[5/6] Optimize i386 syscall inlining
Commit Message
On Wed, Oct 21, 2015 at 9:39 AM, Joseph Myers <joseph@codesourcery.com> wrote:
> On Wed, 21 Oct 2015, H.J. Lu wrote:
>
>> On Wed, Oct 21, 2015 at 8:01 AM, Andreas Schwab <schwab@suse.de> wrote:
>> > "H.J. Lu" <hjl.tools@gmail.com> writes:
>> >
>> >> Which GCC are you using?
>> >
>> > https://build.opensuse.org/package/show/openSUSE:Factory/gcc5
>> >
>> > Andreas.
>>
>> I am testing this patch and will check it in if it passes check.
>
> Do you also need to change libc-do-syscall.S to build __libc_do_syscall
> for the profiling libc?
>
Yes. I checked in this patch to provide __libc_do_syscall for
profiling libc.
From 95b097779a670dca5f06fbceede31de60046ed76 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Wed, 21 Oct 2015 09:54:36 -0700
Subject: [PATCH] Build i386 __libc_do_syscall when PROF is defined
Need to provide i386 __libc_do_syscall when PROF is defined.
Define OPTIMIZE_FOR_GCC_5 for .S files so that it can be used
in libc-do-syscall.S.
* sysdeps/unix/sysv/linux/i386/libc-do-syscall.S: Replace
__GNUC_PREREQ (5,0) with OPTIMIZE_FOR_GCC_5.
* sysdeps/unix/sysv/linux/i386/sysdep.h (OPTIMIZE_FOR_GCC_5):
Moved before "#ifdef __ASSEMBLER__".
---
ChangeLog | 7 +++++++
sysdeps/unix/sysv/linux/i386/libc-do-syscall.S | 2 +-
sysdeps/unix/sysv/linux/i386/sysdep.h | 19 +++++++++----------
3 files changed, 17 insertions(+), 11 deletions(-)
@@ -1,3 +1,10 @@
+2015-10-21 H.J. Lu <hongjiu.lu@intel.com>
+
+ * sysdeps/unix/sysv/linux/i386/libc-do-syscall.S: Replace
+ __GNUC_PREREQ (5,0) with OPTIMIZE_FOR_GCC_5.
+ * sysdeps/unix/sysv/linux/i386/sysdep.h (OPTIMIZE_FOR_GCC_5):
+ Moved before "#ifdef __ASSEMBLER__".
+
2015-10-21 Joseph Myers <joseph@codesourcery.com>
[BZ #19156]
@@ -18,7 +18,7 @@
#include <sysdep.h>
-#if !__GNUC_PREREQ (5,0)
+#ifndef OPTIMIZE_FOR_GCC_5
/* %eax, %ecx, %edx and %esi contain the values expected by the kernel.
%edi points to a structure with the values of %ebx, %edi and %ebp. */
@@ -41,6 +41,15 @@
# undef I386_USE_SYSENTER
#endif
+/* Since GCC 5 and above can properly spill %ebx with PIC when needed,
+ we can inline syscalls with 6 arguments if GCC 5 or above is used
+ to compile glibc. Disable GCC 5 optimization when compiling for
+ profiling since asm ("ebp") can't be used to put the 6th argument
+ in %ebp for syscall. */
+#if __GNUC_PREREQ (5,0) && !defined PROF
+# define OPTIMIZE_FOR_GCC_5
+#endif
+
#ifdef __ASSEMBLER__
/* Linux uses a negative return value to indicate syscall errors,
@@ -227,16 +236,6 @@
extern int __syscall_error (int)
attribute_hidden __attribute__ ((__regparm__ (1)));
-/* Since GCC 5 and above can properly spill %ebx with PIC when needed,
- we can inline syscalls with 6 arguments if GCC 5 or above is used
- to compile glibc. Disable GCC 5 optimization when compiling for
- profiling since asm ("ebp") can't be used to put the 6th argument
- in %ebp for syscall. */
-
-#if __GNUC_PREREQ (5,0) && !defined PROF
-# define OPTIMIZE_FOR_GCC_5
-#endif
-
#ifndef OPTIMIZE_FOR_GCC_5
/* We need some help from the assembler to generate optimal code. We
define some macros here which later will be used. */
--
2.4.3