/* Data references and dependences detectors.
- Copyright (C) 2003, 2004 Free Software Foundation, Inc.
+ Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc.
Contributed by Sebastian Pop <s.pop@laposte.net>
This file is part of GCC.
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, 59 Temple Place - Suite 330, Boston, MA
-02111-1307, USA. */
+Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301, USA. */
/* This pass walks a given loop structure searching for array
references. The information about the array accesses is recorded
- polyhedron dependence
or with the chains of recurrences based representation,
- - to define a knowledge base for storing the data dependences
+ - to define a knowledge base for storing the data dependence
information,
- to define an interface to access this data.
#include "system.h"
#include "coretypes.h"
#include "tm.h"
-#include "errors.h"
#include "ggc.h"
#include "tree.h"
#include "tree-data-ref.h"
#include "tree-scalar-evolution.h"
#include "tree-pass.h"
-#include "lambda.h"
+
+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);
+
+/* Determine if PTR and DECL may alias, the result is put in ALIASED.
+ Return FALSE if there is no type 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))->type_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 type 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))->type_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))->type_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 type 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
utility will not be necessary when alias_sets_conflict_p will be
less conservative. */
-bool
-array_base_name_differ_p (struct data_reference *a,
- struct data_reference *b,
- bool *differ_p)
+static bool
+base_object_differ_p (struct data_reference *a,
+ struct data_reference *b,
+ bool *differ_p)
{
- tree base_a = DR_BASE_NAME (a);
- tree base_b = DR_BASE_NAME (b);
- tree ta = TREE_TYPE (base_a);
- tree tb = TREE_TYPE (base_b);
+ 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. */
return true;
}
- /* record/union based accesses - s.a[i], t.b[j]. bases are s.a,t.b. */
+ /* 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))
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), which bases are p and q,
- may still pointing to the same base. In SSAed GIMPLE p and q will
- be SSA_NAMES in this case. Therefore, here we check if it's
- really two diferent declarations. */
+ 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
return true;
}
- /* Compare a record/union access and an array access. */
- if ((TREE_CODE (base_a) == VAR_DECL
- && (TREE_CODE (base_b) == COMPONENT_REF
- && TREE_CODE (TREE_OPERAND (base_b, 0)) == VAR_DECL))
- || (TREE_CODE (base_b) == VAR_DECL
- && (TREE_CODE (base_a) == COMPONENT_REF
- && TREE_CODE (TREE_OPERAND (base_a, 0)) == VAR_DECL)))
+ /* 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;
}
- if (!alias_sets_conflict_p (get_alias_set (base_a), get_alias_set (base_b)))
+ /* 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;
}
- /* An instruction writing through a restricted pointer is
- "independent" of any instruction reading or writing through a
- different pointer, in the same block/scope. */
- if ((TREE_CODE (ta) == POINTER_TYPE && TYPE_RESTRICT (ta)
- && !DR_IS_READ(a))
- || (TREE_CODE (tb) == POINTER_TYPE && TYPE_RESTRICT (tb)
- && !DR_IS_READ(b)))
+ 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;
}
+
/* Returns true iff A divides B. */
static inline bool
-tree_fold_divides_p (tree type,
- tree a,
+tree_fold_divides_p (tree a,
tree b)
{
- if (integer_onep (a))
- return true;
-
/* Determines whether (A == gcd (A, B)). */
- return integer_zerop
- (fold (build (MINUS_EXPR, type, a, tree_fold_gcd (a, b))));
+ return tree_int_cst_equal (a, tree_fold_gcd (a, b));
}
-/* Bezout: Let A1 and A2 be two integers; there exist two integers U11
- and U12 such that,
-
- | U11 * A1 + U12 * A2 = gcd (A1, A2).
-
- This function computes the greatest common divisor using the
- Blankinship algorithm. The gcd is returned, and the coefficients
- of the unimodular matrix U are (U11, U12, U21, U22) such that,
-
- | U.A = S
-
- | (U11 U12) (A1) = (gcd)
- | (U21 U22) (A2) (0)
-
- FIXME: Use lambda_..._hermite for implementing this function.
-*/
+/* Compute the greatest common denominator of two numbers using
+ Euclid's algorithm. */
-static tree
-tree_fold_bezout (tree a1,
- tree a2,
- tree *u11, tree *u12,
- tree *u21, tree *u22)
+static int
+gcd (int a, int b)
{
- tree s1, s2;
-
- /* Initialize S with the coefficients of A. */
- s1 = a1;
- s2 = a2;
- /* Initialize the U matrix */
- *u11 = integer_one_node;
- *u12 = integer_zero_node;
- *u21 = integer_zero_node;
- *u22 = integer_one_node;
+ int x, y, z;
- if (integer_zerop (a1)
- || integer_zerop (a2))
- return integer_zero_node;
-
- while (!integer_zerop (s2))
- {
- int sign;
- tree z, zu21, zu22, zs2;
-
- sign = tree_int_cst_sgn (s1) * tree_int_cst_sgn (s2);
- z = fold (build (FLOOR_DIV_EXPR, integer_type_node,
- fold (build1 (ABS_EXPR, integer_type_node, s1)),
- fold (build1 (ABS_EXPR, integer_type_node, s2))));
- zu21 = fold (build (MULT_EXPR, integer_type_node, z, *u21));
- zu22 = fold (build (MULT_EXPR, integer_type_node, z, *u22));
- zs2 = fold (build (MULT_EXPR, integer_type_node, z, s2));
-
- /* row1 -= z * row2. */
- gcc_assert (sign != 0);
- if (sign < 0)
- {
- *u11 = fold (build (PLUS_EXPR, integer_type_node, *u11, zu21));
- *u12 = fold (build (PLUS_EXPR, integer_type_node, *u12, zu22));
- s1 = fold (build (PLUS_EXPR, integer_type_node, s1, zs2));
- }
- else
- {
- *u11 = fold (build (MINUS_EXPR, integer_type_node, *u11, zu21));
- *u12 = fold (build (MINUS_EXPR, integer_type_node, *u12, zu22));
- s1 = fold (build (MINUS_EXPR, integer_type_node, s1, zs2));
- }
-
- /* Interchange row1 and row2. */
- {
- tree flip;
-
- flip = *u11;
- *u11 = *u21;
- *u21 = flip;
+ x = abs (a);
+ y = abs (b);
- flip = *u12;
- *u12 = *u22;
- *u22 = flip;
-
- flip = s1;
- s1 = s2;
- s2 = flip;
- }
- }
-
- if (tree_int_cst_sgn (s1) < 0)
+ while (x>0)
{
- *u11 = fold (build (MULT_EXPR, integer_type_node, *u11,
- integer_minus_one_node));
- *u12 = fold (build (MULT_EXPR, integer_type_node, *u12,
- integer_minus_one_node));
- s1 = fold (build (MULT_EXPR, integer_type_node, s1, integer_minus_one_node));
+ z = y % x;
+ y = x;
+ x = z;
}
-
- return s1;
+
+ return (y);
+}
+
+/* Returns true iff A divides B. */
+
+static inline bool
+int_divides_p (int a, int b)
+{
+ return ((b % a) == 0);
}
\f
fprintf (outf, " ref: ");
print_generic_stmt (outf, DR_REF (dr), 0);
fprintf (outf, " base_name: ");
- print_generic_stmt (outf, DR_BASE_NAME (dr), 0);
+ print_generic_stmt (outf, DR_BASE_OBJECT (dr), 0);
for (i = 0; i < DR_NUM_DIMENSIONS (dr); i++)
{
fprintf (outf, ")\n");
}
+/* Dump function for a SUBSCRIPT structure. */
+
+void
+dump_subscript (FILE *outf, struct subscript *subscript)
+{
+ tree chrec = 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
+ {
+ tree last_iteration = SUB_LAST_CONFLICT (subscript);
+ fprintf (outf, " last_conflict: ");
+ print_generic_stmt (outf, last_iteration, 0);
+ }
+
+ chrec = 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
+ {
+ tree last_iteration = SUB_LAST_CONFLICT (subscript);
+ fprintf (outf, " last_conflict: ");
+ print_generic_stmt (outf, last_iteration, 0);
+ }
+
+ fprintf (outf, " (Subscript distance: ");
+ print_generic_stmt (outf, SUB_DISTANCE (subscript), 0);
+ fprintf (outf, " )\n");
+ fprintf (outf, " )\n");
+}
+
/* Dump function for a DATA_DEPENDENCE_RELATION structure. */
void
dump_data_dependence_relation (FILE *outf,
struct data_dependence_relation *ddr)
{
- unsigned int i;
struct data_reference *dra, *drb;
-
+
dra = DDR_A (ddr);
drb = DDR_B (ddr);
-
- if (dra && drb)
- fprintf (outf, "(Data Dep:");
- else
- fprintf (outf, "(Data Dep:");
-
- if (chrec_contains_undetermined (DDR_ARE_DEPENDENT (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)
fprintf (outf, " (no dependence)\n");
- else
+ else if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE)
{
+ unsigned int i;
for (i = 0; i < DDR_NUM_SUBSCRIPTS (ddr); i++)
{
- tree chrec;
- struct subscript *subscript = DDR_SUBSCRIPT (ddr, i);
-
- fprintf (outf, "\n (subscript %d:\n", i);
fprintf (outf, " access_fn_A: ");
print_generic_stmt (outf, DR_ACCESS_FN (dra, i), 0);
fprintf (outf, " access_fn_B: ");
print_generic_stmt (outf, DR_ACCESS_FN (drb, i), 0);
-
- chrec = SUB_CONFLICTS_IN_A (subscript);
- 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
- {
- tree last_iteration = SUB_LAST_CONFLICT_IN_A (subscript);
- fprintf (outf, " last_iteration_that_access_an_element_twice_in_A: ");
- print_generic_stmt (outf, last_iteration, 0);
- }
-
- chrec = 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
- {
- tree last_iteration = SUB_LAST_CONFLICT_IN_B (subscript);
- fprintf (outf, " last_iteration_that_access_an_element_twice_in_B: ");
- print_generic_stmt (outf, last_iteration, 0);
- }
-
- fprintf (outf, " )\n");
+ dump_subscript (outf, DDR_SUBSCRIPT (ddr, i));
}
-
- fprintf (outf, " (Distance Vector: \n");
- for (i = 0; i < DDR_NUM_SUBSCRIPTS (ddr); i++)
+ if (DDR_DIST_VECT (ddr))
{
- struct subscript *subscript = DDR_SUBSCRIPT (ddr, i);
-
- fprintf (outf, "(");
- print_generic_stmt (outf, SUB_DISTANCE (subscript), 0);
- fprintf (outf, ")\n");
+ fprintf (outf, " distance_vect: ");
+ print_lambda_vector (outf, DDR_DIST_VECT (ddr), DDR_SIZE_VECT (ddr));
+ }
+ if (DDR_DIR_VECT (ddr))
+ {
+ fprintf (outf, " direction_vect: ");
+ print_lambda_vector (outf, DDR_DIR_VECT (ddr), DDR_SIZE_VECT (ddr));
}
- fprintf (outf, " )\n");
}
fprintf (outf, ")\n");
}
}
+/* Dumps the distance and direction vectors in FILE. DDRS contains
+ the dependence relations, and VECT_SIZE is the size of the
+ dependence vectors, or in other words the number of loops in the
+ considered nest. */
+
+void
+dump_dist_dir_vectors (FILE *file, varray_type ddrs)
+{
+ unsigned int i;
+
+ for (i = 0; i < VARRAY_ACTIVE_SIZE (ddrs); i++)
+ {
+ struct data_dependence_relation *ddr =
+ (struct data_dependence_relation *)
+ VARRAY_GENERIC_PTR (ddrs, i);
+ if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE
+ && DDR_AFFINE_P (ddr))
+ {
+ fprintf (file, "DISTANCE_V (");
+ print_lambda_vector (file, DDR_DIST_VECT (ddr), DDR_SIZE_VECT (ddr));
+ fprintf (file, ")\n");
+ fprintf (file, "DIRECTION_V (");
+ print_lambda_vector (file, DDR_DIR_VECT (ddr), DDR_SIZE_VECT (ddr));
+ fprintf (file, ")\n");
+ }
+ }
+ fprintf (file, "\n\n");
+}
+
+/* Dumps the data dependence relations DDRS in FILE. */
+
+void
+dump_ddrs (FILE *file, varray_type ddrs)
+{
+ unsigned int i;
+
+ for (i = 0; i < VARRAY_ACTIVE_SIZE (ddrs); i++)
+ {
+ struct data_dependence_relation *ddr =
+ (struct data_dependence_relation *)
+ VARRAY_GENERIC_PTR (ddrs, i);
+ dump_data_dependence_relation (file, ddr);
+ }
+ fprintf (file, "\n\n");
+}
+
\f
+/* Estimate the number of iterations from the size of the data and the
+ access functions. */
+
+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;
+
+ data_size = fold_build2 (EXACT_DIV_EXPR, integer_type_node,
+ array_size, element_size);
+
+ if (init != NULL_TREE
+ && step != NULL_TREE
+ && TREE_CODE (init) == INTEGER_CST
+ && TREE_CODE (step) == INTEGER_CST)
+ {
+ tree i_plus_s = fold_build2 (PLUS_EXPR, integer_type_node, init, step);
+ tree sign = fold_build2 (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]". The function returns the base name:
- "A". */
+ 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". */
static tree
analyze_array_indexes (struct loop *loop,
- varray_type *access_fns,
- tree ref)
+ VEC(tree,heap) **access_fns,
+ tree ref, tree stmt,
+ bool estimate_only)
{
tree opnd0, opnd1;
tree access_fn;
the optimizers. */
access_fn = instantiate_parameters
(loop, analyze_scalar_evolution (loop, opnd1));
-
- VARRAY_PUSH_TREE (*access_fns, access_fn);
+
+ 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);
+ return analyze_array_indexes (loop, access_fns, opnd0, stmt, estimate_only);
/* Return the base name of the data access. */
else
return opnd0;
}
+/* For an array reference REF contained in STMT, attempt to bound the
+ number of iterations in the loop containing STMT */
+
+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
analyze_array (tree stmt, tree ref, bool is_read)
{
struct data_reference *res;
+ VEC(tree,heap) *acc_fns;
if (dump_file && (dump_flags & TDF_DETAILS))
{
DR_STMT (res) = stmt;
DR_REF (res) = ref;
- VARRAY_TREE_INIT (DR_ACCESS_FNS (res), 3, "access_fns");
- DR_BASE_NAME (res) = analyze_array_indexes
- (loop_containing_stmt (stmt), &(DR_ACCESS_FNS (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;
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, ")\n");
return res;
}
+
+/* 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. */
+
+static struct data_reference *
+analyze_indirect_ref (tree stmt, tree ref, bool is_read)
+{
+ 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;
+
+ if (TREE_CODE (ptr_ref) == SSA_NAME)
+ ptr_info = SSA_NAME_PTR_INFO (ptr_ref);
+
+ STRIP_NOPS (init);
+ if (access_fn == chrec_dont_know || !init || init == chrec_dont_know)
+ {
+ 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;
+ }
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "\nAccess function of ptr: ");
+ print_generic_expr (dump_file, access_fn, TDF_SLIM);
+ fprintf (dump_file, "\n");
+ }
+
+ if (!expr_invariant_in_loop_p (loop, init))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "\ninitial condition is not loop invariant.\n");
+ }
+ 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 (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");
+ }
+ }
+ else
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "\nunknown evolution of ptr.\n");
+ }
+ 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);
+}
+
/* For a data reference REF contained in the statement STMT, initialize
a DATA_REFERENCE structure, and return it. */
tree ref,
tree base,
tree access_fn,
- bool is_read)
+ 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;
if (dump_file && (dump_flags & TDF_DETAILS))
{
DR_STMT (res) = stmt;
DR_REF (res) = ref;
- VARRAY_TREE_INIT (DR_ACCESS_FNS (res), 5, "access_fns");
- DR_BASE_NAME (res) = base;
- VARRAY_PUSH_TREE (DR_ACCESS_FNS (res), access_fn);
+ 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;
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, ")\n");
\f
-/* When there exists a dependence relation, determine its distance
- vector. */
+/* Function strip_conversions
-static void
-compute_distance_vector (struct data_dependence_relation *ddr)
+ Strip conversions that don't narrow the mode. */
+
+static tree
+strip_conversion (tree expr)
{
- if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE)
+ tree to, ti, oprnd0;
+
+ while (TREE_CODE (expr) == NOP_EXPR || TREE_CODE (expr) == CONVERT_EXPR)
{
- unsigned int i;
+ 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;
- 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);
- 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;
- }
+ expr = oprnd0;
}
+ return expr;
}
+\f
-/* Initialize a ddr. */
+/* Function analyze_offset_expr
-struct data_dependence_relation *
-initialize_data_dependence_relation (struct data_reference *a,
- struct data_reference *b)
-{
- struct data_dependence_relation *res;
- bool differ_p;
-
- res = xmalloc (sizeof (struct data_dependence_relation));
- DDR_A (res) = a;
- DDR_B (res) = b;
+ 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.
+
+*/
+
+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;
+
+ *step = NULL_TREE;
+ *misalign = NULL_TREE;
+ *aligned_to = NULL_TREE;
+ *initial_offset = NULL_TREE;
+
+ /* Strip conversions that don't narrow the mode. */
+ expr = strip_conversion (expr);
+ if (!expr)
+ return false;
+
+ /* Stop conditions:
+ 1. Constant. */
+ if (TREE_CODE (expr) == INTEGER_CST)
+ {
+ *initial_offset = fold_convert (ssizetype, expr);
+ *misalign = fold_convert (ssizetype, expr);
+ *step = ssize_int (0);
+ return true;
+ }
+
+ /* 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);
+
+ if (access_fn == chrec_dont_know)
+ /* No access_fn. */
+ return false;
+
+ 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;
+
+ evolution = evolution_part_in_loop_num (access_fn, loop->num);
+ if (evolution && TREE_CODE (evolution) != INTEGER_CST)
+ /* Evolution is not constant. */
+ return false;
+
+ if (TREE_CODE (init) == INTEGER_CST)
+ *misalign = fold_convert (ssizetype, init);
+ else
+ /* Not constant, misalignment cannot be calculated. */
+ *misalign = NULL_TREE;
+
+ *initial_offset = fold_convert (ssizetype, init);
+
+ *step = evolution ? fold_convert (ssizetype, evolution) : ssize_int (0);
+ return true;
+ }
+
+ /* 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);
+
+ 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;
+
+ /* 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;
+
+ /* 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;
+ }
+
+ /* 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);
+
+ /* Unknown alignment. */
+ if ((!left_misalign && !left_aligned_to)
+ || (!right_misalign && !right_aligned_to))
+ {
+ *misalign = NULL_TREE;
+ *aligned_to = NULL_TREE;
+ break;
+ }
+
+ if (left_misalign && right_misalign)
+ *misalign = size_binop (code, left_misalign, right_misalign);
+ else
+ *misalign = left_misalign ? 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;
+
+ break;
+
+ default:
+ gcc_unreachable ();
+ }
+
+ /* Compute offset. */
+ *initial_offset = fold_convert (ssizetype,
+ fold_build2 (code, TREE_TYPE (left_offset),
+ left_offset,
+ right_offset));
+ return true;
+}
+
+/* Function address_analysis
+
+ 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
+
+ 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.
+ */
+
+static tree
+address_analysis (tree expr, tree stmt, bool is_read, struct data_reference *dr,
+ tree *offset, tree *misalign, tree *aligned_to, tree *step)
+{
+ 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;
+
+ 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;
+ }
+
+ /* 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;
+ }
+
+ /* 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;
+
+ 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;
+
+ 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;
+ }
+}
+
+
+/* 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;
+
+ *ptr_info = NULL;
+
+ /* Part 1: */
+ /* Case 1. handled_component_p refs. */
+ if (handled_component_p (memref))
+ {
+ /* 1.1 build data-reference structure for MEMREF. */
+ /* TODO: handle COMPONENT_REFs. */
+ if (!(*dr))
+ {
+ if (TREE_CODE (memref) == ARRAY_REF)
+ *dr = analyze_array (stmt, memref, is_read);
+ else
+ {
+ /* FORNOW. */
+ 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 (a == NULL || b == NULL
- || DR_BASE_NAME (a) == NULL_TREE
- || DR_BASE_NAME (b) == NULL_TREE)
- DDR_ARE_DEPENDENT (res) = chrec_dont_know;
+ /* 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;
+ }
- /* When the dimensions of A and B differ, we directly initialize
- the relation to "there is no dependence": chrec_known. */
- else if (DR_NUM_DIMENSIONS (a) != DR_NUM_DIMENSIONS (b)
- || (array_base_name_differ_p (a, b, &differ_p) && differ_p))
- DDR_ARE_DEPENDENT (res) = chrec_known;
+ /* 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;
+ }
+
+ /* Add bit position to OFFSET and MISALIGN. */
+
+ 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. */
+ if (!(*dr))
+ {
+ 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;
+ }
+
+ /* 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;
+ }
+
+ /* Part 1: Case 3. INDIRECT_REFs. */
+ else if (TREE_CODE (memref) == INDIRECT_REF)
+ {
+ tree ptr_ref = TREE_OPERAND (memref, 0);
+ if (TREE_CODE (ptr_ref) == SSA_NAME)
+ *ptr_info = SSA_NAME_PTR_INFO (ptr_ref);
+
+ /* 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;
+ }
+
+ /* 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;
+ }
+
+ 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))
+ {
+ fprintf (dump_file, "\nfailed to analyze address ");
+ print_generic_expr (dump_file, ptr_init, TDF_SLIM);
+ fprintf (dump_file, "\n");
+ }
+ return NULL_TREE;
+ }
+
+ /* 3.5 extract memory tag. */
+ switch (TREE_CODE (base_address))
+ {
+ case SSA_NAME:
+ *memtag = get_var_ann (SSA_NAME_VAR (base_address))->type_mem_tag;
+ if (!(*memtag) && TREE_CODE (TREE_OPERAND (memref, 0)) == SSA_NAME)
+ *memtag = get_var_ann (
+ SSA_NAME_VAR (TREE_OPERAND (memref, 0)))->type_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 (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);
+
+ 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);
+
+ return base_address;
+}
+
+/* Function analyze_offset.
+
+ Extract INVARIANT and CONSTANT parts from OFFSET.
+
+*/
+static void
+analyze_offset (tree offset, tree *invariant, tree *constant)
+{
+ tree op0, op1, constant_0, constant_1, invariant_0, invariant_1;
+ enum tree_code code = TREE_CODE (offset);
+
+ *invariant = NULL_TREE;
+ *constant = NULL_TREE;
+
+ /* Not PLUS/MINUS expression - recursion stop condition. */
+ if (code != PLUS_EXPR && code != MINUS_EXPR)
+ {
+ if (TREE_CODE (offset) == INTEGER_CST)
+ *constant = offset;
+ else
+ *invariant = offset;
+ return;
+ }
+
+ 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);
+
+ /* 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;
+}
+
+
+/* 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
+
+ Output:
+ DR (returned value) - data_reference struct for MEMREF
+*/
+
+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;
+
+ if (!memref)
+ return NULL;
+
+ base_address = object_analysis (memref, stmt, is_read, &dr, &offset,
+ &misalign, &aligned_to, &step, &memtag,
+ &ptr_info, &subvars);
+ if (!dr || !base_address)
+ {
+ 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;
+ }
+
+ 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))));
+
+ /* 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 access_fn;
+ tree new_step;
+
+ /* Extract CONSTANT and INVARIANT from OFFSET, and put them in DR_INIT and
+ DR_OFFSET fields of DR. */
+ analyze_offset (offset, &invariant, &constant);
+ if (constant)
+ {
+ DR_INIT (dr) = fold_convert (ssizetype, constant);
+ init_cond = fold_build2 (TRUNC_DIV_EXPR, TREE_TYPE (constant),
+ constant, type_size);
+ }
+ else
+ DR_INIT (dr) = init_cond = ssize_int (0);;
+
+ if (invariant)
+ DR_OFFSET (dr) = invariant;
+ else
+ DR_OFFSET (dr) = ssize_int (0);
+
+ /* Update access function. */
+ access_fn = DR_ACCESS_FN (dr, 0);
+ new_step = size_binop (TRUNC_DIV_EXPR,
+ fold_convert (ssizetype, step), type_size);
+
+ access_fn = chrec_replace_initial_condition (access_fn, init_cond);
+ access_fn = reset_evolution_in_loop (loop->num, access_fn, new_step);
+
+ VEC_replace (tree, DR_ACCESS_FNS (dr), 0, access_fn);
+ }
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ struct ptr_info_def *pi = DR_PTR_INFO (dr);
+
+ 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;
+}
+
+
+/* Returns true when all the functions of a tree_vec CHREC are the
+ same. */
+
+static bool
+all_chrecs_equal_p (tree chrec)
+{
+ int j;
+
+ for (j = 0; j < TREE_VEC_LENGTH (chrec) - 1; j++)
+ {
+ tree chrec_j = TREE_VEC_ELT (chrec, j);
+ tree chrec_j_1 = TREE_VEC_ELT (chrec, j + 1);
+ if (!integer_zerop
+ (chrec_fold_minus
+ (integer_type_node, chrec_j, chrec_j_1)))
+ return false;
+ }
+ return true;
+}
+
+/* Determine for each subscript in the data dependence relation DDR
+ the distance. */
+
+void
+compute_subscript_distance (struct data_dependence_relation *ddr)
+{
+ if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE)
{
unsigned int i;
- DDR_ARE_DEPENDENT (res) = NULL_TREE;
- DDR_SUBSCRIPTS_VECTOR_INIT (res, DR_NUM_DIMENSIONS (a));
- for (i = 0; i < DR_NUM_DIMENSIONS (a); i++)
- {
- struct subscript *subscript;
+ 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 (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);
+ }
+
+ 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);
+ }
+
+ 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;
+ }
+ }
+}
+
+/* Initialize a ddr. */
+
+struct data_dependence_relation *
+initialize_data_dependence_relation (struct data_reference *a,
+ struct data_reference *b)
+{
+ struct data_dependence_relation *res;
+ bool differ_p;
+ unsigned int i;
+
+ res = xmalloc (sizeof (struct data_dependence_relation));
+ DDR_A (res) = a;
+ DDR_B (res) = b;
+
+ if (a == NULL || b == NULL)
+ {
+ 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))
+ {
+ DDR_ARE_DEPENDENT (res) = chrec_known;
+ return res;
+ }
+
+ /* Compare the bases of the data-refs. */
+ if (!base_addr_differ_p (a, b, &differ_p))
+ {
+ /* Can't determine whether the data-refs access the same memory
+ region. */
+ DDR_ARE_DEPENDENT (res) = chrec_dont_know;
+ return res;
+ }
+ if (differ_p)
+ {
+ DDR_ARE_DEPENDENT (res) = chrec_known;
+ return res;
+ }
+
+ DDR_AFFINE_P (res) = true;
+ DDR_ARE_DEPENDENT (res) = NULL_TREE;
+ DDR_SUBSCRIPTS_VECTOR_INIT (res, DR_NUM_DIMENSIONS (a));
+ DDR_SIZE_VECT (res) = 0;
+ DDR_DIST_VECT (res) = NULL;
+ DDR_DIR_VECT (res) = NULL;
+
+ for (i = 0; i < DR_NUM_DIMENSIONS (a); i++)
+ {
+ struct subscript *subscript;
- subscript = xmalloc (sizeof (struct subscript));
- SUB_CONFLICTS_IN_A (subscript) = chrec_dont_know;
- SUB_CONFLICTS_IN_B (subscript) = chrec_dont_know;
- SUB_LAST_CONFLICT_IN_A (subscript) = chrec_dont_know;
- SUB_LAST_CONFLICT_IN_B (subscript) = chrec_dont_know;
- SUB_DISTANCE (subscript) = chrec_dont_know;
- VARRAY_PUSH_GENERIC_PTR (DDR_SUBSCRIPTS (res), subscript);
- }
+ subscript = xmalloc (sizeof (struct subscript));
+ SUB_CONFLICTS_IN_A (subscript) = chrec_dont_know;
+ SUB_CONFLICTS_IN_B (subscript) = chrec_dont_know;
+ SUB_LAST_CONFLICT (subscript) = chrec_dont_know;
+ SUB_DISTANCE (subscript) = chrec_dont_know;
+ VARRAY_PUSH_GENERIC_PTR (DDR_SUBSCRIPTS (res), subscript);
}
return res;
varray_clear (DDR_SUBSCRIPTS (ddr));
}
+/* The dependence relation DDR cannot be represented by a distance
+ vector. */
+
+static inline void
+non_affine_dependence_relation (struct data_dependence_relation *ddr)
+{
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "(Dependence relation cannot be represented by distance vector.) \n");
+
+ DDR_AFFINE_P (ddr) = false;
+}
+
\f
/* This section contains the classic Banerjee tests. */
analyze_ziv_subscript (tree chrec_a,
tree chrec_b,
tree *overlaps_a,
- tree *overlaps_b)
+ tree *overlaps_b,
+ tree *last_conflicts)
{
tree difference;
overlaps for each iteration in the loop. */
*overlaps_a = integer_zero_node;
*overlaps_b = integer_zero_node;
+ *last_conflicts = chrec_dont_know;
}
else
{
/* The accesses do not overlap. */
*overlaps_a = chrec_known;
- *overlaps_b = chrec_known;
+ *overlaps_b = chrec_known;
+ *last_conflicts = integer_zero_node;
}
break;
/* We're not sure whether the indexes overlap. For the moment,
conservatively answer "don't know". */
*overlaps_a = chrec_dont_know;
- *overlaps_b = chrec_dont_know;
+ *overlaps_b = chrec_dont_know;
+ *last_conflicts = chrec_dont_know;
break;
}
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. */
+
+static tree
+get_number_of_iters_for_loop (int loopnum)
+{
+ tree numiter = number_of_iterations_in_loop (current_loops->parray[loopnum]);
+
+ 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
analyze_siv_subscript_cst_affine (tree chrec_a,
tree chrec_b,
tree *overlaps_a,
- tree *overlaps_b)
+ tree *overlaps_b,
+ tree *last_conflicts)
{
bool value0, value1, value2;
tree difference = chrec_fold_minus
{
*overlaps_a = chrec_dont_know;
*overlaps_b = chrec_dont_know;
+ *last_conflicts = chrec_dont_know;
return;
}
else
{
*overlaps_a = chrec_dont_know;
*overlaps_b = chrec_dont_know;
+ *last_conflicts = chrec_dont_know;
return;
}
else
chrec_b = {10, +, 1}
*/
- if (tree_fold_divides_p
- (integer_type_node, CHREC_RIGHT (chrec_b), difference))
+ 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
- (build (EXACT_DIV_EXPR, integer_type_node,
- fold (build1 (ABS_EXPR, integer_type_node, difference)),
- CHREC_RIGHT (chrec_b)));
+ *overlaps_b = fold_build2 (EXACT_DIV_EXPR, integer_type_node,
+ fold_build1 (ABS_EXPR,
+ integer_type_node,
+ difference),
+ CHREC_RIGHT (chrec_b));
+ *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);
+
+ if (numiter != NULL_TREE
+ && TREE_CODE (*overlaps_b) == INTEGER_CST
+ && tree_int_cst_lt (numiter, *overlaps_b))
+ {
+ *overlaps_a = chrec_known;
+ *overlaps_b = chrec_known;
+ *last_conflicts = integer_zero_node;
+ return;
+ }
return;
}
- /* When the step does not divides the difference, there are
+ /* When the step does not divide the difference, there are
no overlaps. */
else
{
*overlaps_a = chrec_known;
*overlaps_b = chrec_known;
+ *last_conflicts = integer_zero_node;
return;
}
}
In this case, chrec_a will not overlap with chrec_b. */
*overlaps_a = chrec_known;
*overlaps_b = chrec_known;
+ *last_conflicts = integer_zero_node;
return;
}
}
{
*overlaps_a = chrec_dont_know;
*overlaps_b = chrec_dont_know;
+ *last_conflicts = chrec_dont_know;
return;
}
else
chrec_a = 3
chrec_b = {10, +, -1}
*/
- if (tree_fold_divides_p
- (integer_type_node, CHREC_RIGHT (chrec_b), difference))
+ 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
- (build (EXACT_DIV_EXPR, integer_type_node, difference,
- CHREC_RIGHT (chrec_b)));
+ *overlaps_b = fold_build2 (EXACT_DIV_EXPR,
+ integer_type_node, difference,
+ CHREC_RIGHT (chrec_b));
+ *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);
+
+ if (numiter != NULL_TREE
+ && TREE_CODE (*overlaps_b) == INTEGER_CST
+ && tree_int_cst_lt (numiter, *overlaps_b))
+ {
+ *overlaps_a = chrec_known;
+ *overlaps_b = chrec_known;
+ *last_conflicts = integer_zero_node;
+ return;
+ }
return;
}
- /* When the step does not divides the difference, there
+ /* When the step does not divide the difference, there
are no overlaps. */
else
{
*overlaps_a = chrec_known;
*overlaps_b = chrec_known;
+ *last_conflicts = integer_zero_node;
return;
}
}
In this case, chrec_a will not overlap with chrec_b. */
*overlaps_a = chrec_known;
*overlaps_b = chrec_known;
+ *last_conflicts = integer_zero_node;
return;
}
}
}
}
-}
-
-/* Analyze a SIV (Single Index Variable) subscript where CHREC_A is an
- affine function, and CHREC_B is a constant. *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_affine_cst (tree chrec_a,
- tree chrec_b,
- tree *overlaps_a,
- tree *overlaps_b)
-{
- analyze_siv_subscript_cst_affine (chrec_b, chrec_a, overlaps_b, overlaps_a);
+}
+
+/* Helper recursive function for initializing the matrix A. Returns
+ the initial value of CHREC. */
+
+static int
+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);
+
+ A[index][0] = mult * int_cst_value (CHREC_RIGHT (chrec));
+ return initialize_matrix_A (A, CHREC_LEFT (chrec), index + 1, mult);
+}
+
+#define FLOOR_DIV(x,y) ((x) / (y))
+
+/* 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
+ number of iterations that loops X and Y run. The overlaps will be
+ 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,
+ tree *last_conflicts, int dim)
+{
+ if (((step_a > 0 && step_b > 0)
+ || (step_a < 0 && step_b < 0)))
+ {
+ int step_overlaps_a, step_overlaps_b;
+ int gcd_steps_a_b, last_conflict, tau2;
+
+ gcd_steps_a_b = gcd (step_a, step_b);
+ step_overlaps_a = step_b / gcd_steps_a_b;
+ step_overlaps_b = step_a / gcd_steps_a_b;
+
+ tau2 = FLOOR_DIV (niter, step_overlaps_a);
+ tau2 = MIN (tau2, FLOOR_DIV (niter, step_overlaps_b));
+ last_conflict = tau2;
+
+ *overlaps_a = build_polynomial_chrec
+ (dim, integer_zero_node,
+ build_int_cst (NULL_TREE, step_overlaps_a));
+ *overlaps_b = build_polynomial_chrec
+ (dim, integer_zero_node,
+ build_int_cst (NULL_TREE, step_overlaps_b));
+ *last_conflicts = build_int_cst (NULL_TREE, last_conflict);
+ }
+
+ else
+ {
+ *overlaps_a = integer_zero_node;
+ *overlaps_b = 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,
+
+ | {{0, +, 1}_x, +, 1335}_y = {0, +, 1336}_z
+
+ has the following overlapping functions:
+
+ | x (t, u, v) = {{0, +, 1336}_t, +, 1}_v
+ | y (t, u, v) = {{0, +, 1336}_u, +, 1}_v
+ | z (t, u, v) = {{{0, +, 1}_t, +, 1335}_u, +, 1}_v
+
+ FORNOW: This is a specialized implementation for a case occurring in
+ 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,
+ 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;
+
+ 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)
+ {
+ *overlaps_a = chrec_dont_know;
+ *overlaps_b = chrec_dont_know;
+ *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,
+ &overlaps_b_xz,
+ &last_conflicts_xz, 1);
+ niter = MIN (niter_y, niter_z);
+ compute_overlap_steps_for_affine_univar (niter, step_y, step_z,
+ &overlaps_a_yz,
+ &overlaps_b_yz,
+ &last_conflicts_yz, 2);
+ niter = MIN (niter_x, niter_z);
+ niter = MIN (niter_y, niter);
+ compute_overlap_steps_for_affine_univar (niter, step_x + step_y, step_z,
+ &overlaps_a_xyz,
+ &overlaps_b_xyz,
+ &last_conflicts_xyz, 3);
+
+ xz_p = !integer_zerop (last_conflicts_xz);
+ yz_p = !integer_zerop (last_conflicts_yz);
+ xyz_p = !integer_zerop (last_conflicts_xyz);
+
+ 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;
+ if (xz_p)
+ {
+ TREE_VEC_ELT (*overlaps_a, 0) =
+ chrec_fold_plus (integer_type_node, TREE_VEC_ELT (*overlaps_a, 0),
+ overlaps_a_xz);
+ *overlaps_b =
+ chrec_fold_plus (integer_type_node, *overlaps_b, overlaps_b_xz);
+ *last_conflicts = last_conflicts_xz;
+ }
+ if (yz_p)
+ {
+ TREE_VEC_ELT (*overlaps_a, 1) =
+ chrec_fold_plus (integer_type_node, TREE_VEC_ELT (*overlaps_a, 1),
+ overlaps_a_yz);
+ *overlaps_b =
+ chrec_fold_plus (integer_type_node, *overlaps_b, overlaps_b_yz);
+ *last_conflicts = last_conflicts_yz;
+ }
+ if (xyz_p)
+ {
+ TREE_VEC_ELT (*overlaps_a, 0) =
+ chrec_fold_plus (integer_type_node, TREE_VEC_ELT (*overlaps_a, 0),
+ overlaps_a_xyz);
+ TREE_VEC_ELT (*overlaps_a, 1) =
+ chrec_fold_plus (integer_type_node, TREE_VEC_ELT (*overlaps_a, 1),
+ overlaps_a_xyz);
+ *overlaps_b =
+ chrec_fold_plus (integer_type_node, *overlaps_b, overlaps_b_xyz);
+ *last_conflicts = last_conflicts_xyz;
+ }
+ }
+ else
+ {
+ *overlaps_a = integer_zero_node;
+ *overlaps_b = integer_zero_node;
+ *last_conflicts = integer_zero_node;
+ }
}
/* Determines the overlapping elements due to accesses CHREC_A and
analyze_subscript_affine_affine (tree chrec_a,
tree chrec_b,
tree *overlaps_a,
- tree *overlaps_b)
+ tree *overlaps_b,
+ tree *last_conflicts)
{
- tree left_a, left_b, right_a, right_b;
-
+ unsigned nb_vars_a, nb_vars_b, dim;
+ int init_a, init_b, gamma, gcd_alpha_beta;
+ int tau1, tau2;
+ lambda_matrix A, U, S;
+ tree difference = chrec_fold_minus (integer_type_node, chrec_a, chrec_b);
+
+ if (integer_zerop (difference))
+ {
+ /* 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;
+ *last_conflicts = chrec_dont_know;
+ return;
+ }
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "(analyze_subscript_affine_affine \n");
there is no dependence. This function outputs a description of
the iterations that hold the intersections. */
- left_a = CHREC_LEFT (chrec_a);
- left_b = CHREC_LEFT (chrec_b);
- right_a = CHREC_RIGHT (chrec_a);
- right_b = CHREC_RIGHT (chrec_b);
- if (chrec_zerop (chrec_fold_minus (integer_type_node, left_a, left_b)))
+ nb_vars_a = nb_vars_in_chrec (chrec_a);
+ nb_vars_b = nb_vars_in_chrec (chrec_b);
+
+ dim = nb_vars_a + nb_vars_b;
+ U = lambda_matrix_new (dim, dim);
+ A = lambda_matrix_new (dim, 1);
+ S = lambda_matrix_new (dim, 1);
+
+ init_a = initialize_matrix_A (A, chrec_a, 0, 1);
+ init_b = 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,
+ | {3, +, 1}_1
+ | {3, +, 4}_2
+ | gamma = 3 - 3 = 0.
+ Then the first overlap occurs during the first iterations:
+ | {3, +, 1}_1 ({0, +, 4}_x) = {3, +, 4}_2 ({0, +, 1}_x)
+ */
+ if (gamma == 0)
{
- /* The first element accessed twice is on the first
- iteration. */
- *overlaps_a = build_polynomial_chrec
- (CHREC_VARIABLE (chrec_b), integer_zero_node, integer_one_node);
- *overlaps_b = build_polynomial_chrec
- (CHREC_VARIABLE (chrec_a), integer_zero_node, integer_one_node);
- }
-
- else if (TREE_CODE (left_a) == INTEGER_CST
- && TREE_CODE (left_b) == INTEGER_CST
- && TREE_CODE (right_a) == INTEGER_CST
- && TREE_CODE (right_b) == INTEGER_CST
-
- /* Both functions should have the same evolution sign. */
- && ((tree_int_cst_sgn (right_a) > 0
- && tree_int_cst_sgn (right_b) > 0)
- || (tree_int_cst_sgn (right_a) < 0
- && tree_int_cst_sgn (right_b) < 0)))
- {
- /* Here we have to solve the Diophantine equation. Reference
- book: "Loop Transformations for Restructuring Compilers - The
- Foundations" by Utpal Banerjee, pages 59-80.
-
- ALPHA * X0 = BETA * Y0 + GAMMA.
-
- with:
- ALPHA = RIGHT_A
- BETA = RIGHT_B
- GAMMA = LEFT_B - LEFT_A
- CHREC_A = {LEFT_A, +, RIGHT_A}
- CHREC_B = {LEFT_B, +, RIGHT_B}
-
- The Diophantine equation has a solution if and only if gcd
- (ALPHA, BETA) divides GAMMA. This is commonly known under
- the name of the "gcd-test".
- */
- tree alpha, beta, gamma;
- tree la, lb;
- tree gcd_alpha_beta;
- tree u11, u12, u21, u22;
-
- /* Both alpha and beta have to be integer_type_node. The gcd
- function does not work correctly otherwise. */
- alpha = copy_node (right_a);
- beta = copy_node (right_b);
- la = copy_node (left_a);
- lb = copy_node (left_b);
- TREE_TYPE (alpha) = integer_type_node;
- TREE_TYPE (beta) = integer_type_node;
- TREE_TYPE (la) = integer_type_node;
- TREE_TYPE (lb) = integer_type_node;
-
- gamma = fold (build (MINUS_EXPR, integer_type_node, lb, la));
-
- /* FIXME: Use lambda_*_Hermite for implementing Bezout. */
- gcd_alpha_beta = tree_fold_bezout
- (alpha,
- fold (build (MULT_EXPR, integer_type_node, beta,
- integer_minus_one_node)),
- &u11, &u12,
- &u21, &u22);
-
- if (dump_file && (dump_flags & TDF_DETAILS))
+ if (nb_vars_a == 1 && nb_vars_b == 1)
{
- fprintf (dump_file, " (alpha = ");
- print_generic_expr (dump_file, alpha, 0);
- fprintf (dump_file, ")\n (beta = ");
- print_generic_expr (dump_file, beta, 0);
- fprintf (dump_file, ")\n (gamma = ");
- print_generic_expr (dump_file, gamma, 0);
- fprintf (dump_file, ")\n (gcd_alpha_beta = ");
- print_generic_expr (dump_file, gcd_alpha_beta, 0);
- fprintf (dump_file, ")\n");
+ 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)
+ {
+ *overlaps_a = chrec_dont_know;
+ *overlaps_b = chrec_dont_know;
+ *last_conflicts = chrec_dont_know;
+ return;
+ }
+
+ niter_a = int_cst_value (numiter_a);
+ niter_b = int_cst_value (numiter_b);
+ 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,
+ last_conflicts, 1);
}
-
- /* The classic "gcd-test". */
- if (!tree_fold_divides_p (integer_type_node, gcd_alpha_beta, gamma))
+
+ else if (nb_vars_a == 2 && nb_vars_b == 1)
+ compute_overlap_steps_for_affine_1_2
+ (chrec_a, chrec_b, overlaps_a, overlaps_b, last_conflicts);
+
+ else if (nb_vars_a == 1 && nb_vars_b == 2)
+ compute_overlap_steps_for_affine_1_2
+ (chrec_b, chrec_a, overlaps_b, overlaps_a, last_conflicts);
+
+ else
{
- /* 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 = chrec_dont_know;
+ *overlaps_b = chrec_dont_know;
+ *last_conflicts = chrec_dont_know;
}
-
- else
+ return;
+ }
+
+ /* U.A = S */
+ lambda_matrix_right_hermite (A, dim, 1, S, U);
+
+ if (S[0][0] < 0)
+ {
+ S[0][0] *= -1;
+ lambda_matrix_row_negate (U, dim, 0);
+ }
+ gcd_alpha_beta = S[0][0];
+
+ /* The classic "gcd-test". */
+ if (!int_divides_p (gcd_alpha_beta, gamma))
+ {
+ /* 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;
+ *last_conflicts = integer_zero_node;
+ }
+
+ /* Both access functions are univariate. This includes SIV and MIV cases. */
+ else if (nb_vars_a == 1 && nb_vars_b == 1)
+ {
+ /* Both functions should have the same evolution sign. */
+ if (((A[0][0] > 0 && -A[1][0] > 0)
+ || (A[0][0] < 0 && -A[1][0] < 0)))
{
/* The solutions are given by:
|
- | [GAMMA/GCD_ALPHA_BETA t].[u11 u12] = [X]
- | [u21 u22] [Y]
-
+ | [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:
-
- | x = i0 + i1 * t,
- | y = j0 + j1 * t. */
-
- tree i0, j0, i1, j1, t;
- tree gamma_gcd;
-
+
+ | 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). */
- tree x0, y0;
-
- /* Exact div because in this case gcd_alpha_beta divides
- gamma. */
- gamma_gcd = fold (build (EXACT_DIV_EXPR, integer_type_node, gamma,
- gcd_alpha_beta));
- i0 = fold (build (MULT_EXPR, integer_type_node, u11, gamma_gcd));
- j0 = fold (build (MULT_EXPR, integer_type_node, u12, gamma_gcd));
- i1 = u21;
- j1 = u22;
-
- if ((tree_int_cst_sgn (i1) == 0
- && tree_int_cst_sgn (i0) < 0)
- || (tree_int_cst_sgn (j1) == 0
- && tree_int_cst_sgn (j0) < 0))
+ 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)
+ {
+ *overlaps_a = chrec_dont_know;
+ *overlaps_b = chrec_dont_know;
+ *last_conflicts = chrec_dont_know;
+ return;
+ }
+
+ niter_a = int_cst_value (numiter_a);
+ niter_b = int_cst_value (numiter_b);
+ niter = MIN (niter_a, niter_b);
+
+ i0 = U[0][0] * gamma / gcd_alpha_beta;
+ j0 = U[0][1] * gamma / gcd_alpha_beta;
+ i1 = U[1][0];
+ j1 = U[1][1];
+
+ if ((i1 == 0 && i0 < 0)
+ || (j1 == 0 && j0 < 0))
{
/* There is no solution.
FIXME: The case "i0 > nb_iterations, j0 > nb_iterations"
upper bound of the iteration domain. */
*overlaps_a = chrec_known;
*overlaps_b = chrec_known;
- }
-
+ *last_conflicts = integer_zero_node;
+ }
+
else
{
- if (tree_int_cst_sgn (i1) > 0)
+ if (i1 > 0)
{
- t = fold
- (build (CEIL_DIV_EXPR, integer_type_node,
- fold (build (MULT_EXPR, integer_type_node, i0,
- integer_minus_one_node)),
- i1));
-
- if (tree_int_cst_sgn (j1) > 0)
+ tau1 = CEIL (-i0, i1);
+ tau2 = FLOOR_DIV (niter - i0, i1);
+
+ if (j1 > 0)
{
- t = fold
- (build (MAX_EXPR, integer_type_node, t,
- fold (build (CEIL_DIV_EXPR, integer_type_node,
- fold (build
- (MULT_EXPR,
- integer_type_node, j0,
- integer_minus_one_node)),
- j1))));
-
- x0 = fold
- (build (PLUS_EXPR, integer_type_node, i0,
- fold (build
- (MULT_EXPR, integer_type_node, i1, t))));
- y0 = fold
- (build (PLUS_EXPR, integer_type_node, j0,
- fold (build
- (MULT_EXPR, integer_type_node, j1, t))));
-
- *overlaps_a = build_polynomial_chrec
- (CHREC_VARIABLE (chrec_b), x0, u21);
- *overlaps_b = build_polynomial_chrec
- (CHREC_VARIABLE (chrec_a), y0, u22);
+ 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);
+ }
}
else
{
/* FIXME: For the moment, the upper bound of the
- iteration domain for j is not checked. */
+ iteration domain for j is not checked. */
*overlaps_a = chrec_dont_know;
*overlaps_b = chrec_dont_know;
+ *last_conflicts = chrec_dont_know;
}
}
-
+
else
{
/* FIXME: For the moment, the upper bound of the
- iteration domain for i is not checked. */
+ iteration domain for i is not checked. */
*overlaps_a = chrec_dont_know;
*overlaps_b = chrec_dont_know;
+ *last_conflicts = chrec_dont_know;
}
}
}
+ else
+ {
+ *overlaps_a = chrec_dont_know;
+ *overlaps_b = chrec_dont_know;
+ *last_conflicts = chrec_dont_know;
+ }
}
-
+
else
{
- /* For the moment, "don't know". */
*overlaps_a = chrec_dont_know;
*overlaps_b = chrec_dont_know;
+ *last_conflicts = chrec_dont_know;
}
-
+
+
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, " (overlaps_a = ");
analyze_siv_subscript (tree chrec_a,
tree chrec_b,
tree *overlaps_a,
- tree *overlaps_b)
+ tree *overlaps_b,
+ tree *last_conflicts)
{
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,
- overlaps_a, overlaps_b);
+ overlaps_a, overlaps_b, last_conflicts);
else if (evolution_function_is_affine_p (chrec_a)
&& evolution_function_is_constant_p (chrec_b))
- analyze_siv_subscript_affine_cst (chrec_a, chrec_b,
- overlaps_a, overlaps_b);
+ 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)
- && (CHREC_VARIABLE (chrec_a) == CHREC_VARIABLE (chrec_b)))
+ && evolution_function_is_affine_p (chrec_b))
analyze_subscript_affine_affine (chrec_a, chrec_b,
- overlaps_a, overlaps_b);
+ overlaps_a, overlaps_b, last_conflicts);
else
{
*overlaps_a = chrec_dont_know;
*overlaps_b = chrec_dont_know;
+ *last_conflicts = chrec_dont_know;
}
if (dump_file && (dump_flags & TDF_DETAILS))
switch (TREE_CODE (chrec))
{
case POLYNOMIAL_CHREC:
- return (tree_fold_divides_p (integer_type_node, CHREC_RIGHT (chrec), cst)
+ return (tree_fold_divides_p (CHREC_RIGHT (chrec), cst)
&& chrec_steps_divide_constant_p (CHREC_LEFT (chrec), cst));
default:
analyze_miv_subscript (tree chrec_a,
tree chrec_b,
tree *overlaps_a,
- tree *overlaps_b)
+ tree *overlaps_b,
+ tree *last_conflicts)
{
/* FIXME: This is a MIV subscript, not yet handled.
Example: (A[{1, +, 1}_1] vs. A[{1, +, 1}_2]) that comes from
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));
+
}
else if (evolution_function_is_constant_p (difference)
consequently there are no overlapping elements. */
*overlaps_a = chrec_known;
*overlaps_b = chrec_known;
+ *last_conflicts = integer_zero_node;
}
- else if (evolution_function_is_univariate_p (chrec_a)
- && evolution_function_is_univariate_p (chrec_b))
+ else if (evolution_function_is_affine_multivariate_p (chrec_a)
+ && evolution_function_is_affine_multivariate_p (chrec_b))
{
/* testsuite/.../ssa-chrec-35.c
{0, +, 1}_2 vs. {0, +, 1}_3
the overlapping elements are respectively located at iterations:
- {0, +, 1}_3 and {0, +, 1}_2.
+ {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) =
+ {0, +, 1}_1 ({{0, +, 1}_x, +, 2}_y)
+
+ {{0, +, 2}_1, +, 3}_2 ({0, +, 1}_y, {0, +, 1}_x) =
+ {{0, +, 3}_1, +, 2}_2 ({0, +, 1}_x, {0, +, 1}_y)
*/
- if (evolution_function_is_affine_p (chrec_a)
- && evolution_function_is_affine_p (chrec_b))
- analyze_subscript_affine_affine (chrec_a, chrec_b,
- overlaps_a, overlaps_b);
- else
- {
- *overlaps_a = chrec_dont_know;
- *overlaps_b = chrec_dont_know;
- }
+ analyze_subscript_affine_affine (chrec_a, chrec_b,
+ overlaps_a, overlaps_b, last_conflicts);
}
else
/* When the analysis is too difficult, answer "don't know". */
*overlaps_a = chrec_dont_know;
*overlaps_b = chrec_dont_know;
+ *last_conflicts = chrec_dont_know;
}
if (dump_file && (dump_flags & TDF_DETAILS))
analyze_overlapping_iterations (tree chrec_a,
tree chrec_b,
tree *overlap_iterations_a,
- tree *overlap_iterations_b)
+ tree *overlap_iterations_b,
+ tree *last_conflicts)
{
if (dump_file && (dump_flags & TDF_DETAILS))
{
else if (ziv_subscript_p (chrec_a, chrec_b))
analyze_ziv_subscript (chrec_a, chrec_b,
- overlap_iterations_a, overlap_iterations_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);
+ overlap_iterations_a, overlap_iterations_b,
+ last_conflicts);
else
analyze_miv_subscript (chrec_a, chrec_b,
- overlap_iterations_a, overlap_iterations_b);
+ overlap_iterations_a, overlap_iterations_b,
+ last_conflicts);
if (dump_file && (dump_flags & TDF_DETAILS))
{
unsigned int i;
struct data_reference *dra = DDR_A (ddr);
struct data_reference *drb = DDR_B (ddr);
+ tree last_conflicts;
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "(subscript_dependence_tester \n");
analyze_overlapping_iterations (DR_ACCESS_FN (dra, i),
DR_ACCESS_FN (drb, i),
- &overlaps_a, &overlaps_b);
+ &overlaps_a, &overlaps_b,
+ &last_conflicts);
if (chrec_contains_undetermined (overlaps_a)
|| chrec_contains_undetermined (overlaps_b))
{
SUB_CONFLICTS_IN_A (subscript) = overlaps_a;
SUB_CONFLICTS_IN_B (subscript) = overlaps_b;
+ SUB_LAST_CONFLICT (subscript) = last_conflicts;
}
}
DDR is the data dependence relation to build a vector from.
NB_LOOPS is the total number of loops we are considering.
- FIRST_LOOP is the loop->num of the first loop. */
+ FIRST_LOOP_DEPTH is the loop->depth of the first loop in the analyzed
+ loop nest.
+ Return FALSE when fail to represent the data dependence as a distance
+ vector.
+ Return TRUE otherwise. */
-static void
+static bool
build_classic_dist_vector (struct data_dependence_relation *ddr,
- int nb_loops, unsigned int first_loop)
+ int nb_loops, int first_loop_depth)
{
unsigned i;
lambda_vector dist_v, init_v;
lambda_vector_clear (init_v, nb_loops);
if (DDR_ARE_DEPENDENT (ddr) != NULL_TREE)
- return;
+ return true;
for (i = 0; i < DDR_NUM_SUBSCRIPTS (ddr); i++)
{
+ tree access_fn_a, access_fn_b;
struct subscript *subscript = DDR_SUBSCRIPT (ddr, i);
if (chrec_contains_undetermined (SUB_DISTANCE (subscript)))
- return;
+ {
+ non_affine_dependence_relation (ddr);
+ return true;
+ }
- if (TREE_CODE (SUB_CONFLICTS_IN_A (subscript)) == POLYNOMIAL_CHREC)
+ access_fn_a = DR_ACCESS_FN (DDR_A (ddr), i);
+ access_fn_b = DR_ACCESS_FN (DDR_B (ddr), i);
+
+ if (TREE_CODE (access_fn_a) == POLYNOMIAL_CHREC
+ && TREE_CODE (access_fn_b) == POLYNOMIAL_CHREC)
{
- int dist;
- int loop_nb;
- loop_nb = CHREC_VARIABLE (SUB_CONFLICTS_IN_A (subscript));
- loop_nb -= first_loop;
+ int dist, loop_nb, loop_depth;
+ int loop_nb_a = CHREC_VARIABLE (access_fn_a);
+ int loop_nb_b = CHREC_VARIABLE (access_fn_b);
+ struct loop *loop_a = current_loops->parray[loop_nb_a];
+ struct loop *loop_b = current_loops->parray[loop_nb_b];
+
+ /* If the loop for either variable is at a lower depth than
+ the first_loop's depth, then we can't possibly have a
+ dependency at this level of the loop. */
+
+ if (loop_a->depth < first_loop_depth
+ || loop_b->depth < first_loop_depth)
+ return false;
+
+ if (loop_nb_a != loop_nb_b
+ && !flow_loop_nested_p (loop_a, loop_b)
+ && !flow_loop_nested_p (loop_b, loop_a))
+ {
+ /* Example: when there are two consecutive loops,
+
+ | loop_1
+ | A[{0, +, 1}_1]
+ | endloop_1
+ | loop_2
+ | A[{0, +, 1}_2]
+ | endloop_2
+
+ the dependence relation cannot be captured by the
+ distance abstraction. */
+ non_affine_dependence_relation (ddr);
+ return true;
+ }
+
+ /* The dependence is carried by the outermost loop. Example:
+ | loop_1
+ | A[{4, +, 1}_1]
+ | loop_2
+ | A[{5, +, 1}_2]
+ | endloop_2
+ | endloop_1
+ In this case, the dependence is carried by loop_1. */
+ loop_nb = loop_nb_a < loop_nb_b ? loop_nb_a : loop_nb_b;
+ loop_depth = current_loops->parray[loop_nb]->depth - first_loop_depth;
+
/* If the loop number is still greater than the number of
loops we've been asked to analyze, or negative,
something is borked. */
- gcc_assert (loop_nb >= 0);
- gcc_assert (loop_nb < nb_loops);
+ gcc_assert (loop_depth >= 0);
+ gcc_assert (loop_depth < nb_loops);
+ if (chrec_contains_undetermined (SUB_DISTANCE (subscript)))
+ {
+ non_affine_dependence_relation (ddr);
+ return true;
+ }
+
dist = int_cst_value (SUB_DISTANCE (subscript));
/* This is the subscript coupling test.
| ... = T[i][i]
| endloop
There is no dependence. */
- if (init_v[loop_nb] != 0
- && dist_v[loop_nb] != dist)
+ if (init_v[loop_depth] != 0
+ && dist_v[loop_depth] != dist)
{
finalize_ddr_dependent (ddr, chrec_known);
- return;
+ return true;
}
- dist_v[loop_nb] = dist;
- init_v[loop_nb] = 1;
+ dist_v[loop_depth] = dist;
+ init_v[loop_depth] = 1;
}
}
struct loop *lca, *loop_a, *loop_b;
struct data_reference *a = DDR_A (ddr);
struct data_reference *b = DDR_B (ddr);
- int lca_nb;
+ int lca_depth;
loop_a = loop_containing_stmt (DR_STMT (a));
loop_b = loop_containing_stmt (DR_STMT (b));
/* Get the common ancestor loop. */
lca = find_common_loop (loop_a, loop_b);
- lca_nb = lca->num;
- lca_nb -= first_loop;
- gcc_assert (lca_nb >= 0);
- gcc_assert (lca_nb < nb_loops);
+ lca_depth = lca->depth;
+ lca_depth -= first_loop_depth;
+ gcc_assert (lca_depth >= 0);
+ gcc_assert (lca_depth < nb_loops);
+
/* For each outer loop where init_v is not set, the accesses are
in dependence of distance 1 in the loop. */
if (lca != loop_a
&& lca != loop_b
- && init_v[lca_nb] == 0)
- dist_v[lca_nb] = 1;
+ && init_v[lca_depth] == 0)
+ dist_v[lca_depth] = 1;
lca = lca->outer;
if (lca)
{
- lca_nb = lca->num - first_loop;
+ lca_depth = lca->depth - first_loop_depth;
while (lca->depth != 0)
{
- gcc_assert (lca_nb >= 0);
- gcc_assert (lca_nb < nb_loops);
- if (init_v[lca_nb] == 0)
- dist_v[lca_nb] = 1;
+ /* If we're considering just a sub-nest, then don't record
+ any information on the outer loops. */
+ if (lca_depth < 0)
+ break;
+
+ gcc_assert (lca_depth < nb_loops);
+
+ if (init_v[lca_depth] == 0)
+ dist_v[lca_depth] = 1;
lca = lca->outer;
- lca_nb = lca->num - first_loop;
+ lca_depth = lca->depth - first_loop_depth;
}
}
}
DDR_DIST_VECT (ddr) = dist_v;
+ DDR_SIZE_VECT (ddr) = nb_loops;
+
+ /* Verify a basic constraint: classic distance vectors should always
+ be lexicographically positive. */
+ if (!lambda_vector_lexico_pos (DDR_DIST_VECT (ddr),
+ DDR_SIZE_VECT (ddr)))
+ {
+ if (DDR_SIZE_VECT (ddr) == 1)
+ /* This one is simple to fix, and can be fixed.
+ Multidimensional arrays cannot be fixed that simply. */
+ lambda_vector_negate (DDR_DIST_VECT (ddr), DDR_DIST_VECT (ddr),
+ DDR_SIZE_VECT (ddr));
+ else
+ /* This is not valid: we need the delta test for properly
+ fixing all this. */
+ return false;
+ }
+
+ return true;
}
/* Compute the classic per loop direction vector.
DDR is the data dependence relation to build a vector from.
NB_LOOPS is the total number of loops we are considering.
- FIRST_LOOP is the loop->num of the first loop. */
+ FIRST_LOOP_DEPTH is the loop->depth of the first loop in the analyzed
+ loop nest.
+ Return FALSE if the dependence relation is outside of the loop nest
+ at FIRST_LOOP_DEPTH.
+ Return TRUE otherwise. */
-static void
+static bool
build_classic_dir_vector (struct data_dependence_relation *ddr,
- int nb_loops, unsigned int first_loop)
+ int nb_loops, int first_loop_depth)
{
unsigned i;
lambda_vector dir_v, init_v;
lambda_vector_clear (init_v, nb_loops);
if (DDR_ARE_DEPENDENT (ddr) != NULL_TREE)
- return;
+ return true;
for (i = 0; i < DDR_NUM_SUBSCRIPTS (ddr); i++)
{
+ tree access_fn_a, access_fn_b;
struct subscript *subscript = DDR_SUBSCRIPT (ddr, i);
- if (TREE_CODE (SUB_CONFLICTS_IN_A (subscript)) == POLYNOMIAL_CHREC
- && TREE_CODE (SUB_CONFLICTS_IN_B (subscript)) == POLYNOMIAL_CHREC)
+ if (chrec_contains_undetermined (SUB_DISTANCE (subscript)))
{
- int loop_nb;
-
+ non_affine_dependence_relation (ddr);
+ return true;
+ }
+
+ access_fn_a = DR_ACCESS_FN (DDR_A (ddr), i);
+ access_fn_b = DR_ACCESS_FN (DDR_B (ddr), i);
+ if (TREE_CODE (access_fn_a) == POLYNOMIAL_CHREC
+ && TREE_CODE (access_fn_b) == POLYNOMIAL_CHREC)
+ {
+ int dist, loop_nb, loop_depth;
enum data_dependence_direction dir = dir_star;
- loop_nb = CHREC_VARIABLE (SUB_CONFLICTS_IN_A (subscript));
- loop_nb -= first_loop;
+ int loop_nb_a = CHREC_VARIABLE (access_fn_a);
+ int loop_nb_b = CHREC_VARIABLE (access_fn_b);
+ struct loop *loop_a = current_loops->parray[loop_nb_a];
+ struct loop *loop_b = current_loops->parray[loop_nb_b];
+
+ /* If the loop for either variable is at a lower depth than
+ the first_loop's depth, then we can't possibly have a
+ dependency at this level of the loop. */
+
+ if (loop_a->depth < first_loop_depth
+ || loop_b->depth < first_loop_depth)
+ return false;
+
+ if (loop_nb_a != loop_nb_b
+ && !flow_loop_nested_p (loop_a, loop_b)
+ && !flow_loop_nested_p (loop_b, loop_a))
+ {
+ /* Example: when there are two consecutive loops,
+
+ | loop_1
+ | A[{0, +, 1}_1]
+ | endloop_1
+ | loop_2
+ | A[{0, +, 1}_2]
+ | endloop_2
+
+ the dependence relation cannot be captured by the
+ distance abstraction. */
+ non_affine_dependence_relation (ddr);
+ return true;
+ }
+
+ /* The dependence is carried by the outermost loop. Example:
+ | loop_1
+ | A[{4, +, 1}_1]
+ | loop_2
+ | A[{5, +, 1}_2]
+ | endloop_2
+ | endloop_1
+ In this case, the dependence is carried by loop_1. */
+ loop_nb = loop_nb_a < loop_nb_b ? loop_nb_a : loop_nb_b;
+ loop_depth = current_loops->parray[loop_nb]->depth - first_loop_depth;
/* If the loop number is still greater than the number of
loops we've been asked to analyze, or negative,
something is borked. */
- gcc_assert (loop_nb >= 0);
- gcc_assert (loop_nb < nb_loops);
- if (!chrec_contains_undetermined (SUB_DISTANCE (subscript)))
+ gcc_assert (loop_depth >= 0);
+ gcc_assert (loop_depth < nb_loops);
+
+ if (chrec_contains_undetermined (SUB_DISTANCE (subscript)))
{
- int dist = int_cst_value (SUB_DISTANCE (subscript));
-
- if (dist == 0)
- dir = dir_equal;
- else if (dist > 0)
- dir = dir_positive;
- else if (dist < 0)
- dir = dir_negative;
+ non_affine_dependence_relation (ddr);
+ return true;
}
+
+ dist = int_cst_value (SUB_DISTANCE (subscript));
+
+ if (dist == 0)
+ dir = dir_equal;
+ else if (dist > 0)
+ dir = dir_positive;
+ else if (dist < 0)
+ dir = dir_negative;
/* This is the subscript coupling test.
| loop i = 0, N, 1
| ... = T[i][i]
| endloop
There is no dependence. */
- if (init_v[loop_nb] != 0
+ if (init_v[loop_depth] != 0
&& dir != dir_star
- && (enum data_dependence_direction) dir_v[loop_nb] != dir
- && (enum data_dependence_direction) dir_v[loop_nb] != dir_star)
+ && (enum data_dependence_direction) dir_v[loop_depth] != dir
+ && (enum data_dependence_direction) dir_v[loop_depth] != dir_star)
{
finalize_ddr_dependent (ddr, chrec_known);
- return;
+ return true;
}
- dir_v[loop_nb] = dir;
- init_v[loop_nb] = 1;
+ dir_v[loop_depth] = dir;
+ init_v[loop_depth] = 1;
}
}
struct loop *lca, *loop_a, *loop_b;
struct data_reference *a = DDR_A (ddr);
struct data_reference *b = DDR_B (ddr);
- int lca_nb;
+ int lca_depth;
loop_a = loop_containing_stmt (DR_STMT (a));
loop_b = loop_containing_stmt (DR_STMT (b));
/* Get the common ancestor loop. */
lca = find_common_loop (loop_a, loop_b);
- lca_nb = lca->num - first_loop;
+ lca_depth = lca->depth - first_loop_depth;
+
+ gcc_assert (lca_depth >= 0);
+ gcc_assert (lca_depth < nb_loops);
- gcc_assert (lca_nb >= 0);
- gcc_assert (lca_nb < nb_loops);
/* For each outer loop where init_v is not set, the accesses are
in dependence of distance 1 in the loop. */
if (lca != loop_a
&& lca != loop_b
- && init_v[lca_nb] == 0)
- dir_v[lca_nb] = dir_positive;
+ && init_v[lca_depth] == 0)
+ dir_v[lca_depth] = dir_positive;
lca = lca->outer;
if (lca)
{
- lca_nb = lca->num - first_loop;
+ lca_depth = lca->depth - first_loop_depth;
while (lca->depth != 0)
{
- gcc_assert (lca_nb >= 0);
- gcc_assert (lca_nb < nb_loops);
- if (init_v[lca_nb] == 0)
- dir_v[lca_nb] = dir_positive;
+ /* If we're considering just a sub-nest, then don't record
+ any information on the outer loops. */
+ if (lca_depth < 0)
+ break;
+
+ gcc_assert (lca_depth < nb_loops);
+
+ if (init_v[lca_depth] == 0)
+ dir_v[lca_depth] = dir_positive;
lca = lca->outer;
- lca_nb = lca->num - first_loop;
+ lca_depth = lca->depth - first_loop_depth;
}
}
}
DDR_DIR_VECT (ddr) = dir_v;
+ DDR_SIZE_VECT (ddr) = nb_loops;
+ return true;
}
/* Returns true when all the access functions of A are affine or
access_functions_are_affine_or_constant_p (struct data_reference *a)
{
unsigned int i;
- varray_type fns = DR_ACCESS_FNS (a);
+ VEC(tree,heap) **fns = DR_ACCESS_FNS_ADDR (a);
+ tree t;
- for (i = 0; i < VARRAY_ACTIVE_SIZE (fns); i++)
- if (!evolution_function_is_constant_p (VARRAY_TREE (fns, i))
- && !evolution_function_is_affine_multivariate_p (VARRAY_TREE (fns, i)))
+ for (i = 0; VEC_iterate (tree, *fns, i, t); i++)
+ if (!evolution_function_is_constant_p (t)
+ && !evolution_function_is_affine_multivariate_p (t))
return false;
return true;
fprintf (dump_file, ")\n");
}
+/* This computes the dependence relation for the same data
+ reference into DDR. */
+
+static void
+compute_self_dependence (struct data_dependence_relation *ddr)
+{
+ unsigned int i;
+
+ for (i = 0; i < DDR_NUM_SUBSCRIPTS (ddr); i++)
+ {
+ struct subscript *subscript = DDR_SUBSCRIPT (ddr, i);
+
+ /* The accessed index overlaps for each iteration. */
+ SUB_CONFLICTS_IN_A (subscript) = integer_zero_node;
+ SUB_CONFLICTS_IN_B (subscript) = integer_zero_node;
+ SUB_LAST_CONFLICT (subscript) = chrec_dont_know;
+ }
+}
+
+
+typedef struct data_dependence_relation *ddr_p;
+DEF_VEC_P(ddr_p);
+DEF_VEC_ALLOC_P(ddr_p,heap);
+
/* Compute a subset of the data dependence relation graph. Don't
- compute read-read relations, and avoid the computation of the
- opposite relation, i.e. when AB has been computed, don't compute BA.
+ compute read-read and self relations if
+ COMPUTE_SELF_AND_READ_READ_DEPENDENCES is FALSE, and avoid the computation
+ of the opposite relation, i.e. when AB has been computed, don't compute BA.
DATAREFS contains a list of data references, and the result is set
in DEPENDENCE_RELATIONS. */
static void
compute_all_dependences (varray_type datarefs,
- varray_type *dependence_relations)
+ bool compute_self_and_read_read_dependences,
+ VEC(ddr_p,heap) **dependence_relations)
{
unsigned int i, j, N;
N = VARRAY_ACTIVE_SIZE (datarefs);
+ /* Note that we specifically skip i == j because it's a self dependence, and
+ use compute_self_dependence below. */
+
for (i = 0; i < N; i++)
- for (j = i; j < N; j++)
+ for (j = i + 1; j < N; j++)
{
struct data_reference *a, *b;
struct data_dependence_relation *ddr;
a = VARRAY_GENERIC_PTR (datarefs, i);
b = VARRAY_GENERIC_PTR (datarefs, j);
-
+ if (DR_IS_READ (a) && DR_IS_READ (b)
+ && !compute_self_and_read_read_dependences)
+ continue;
ddr = initialize_data_dependence_relation (a, b);
- VARRAY_PUSH_GENERIC_PTR (*dependence_relations, ddr);
+ VEC_safe_push (ddr_p, heap, *dependence_relations, ddr);
compute_affine_dependence (ddr);
- compute_distance_vector (ddr);
+ compute_subscript_distance (ddr);
}
+ if (!compute_self_and_read_read_dependences)
+ return;
+
+ /* Compute self dependence relation of each dataref to itself. */
+
+ for (i = 0; i < N; i++)
+ {
+ struct data_reference *a, *b;
+ struct data_dependence_relation *ddr;
+
+ a = VARRAY_GENERIC_PTR (datarefs, i);
+ b = VARRAY_GENERIC_PTR (datarefs, i);
+ ddr = initialize_data_dependence_relation (a, b);
+
+ VEC_safe_push (ddr_p, heap, *dependence_relations, ddr);
+ compute_self_dependence (ddr);
+ compute_subscript_distance (ddr);
+ }
}
/* 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.
- FIXME: This is a "dumb" walker over all the trees in the loop body.
- Find another technique that avoids this costly walk. This is
- acceptable for the moment, since this function is used only for
- debugging purposes. */
+ TODO: This function should be made smarter so that it can handle address
+ arithmetic as if they were array accesses, etc. */
-static tree
+tree
find_data_references_in_loop (struct loop *loop, varray_type *datarefs)
{
- basic_block bb;
+ basic_block bb, *bbs;
+ unsigned int i;
block_stmt_iterator bsi;
-
- FOR_EACH_BB (bb)
+ struct data_reference *dr;
+
+ bbs = get_loop_body (loop);
+
+ for (i = 0; i < loop->num_nodes; i++)
{
- if (!flow_bb_inside_loop_p (loop, bb))
- continue;
-
+ bb = bbs[i];
+
for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
{
tree stmt = bsi_stmt (bsi);
- stmt_ann_t ann = stmt_ann (stmt);
- if (TREE_CODE (stmt) != MODIFY_EXPR)
- continue;
+ /* 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 (!VUSE_OPS (ann)
- && !V_MUST_DEF_OPS (ann)
- && !V_MAY_DEF_OPS (ann))
+ if (ZERO_SSA_OPERANDS (stmt, SSA_OP_ALL_VIRTUALS))
continue;
- /* In the GIMPLE representation, a modify expression
- contains a single load or store to memory. */
- if (TREE_CODE (TREE_OPERAND (stmt, 0)) == ARRAY_REF)
- VARRAY_PUSH_GENERIC_PTR
- (*datarefs, analyze_array (stmt, TREE_OPERAND (stmt, 0),
- false));
+ 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)
+ {
+ dr = create_data_ref (opnd0, stmt, false);
+ if (dr)
+ {
+ VARRAY_PUSH_GENERIC_PTR (*datarefs, dr);
+ one_inserted = true;
+ }
+ }
+
+ if (TREE_CODE (opnd1) == ARRAY_REF
+ || TREE_CODE (opnd1) == INDIRECT_REF)
+ {
+ dr = create_data_ref (opnd1, stmt, true);
+ if (dr)
+ {
+ VARRAY_PUSH_GENERIC_PTR (*datarefs, dr);
+ one_inserted = true;
+ }
+ }
+
+ if (!one_inserted)
+ goto insert_dont_know_node;
+
+ break;
+ }
+
+ 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)
+ {
+ dr = create_data_ref (TREE_VALUE (args), stmt, true);
+ if (dr)
+ {
+ VARRAY_PUSH_GENERIC_PTR (*datarefs, dr);
+ one_inserted = true;
+ }
+ }
+
+ if (!one_inserted)
+ goto insert_dont_know_node;
- else if (TREE_CODE (TREE_OPERAND (stmt, 1)) == ARRAY_REF)
- VARRAY_PUSH_GENERIC_PTR
- (*datarefs, analyze_array (stmt, TREE_OPERAND (stmt, 1),
- true));
+ break;
+ }
+
+ default:
+ {
+ struct data_reference *res;
+
+ insert_dont_know_node:;
+ res = xmalloc (sizeof (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;
+ VARRAY_PUSH_GENERIC_PTR (*datarefs, res);
+
+ free (bbs);
+ return chrec_dont_know;
+ }
+ }
- else
- return chrec_dont_know;
+ /* 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 (bbs);
+
return NULL_TREE;
}
/* 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. */
+ *DEPENDENCE_RELATIONS contains the relations between the data references.
+ Compute read-read and self relations if
+ COMPUTE_SELF_AND_READ_READ_DEPENDENCES is TRUE. */
void
-compute_data_dependences_for_loop (unsigned nb_loops,
- struct loop *loop,
+compute_data_dependences_for_loop (struct loop *loop,
+ bool compute_self_and_read_read_dependences,
varray_type *datarefs,
varray_type *dependence_relations)
{
- unsigned int i;
+ unsigned int i, nb_loops;
+ VEC(ddr_p,heap) *allrelations;
+ struct data_dependence_relation *ddr;
+ struct loop *loop_nest = loop;
+
+ while (loop_nest && loop_nest->outer && loop_nest->outer->outer)
+ loop_nest = loop_nest->outer;
+
+ nb_loops = loop_nest->level;
/* If one of the data references is not computable, give up without
spending time to compute other dependences. */
chrec_dont_know. */
ddr = initialize_data_dependence_relation (NULL, NULL);
VARRAY_PUSH_GENERIC_PTR (*dependence_relations, ddr);
- build_classic_dist_vector (ddr, nb_loops, loop->num);
- build_classic_dir_vector (ddr, nb_loops, loop->num);
+ build_classic_dist_vector (ddr, nb_loops, loop->depth);
+ build_classic_dir_vector (ddr, nb_loops, loop->depth);
return;
}
- compute_all_dependences (*datarefs, dependence_relations);
+ allrelations = NULL;
+ compute_all_dependences (*datarefs, compute_self_and_read_read_dependences,
+ &allrelations);
- for (i = 0; i < VARRAY_ACTIVE_SIZE (*dependence_relations); i++)
+ for (i = 0; VEC_iterate (ddr_p, allrelations, i, ddr); i++)
{
- struct data_dependence_relation *ddr;
- ddr = VARRAY_GENERIC_PTR (*dependence_relations, i);
- build_classic_dist_vector (ddr, nb_loops, loop->num);
- build_classic_dir_vector (ddr, nb_loops, loop->num);
+ if (build_classic_dist_vector (ddr, nb_loops, loop_nest->depth))
+ {
+ VARRAY_PUSH_GENERIC_PTR (*dependence_relations, ddr);
+ build_classic_dir_vector (ddr, nb_loops, loop_nest->depth);
+ }
}
}
"dependence_relations");
/* Compute DDs on the whole function. */
- compute_data_dependences_for_loop (loops->num, loops->parray[0],
+ compute_data_dependences_for_loop (loops->parray[0], false,
&datarefs, &dependence_relations);
if (dump_file)
{
dump_data_dependence_relations (dump_file, dependence_relations);
fprintf (dump_file, "\n\n");
- }
-
- /* Don't dump distances in order to avoid to update the
- testsuite. */
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- for (i = 0; i < VARRAY_ACTIVE_SIZE (dependence_relations); i++)
- {
- struct data_dependence_relation *ddr =
- (struct data_dependence_relation *)
- VARRAY_GENERIC_PTR (dependence_relations, i);
- if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE)
- {
- fprintf (dump_file, "DISTANCE_V (");
- print_lambda_vector (dump_file, DDR_DIST_VECT (ddr), loops->num);
- fprintf (dump_file, ")\n");
- fprintf (dump_file, "DIRECTION_V (");
- print_lambda_vector (dump_file, DDR_DIR_VECT (ddr), loops->num);
- fprintf (dump_file, ")\n");
- }
- }
- fprintf (dump_file, "\n\n");
- }
- if (dump_file && (dump_flags & TDF_STATS))
- {
- unsigned nb_top_relations = 0;
- unsigned nb_bot_relations = 0;
- unsigned nb_basename_differ = 0;
- unsigned nb_chrec_relations = 0;
+ if (dump_flags & TDF_DETAILS)
+ dump_dist_dir_vectors (dump_file, dependence_relations);
- for (i = 0; i < VARRAY_ACTIVE_SIZE (dependence_relations); i++)
+ if (dump_flags & TDF_STATS)
{
- struct data_dependence_relation *ddr;
- ddr = VARRAY_GENERIC_PTR (dependence_relations, i);
+ unsigned nb_top_relations = 0;
+ unsigned nb_bot_relations = 0;
+ unsigned nb_basename_differ = 0;
+ unsigned nb_chrec_relations = 0;
+
+ for (i = 0; i < VARRAY_ACTIVE_SIZE (dependence_relations); i++)
+ {
+ struct data_dependence_relation *ddr;
+ ddr = VARRAY_GENERIC_PTR (dependence_relations, i);
- if (chrec_contains_undetermined (DDR_ARE_DEPENDENT (ddr)))
- nb_top_relations++;
+ 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;
+ 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_NUM_DIMENSIONS (a) != DR_NUM_DIMENSIONS (b)
- || (array_base_name_differ_p (a, b, &differ_p) && differ_p))
- nb_basename_differ++;
- else
- nb_bot_relations++;
- }
+ 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++;
- }
+ else
+ nb_chrec_relations++;
+ }
- gather_stats_on_scev_database ();
+ gather_stats_on_scev_database ();
+ }
}
free_dependence_relations (dependence_relations);
{
struct data_reference *dr = (struct data_reference *)
VARRAY_GENERIC_PTR (datarefs, i);
- if (dr && DR_ACCESS_FNS (dr))
- varray_clear (DR_ACCESS_FNS (dr));
+ if (dr)
+ {
+ DR_FREE_ACCESS_FNS (dr);
+ free (dr);
+ }
}
varray_clear (datarefs);
}
+
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