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re PR tree-optimization/58223 (wrong code at -O3 on x86_64-linux-gnu)

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2013-08-30  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/58223
	* tree-loop-distribution.c (has_anti_dependence): Rename to ...
	(has_anti_or_output_dependence): ... this and adjust to also
	look for output dependences.
	(mark_nodes_having_upstream_mem_writes): Adjust.
	(rdg_flag_uses): Likewise.

	* gcc.dg/torture/pr58223.c: New testcase.
	* gcc.dg/tree-ssa/ldist-16.c: Flip expected behavior.

From-SVN: r202096
This commit is contained in:
Richard Biener 2013-08-30 07:48:53 +00:00 • committed by Richard Biener
parent 7a764c608a
commit 062ef2c8f9
5 changed files with 45 additions and 13 deletions
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9
gcc/ChangeLog
View file

@ -1,3 +1,12 @@
2013-08-30 Richard Biener <rguenther@suse.de>
PR tree-optimization/58223
* tree-loop-distribution.c (has_anti_dependence): Rename to ...
(has_anti_or_output_dependence): ... this and adjust to also
look for output dependences.
(mark_nodes_having_upstream_mem_writes): Adjust.
(rdg_flag_uses): Likewise.
2013-08-30 Richard Biener <rguenther@suse.de>
PR tree-optimization/58010

6
gcc/testsuite/ChangeLog
View file

@ -1,3 +1,9 @@
2013-08-30 Richard Biener <rguenther@suse.de>
PR tree-optimization/58223
* gcc.dg/torture/pr58223.c: New testcase.
* gcc.dg/tree-ssa/ldist-16.c: Flip expected behavior.
2013-08-30 Richard Biener <rguenther@suse.de>
PR tree-optimization/58010

16
gcc/testsuite/gcc.dg/torture/pr58223.c Normal file
View file

@ -0,0 +1,16 @@
/* { dg-do run } */
extern void abort (void);
int a[2], b;
int main ()
{
for (b = 0; b < 2; b++)
{
a[0] = 1;
a[b] = 0;
}
if (a[0] != 1)
abort ();
return 0;
}

6
gcc/testsuite/gcc.dg/tree-ssa/ldist-16.c
View file

@ -14,8 +14,8 @@ void foo (int n)
}
}
/* We should apply loop distribution and generate a memset (0). */
/* We should not apply loop distribution and not generate a memset (0). */
/* { dg-final { scan-tree-dump "distributed: split to 2" "ldist" } } */
/* { dg-final { scan-tree-dump-times "generated memset zero" 1 "ldist" } } */
/* { dg-final { scan-tree-dump "Loop 1 is the same" "ldist" } } */
/* { dg-final { scan-tree-dump-times "generated memset zero" 0 "ldist" } } */
/* { dg-final { cleanup-tree-dump "ldist" } } */

21
gcc/tree-loop-distribution.c
View file

@ -542,17 +542,19 @@ already_processed_vertex_p (bitmap processed, int v)
|| !bitmap_bit_p (remaining_stmts, v));
}
/* Returns NULL when there is no anti-dependence among the successors
of vertex V, otherwise returns the edge with the anti-dep. */
/* Returns NULL when there is no anti-dependence or output-dependence
among the successors of vertex V, otherwise returns the edge with the
dependency. */
static struct graph_edge *
has_anti_dependence (struct vertex *v)
has_anti_or_output_dependence (struct vertex *v)
{
struct graph_edge *e;
if (v->succ)
for (e = v->succ; e; e = e->succ_next)
if (RDGE_TYPE (e) == anti_dd)
if (RDGE_TYPE (e) == anti_dd
|| RDGE_TYPE (e) == output_dd)
return e;
return NULL;
@ -604,11 +606,10 @@ mark_nodes_having_upstream_mem_writes (struct graph *rdg)
|| predecessor_has_mem_write (rdg, &(rdg->vertices[x]))
/* In anti dependences the read should occur before
the write, this is why both the read and the write
should be placed in the same partition. */
|| has_anti_dependence (&(rdg->vertices[x])))
{
bitmap_set_bit (upstream_mem_writes, x);
}
should be placed in the same partition. In output
dependences the writes order need to be preserved. */
|| has_anti_or_output_dependence (&(rdg->vertices[x])))
bitmap_set_bit (upstream_mem_writes, x);
}
nodes.release ();
@ -637,7 +638,7 @@ rdg_flag_uses (struct graph *rdg, int u, partition_t partition, bitmap loops,
use_operand_p use_p;
struct vertex *x = &(rdg->vertices[u]);
gimple stmt = RDGV_STMT (x);
struct graph_edge *anti_dep = has_anti_dependence (x);
struct graph_edge *anti_dep = has_anti_or_output_dependence (x);
/* Keep in the same partition the destination of an antidependence,
because this is a store to the exact same location. Putting this