The following patch fixes
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57018
The patch was successfully bootstrapped and tested on x86/x86-64 (with
different options).
Committed as rev. 198140.
2013-04-22 Vladimir Makarov <vmaka...@redhat.com>
PR target/57018
* lra-eliminations.c (mark_not_eliminable): Prevent elimination of
a set sp if no stack realignment.
2013-04-22 Vladimir Makarov <vmaka...@redhat.com>
PR target/57018
* gcc.target/i386/pr57018.c: New test.
Index: lra-eliminations.c
===================================================================
--- lra-eliminations.c (revision 198092)
+++ lra-eliminations.c (working copy)
@@ -716,7 +716,9 @@ mark_not_eliminable (rtx x)
ep++)
if (ep->to_rtx == SET_DEST (x)
&& SET_DEST (x) != hard_frame_pointer_rtx
- && (GET_CODE (SET_SRC (x)) != PLUS
+ && (! (SUPPORTS_STACK_ALIGNMENT && stack_realign_fp
+ && REGNO (ep->to_rtx) == STACK_POINTER_REGNUM)
+ || GET_CODE (SET_SRC (x)) != PLUS
|| XEXP (SET_SRC (x), 0) != SET_DEST (x)
|| ! CONST_INT_P (XEXP (SET_SRC (x), 1))))
setup_can_eliminate (ep, false);
Index: testsuite/gcc.target/i386/pr57018.c
===================================================================
--- testsuite/gcc.target/i386/pr57018.c (revision 0)
+++ testsuite/gcc.target/i386/pr57018.c (working copy)
@@ -0,0 +1,31 @@
+/* { dg-do run } */
+/* { dg-options "-Os -fomit-frame-pointer -fno-asynchronous-unwind-tables" } */
+/* { dg-additional-options "-march=i686" { target ia32 } } */
+
+struct A { char a[16]; } a;
+
+void __attribute__((noinline, noclone))
+foo (struct A b)
+{
+ if (__builtin_memcmp (b.a, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", 16))
+ __builtin_abort ();
+ asm volatile ("" : : : "memory");
+}
+
+void __attribute__((noinline, noclone))
+bar (struct A b)
+{
+ foo (a);
+ a = b;
+}
+
+int
+main ()
+{
+ struct A b = { "\0\1\2\3\4\5\6\7\10\11\12\13\14\15\16\17" };
+ bar (b);
+ if (__builtin_memcmp (a.a, b.a, 16))
+ __builtin_abort ();
+ return 0;
+}
+
