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[PATCH] Fix shrink-wrapping detection with crtl->drap_reg (PR target/50725)
- From: Jakub Jelinek <jakub at redhat dot com>
- To: gcc-patches at gcc dot gnu dot org
- Cc: Bernd Schmidt <bernds at codesourcery dot com>
- Date: Wed, 30 Nov 2011 18:38:37 +0100
- Subject: [PATCH] Fix shrink-wrapping detection with crtl->drap_reg (PR target/50725)
- Reply-to: Jakub Jelinek <jakub at redhat dot com>
Hi!
As the following testcase shows, when the prologue computes crtl->drap_reg
(when stack_realign_drap) and something e.g. in the first bb uses that
register, we can incorrectly shrink-wrap it and use uninitialized %ecx/%r10
etc. register.
Fixed by making the drap regno also added to SET_UP_BY_PROLOGUE regset.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2011-11-30 Jakub Jelinek <jakub@redhat.com>
PR target/50725
* function.c (thread_prologue_and_epilogue_insns): If
stack_realign_drap, add drap_reg to SET_UP_BY_PROLOGUE
regset.
* gcc.target/i386/pr50725.c: New test.
--- gcc/function.c.jj 2011-11-29 08:58:52.000000000 +0100
+++ gcc/function.c 2011-11-30 10:29:18.720041709 +0100
@@ -5893,6 +5893,9 @@ thread_prologue_and_epilogue_insns (void
if (pic_offset_table_rtx)
add_to_hard_reg_set (&set_up_by_prologue, Pmode,
PIC_OFFSET_TABLE_REGNUM);
+ if (stack_realign_drap && crtl->drap_reg)
+ add_to_hard_reg_set (&set_up_by_prologue, GET_MODE (crtl->drap_reg),
+ REGNO (crtl->drap_reg));
/* We don't use a different max size depending on
optimize_bb_for_speed_p because increasing shrink-wrapping
--- gcc/testsuite/gcc.target/i386/pr50725.c.jj 2011-11-30 10:45:00.703961208 +0100
+++ gcc/testsuite/gcc.target/i386/pr50725.c 2011-11-30 10:54:18.900654771 +0100
@@ -0,0 +1,48 @@
+/* PR target/50725 */
+/* { dg-do run { target avx_runtime } } */
+/* { dg-options "-O2 -mavx" } */
+
+extern void abort (void);
+
+typedef int __attribute__((vector_size (32))) m256i;
+
+__attribute__((noinline, noclone)) void
+foo (int *x, m256i *y)
+{
+ asm volatile ("" : : "r" (x), "r" (y) : "memory");
+}
+
+__attribute__((noinline, noclone)) int
+bar (int x)
+{
+ if (x > 20)
+ return 24;
+ m256i i;
+ foo (__builtin_alloca (x), &i);
+ return 128;
+}
+
+__attribute__((noinline, noclone)) int
+baz (int d0, int d1, int d2, int d3, int d4, int d5, int x)
+{
+ if (x > 20)
+ return 24;
+ m256i i;
+ d0 += d1 + d2 + d3 + d4 + d5; d1 += d0;
+ foo (__builtin_alloca (x), &i);
+ return 128;
+}
+
+int
+main ()
+{
+ if (bar (22) != 24 || bar (20) != 128)
+ abort ();
+#ifdef __x86_64__
+ register long r10 __asm__ ("r10") = 0xdeadbeefdeadbeefUL;
+ asm volatile ("" : "+r" (r10));
+#endif
+ if (baz (0, 0, 0, 0, 0, 0, 22) != 24 || baz (0, 0, 0, 0, 0, 0, 20) != 128)
+ abort ();
+ return 0;
+}
Jakub