Hello!
Attached patch fixes runtime comparison failure of 454.calculix due to
wrong movement of vzeroupper in jump2 pass. It turns out, that
can_move_insns_accross function does not special-case
unspec_volatiles, so vzeroupper is allowed to pass various 256bit avx
instructions.
The patch rejects moves of unspec_volatile insns in can_move_insn_accross.
2012-01-06 Uros Bizjak <[email protected]>
PR rtl-optimization/55845
* df-problems.c (can_move_insns_across): Stop scanning at
unspec_volatile source instruction.
2012-01-06 Uros Bizjak <[email protected]>
Vladimir Yakovlev <[email protected]>
PR rtl-optimization/55845
* gcc.target/i386/pr55845.c: New test.
Bootstrapped and regression tested on x86_64-pc-linux-gnu {,-m32} AVX target.
OK for mainline and 4.7 branch?
Uros.
Index: df-problems.c
===================================================================
--- df-problems.c (revision 194945)
+++ df-problems.c (working copy)
@@ -3916,6 +3916,10 @@ can_move_insns_across (rtx from, rtx to, rtx acros
break;
if (NONDEBUG_INSN_P (insn))
{
+ /* Do not move unspec_volatile insns. */
+ if (GET_CODE (PATTERN (insn)) == UNSPEC_VOLATILE)
+ break;
+
if (may_trap_or_fault_p (PATTERN (insn))
&& (trapping_insns_in_across || other_branch_live != NULL))
break;
Index: testsuite/gcc.target/i386/pr55845.c
===================================================================
--- testsuite/gcc.target/i386/pr55845.c (revision 0)
+++ testsuite/gcc.target/i386/pr55845.c (working copy)
@@ -0,0 +1,39 @@
+/* { dg-do run } */
+/* { dg-require-effective-target avx } */
+/* { dg-options "-O3 -ffast-math -fschedule-insns -mavx -mvzeroupper" } */
+
+#include "avx-check.h"
+
+#define N 100
+
+double
+__attribute__((noinline))
+foo (int size, double y[], double x[])
+{
+ double sum = 0.0;
+ int i;
+ for (i = 0, sum = 0.; i < size; i++)
+ sum += y[i] * x[i];
+ return (sum);
+}
+
+static void
+__attribute__ ((noinline))
+avx_test ()
+{
+ double x[N];
+ double y[N];
+ double s;
+ int i;
+
+ for (i = 0; i < N; i++)
+ {
+ x[i] = i;
+ y[i] = i;
+ }
+
+ s = foo (N, y, x);
+
+ if (s != 328350.0)
+ abort ();
+}
