS_IN_A (subscript) + = conflict_fn (1, affine_fn_cst (integer_zero_node)); + SUB_CONFLICTS_IN_B (subscript) + = conflict_fn (1, affine_fn_cst (integer_zero_node)); SUB_LAST_CONFLICT (subscript) = chrec_dont_know; } @@ -3957,7 +4053,7 @@ compute_self_dependence (struct data_dependence_relation *ddr) COMPUTE_SELF_AND_RR is FALSE, don't compute read-read and self relations. */ -static void +void compute_all_dependences (VEC (data_reference_p, heap) *datarefs, VEC (ddr_p, heap) **dependence_relations, VEC (loop_p, heap) *loop_nest, @@ -3967,420 +4063,1111 @@ compute_all_dependences (VEC (data_reference_p, heap) *datarefs, struct data_reference *a, *b; unsigned int i, j; - for (i = 0; VEC_iterate (data_reference_p, datarefs, i, a); i++) - for (j = i + 1; VEC_iterate (data_reference_p, datarefs, j, b); j++) - if (!DR_IS_READ (a) || !DR_IS_READ (b) || compute_self_and_rr) + for (i = 0; VEC_iterate (data_reference_p, datarefs, i, a); i++) + for (j = i + 1; VEC_iterate (data_reference_p, datarefs, j, b); j++) + if (!DR_IS_READ (a) || !DR_IS_READ (b) || compute_self_and_rr) + { + ddr = initialize_data_dependence_relation (a, b, loop_nest); + VEC_safe_push (ddr_p, heap, *dependence_relations, ddr); + if (loop_nest) + compute_affine_dependence (ddr, VEC_index (loop_p, loop_nest, 0)); + } + + if (compute_self_and_rr) + for (i = 0; VEC_iterate (data_reference_p, datarefs, i, a); i++) + { + ddr = initialize_data_dependence_relation (a, a, loop_nest); + VEC_safe_push (ddr_p, heap, *dependence_relations, ddr); + compute_self_dependence (ddr); + } +} + +/* Stores the locations of memory references in STMT to REFERENCES. Returns + true if STMT clobbers memory, false otherwise. */ + +bool +get_references_in_stmt (gimple stmt, VEC (data_ref_loc, heap) **references) +{ + bool clobbers_memory = false; + data_ref_loc *ref; + tree *op0, *op1; + enum gimple_code stmt_code = gimple_code (stmt); + + *references = NULL; + + /* ASM_EXPR and CALL_EXPR may embed arbitrary side effects. + Calls have side-effects, except those to const or pure + functions. */ + if ((stmt_code == GIMPLE_CALL + && !(gimple_call_flags (stmt) & (ECF_CONST | ECF_PURE))) + || (stmt_code == GIMPLE_ASM + && gimple_asm_volatile_p (stmt))) + clobbers_memory = true; + + if (!gimple_vuse (stmt)) + return clobbers_memory; + + if (stmt_code == GIMPLE_ASSIGN) + { + tree base; + op0 = gimple_assign_lhs_ptr (stmt); + op1 = gimple_assign_rhs1_ptr (stmt); + + if (DECL_P (*op1) + || (REFERENCE_CLASS_P (*op1) + && (base = get_base_address (*op1)) + && TREE_CODE (base) != SSA_NAME)) + { + ref = VEC_safe_push (data_ref_loc, heap, *references, NULL); + ref->pos = op1; + ref->is_read = true; + } + + if (DECL_P (*op0) + || (REFERENCE_CLASS_P (*op0) && get_base_address (*op0))) + { + ref = VEC_safe_push (data_ref_loc, heap, *references, NULL); + ref->pos = op0; + ref->is_read = false; + } + } + else if (stmt_code == GIMPLE_CALL) + { + unsigned i, n = gimple_call_num_args (stmt); + + for (i = 0; i < n; i++) + { + op0 = gimple_call_arg_ptr (stmt, i); + + if (DECL_P (*op0) + || (REFERENCE_CLASS_P (*op0) && get_base_address (*op0))) + { + ref = VEC_safe_push (data_ref_loc, heap, *references, NULL); + ref->pos = op0; + ref->is_read = true; + } + } + } + + return clobbers_memory; +} + +/* Stores the data references in STMT to DATAREFS. If there is an unanalyzable + reference, returns false, otherwise returns true. NEST is the outermost + loop of the loop nest in which the references should be analyzed. */ + +bool +find_data_references_in_stmt (struct loop *nest, gimple stmt, + VEC (data_reference_p, heap) **datarefs) +{ + unsigned i; + VEC (data_ref_loc, heap) *references; + data_ref_loc *ref; + bool ret = true; + data_reference_p dr; + + if (get_references_in_stmt (stmt, &references)) + { + VEC_free (data_ref_loc, heap, references); + return false; + } + + for (i = 0; VEC_iterate (data_ref_loc, references, i, ref); i++) + { + dr = create_data_ref (nest, *ref->pos, stmt, ref->is_read); + gcc_assert (dr != NULL); + + /* FIXME -- data dependence analysis does not work correctly for objects + with invariant addresses in loop nests. Let us fail here until the + problem is fixed. */ + if (dr_address_invariant_p (dr) && nest) + { + free_data_ref (dr); + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, "\tFAILED as dr address is invariant\n"); + ret = false; + break; + } + + VEC_safe_push (data_reference_p, heap, *datarefs, dr); + } + VEC_free (data_ref_loc, heap, references); + return ret; +} + +/* Stores the data references in STMT to DATAREFS. If there is an unanalyzable + reference, returns false, otherwise returns true. NEST is the outermost + loop of the loop nest in which the references should be analyzed. */ + +bool +graphite_find_data_references_in_stmt (struct loop *nest, gimple stmt, + VEC (data_reference_p, heap) **datarefs) +{ + unsigned i; + VEC (data_ref_loc, heap) *references; + data_ref_loc *ref; + bool ret = true; + data_reference_p dr; + + if (get_references_in_stmt (stmt, &references)) + { + VEC_free (data_ref_loc, heap, references); + return false; + } + + for (i = 0; VEC_iterate (data_ref_loc, references, i, ref); i++) + { + dr = create_data_ref (nest, *ref->pos, stmt, ref->is_read); + gcc_assert (dr != NULL); + VEC_safe_push (data_reference_p, heap, *datarefs, dr); + } + + VEC_free (data_ref_loc, heap, references); + return ret; +} + +/* Search the data references in LOOP, and record the information into + DATAREFS. Returns chrec_dont_know when failing to analyze a + difficult case, returns NULL_TREE otherwise. */ + +static tree +find_data_references_in_bb (struct loop *loop, basic_block bb, + VEC (data_reference_p, heap) **datarefs) +{ + gimple_stmt_iterator bsi; + + for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi)) + { + gimple stmt = gsi_stmt (bsi); + + if (!find_data_references_in_stmt (loop, stmt, datarefs)) + { + struct data_reference *res; + res = XCNEW (struct data_reference); + VEC_safe_push (data_reference_p, heap, *datarefs, res); + + return chrec_dont_know; + } + } + + return NULL_TREE; +} + +/* Search the data references in LOOP, and record the information into + DATAREFS. Returns chrec_dont_know when failing to analyze a + difficult case, returns NULL_TREE otherwise. + + TODO: This function should be made smarter so that it can handle address + arithmetic as if they were array accesses, etc. */ + +tree +find_data_references_in_loop (struct loop *loop, + VEC (data_reference_p, heap) **datarefs) +{ + basic_block bb, *bbs; + unsigned int i; + + bbs = get_loop_body_in_dom_order (loop); + + for (i = 0; i < loop->num_nodes; i++) + { + bb = bbs[i]; + + if (find_data_references_in_bb (loop, bb, datarefs) == chrec_dont_know) + { + free (bbs); + return chrec_dont_know; + } + } + free (bbs); + + return NULL_TREE; +} + +/* Recursive helper function. */ + +static bool +find_loop_nest_1 (struct loop *loop, VEC (loop_p, heap) **loop_nest) +{ + /* Inner loops of the nest should not contain siblings. Example: + when there are two consecutive loops, + + | loop_0 + | loop_1 + | A[{0, +, 1}_1] + | endloop_1 + | loop_2 + | A[{0, +, 1}_2] + | endloop_2 + | endloop_0 + + the dependence relation cannot be captured by the distance + abstraction. */ + if (loop->next) + return false; + + VEC_safe_push (loop_p, heap, *loop_nest, loop); + if (loop->inner) + return find_loop_nest_1 (loop->inner, loop_nest); + return true; +} + +/* Return false when the LOOP is not well nested. Otherwise return + true and insert in LOOP_NEST the loops of the nest. LOOP_NEST will + contain the loops from the outermost to the innermost, as they will + appear in the classic distance vector. */ + +bool +find_loop_nest (struct loop *loop, VEC (loop_p, heap) **loop_nest) +{ + VEC_safe_push (loop_p, heap, *loop_nest, loop); + if (loop->inner) + return find_loop_nest_1 (loop->inner, loop_nest); + return true; +} + +/* Returns true when the data dependences have been computed, false otherwise. + Given a loop nest LOOP, the following vectors are returned: + DATAREFS is initialized to all the array elements contained in this loop, + DEPENDENCE_RELATIONS contains the relations between the data references. + Compute read-read and self relations if + COMPUTE_SELF_AND_READ_READ_DEPENDENCES is TRUE. */ + +bool +compute_data_dependences_for_loop (struct loop *loop, + bool compute_self_and_read_read_dependences, + VEC (data_reference_p, heap) **datarefs, + VEC (ddr_p, heap) **dependence_relations) +{ + bool res = true; + VEC (loop_p, heap) *vloops = VEC_alloc (loop_p, heap, 3); + + memset (&dependence_stats, 0, sizeof (dependence_stats)); + + /* If the loop nest is not well formed, or one of the data references + is not computable, give up without spending time to compute other + dependences. */ + if (!loop + || !find_loop_nest (loop, &vloops) + || find_data_references_in_loop (loop, datarefs) == chrec_dont_know) + { + struct data_dependence_relation *ddr; + + /* Insert a single relation into dependence_relations: + chrec_dont_know. */ + ddr = initialize_data_dependence_relation (NULL, NULL, vloops); + VEC_safe_push (ddr_p, heap, *dependence_relations, ddr); + res = false; + } + else + compute_all_dependences (*datarefs, dependence_relations, vloops, + compute_self_and_read_read_dependences); + + if (dump_file && (dump_flags & TDF_STATS)) + { + fprintf (dump_file, "Dependence tester statistics:\n"); + + fprintf (dump_file, "Number of dependence tests: %d\n", + dependence_stats.num_dependence_tests); + fprintf (dump_file, "Number of dependence tests classified dependent: %d\n", + dependence_stats.num_dependence_dependent); + fprintf (dump_file, "Number of dependence tests classified independent: %d\n", + dependence_stats.num_dependence_independent); + fprintf (dump_file, "Number of undetermined dependence tests: %d\n", + dependence_stats.num_dependence_undetermined); + + fprintf (dump_file, "Number of subscript tests: %d\n", + dependence_stats.num_subscript_tests); + fprintf (dump_file, "Number of undetermined subscript tests: %d\n", + dependence_stats.num_subscript_undetermined); + fprintf (dump_file, "Number of same subscript function: %d\n", + dependence_stats.num_same_subscript_function); + + fprintf (dump_file, "Number of ziv tests: %d\n", + dependence_stats.num_ziv); + fprintf (dump_file, "Number of ziv tests returning dependent: %d\n", + dependence_stats.num_ziv_dependent); + fprintf (dump_file, "Number of ziv tests returning independent: %d\n", + dependence_stats.num_ziv_independent); + fprintf (dump_file, "Number of ziv tests unimplemented: %d\n", + dependence_stats.num_ziv_unimplemented); + + fprintf (dump_file, "Number of siv tests: %d\n", + dependence_stats.num_siv); + fprintf (dump_file, "Number of siv tests returning dependent: %d\n", + dependence_stats.num_siv_dependent); + fprintf (dump_file, "Number of siv tests returning independent: %d\n", + dependence_stats.num_siv_independent); + fprintf (dump_file, "Number of siv tests unimplemented: %d\n", + dependence_stats.num_siv_unimplemented); + + fprintf (dump_file, "Number of miv tests: %d\n", + dependence_stats.num_miv); + fprintf (dump_file, "Number of miv tests returning dependent: %d\n", + dependence_stats.num_miv_dependent); + fprintf (dump_file, "Number of miv tests returning independent: %d\n", + dependence_stats.num_miv_independent); + fprintf (dump_file, "Number of miv tests unimplemented: %d\n", + dependence_stats.num_miv_unimplemented); + } + + return res; +} + +/* Returns true when the data dependences for the basic block BB have been + computed, false otherwise. + DATAREFS is initialized to all the array elements contained in this basic + block, DEPENDENCE_RELATIONS contains the relations between the data + references. Compute read-read and self relations if + COMPUTE_SELF_AND_READ_READ_DEPENDENCES is TRUE. */ +bool +compute_data_dependences_for_bb (basic_block bb, + bool compute_self_and_read_read_dependences, + VEC (data_reference_p, heap) **datarefs, + VEC (ddr_p, heap) **dependence_relations) +{ + if (find_data_references_in_bb (NULL, bb, datarefs) == chrec_dont_know) + return false; + + compute_all_dependences (*datarefs, dependence_relations, NULL, + compute_self_and_read_read_dependences); + return true; +} + +/* Entry point (for testing only). Analyze all the data references + and the dependence relations in LOOP. + + The data references are computed first. + + A relation on these nodes is represented by a complete graph. Some + of the relations could be of no interest, thus the relations can be + computed on demand. + + In the following function we compute all the relations. This is + just a first implementation that is here for: + - for showing how to ask for the dependence relations, + - for the debugging the whole dependence graph, + - for the dejagnu testcases and maintenance. + + It is possible to ask only for a part of the graph, avoiding to + compute the whole dependence graph. The computed dependences are + stored in a knowledge base (KB) such that later queries don't + recompute the same information. The implementation of this KB is + transparent to the optimizer, and thus the KB can be changed with a + more efficient implementation, or the KB could be disabled. */ +static void +analyze_all_data_dependences (struct loop *loop) +{ + unsigned int i; + int nb_data_refs = 10; + VEC (data_reference_p, heap) *datarefs = + VEC_alloc (data_reference_p, heap, nb_data_refs); + VEC (ddr_p, heap) *dependence_relations = + VEC_alloc (ddr_p, heap, nb_data_refs * nb_data_refs); + + /* Compute DDs on the whole function. */ + compute_data_dependences_for_loop (loop, false, &datarefs, + &dependence_relations); + + if (dump_file) + { + dump_data_dependence_relations (dump_file, dependence_relations); + fprintf (dump_file, "\n\n"); + + if (dump_flags & TDF_DETAILS) + dump_dist_dir_vectors (dump_file, dependence_relations); + + if (dump_flags & TDF_STATS) + { + unsigned nb_top_relations = 0; + unsigned nb_bot_relations = 0; + unsigned nb_chrec_relations = 0; + struct data_dependence_relation *ddr; + + for (i = 0; VEC_iterate (ddr_p, dependence_relations, i, ddr); i++) + { + if (chrec_contains_undetermined (DDR_ARE_DEPENDENT (ddr))) + nb_top_relations++; + + else if (DDR_ARE_DEPENDENT (ddr) == chrec_known) + nb_bot_relations++; + + else + nb_chrec_relations++; + } + + gather_stats_on_scev_database (); + } + } + + free_dependence_relations (dependence_relations); + free_data_refs (datarefs); +} + +/* Computes all the data dependences and check that the results of + several analyzers are the same. */ + +void +tree_check_data_deps (void) +{ + loop_iterator li; + struct loop *loop_nest; + + FOR_EACH_LOOP (li, loop_nest, 0) + analyze_all_data_dependences (loop_nest); +} + +/* Free the memory used by a data dependence relation DDR. */ + +void +free_dependence_relation (struct data_dependence_relation *ddr) +{ + if (ddr == NULL) + return; + + if (DDR_SUBSCRIPTS (ddr)) + free_subscripts (DDR_SUBSCRIPTS (ddr)); + if (DDR_DIST_VECTS (ddr)) + VEC_free (lambda_vector, heap, DDR_DIST_VECTS (ddr)); + if (DDR_DIR_VECTS (ddr)) + VEC_free (lambda_vector, heap, DDR_DIR_VECTS (ddr)); + + free (ddr); +} + +/* Free the memory used by the data dependence relations from + DEPENDENCE_RELATIONS. */ + +void +free_dependence_relations (VEC (ddr_p, heap) *dependence_relations) +{ + unsigned int i; + struct data_dependence_relation *ddr; + VEC (loop_p, heap) *loop_nest = NULL; + + for (i = 0; VEC_iterate (ddr_p, dependence_relations, i, ddr); i++) + { + if (ddr == NULL) + continue; + if (loop_nest == NULL) + loop_nest = DDR_LOOP_NEST (ddr); + else + gcc_assert (DDR_LOOP_NEST (ddr) == NULL + || DDR_LOOP_NEST (ddr) == loop_nest); + free_dependence_relation (ddr); + } + + if (loop_nest) + VEC_free (loop_p, heap, loop_nest); + VEC_free (ddr_p, heap, dependence_relations); +} + +/* Free the memory used by the data references from DATAREFS. */ + +void +free_data_refs (VEC (data_reference_p, heap) *datarefs) +{ + unsigned int i; + struct data_reference *dr; + + for (i = 0; VEC_iterate (data_reference_p, datarefs, i, dr); i++) + free_data_ref (dr); + VEC_free (data_reference_p, heap, datarefs); +} + + + +/* Dump vertex I in RDG to FILE. */ + +void +dump_rdg_vertex (FILE *file, struct graph *rdg, int i) +{ + struct vertex *v = &(rdg->vertices[i]); + struct graph_edge *e; + + fprintf (file, "(vertex %d: (%s%s) (in:", i, + RDG_MEM_WRITE_STMT (rdg, i) ? "w" : "", + RDG_MEM_READS_STMT (rdg, i) ? "r" : ""); + + if (v->pred) + for (e = v->pred; e; e = e->pred_next) + fprintf (file, " %d", e->src); + + fprintf (file, ") (out:"); + + if (v->succ) + for (e = v->succ; e; e = e->succ_next) + fprintf (file, " %d", e->dest); + + fprintf (file, ") \n"); + print_gimple_stmt (file, RDGV_STMT (v), 0, TDF_VOPS|TDF_MEMSYMS); + fprintf (file, ")\n"); +} + +/* Call dump_rdg_vertex on stderr. */ + +void +debug_rdg_vertex (struct graph *rdg, int i) +{ + dump_rdg_vertex (stderr, rdg, i); +} + +/* Dump component C of RDG to FILE. If DUMPED is non-null, set the + dumped vertices to that bitmap. */ + +void dump_rdg_component (FILE *file, struct graph *rdg, int c, bitmap dumped) +{ + int i; + + fprintf (file, "(%d\n", c); + + for (i = 0; i < rdg->n_vertices; i++) + if (rdg->vertices[i].component == c) + { + if (dumped) + bitmap_set_bit (dumped, i); + + dump_rdg_vertex (file, rdg, i); + } + + fprintf (file, ")\n"); +} + +/* Call dump_rdg_vertex on stderr. */ + +void +debug_rdg_component (struct graph *rdg, int c) +{ + dump_rdg_component (stderr, rdg, c, NULL); +} + +/* Dump the reduced dependence graph RDG to FILE. */ + +void +dump_rdg (FILE *file, struct graph *rdg) +{ + int i; + bitmap dumped = BITMAP_ALLOC (NULL); + + fprintf (file, "(rdg\n"); + + for (i = 0; i < rdg->n_vertices; i++) + if (!bitmap_bit_p (dumped, i)) + dump_rdg_component (file, rdg, rdg->vertices[i].component, dumped); + + fprintf (file, ")\n"); + BITMAP_FREE (dumped); +} + +/* Call dump_rdg on stderr. */ + +void +debug_rdg (struct graph *rdg) +{ + dump_rdg (stderr, rdg); +} + +/* This structure is used for recording the mapping statement index in + the RDG. */ + +struct GTY(()) rdg_vertex_info +{ + gimple stmt; + int index; +}; + +/* Returns the index of STMT in RDG. */ + +int +rdg_vertex_for_stmt (struct graph *rdg, gimple stmt) +{ + struct rdg_vertex_info rvi, *slot; + + rvi.stmt = stmt; + slot = (struct rdg_vertex_info *) htab_find (rdg->indices, &rvi); + + if (!slot) + return -1; + + return slot->index; +} + +/* Creates an edge in RDG for each distance vector from DDR. The + order that we keep track of in the RDG is the order in which + statements have to be executed. */ + +static void +create_rdg_edge_for_ddr (struct graph *rdg, ddr_p ddr) +{ + struct graph_edge *e; + int va, vb; + data_reference_p dra = DDR_A (ddr); + data_reference_p drb = DDR_B (ddr); + unsigned level = ddr_dependence_level (ddr); + + /* For non scalar dependences, when the dependence is REVERSED, + statement B has to be executed before statement A. */ + if (level > 0 + && !DDR_REVERSED_P (ddr)) + { + data_reference_p tmp = dra; + dra = drb; + drb = tmp; + } + + va = rdg_vertex_for_stmt (rdg, DR_STMT (dra)); + vb = rdg_vertex_for_stmt (rdg, DR_STMT (drb)); + + if (va < 0 || vb < 0) + return; + + e = add_edge (rdg, va, vb); + e->data = XNEW (struct rdg_edge); + + RDGE_LEVEL (e) = level; + RDGE_RELATION (e) = ddr; + + /* Determines the type of the data dependence. */ + if (DR_IS_READ (dra) && DR_IS_READ (drb)) + RDGE_TYPE (e) = input_dd; + else if (!DR_IS_READ (dra) && !DR_IS_READ (drb)) + RDGE_TYPE (e) = output_dd; + else if (!DR_IS_READ (dra) && DR_IS_READ (drb)) + RDGE_TYPE (e) = flow_dd; + else if (DR_IS_READ (dra) && !DR_IS_READ (drb)) + RDGE_TYPE (e) = anti_dd; +} + +/* Creates dependence edges in RDG for all the uses of DEF. IDEF is + the index of DEF in RDG. */ + +static void +create_rdg_edges_for_scalar (struct graph *rdg, tree def, int idef) +{ + use_operand_p imm_use_p; + imm_use_iterator iterator; + + FOR_EACH_IMM_USE_FAST (imm_use_p, iterator, def) + { + struct graph_edge *e; + int use = rdg_vertex_for_stmt (rdg, USE_STMT (imm_use_p)); + + if (use < 0) + continue; + + e = add_edge (rdg, idef, use); + e->data = XNEW (struct rdg_edge); + RDGE_TYPE (e) = flow_dd; + RDGE_RELATION (e) = NULL; + } +} + +/* Creates the edges of the reduced dependence graph RDG. */ + +static void +create_rdg_edges (struct graph *rdg, VEC (ddr_p, heap) *ddrs) +{ + int i; + struct data_dependence_relation *ddr; + def_operand_p def_p; + ssa_op_iter iter; + + for (i = 0; VEC_iterate (ddr_p, ddrs, i, ddr); i++) + if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE) + create_rdg_edge_for_ddr (rdg, ddr); + + for (i = 0; i < rdg->n_vertices; i++) + FOR_EACH_PHI_OR_STMT_DEF (def_p, RDG_STMT (rdg, i), + iter, SSA_OP_DEF) + create_rdg_edges_for_scalar (rdg, DEF_FROM_PTR (def_p), i); +} + +/* Build the vertices of the reduced dependence graph RDG. */ + +void +create_rdg_vertices (struct graph *rdg, VEC (gimple, heap) *stmts) +{ + int i, j; + gimple stmt; + + for (i = 0; VEC_iterate (gimple, stmts, i, stmt); i++) + { + VEC (data_ref_loc, heap) *references; + data_ref_loc *ref; + struct vertex *v = &(rdg->vertices[i]); + struct rdg_vertex_info *rvi = XNEW (struct rdg_vertex_info); + struct rdg_vertex_info **slot; + + rvi->stmt = stmt; + rvi->index = i; + slot = (struct rdg_vertex_info **) htab_find_slot (rdg->indices, rvi, INSERT); + + if (!*slot) + *slot = rvi; + else + free (rvi); + + v->data = XNEW (struct rdg_vertex); + RDG_STMT (rdg, i) = stmt; + + RDG_MEM_WRITE_STMT (rdg, i) = false; + RDG_MEM_READS_STMT (rdg, i) = false; + if (gimple_code (stmt) == GIMPLE_PHI) + continue; + + get_references_in_stmt (stmt, &references); + for (j = 0; VEC_iterate (data_ref_loc, references, j, ref); j++) + if (!ref->is_read) + RDG_MEM_WRITE_STMT (rdg, i) = true; + else + RDG_MEM_READS_STMT (rdg, i) = true; + + VEC_free (data_ref_loc, heap, references); + } +} + +/* Initialize STMTS with all the statements of LOOP. When + INCLUDE_PHIS is true, include also the PHI nodes. The order in + which we discover statements is important as + generate_loops_for_partition is using the same traversal for + identifying statements. */ + +static void +stmts_from_loop (struct loop *loop, VEC (gimple, heap) **stmts) +{ + unsigned int i; + basic_block *bbs = get_loop_body_in_dom_order (loop); + + for (i = 0; i < loop->num_nodes; i++) + { + basic_block bb = bbs[i]; + gimple_stmt_iterator bsi; + gimple stmt; + + for (bsi = gsi_start_phis (bb); !gsi_end_p (bsi); gsi_next (&bsi)) + VEC_safe_push (gimple, heap, *stmts, gsi_stmt (bsi)); + + for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi)) { - ddr = initialize_data_dependence_relation (a, b, loop_nest); - VEC_safe_push (ddr_p, heap, *dependence_relations, ddr); - compute_affine_dependence (ddr); + stmt = gsi_stmt (bsi); + if (gimple_code (stmt) != GIMPLE_LABEL) + VEC_safe_push (gimple, heap, *stmts, stmt); } + } - if (compute_self_and_rr) - for (i = 0; VEC_iterate (data_reference_p, datarefs, i, a); i++) - { - ddr = initialize_data_dependence_relation (a, a, loop_nest); - VEC_safe_push (ddr_p, heap, *dependence_relations, ddr); - compute_self_dependence (ddr); - } + free (bbs); } -/* Search the data references in LOOP, and record the information into - DATAREFS. Returns chrec_dont_know when failing to analyze a - difficult case, returns NULL_TREE otherwise. - - TODO: This function should be made smarter so that it can handle address - arithmetic as if they were array accesses, etc. */ +/* Returns true when all the dependences are computable. */ -tree -find_data_references_in_loop (struct loop *loop, - VEC (data_reference_p, heap) **datarefs) +static bool +known_dependences_p (VEC (ddr_p, heap) *dependence_relations) { - basic_block bb, *bbs; + ddr_p ddr; unsigned int i; - block_stmt_iterator bsi; - struct data_reference *dr; - bbs = get_loop_body (loop); + for (i = 0; VEC_iterate (ddr_p, dependence_relations, i, ddr); i++) + if (DDR_ARE_DEPENDENT (ddr) == chrec_dont_know) + return false; - for (i = 0; i < loop->num_nodes; i++) - { - bb = bbs[i]; + return true; +} - for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi)) - { - tree stmt = bsi_stmt (bsi); - - /* ASM_EXPR and CALL_EXPR may embed arbitrary side effects. - Calls have side-effects, except those to const or pure - functions. */ - if ((TREE_CODE (stmt) == CALL_EXPR - && !(call_expr_flags (stmt) & (ECF_CONST | ECF_PURE))) - || (TREE_CODE (stmt) == ASM_EXPR - && ASM_VOLATILE_P (stmt))) - goto insert_dont_know_node; - - if (ZERO_SSA_OPERANDS (stmt, SSA_OP_ALL_VIRTUALS)) - continue; +/* Computes a hash function for element ELT. */ - switch (TREE_CODE (stmt)) - { - case MODIFY_EXPR: - { - bool one_inserted = false; - tree opnd0 = TREE_OPERAND (stmt, 0); - tree opnd1 = TREE_OPERAND (stmt, 1); - - if (TREE_CODE (opnd0) == ARRAY_REF - || TREE_CODE (opnd0) == INDIRECT_REF - || TREE_CODE (opnd0) == COMPONENT_REF) - { - dr = create_data_ref (opnd0, stmt, false); - if (dr) - { - VEC_safe_push (data_reference_p, heap, *datarefs, dr); - one_inserted = true; - } - } - - if (TREE_CODE (opnd1) == ARRAY_REF - || TREE_CODE (opnd1) == INDIRECT_REF - || TREE_CODE (opnd1) == COMPONENT_REF) - { - dr = create_data_ref (opnd1, stmt, true); - if (dr) - { - VEC_safe_push (data_reference_p, heap, *datarefs, dr); - one_inserted = true; - } - } - - if (!one_inserted) - goto insert_dont_know_node; - - break; - } +static hashval_t +hash_stmt_vertex_info (const void *elt) +{ + const struct rdg_vertex_info *const rvi = + (const struct rdg_vertex_info *) elt; + gimple stmt = rvi->stmt; - case CALL_EXPR: - { - tree args; - bool one_inserted = false; - - for (args = TREE_OPERAND (stmt, 1); args; - args = TREE_CHAIN (args)) - if (TREE_CODE (TREE_VALUE (args)) == ARRAY_REF - || TREE_CODE (TREE_VALUE (args)) == INDIRECT_REF - || TREE_CODE (TREE_VALUE (args)) == COMPONENT_REF) - { - dr = create_data_ref (TREE_VALUE (args), stmt, true); - if (dr) - { - VEC_safe_push (data_reference_p, heap, *datarefs, dr); - one_inserted = true; - } - } + return htab_hash_pointer (stmt); +} - if (!one_inserted) - goto insert_dont_know_node; +/* Compares database elements E1 and E2. */ - break; - } +static int +eq_stmt_vertex_info (const void *e1, const void *e2) +{ + const struct rdg_vertex_info *elt1 = (const struct rdg_vertex_info *) e1; + const struct rdg_vertex_info *elt2 = (const struct rdg_vertex_info *) e2; - default: - { - struct data_reference *res; - - insert_dont_know_node:; - res = XNEW (struct data_reference); - DR_STMT (res) = NULL_TREE; - DR_REF (res) = NULL_TREE; - DR_BASE_OBJECT (res) = NULL; - DR_TYPE (res) = ARRAY_REF_TYPE; - DR_SET_ACCESS_FNS (res, NULL); - DR_BASE_OBJECT (res) = NULL; - DR_IS_READ (res) = false; - DR_BASE_ADDRESS (res) = NULL_TREE; - DR_OFFSET (res) = NULL_TREE; - DR_INIT (res) = NULL_TREE; - DR_STEP (res) = NULL_TREE; - DR_OFFSET_MISALIGNMENT (res) = NULL_TREE; - DR_MEMTAG (res) = NULL_TREE; - DR_PTR_INFO (res) = NULL; - VEC_safe_push (data_reference_p, heap, *datarefs, res); - - free (bbs); - return chrec_dont_know; - } - } + return elt1->stmt == elt2->stmt; +} - /* When there are no defs in the loop, the loop is parallel. */ - if (!ZERO_SSA_OPERANDS (stmt, SSA_OP_VIRTUAL_DEFS)) - loop->parallel_p = false; - } - } +/* Free the element E. */ - free (bbs); +static void +hash_stmt_vertex_del (void *e) +{ + free (e); +} - return NULL_TREE; +/* Build the Reduced Dependence Graph (RDG) with one vertex per + statement of the loop nest, and one edge per data dependence or + scalar dependence. */ + +struct graph * +build_empty_rdg (int n_stmts) +{ + int nb_data_refs = 10; + struct graph *rdg = new_graph (n_stmts); + + rdg->indices = htab_create (nb_data_refs, hash_stmt_vertex_info, + eq_stmt_vertex_info, hash_stmt_vertex_del); + return rdg; } -/* Recursive helper function. */ +/* Build the Reduced Dependence Graph (RDG) with one vertex per + statement of the loop nest, and one edge per data dependence or + scalar dependence. */ -static bool -find_loop_nest_1 (struct loop *loop, VEC (loop_p, heap) *loop_nest) +struct graph * +build_rdg (struct loop *loop) { - /* Inner loops of the nest should not contain siblings. Example: - when there are two consecutive loops, + int nb_data_refs = 10; + struct graph *rdg = NULL; + VEC (ddr_p, heap) *dependence_relations; + VEC (data_reference_p, heap) *datarefs; + VEC (gimple, heap) *stmts = VEC_alloc (gimple, heap, nb_data_refs); + + dependence_relations = VEC_alloc (ddr_p, heap, nb_data_refs * nb_data_refs) ; + datarefs = VEC_alloc (data_reference_p, heap, nb_data_refs); + compute_data_dependences_for_loop (loop, + false, + &datarefs, + &dependence_relations); + + if (!known_dependences_p (dependence_relations)) + { + free_dependence_relations (dependence_relations); + free_data_refs (datarefs); + VEC_free (gimple, heap, stmts); - | loop_0 - | loop_1 - | A[{0, +, 1}_1] - | endloop_1 - | loop_2 - | A[{0, +, 1}_2] - | endloop_2 - | endloop_0 + return rdg; + } - the dependence relation cannot be captured by the distance - abstraction. */ - if (loop->next) - return false; + stmts_from_loop (loop, &stmts); + rdg = build_empty_rdg (VEC_length (gimple, stmts)); - VEC_safe_push (loop_p, heap, loop_nest, loop); - if (loop->inner) - return find_loop_nest_1 (loop->inner, loop_nest); - return true; + rdg->indices = htab_create (nb_data_refs, hash_stmt_vertex_info, + eq_stmt_vertex_info, hash_stmt_vertex_del); + create_rdg_vertices (rdg, stmts); + create_rdg_edges (rdg, dependence_relations); + + VEC_free (gimple, heap, stmts); + return rdg; } -/* Return false when the LOOP is not well nested. Otherwise return - true and insert in LOOP_NEST the loops of the nest. LOOP_NEST will - contain the loops from the outermost to the innermost, as they will - appear in the classic distance vector. */ +/* Free the reduced dependence graph RDG. */ -static bool -find_loop_nest (struct loop *loop, VEC (loop_p, heap) *loop_nest) +void +free_rdg (struct graph *rdg) { - VEC_safe_push (loop_p, heap, loop_nest, loop); - if (loop->inner) - return find_loop_nest_1 (loop->inner, loop_nest); - return true; + int i; + + for (i = 0; i < rdg->n_vertices; i++) + free (rdg->vertices[i].data); + + htab_delete (rdg->indices); + free_graph (rdg); } -/* Given a loop nest LOOP, the following vectors are returned: - DATAREFS is initialized to all the array elements contained in this loop, - DEPENDENCE_RELATIONS contains the relations between the data references. - Compute read-read and self relations if - COMPUTE_SELF_AND_READ_READ_DEPENDENCES is TRUE. */ +/* Initialize STMTS with all the statements of LOOP that contain a + store to memory. */ void -compute_data_dependences_for_loop (struct loop *loop, - bool compute_self_and_read_read_dependences, - VEC (data_reference_p, heap) **datarefs, - VEC (ddr_p, heap) **dependence_relations) +stores_from_loop (struct loop *loop, VEC (gimple, heap) **stmts) { - struct loop *loop_nest = loop; - VEC (loop_p, heap) *vloops = VEC_alloc (loop_p, heap, 3); - - memset (&dependence_stats, 0, sizeof (dependence_stats)); + unsigned int i; + basic_block *bbs = get_loop_body_in_dom_order (loop); - /* If the loop nest is not well formed, or one of the data references - is not computable, give up without spending time to compute other - dependences. */ - if (!loop_nest - || !find_loop_nest (loop_nest, vloops) - || find_data_references_in_loop (loop, datarefs) == chrec_dont_know) + for (i = 0; i < loop->num_nodes; i++) { - struct data_dependence_relation *ddr; + basic_block bb = bbs[i]; + gimple_stmt_iterator bsi; - /* Insert a single relation into dependence_relations: - chrec_dont_know. */ - ddr = initialize_data_dependence_relation (NULL, NULL, vloops); - VEC_safe_push (ddr_p, heap, *dependence_relations, ddr); + for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi)) + if (gimple_vdef (gsi_stmt (bsi))) + VEC_safe_push (gimple, heap, *stmts, gsi_stmt (bsi)); } - else - compute_all_dependences (*datarefs, dependence_relations, vloops, - compute_self_and_read_read_dependences); - if (dump_file && (dump_flags & TDF_STATS)) - { - fprintf (dump_file, "Dependence tester statistics:\n"); + free (bbs); +} - fprintf (dump_file, "Number of dependence tests: %d\n", - dependence_stats.num_dependence_tests); - fprintf (dump_file, "Number of dependence tests classified dependent: %d\n", - dependence_stats.num_dependence_dependent); - fprintf (dump_file, "Number of dependence tests classified independent: %d\n", - dependence_stats.num_dependence_independent); - fprintf (dump_file, "Number of undetermined dependence tests: %d\n", - dependence_stats.num_dependence_undetermined); +/* For a data reference REF, return the declaration of its base + address or NULL_TREE if the base is not determined. */ - fprintf (dump_file, "Number of subscript tests: %d\n", - dependence_stats.num_subscript_tests); - fprintf (dump_file, "Number of undetermined subscript tests: %d\n", - dependence_stats.num_subscript_undetermined); - fprintf (dump_file, "Number of same subscript function: %d\n", - dependence_stats.num_same_subscript_function); +static inline tree +ref_base_address (gimple stmt, data_ref_loc *ref) +{ + tree base = NULL_TREE; + tree base_address; + struct data_reference *dr = XCNEW (struct data_reference); - fprintf (dump_file, "Number of ziv tests: %d\n", - dependence_stats.num_ziv); - fprintf (dump_file, "Number of ziv tests returning dependent: %d\n", - dependence_stats.num_ziv_dependent); - fprintf (dump_file, "Number of ziv tests returning independent: %d\n", - dependence_stats.num_ziv_independent); - fprintf (dump_file, "Number of ziv tests unimplemented: %d\n", - dependence_stats.num_ziv_unimplemented); + DR_STMT (dr) = stmt; + DR_REF (dr) = *ref->pos; + dr_analyze_innermost (dr); + base_address = DR_BASE_ADDRESS (dr); - fprintf (dump_file, "Number of siv tests: %d\n", - dependence_stats.num_siv); - fprintf (dump_file, "Number of siv tests returning dependent: %d\n", - dependence_stats.num_siv_dependent); - fprintf (dump_file, "Number of siv tests returning independent: %d\n", - dependence_stats.num_siv_independent); - fprintf (dump_file, "Number of siv tests unimplemented: %d\n", - dependence_stats.num_siv_unimplemented); + if (!base_address) + goto end; - fprintf (dump_file, "Number of miv tests: %d\n", - dependence_stats.num_miv); - fprintf (dump_file, "Number of miv tests returning dependent: %d\n", - dependence_stats.num_miv_dependent); - fprintf (dump_file, "Number of miv tests returning independent: %d\n", - dependence_stats.num_miv_independent); - fprintf (dump_file, "Number of miv tests unimplemented: %d\n", - dependence_stats.num_miv_unimplemented); - } + switch (TREE_CODE (base_address)) + { + case ADDR_EXPR: + base = TREE_OPERAND (base_address, 0); + break; + + default: + base = base_address; + break; + } + + end: + free_data_ref (dr); + return base; } -/* Entry point (for testing only). Analyze all the data references - and the dependence relations. +/* Determines whether the statement from vertex V of the RDG has a + definition used outside the loop that contains this statement. */ - The data references are computed first. - - A relation on these nodes is represented by a complete graph. Some - of the relations could be of no interest, thus the relations can be - computed on demand. - - In the following function we compute all the relations. This is - just a first implementation that is here for: - - for showing how to ask for the dependence relations, - - for the debugging the whole dependence graph, - - for the dejagnu testcases and maintenance. - - It is possible to ask only for a part of the graph, avoiding to - compute the whole dependence graph. The computed dependences are - stored in a knowledge base (KB) such that later queries don't - recompute the same information. The implementation of this KB is - transparent to the optimizer, and thus the KB can be changed with a - more efficient implementation, or the KB could be disabled. */ -#if 0 -static void -analyze_all_data_dependences (struct loops *loops) +bool +rdg_defs_used_in_other_loops_p (struct graph *rdg, int v) { - unsigned int i; - int nb_data_refs = 10; - VEC (data_reference_p, heap) *datarefs = - VEC_alloc (data_reference_p, heap, nb_data_refs); - VEC (ddr_p, heap) *dependence_relations = - VEC_alloc (ddr_p, heap, nb_data_refs * nb_data_refs); + gimple stmt = RDG_STMT (rdg, v); + struct loop *loop = loop_containing_stmt (stmt); + use_operand_p imm_use_p; + imm_use_iterator iterator; + ssa_op_iter it; + def_operand_p def_p; - /* Compute DDs on the whole function. */ - compute_data_dependences_for_loop (loops->parray[0], false, - &datarefs, &dependence_relations); + if (!loop) + return true; - if (dump_file) + FOR_EACH_PHI_OR_STMT_DEF (def_p, stmt, it, SSA_OP_DEF) { - dump_data_dependence_relations (dump_file, dependence_relations); - fprintf (dump_file, "\n\n"); + FOR_EACH_IMM_USE_FAST (imm_use_p, iterator, DEF_FROM_PTR (def_p)) + { + if (loop_containing_stmt (USE_STMT (imm_use_p)) != loop) + return true; + } + } - if (dump_flags & TDF_DETAILS) - dump_dist_dir_vectors (dump_file, dependence_relations); + return false; +} - if (dump_flags & TDF_STATS) - { - unsigned nb_top_relations = 0; - unsigned nb_bot_relations = 0; - unsigned nb_basename_differ = 0; - unsigned nb_chrec_relations = 0; - struct data_dependence_relation *ddr; +/* Determines whether statements S1 and S2 access to similar memory + locations. Two memory accesses are considered similar when they + have the same base address declaration, i.e. when their + ref_base_address is the same. */ - for (i = 0; VEC_iterate (ddr_p, dependence_relations, i, ddr); i++) +bool +have_similar_memory_accesses (gimple s1, gimple s2) +{ + bool res = false; + unsigned i, j; + VEC (data_ref_loc, heap) *refs1, *refs2; + data_ref_loc *ref1, *ref2; + + get_references_in_stmt (s1, &refs1); + get_references_in_stmt (s2, &refs2); + + for (i = 0; VEC_iterate (data_ref_loc, refs1, i, ref1); i++) + { + tree base1 = ref_base_address (s1, ref1); + + if (base1) + for (j = 0; VEC_iterate (data_ref_loc, refs2, j, ref2); j++) + if (base1 == ref_base_address (s2, ref2)) { - if (chrec_contains_undetermined (DDR_ARE_DEPENDENT (ddr))) - nb_top_relations++; - - else if (DDR_ARE_DEPENDENT (ddr) == chrec_known) - { - struct data_reference *a = DDR_A (ddr); - struct data_reference *b = DDR_B (ddr); - bool differ_p; - - if ((DR_BASE_OBJECT (a) && DR_BASE_OBJECT (b) - && DR_NUM_DIMENSIONS (a) != DR_NUM_DIMENSIONS (b)) - || (base_object_differ_p (a, b, &differ_p) - && differ_p)) - nb_basename_differ++; - else - nb_bot_relations++; - } - - else - nb_chrec_relations++; + res = true; + goto end; } - - gather_stats_on_scev_database (); - } } - free_dependence_relations (dependence_relations); - free_data_refs (datarefs); + end: + VEC_free (data_ref_loc, heap, refs1); + VEC_free (data_ref_loc, heap, refs2); + return res; } -#endif -/* Free the memory used by a data dependence relation DDR. */ +/* Helper function for the hashtab. */ -void -free_dependence_relation (struct data_dependence_relation *ddr) +static int +have_similar_memory_accesses_1 (const void *s1, const void *s2) { - if (ddr == NULL) - return; - - if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE && DDR_SUBSCRIPTS (ddr)) - VEC_free (subscript_p, heap, DDR_SUBSCRIPTS (ddr)); - - free (ddr); + return have_similar_memory_accesses (CONST_CAST_GIMPLE ((const_gimple) s1), + CONST_CAST_GIMPLE ((const_gimple) s2)); } -/* Free the memory used by the data dependence relations from - DEPENDENCE_RELATIONS. */ +/* Helper function for the hashtab. */ -void -free_dependence_relations (VEC (ddr_p, heap) *dependence_relations) +static hashval_t +ref_base_address_1 (const void *s) { - unsigned int i; - struct data_dependence_relation *ddr; + gimple stmt = CONST_CAST_GIMPLE ((const_gimple) s); + unsigned i; + VEC (data_ref_loc, heap) *refs; + data_ref_loc *ref; + hashval_t res = 0; - for (i = 0; VEC_iterate (ddr_p, dependence_relations, i, ddr); i++) - free_dependence_relation (ddr); + get_references_in_stmt (stmt, &refs); - VEC_free (ddr_p, heap, dependence_relations); + for (i = 0; VEC_iterate (data_ref_loc, refs, i, ref); i++) + if (!ref->is_read) + { + res = htab_hash_pointer (ref_base_address (stmt, ref)); + break; + } + + VEC_free (data_ref_loc, heap, refs); + return res; } -/* Free the memory used by the data references from DATAREFS. */ +/* Try to remove duplicated write data references from STMTS. */ void -free_data_refs (VEC (data_reference_p, heap) *datarefs) +remove_similar_memory_refs (VEC (gimple, heap) **stmts) { - unsigned int i; - struct data_reference *dr; + unsigned i; + gimple stmt; + htab_t seen = htab_create (VEC_length (gimple, *stmts), ref_base_address_1, + have_similar_memory_accesses_1, NULL); - for (i = 0; VEC_iterate (data_reference_p, datarefs, i, dr); i++) + for (i = 0; VEC_iterate (gimple, *stmts, i, stmt); ) { - if (DR_TYPE(dr) == ARRAY_REF_TYPE) - VEC_free (tree, heap, (dr)->object_info.access_fns); - else - VEC_free (tree, heap, (dr)->first_location.access_fns); + void **slot; + + slot = htab_find_slot (seen, stmt, INSERT); - free (dr); + if (*slot) + VEC_ordered_remove (gimple, *stmts, i); + else + { + *slot = (void *) stmt; + i++; + } } - VEC_free (data_reference_p, heap, datarefs); + + htab_delete (seen); } +/* Returns the index of PARAMETER in the parameters vector of the + ACCESS_MATRIX. If PARAMETER does not exist return -1. */ + +int +access_matrix_get_index_for_parameter (tree parameter, + struct access_matrix *access_matrix) +{ + int i; + VEC (tree,heap) *lambda_parameters = AM_PARAMETERS (access_matrix); + tree lambda_parameter; + + for (i = 0; VEC_iterate (tree, lambda_parameters, i, lambda_parameter); i++) + if (lambda_parameter == parameter) + return i + AM_NB_INDUCTION_VARS (access_matrix); + + return -1; +}