/* Data references and dependences detectors.
- Copyright (C) 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
+ Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009
+ Free Software Foundation, Inc.
Contributed by Sebastian Pop <pop@cri.ensmp.fr>
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
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
+<http://www.gnu.org/licenses/>. */
/* 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"
#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 "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
{
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);
\f
-/* 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;
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;
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: ");
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)
{
/* Debug version. */
-void
+void
debug_data_dependence_relation (struct data_dependence_relation *ddr)
{
dump_data_dependence_relation (stderr, 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;
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);
/* 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;
}
}
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;
/* Dumps the data dependence relations DDRS in FILE. */
-void
+void
dump_ddrs (FILE *file, VEC (ddr_p, heap) *ddrs)
{
unsigned int i;
fprintf (file, "\n\n");
}
-\f
-
-/* 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);
}
-\f
-/* 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);
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))
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
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));
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))
{
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
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:
{
/* 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, CHREC_LEFT (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;
}
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;
{
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;
{
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;
}
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;
/* 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
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)
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
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,
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
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;
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,
A = lambda_matrix_new (dim, 1);
S = lambda_matrix_new (dim, 1);
- 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)
{
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;
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;
}
{
/* 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;
}
|| (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;
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:
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");
}
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)
*/
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))
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);
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++;
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");
|| 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");
}
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;
non_affine_dependence_relation (ddr);
return false;
}
-
+
dist = int_cst_value (SUB_DISTANCE (subscript));
/* This is the subscript coupling test. If we have already
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
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)
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;
}
/* 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);
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;
}
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))
{
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);
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:
| T[j][i] = t + 2; // B
| }
- the vectors are:
+ the vectors are:
(0, 1, -1)
(1, 1, -1)
(1, -1, 1)
{
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
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;
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;
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))
}
/* 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);
-/* This computes the dependence relation for the same data
+ 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. */
static void
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;
}
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,
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);
+}
+
+\f
+
+/* 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;
+}
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