Patchwork [5/6] Optimize i386 syscall inlining

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Submitter H.J. Lu
Date Oct. 21, 2015, 5:20 p.m.
Message ID <CAMe9rOqQmc5P_qMg5cPAc7Hg7Grqht6B+9TDdhG+7L8RcYUULQ@mail.gmail.com>
Download mbox | patch
Permalink /patch/9298/
State New
Headers show

Comments

H.J. Lu - Oct. 21, 2015, 5:20 p.m.
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.

Patch

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(-)

diff --git a/ChangeLog b/ChangeLog
index bc95bda..1300047 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -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]
diff --git a/sysdeps/unix/sysv/linux/i386/libc-do-syscall.S b/sysdeps/unix/sysv/linux/i386/libc-do-syscall.S
index cdef3d5..f748cf2 100644
--- a/sysdeps/unix/sysv/linux/i386/libc-do-syscall.S
+++ b/sysdeps/unix/sysv/linux/i386/libc-do-syscall.S
@@ -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.  */
diff --git a/sysdeps/unix/sysv/linux/i386/sysdep.h b/sysdeps/unix/sysv/linux/i386/sysdep.h
index 5830544..dbe5654 100644
--- a/sysdeps/unix/sysv/linux/i386/sysdep.h
+++ b/sysdeps/unix/sysv/linux/i386/sysdep.h
@@ -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