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Date: Tue, 13 Jul 2010 20:40:00 -0000
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Subject: Re: Turn on -fomit-frame-pointer by default for 32bit x86?
From: Richard Guenther <richard.guenther@gmail.com>
To: "H.J. Lu" <hjl.tools@gmail.com>
Cc: GCC Patches <gcc-patches@gcc.gnu.org>, Uros Bizjak <ubizjak@gmail.com>
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On Tue, Jul 13, 2010 at 8:15 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> Hi,
>
> I checked the default code for 32bit. We currently generate
>
> [hjl@gnu-6 tmp]$ cat x.c
> void
> foo ()
> {
> }
> [hjl@gnu-6 tmp]$ /usr/gcc-4.5/bin/gcc -m32 -S x.c -O3
> [hjl@gnu-6 tmp]$ cat x.s
> =A0 =A0 =A0 =A0.file =A0 "x.c"
> =A0 =A0 =A0 =A0.text
> .globl foo
> =A0 =A0 =A0 =A0.type =A0 foo, @function
> foo:
> =A0 =A0 =A0 =A0pushl =A0 %ebp
> =A0 =A0 =A0 =A0movl =A0 =A0%esp, %ebp
> =A0 =A0 =A0 =A0popl =A0 =A0%ebp
> =A0 =A0 =A0 =A0ret
>
> Can we turn on -fomit-frame-pointer by default for 32bit?

No, we don't have unwind information by default for 32bit.

Richard.

>
> --
> H.J.
>