[PATCH 5/6] Optimize i386 syscall inlining

[Roland McGrath]

> On Thu, Oct 15, 2015 at 12:54 PM, Roland McGrath <roland@hack.frob.com> wrote:
> > This needs comments explaining why the compiler version conditional
> > makes sense.
> 
> How about this?

Looks OK.

> -- 
> H.J.
> ----
> diff --git a/sysdeps/unix/sysv/linux/i386/sysdep.h
> b/sysdeps/unix/sysv/linux/i386/sysdep.h
> index 5324da6..76db7b8 100644
> --- a/sysdeps/unix/sysv/linux/i386/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/i386/sysdep.h
> @@ -227,6 +227,10 @@
>  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.  */
> +
>  #if !__GNUC_PREREQ (5,0)
>  /* We need some help from the assembler to generate optimal code.  We
>     define some macros here which later will be used.  */