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Fix MIPS32 frame-pointer forcing for more recent GCC
- From: "Joseph S. Myers" <joseph at codesourcery dot com>
- To: libc-ports at sourceware dot org
- Date: Thu, 14 Jun 2012 15:21:08 +0000 (UTC)
- Subject: Fix MIPS32 frame-pointer forcing for more recent GCC
The alloca call in FORCE_FRAME_POINTER in
sysdeps/unix/sysv/linux/mips/mips32/sysdep.h is optimized away by GCC 4.7,
resulting in failures of nptl/tst-cancel4, tst-cancel5, tst-cancelx4,
tst-cancelx5. I've applied this patch that fixes those failures by
assigning the result of alloca to a volatile variable, so preventing it
from being optimized away.
diff --git a/ChangeLog.mips b/ChangeLog.mips
index 853f286..9469b5c 100644
--- a/ChangeLog.mips
+++ b/ChangeLog.mips
@@ -1,3 +1,9 @@
+2012-06-14 Joseph Myers <joseph@codesourcery.com>
+
+ * sysdeps/unix/sysv/linux/mips/mips32/sysdep.h
+ (FORCE_FRAME_POINTER): Assign result of alloca to a volatile
+ variable.
+
2012-06-01 Joseph Myers <joseph@codesourcery.com>
* sysdeps/mips/mips64/n32/s_fma.c: New file.
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/sysdep.h b/sysdeps/unix/sysv/linux/mips/mips32/sysdep.h
index e51f329..8c024b0 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/sysdep.h
+++ b/sysdeps/unix/sysv/linux/mips/mips32/sysdep.h
@@ -194,8 +194,9 @@
/* We need to use a frame pointer for the functions in which we
adjust $sp around the syscall, or debug information and unwind
information will be $sp relative and thus wrong during the syscall. As
- of GCC 3.4.3, this is sufficient. */
-#define FORCE_FRAME_POINTER alloca (4)
+ of GCC 4.7, this is sufficient. */
+#define FORCE_FRAME_POINTER \
+ void *volatile __fp_force __attribute__ ((unused)) = alloca (4)
#define internal_syscall5(ncs_init, cs_init, input, err, arg1, arg2, arg3, arg4, arg5)\
({ \
--
Joseph S. Myers
joseph@codesourcery.com