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tree-ssa-loop-prefetch.c (mem_ref_group, ar_data): Change step to tree. 

2010-05-19  Christian Borntraeger  <borntraeger@de.ibm.com>

        * tree-ssa-loop-prefetch.c (mem_ref_group, ar_data): Change step
	to tree.
        (dump_mem_ref): Adopt debug code to handle a tree as step.  This
	also checks for a constant int vs.  non-constant but
	loop-invariant steps.
        (find_or_create_group): Change the sort algorithm to only consider
	steps that are constant ints.
        (idx_analyze_ref): Adopt code to handle a tree instead of a
	HOST_WIDE_INT for step.
        (gather_memory_references_ref): Handle tree instead of int and be
	prepared to see a NULL_TREE.
        (prune_ref_by_self_reuse, prune_ref_by_group_reuse): Do not prune
	prefetches if the step cannot be calculated at compile time.
        (issue_prefetch_ref): Issue prefetches for non-constant but
	loop-invariant steps.

From-SVN: r159557
This commit is contained in:
Christian Borntraeger 2010-05-19 10:36:40 +00:00 committed by Andreas Krebbel
parent 8abd2cbee2
commit 81f3232690
2 changed files with 93 additions and 32 deletions
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18
gcc/ChangeLog
View File

@ -1,3 +1,21 @@
2010-05-19 Christian Borntraeger <borntraeger@de.ibm.com>
* tree-ssa-loop-prefetch.c (mem_ref_group, ar_data): Change step
to tree.
(dump_mem_ref): Adopt debug code to handle a tree as step. This
also checks for a constant int vs. non-constant but
loop-invariant steps.
(find_or_create_group): Change the sort algorithm to only consider
steps that are constant ints.
(idx_analyze_ref): Adopt code to handle a tree instead of a
HOST_WIDE_INT for step.
(gather_memory_references_ref): Handle tree instead of int and be
prepared to see a NULL_TREE.
(prune_ref_by_self_reuse, prune_ref_by_group_reuse): Do not prune
prefetches if the step cannot be calculated at compile time.
(issue_prefetch_ref): Issue prefetches for non-constant but
loop-invariant steps.
2010-05-18 Nathan Froyd <froydnj@codesourcery.com>
Revert:

107
gcc/tree-ssa-loop-prefetch.c
View File

@ -216,7 +216,7 @@ along with GCC; see the file COPYING3. If not see
struct mem_ref_group
{
tree base; /* Base of the reference. */
HOST_WIDE_INT step; /* Step of the reference. */
tree step; /* Step of the reference. */
struct mem_ref *refs; /* References in the group. */
struct mem_ref_group *next; /* Next group of references. */
};
@ -271,7 +271,10 @@ dump_mem_ref (FILE *file, struct mem_ref *ref)
fprintf (file, " group %p (base ", (void *) ref->group);
print_generic_expr (file, ref->group->base, TDF_SLIM);
fprintf (file, ", step ");
fprintf (file, HOST_WIDE_INT_PRINT_DEC, ref->group->step);
if (cst_and_fits_in_hwi (ref->group->step))
fprintf (file, HOST_WIDE_INT_PRINT_DEC, int_cst_value (ref->group->step));
else
print_generic_expr (file, ref->group->step, TDF_TREE);
fprintf (file, ")\n");
fprintf (file, " delta ");
@ -287,19 +290,20 @@ dump_mem_ref (FILE *file, struct mem_ref *ref)
exist. */
static struct mem_ref_group *
find_or_create_group (struct mem_ref_group **groups, tree base,
HOST_WIDE_INT step)
find_or_create_group (struct mem_ref_group **groups, tree base, tree step)
{
struct mem_ref_group *group;
for (; *groups; groups = &(*groups)->next)
{
if ((*groups)->step == step
if (operand_equal_p ((*groups)->step, step, 0)
&& operand_equal_p ((*groups)->base, base, 0))
return *groups;
/* Keep the list of groups sorted by decreasing step. */
if ((*groups)->step < step)
/* If step is an integer constant, keep the list of groups sorted
by decreasing step. */
if (cst_and_fits_in_hwi ((*groups)->step) && cst_and_fits_in_hwi (step)
&& int_cst_value ((*groups)->step) < int_cst_value (step))
break;
}
@ -384,7 +388,7 @@ struct ar_data
{
struct loop *loop; /* Loop of the reference. */
gimple stmt; /* Statement of the reference. */
HOST_WIDE_INT *step; /* Step of the memory reference. */
tree *step; /* Step of the memory reference. */
HOST_WIDE_INT *delta; /* Offset of the memory reference. */
};
@ -396,7 +400,7 @@ idx_analyze_ref (tree base, tree *index, void *data)
{
struct ar_data *ar_data = (struct ar_data *) data;
tree ibase, step, stepsize;
HOST_WIDE_INT istep, idelta = 0, imult = 1;
HOST_WIDE_INT idelta = 0, imult = 1;
affine_iv iv;
if (TREE_CODE (base) == MISALIGNED_INDIRECT_REF
@ -404,15 +408,11 @@ idx_analyze_ref (tree base, tree *index, void *data)
return false;
if (!simple_iv (ar_data->loop, loop_containing_stmt (ar_data->stmt),
*index, &iv, false))
*index, &iv, true))
return false;
ibase = iv.base;
step = iv.step;
if (!cst_and_fits_in_hwi (step))
return false;
istep = int_cst_value (step);
if (TREE_CODE (ibase) == POINTER_PLUS_EXPR
&& cst_and_fits_in_hwi (TREE_OPERAND (ibase, 1)))
{
@ -425,6 +425,12 @@ idx_analyze_ref (tree base, tree *index, void *data)
ibase = build_int_cst (TREE_TYPE (ibase), 0);
}
if (*ar_data->step == NULL_TREE)
*ar_data->step = step;
else
*ar_data->step = fold_build2 (PLUS_EXPR, sizetype,
fold_convert (sizetype, *ar_data->step),
fold_convert (sizetype, step));
if (TREE_CODE (base) == ARRAY_REF)
{
stepsize = array_ref_element_size (base);
@ -432,11 +438,12 @@ idx_analyze_ref (tree base, tree *index, void *data)
return false;
imult = int_cst_value (stepsize);
istep *= imult;
*ar_data->step = fold_build2 (MULT_EXPR, sizetype,
fold_convert (sizetype, *ar_data->step),
fold_convert (sizetype, step));
idelta *= imult;
}
*ar_data->step += istep;
*ar_data->delta += idelta;
*index = ibase;
@ -450,7 +457,7 @@ idx_analyze_ref (tree base, tree *index, void *data)
static bool
analyze_ref (struct loop *loop, tree *ref_p, tree *base,
HOST_WIDE_INT *step, HOST_WIDE_INT *delta,
tree *step, HOST_WIDE_INT *delta,
gimple stmt)
{
struct ar_data ar_data;
@ -458,7 +465,7 @@ analyze_ref (struct loop *loop, tree *ref_p, tree *base,
HOST_WIDE_INT bit_offset;
tree ref = *ref_p;
*step = 0;
*step = NULL_TREE;
*delta = 0;
/* First strip off the component references. Ignore bitfields. */
@ -493,8 +500,8 @@ static bool
gather_memory_references_ref (struct loop *loop, struct mem_ref_group **refs,
tree ref, bool write_p, gimple stmt)
{
tree base;
HOST_WIDE_INT step, delta;
tree base, step;
HOST_WIDE_INT delta;
struct mem_ref_group *agrp;
if (get_base_address (ref) == NULL)
@ -502,6 +509,9 @@ gather_memory_references_ref (struct loop *loop, struct mem_ref_group **refs,
if (!analyze_ref (loop, &ref, &base, &step, &delta, stmt))
return false;
/* If analyze_ref fails the default is a NULL_TREE. We can stop here. */
if (step == NULL_TREE)
return false;
/* Now we know that REF = &BASE + STEP * iter + DELTA, where DELTA and STEP
are integer constants. */
@ -576,8 +586,16 @@ gather_memory_references (struct loop *loop, bool *no_other_refs, unsigned *ref_
static void
prune_ref_by_self_reuse (struct mem_ref *ref)
{
HOST_WIDE_INT step = ref->group->step;
bool backward = step < 0;
HOST_WIDE_INT step;
bool backward;
/* If the step size is non constant, we cannot calculate prefetch_mod. */
if (!cst_and_fits_in_hwi (ref->group->step))
return;
step = int_cst_value (ref->group->step);
backward = step < 0;
if (step == 0)
{
@ -661,8 +679,8 @@ static void
prune_ref_by_group_reuse (struct mem_ref *ref, struct mem_ref *by,
bool by_is_before)
{
HOST_WIDE_INT step = ref->group->step;
bool backward = step < 0;
HOST_WIDE_INT step;
bool backward;
HOST_WIDE_INT delta_r = ref->delta, delta_b = by->delta;
HOST_WIDE_INT delta = delta_b - delta_r;
HOST_WIDE_INT hit_from;
@ -673,6 +691,16 @@ prune_ref_by_group_reuse (struct mem_ref *ref, struct mem_ref *by,
tree ref_type;
int align_unit;
/* If the step is non constant we cannot calculate prefetch_before. */
if (!cst_and_fits_in_hwi (ref->group->step)) {
return;
}
step = int_cst_value (ref->group->step);
backward = step < 0;
if (delta == 0)
{
/* If the references has the same address, only prefetch the
@ -986,7 +1014,7 @@ static void
issue_prefetch_ref (struct mem_ref *ref, unsigned unroll_factor, unsigned ahead)
{
HOST_WIDE_INT delta;
tree addr, addr_base, write_p, local;
tree addr, addr_base, write_p, local, forward;
gimple prefetch;
gimple_stmt_iterator bsi;
unsigned n_prefetches, ap;
@ -1009,13 +1037,28 @@ issue_prefetch_ref (struct mem_ref *ref, unsigned unroll_factor, unsigned ahead)
for (ap = 0; ap < n_prefetches; ap++)
{
/* Determine the address to prefetch. */
delta = (ahead + ap * ref->prefetch_mod) * ref->group->step;
addr = fold_build2 (POINTER_PLUS_EXPR, ptr_type_node,
addr_base, size_int (delta));
addr = force_gimple_operand_gsi (&bsi, unshare_expr (addr), true, NULL,
true, GSI_SAME_STMT);
if (cst_and_fits_in_hwi (ref->group->step))
{
/* Determine the address to prefetch. */
delta = (ahead + ap * ref->prefetch_mod) *
int_cst_value (ref->group->step);
addr = fold_build2 (POINTER_PLUS_EXPR, ptr_type_node,
addr_base, size_int (delta));
addr = force_gimple_operand_gsi (&bsi, unshare_expr (addr), true, NULL,
true, GSI_SAME_STMT);
}
else
{
/* The step size is non-constant but loop-invariant. We use the
heuristic to simply prefetch ahead iterations ahead. */
forward = fold_build2 (MULT_EXPR, sizetype,
fold_convert (sizetype, ref->group->step),
fold_convert (sizetype, size_int (ahead)));
addr = fold_build2 (POINTER_PLUS_EXPR, ptr_type_node, addr_base,
forward);
addr = force_gimple_operand_gsi (&bsi, unshare_expr (addr), true,
NULL, true, GSI_SAME_STMT);
}
/* Create the prefetch instruction. */
prefetch = gimple_build_call (built_in_decls[BUILT_IN_PREFETCH],
3, addr, write_p, local);