https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111107
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |10walls at gmail dot com
--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
I'd say that
config/i386/cygming.h:#define STACK_REALIGN_DEFAULT TARGET_SSE
is a non-working "fix". The appropriate default would be
-mincoming-stack-boundary=2. MIN_STACK_BOUNDARY should already be 4, so that
leaves PREFERRED_STACK_BOUNDARY_DEFAULT is the way to go here. I also see
/* It should be MIN_STACK_BOUNDARY. But we set it to 128 bits for
both 32bit and 64bit, to support codes that need 128 bit stack
alignment for SSE instructions, but can't realign the stack. */
#define PREFERRED_STACK_BOUNDARY_DEFAULT \
(TARGET_IAMCU ? MIN_STACK_BOUNDARY : 128)
which suggests there might be problems with SSE anyway.
So does the following work?
diff --git a/gcc/config/i386/cygming.h b/gcc/config/i386/cygming.h
index d539f8d0699..e8db548510b 100644
--- a/gcc/config/i386/cygming.h
+++ b/gcc/config/i386/cygming.h
@@ -31,10 +31,9 @@ along with GCC; see the file COPYING3. If not see
#undef MAX_STACK_ALIGNMENT
#define MAX_STACK_ALIGNMENT (TARGET_SEH ? 128 : MAX_OFILE_ALIGNMENT)
-/* 32-bit Windows aligns the stack on a 4-byte boundary but SSE instructions
- may require 16-byte alignment. */
-#undef STACK_REALIGN_DEFAULT
-#define STACK_REALIGN_DEFAULT TARGET_SSE
+/* 32-bit Windows aligns the stack on a 4-byte boundary. */
+#undef PREFERRED_STACK_BOUNDARY_DEFAULT
+#define PREFERRED_STACK_BOUNDARY_DEFAULT (TARGET_64BIT ? 128 : 32)
/* Support hooks for SEH. */
#undef TARGET_ASM_UNWIND_EMIT
