gcc: For Windows x86-32, always attempt to realign stack regardless of SSE

For Windows x86-32 targets, the Microsoft ABI only guarantees that the stack
is aligned to 4-byte boundaries. GCC knows about the default alignment of the
stack. However, before this commit, it did not realign the stack unless SSE
was also enabled.

When a stricter (larger) alignment is requested, it's always necessary to
realign the stack, as what Solaris does.

Reference: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111107#c14
Signed-off-by: LIU Hao <lh_mouse@126.com>
Signed-off-by: Jonathan Yong <10walls@gmail.com>
gcc/ChangeLog:

	PR target/111107
	* config/i386/cygming.h (STACK_REALIGN_DEFAULT): Copy from sol2.h.

diff --git a/gcc/config/i386/cygming.h b/gcc/config/i386/cygming.h
index 3ddcbecb22fdb4059ecbfdbfcd6a14c9ef908c2e..d587d25a58a863baa696add500654182a2588d46 100644 (file)
--- a/gcc/config/i386/cygming.h
+++ b/gcc/config/i386/cygming.h
@@ -36,7 +36,7 @@ along with GCC; see the file COPYING3.  If not see
 /* 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
+#define STACK_REALIGN_DEFAULT (TARGET_64BIT ? 0 : 1)
 
 /* Support hooks for SEH.  */
 #undef  TARGET_ASM_UNWIND_EMIT