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[patch] Fix PR tree-optimization/49926
- From: Ira Rosen <IRAR at il dot ibm dot com>
- To: gcc-patches at gcc dot gnu dot org
- Date: Mon, 1 Aug 2011 19:59:00 +0300
- Subject: [patch] Fix PR tree-optimization/49926
Hi,
This patch adds another missing check for SLP reduction detection: we
should check that a statement in a reduction chain has either one use
inside the loop, or two uses: in the reduction phi node and the loop exit
phi node.
Bootstrapped and tested on powerpc64-suse-linux.
Applied to trunk.
Ira
ChangeLog:
PR tree-optimization/49926
* tree-vect-loop.c (vect_is_slp_reduction): Check that a statement
in a chain doesn't have uses both inside and outside the loop.
testsuite/ChangeLog:
PR tree-optimization/49926
* gcc.dg/vect/pr49926.c: New test.
Index: tree-vect-loop.c
===================================================================
--- tree-vect-loop.c (revision 177062)
+++ tree-vect-loop.c (working copy)
@@ -1730,7 +1730,7 @@ vect_is_slp_reduction (loop_vec_info loop_info, gi
tree lhs;
imm_use_iterator imm_iter;
use_operand_p use_p;
- int nloop_uses, size = 0;
+ int nloop_uses, size = 0, n_out_of_loop_uses;
bool found = false;
if (loop != vect_loop)
@@ -1741,6 +1741,7 @@ vect_is_slp_reduction (loop_vec_info loop_info, gi
while (1)
{
nloop_uses = 0;
+ n_out_of_loop_uses = 0;
FOR_EACH_IMM_USE_FAST (use_p, imm_iter, lhs)
{
gimple use_stmt = USE_STMT (use_p);
@@ -1757,16 +1758,22 @@ vect_is_slp_reduction (loop_vec_info loop_info, gi
break;
}
- if (flow_bb_inside_loop_p (loop, gimple_bb (use_stmt))
- && vinfo_for_stmt (use_stmt)
- && !STMT_VINFO_IN_PATTERN_P (vinfo_for_stmt (use_stmt)))
- {
- loop_use_stmt = use_stmt;
- nloop_uses++;
- }
+ if (flow_bb_inside_loop_p (loop, gimple_bb (use_stmt)))
+ {
+ if (vinfo_for_stmt (use_stmt)
+ && !STMT_VINFO_IN_PATTERN_P (vinfo_for_stmt (use_stmt)))
+ {
+ loop_use_stmt = use_stmt;
+ nloop_uses++;
+ }
+ }
+ else
+ n_out_of_loop_uses++;
- if (nloop_uses > 1)
- return false;
+ /* There are can be either a single use in the loop or two uses
in
+ phi nodes. */
+ if (nloop_uses > 1 || (n_out_of_loop_uses && nloop_uses))
+ return false;
}
if (found)
Index: testsuite/gcc.dg/vect/pr49926.c
===================================================================
--- testsuite/gcc.dg/vect/pr49926.c (revision 0)
+++ testsuite/gcc.dg/vect/pr49926.c (revision 0)
@@ -0,0 +1,23 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target vect_int } */
+
+int a, b, c[10];
+
+void
+foo (unsigned int x, int y, int z, int *w)
+{
+ do
+ {
+ *w = z;
+ y = x;
+ if (y)
+ for (b = -4; b; b++)
+ {
+ z = y &= a &= 1;
+ y &= c[b + 4];
+ }
+ }
+ while (1);
+}
+
+/* { dg-final { cleanup-tree-dump "vect" } } */