/* Data references and dependences detectors.
- Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
+ Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
Free Software Foundation, Inc.
Contributed by Sebastian Pop <pop@cri.ensmp.fr>
#include "tree-scalar-evolution.h"
#include "tree-pass.h"
#include "langhooks.h"
+#include "tree-affine.h"
static struct datadep_stats
{
split_constant_offset (poffset, &poffset, &off1);
off0 = size_binop (PLUS_EXPR, off0, off1);
if (POINTER_TYPE_P (TREE_TYPE (base)))
- base = fold_build2 (POINTER_PLUS_EXPR, TREE_TYPE (base),
- base, fold_convert (sizetype, poffset));
+ base = fold_build_pointer_plus (base, poffset);
else
base = fold_build2 (PLUS_EXPR, TREE_TYPE (base), base,
fold_convert (TREE_TYPE (base), poffset));
*off = ssize_int (0);
STRIP_NOPS (exp);
- if (tree_is_chrec (exp))
+ if (tree_is_chrec (exp)
+ || get_gimple_rhs_class (TREE_CODE (exp)) == GIMPLE_TERNARY_RHS)
return;
otype = TREE_TYPE (exp);
}
/* Analyzes the behavior of the memory reference DR in the innermost loop or
- basic block that contains it. Returns true if analysis succeed or false
+ basic block that contains it. Returns true if analysis succeed or false
otherwise. */
bool
-dr_analyze_innermost (struct data_reference *dr)
+dr_analyze_innermost (struct data_reference *dr, struct loop *nest)
{
gimple stmt = DR_STMT (dr);
struct loop *loop = loop_containing_stmt (stmt);
}
else
base = build_fold_addr_expr (base);
+
if (in_loop)
{
if (!simple_iv (loop, loop_containing_stmt (stmt), base, &base_iv,
false))
{
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "failed: evolution of base is not affine.\n");
- return false;
+ if (nest)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "failed: evolution of base is not"
+ " affine.\n");
+ return false;
+ }
+ else
+ {
+ base_iv.base = base;
+ base_iv.step = ssize_int (0);
+ base_iv.no_overflow = true;
+ }
}
}
else
else if (!simple_iv (loop, loop_containing_stmt (stmt),
poffset, &offset_iv, false))
{
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "failed: evolution of offset is not"
- " affine.\n");
- return false;
+ if (nest)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "failed: evolution of offset is not"
+ " affine.\n");
+ return false;
+ }
+ else
+ {
+ offset_iv.base = poffset;
+ offset_iv.step = ssize_int (0);
+ }
}
}
dr_analyze_indices (struct data_reference *dr, loop_p nest, loop_p loop)
{
VEC (tree, heap) *access_fns = NULL;
- tree ref = unshare_expr (DR_REF (dr)), aref = ref, op;
- tree base, off, access_fn = NULL_TREE;
- basic_block before_loop = NULL;
+ tree ref, aref, op;
+ tree base, off, access_fn;
+ basic_block before_loop;
+
+ /* If analyzing a basic-block there are no indices to analyze
+ and thus no access functions. */
+ if (!nest)
+ {
+ DR_BASE_OBJECT (dr) = DR_REF (dr);
+ DR_ACCESS_FNS (dr) = NULL;
+ return;
+ }
- if (nest)
- before_loop = block_before_loop (nest);
+ ref = unshare_expr (DR_REF (dr));
+ before_loop = block_before_loop (nest);
+
+ /* REALPART_EXPR and IMAGPART_EXPR can be handled like accesses
+ into a two element array with a constant index. The base is
+ then just the immediate underlying object. */
+ if (TREE_CODE (ref) == REALPART_EXPR)
+ {
+ ref = TREE_OPERAND (ref, 0);
+ VEC_safe_push (tree, heap, access_fns, integer_zero_node);
+ }
+ else if (TREE_CODE (ref) == IMAGPART_EXPR)
+ {
+ ref = TREE_OPERAND (ref, 0);
+ VEC_safe_push (tree, heap, access_fns, integer_one_node);
+ }
+ /* Analyze access functions of dimensions we know to be independent. */
+ aref = ref;
while (handled_component_p (aref))
{
if (TREE_CODE (aref) == ARRAY_REF)
{
op = TREE_OPERAND (aref, 1);
- if (nest)
- {
- access_fn = analyze_scalar_evolution (loop, op);
- access_fn = instantiate_scev (before_loop, loop, access_fn);
- VEC_safe_push (tree, heap, access_fns, access_fn);
- }
-
- TREE_OPERAND (aref, 1) = build_int_cst (TREE_TYPE (op), 0);
+ access_fn = analyze_scalar_evolution (loop, op);
+ access_fn = instantiate_scev (before_loop, loop, access_fn);
+ VEC_safe_push (tree, heap, access_fns, access_fn);
+ /* For ARRAY_REFs the base is the reference with the index replaced
+ by zero if we can not strip it as the outermost component. */
+ if (aref == ref)
+ ref = TREE_OPERAND (ref, 0);
+ else
+ TREE_OPERAND (aref, 1) = build_int_cst (TREE_TYPE (op), 0);
}
aref = TREE_OPERAND (aref, 0);
}
- if (nest
- && (INDIRECT_REF_P (aref)
- || TREE_CODE (aref) == MEM_REF))
+ /* If the address operand of a MEM_REF base has an evolution in the
+ analyzed nest, add it as an additional independent access-function. */
+ if (TREE_CODE (aref) == MEM_REF)
{
op = TREE_OPERAND (aref, 0);
access_fn = analyze_scalar_evolution (loop, op);
access_fn = instantiate_scev (before_loop, loop, access_fn);
- base = initial_condition (access_fn);
- split_constant_offset (base, &base, &off);
- if (TREE_CODE (aref) == MEM_REF)
- off = size_binop (PLUS_EXPR, off,
- fold_convert (ssizetype, TREE_OPERAND (aref, 1)));
- access_fn = chrec_replace_initial_condition (access_fn,
- fold_convert (TREE_TYPE (base), off));
-
- TREE_OPERAND (aref, 0) = base;
- VEC_safe_push (tree, heap, access_fns, access_fn);
+ if (TREE_CODE (access_fn) == POLYNOMIAL_CHREC)
+ {
+ base = initial_condition (access_fn);
+ split_constant_offset (base, &base, &off);
+ /* Fold the MEM_REF offset into the evolutions initial
+ value to make more bases comparable. */
+ if (!integer_zerop (TREE_OPERAND (aref, 1)))
+ {
+ off = size_binop (PLUS_EXPR, off,
+ fold_convert (ssizetype,
+ TREE_OPERAND (aref, 1)));
+ TREE_OPERAND (aref, 1)
+ = build_int_cst (TREE_TYPE (TREE_OPERAND (aref, 1)), 0);
+ }
+ access_fn = chrec_replace_initial_condition
+ (access_fn, fold_convert (TREE_TYPE (base), off));
+ TREE_OPERAND (aref, 0) = base;
+ VEC_safe_push (tree, heap, access_fns, access_fn);
+ }
}
- if (TREE_CODE (aref) == MEM_REF)
- TREE_OPERAND (aref, 1)
- = build_int_cst (TREE_TYPE (TREE_OPERAND (aref, 1)), 0);
-
- if (TREE_CODE (ref) == MEM_REF
- && TREE_CODE (TREE_OPERAND (ref, 0)) == ADDR_EXPR
- && integer_zerop (TREE_OPERAND (ref, 1)))
- ref = TREE_OPERAND (TREE_OPERAND (ref, 0), 0);
-
- /* For canonicalization purposes we'd like to strip all outermost
- zero-offset component-refs.
- ??? For now simply handle zero-index array-refs. */
- while (TREE_CODE (ref) == ARRAY_REF
- && integer_zerop (TREE_OPERAND (ref, 1)))
- ref = TREE_OPERAND (ref, 0);
-
DR_BASE_OBJECT (dr) = ref;
DR_ACCESS_FNS (dr) = access_fns;
}
}
}
-/* Returns true if the address of DR is invariant. */
-
-static bool
-dr_address_invariant_p (struct data_reference *dr)
-{
- unsigned i;
- tree idx;
-
- FOR_EACH_VEC_ELT (tree, DR_ACCESS_FNS (dr), i, idx)
- if (tree_contains_chrecs (idx, NULL))
- return false;
-
- return true;
-}
-
/* Frees data reference DR. */
void
DR_REF (dr) = memref;
DR_IS_READ (dr) = is_read;
- dr_analyze_innermost (dr);
+ dr_analyze_innermost (dr, nest);
dr_analyze_indices (dr, nest, loop);
dr_analyze_alias (dr);
if (dump_file && (dump_flags & TDF_DETAILS))
{
+ unsigned i;
fprintf (dump_file, "\tbase_address: ");
print_generic_expr (dump_file, DR_BASE_ADDRESS (dr), TDF_SLIM);
fprintf (dump_file, "\n\toffset from base address: ");
fprintf (dump_file, "\n\tbase_object: ");
print_generic_expr (dump_file, DR_BASE_OBJECT (dr), TDF_SLIM);
fprintf (dump_file, "\n");
+ for (i = 0; i < DR_NUM_DIMENSIONS (dr); i++)
+ {
+ fprintf (dump_file, "\tAccess function %d: ", i);
+ print_generic_stmt (dump_file, DR_ACCESS_FN (dr, i), TDF_SLIM);
+ }
}
return dr;
}
/* Returns false if we can prove that data references A and B do not alias,
- true otherwise. */
+ true otherwise. If LOOP_NEST is false no cross-iteration aliases are
+ considered. */
bool
-dr_may_alias_p (const struct data_reference *a, const struct data_reference *b)
+dr_may_alias_p (const struct data_reference *a, const struct data_reference *b,
+ bool loop_nest)
{
tree addr_a = DR_BASE_OBJECT (a);
tree addr_b = DR_BASE_OBJECT (b);
+ /* If we are not processing a loop nest but scalar code we
+ do not need to care about possible cross-iteration dependences
+ and thus can process the full original reference. Do so,
+ similar to how loop invariant motion applies extra offset-based
+ disambiguation. */
+ if (!loop_nest)
+ {
+ aff_tree off1, off2;
+ double_int size1, size2;
+ get_inner_reference_aff (DR_REF (a), &off1, &size1);
+ get_inner_reference_aff (DR_REF (b), &off2, &size2);
+ aff_combination_scale (&off1, double_int_minus_one);
+ aff_combination_add (&off2, &off1);
+ if (aff_comb_cannot_overlap_p (&off2, size1, size2))
+ return false;
+ }
+
if (DR_IS_WRITE (a) && DR_IS_WRITE (b))
return refs_output_dependent_p (addr_a, addr_b);
else if (DR_IS_READ (a) && DR_IS_WRITE (b))
}
/* If the data references do not alias, then they are independent. */
- if (!dr_may_alias_p (a, b))
+ if (!dr_may_alias_p (a, b, loop_nest != NULL))
{
DDR_ARE_DEPENDENT (res) = chrec_known;
return res;
fprintf (dump_file, ")\n");
}
-/* Sets NIT to the estimated number of executions of the statements in
- LOOP. If CONSERVATIVE is true, we must be sure that NIT is at least as
- large as the number of iterations. If we have no reliable estimate,
- the function returns false, otherwise returns true. */
-
-bool
-estimated_loop_iterations (struct loop *loop, bool conservative,
- double_int *nit)
-{
- estimate_numbers_of_iterations_loop (loop, true);
- if (conservative)
- {
- if (!loop->any_upper_bound)
- return false;
-
- *nit = loop->nb_iterations_upper_bound;
- }
- else
- {
- if (!loop->any_estimate)
- return false;
-
- *nit = loop->nb_iterations_estimate;
- }
-
- return true;
-}
-
-/* Similar to estimated_loop_iterations, but returns the estimate only
- if it fits to HOST_WIDE_INT. If this is not the case, or the estimate
- on the number of iterations of LOOP could not be derived, returns -1. */
-
-HOST_WIDE_INT
-estimated_loop_iterations_int (struct loop *loop, bool conservative)
-{
- double_int nit;
- HOST_WIDE_INT hwi_nit;
-
- if (!estimated_loop_iterations (loop, conservative, &nit))
- return -1;
-
- if (!double_int_fits_in_shwi_p (nit))
- return -1;
- hwi_nit = double_int_to_shwi (nit);
-
- return hwi_nit < 0 ? -1 : hwi_nit;
-}
-
-/* Similar to estimated_loop_iterations, but returns the estimate as a tree,
+/* Similar to max_stmt_executions_int, but returns the bound as a tree,
and only if it fits to the int type. If this is not the case, or the
- estimate on the number of iterations of LOOP could not be derived, returns
+ bound on the number of iterations of LOOP could not be derived, returns
chrec_dont_know. */
static tree
-estimated_loop_iterations_tree (struct loop *loop, bool conservative)
+max_stmt_executions_tree (struct loop *loop)
{
double_int nit;
- tree type;
- if (!estimated_loop_iterations (loop, conservative, &nit))
+ if (!max_stmt_executions (loop, true, &nit))
return chrec_dont_know;
- type = lang_hooks.types.type_for_size (INT_TYPE_SIZE, true);
- if (!double_int_fits_to_tree_p (type, nit))
+ if (!double_int_fits_to_tree_p (unsigned_type_node, nit))
return chrec_dont_know;
- return double_int_to_tree (type, nit);
+ return double_int_to_tree (unsigned_type_node, nit);
}
/* Analyze a SIV (Single Index Variable) subscript where CHREC_A is a
/* Perform weak-zero siv test to see if overlap is
outside the loop bounds. */
- numiter = estimated_loop_iterations_int (loop, false);
+ numiter = max_stmt_executions_int (loop, true);
if (numiter >= 0
&& compare_tree_int (tmp, numiter) > 0)
/* Perform weak-zero siv test to see if overlap is
outside the loop bounds. */
- numiter = estimated_loop_iterations_int (loop, false);
+ numiter = max_stmt_executions_int (loop, true);
if (numiter >= 0
&& compare_tree_int (tmp, numiter) > 0)
step_z = int_cst_value (CHREC_RIGHT (chrec_b));
niter_x =
- estimated_loop_iterations_int (get_chrec_loop (CHREC_LEFT (chrec_a)),
- false);
- niter_y = estimated_loop_iterations_int (get_chrec_loop (chrec_a), false);
- niter_z = estimated_loop_iterations_int (get_chrec_loop (chrec_b), false);
+ max_stmt_executions_int (get_chrec_loop (CHREC_LEFT (chrec_a)), true);
+ niter_y = max_stmt_executions_int (get_chrec_loop (chrec_a), true);
+ niter_z = max_stmt_executions_int (get_chrec_loop (chrec_b), true);
if (niter_x < 0 || niter_y < 0 || niter_z < 0)
{
HOST_WIDE_INT niter, niter_a, niter_b;
affine_fn ova, ovb;
- niter_a = estimated_loop_iterations_int (get_chrec_loop (chrec_a),
- false);
- niter_b = estimated_loop_iterations_int (get_chrec_loop (chrec_b),
- false);
+ niter_a = max_stmt_executions_int (get_chrec_loop (chrec_a), true);
+ niter_b = max_stmt_executions_int (get_chrec_loop (chrec_b), true);
niter = MIN (niter_a, niter_b);
step_a = int_cst_value (CHREC_RIGHT (chrec_a));
step_b = int_cst_value (CHREC_RIGHT (chrec_b));
if (i1 > 0 && j1 > 0)
{
- HOST_WIDE_INT niter_a = estimated_loop_iterations_int
- (get_chrec_loop (chrec_a), false);
- HOST_WIDE_INT niter_b = estimated_loop_iterations_int
- (get_chrec_loop (chrec_b), false);
+ HOST_WIDE_INT niter_a = max_stmt_executions_int
+ (get_chrec_loop (chrec_a), true);
+ HOST_WIDE_INT niter_b = max_stmt_executions_int
+ (get_chrec_loop (chrec_b), true);
HOST_WIDE_INT niter = MIN (niter_a, niter_b);
/* (X0, Y0) is a solution of the Diophantine equation:
in the same order. */
*overlaps_a = conflict_fn (1, affine_fn_cst (integer_zero_node));
*overlaps_b = conflict_fn (1, affine_fn_cst (integer_zero_node));
- *last_conflicts = estimated_loop_iterations_tree
- (get_chrec_loop (chrec_a), true);
+ *last_conflicts = max_stmt_executions_tree (get_chrec_loop (chrec_a));
dependence_stats.num_miv_dependent++;
}
for (i = 0; i <= DDR_INNER_LOOP (ddr)
&& VEC_iterate (loop_p, DDR_LOOP_NEST (ddr), i, loopi); i++)
{
- HOST_WIDE_INT nbi = estimated_loop_iterations_int (loopi, false);
+ HOST_WIDE_INT nbi = max_stmt_executions_int (loopi, true);
/* 0 <= loop_x */
ineq = omega_add_zero_geq (pb, omega_black);
ref->pos = op1;
ref->is_read = true;
}
-
- if (DECL_P (*op0)
- || (REFERENCE_CLASS_P (*op0) && get_base_address (*op0)))
- {
- ref = VEC_safe_push (data_ref_loc, heap, *references, NULL);
- ref->pos = op0;
- ref->is_read = false;
- }
}
else if (stmt_code == GIMPLE_CALL)
{
- unsigned i, n = gimple_call_num_args (stmt);
+ unsigned i, n;
+ op0 = gimple_call_lhs_ptr (stmt);
+ n = gimple_call_num_args (stmt);
for (i = 0; i < n; i++)
{
- op0 = gimple_call_arg_ptr (stmt, i);
+ op1 = gimple_call_arg_ptr (stmt, i);
- if (DECL_P (*op0)
- || (REFERENCE_CLASS_P (*op0) && get_base_address (*op0)))
+ if (DECL_P (*op1)
+ || (REFERENCE_CLASS_P (*op1) && get_base_address (*op1)))
{
ref = VEC_safe_push (data_ref_loc, heap, *references, NULL);
- ref->pos = op0;
+ ref->pos = op1;
ref->is_read = true;
}
}
}
+ else
+ return clobbers_memory;
+ if (*op0
+ && (DECL_P (*op0)
+ || (REFERENCE_CLASS_P (*op0) && get_base_address (*op0))))
+ {
+ ref = VEC_safe_push (data_ref_loc, heap, *references, NULL);
+ ref->pos = op0;
+ ref->is_read = false;
+ }
return clobbers_memory;
}
dr = create_data_ref (nest, loop_containing_stmt (stmt),
*ref->pos, stmt, ref->is_read);
gcc_assert (dr != NULL);
-
- /* FIXME -- data dependence analysis does not work correctly for objects
- with invariant addresses in loop nests. Let us fail here until the
- problem is fixed. */
- if (dr_address_invariant_p (dr) && nest)
- {
- free_data_ref (dr);
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "\tFAILED as dr address is invariant\n");
- ret = false;
- break;
- }
-
VEC_safe_push (data_reference_p, heap, *datarefs, dr);
}
VEC_free (data_ref_loc, heap, references);
for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi))
{
stmt = gsi_stmt (bsi);
- if (gimple_code (stmt) != GIMPLE_LABEL)
+ if (gimple_code (stmt) != GIMPLE_LABEL && !is_gimple_debug (stmt))
VEC_safe_push (gimple, heap, *stmts, stmt);
}
}
DR_STMT (dr) = stmt;
DR_REF (dr) = op0;
- res = dr_analyze_innermost (dr)
+ res = dr_analyze_innermost (dr, loop_containing_stmt (stmt))
&& stride_of_unit_type_p (DR_STEP (dr), TREE_TYPE (op0));
free_data_ref (dr);
DR_STMT (dr) = stmt;
DR_REF (dr) = *ref->pos;
- dr_analyze_innermost (dr);
+ dr_analyze_innermost (dr, loop_containing_stmt (stmt));
base_address = DR_BASE_ADDRESS (dr);
if (!base_address)
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