[prev in list] [next in list] [prev in thread] [next in thread] 

List:       linaro-toolchain
Subject:    Re: Question regarding the arm gcc 5.3 to build android
From:       Jim Wilson <jim.wilson () linaro ! org>
Date:       2016-03-31 17:26:42
Message-ID: CABXYE2XW1QqE1yP5DTNP6M9hYNiabyn6PrvKcB_MG2jd=Gn5SA () mail ! gmail ! com
[Download RAW message or body]

On Thu, Mar 31, 2016 at 5:12 AM, fengwei.yin <fengwei.yin@linaro.org> wrote:
> Because gcc 4.9 could build this file without any issue, I apply
> --save-temps
> with gcc 4.9. The ii file is attached. Can't see significant differences.

There is a patch in gcc-5 to make unified assembler syntax the
default.  Unfortunately, it changes how extended asms work, which is
perhaps a bug.  The message claims it doesn't affect extended asms,
but it does.
    https://gcc.gnu.org/ml/gcc-patches/2015-11/msg01196.html
The interesting bit is the change to ASM_APP_OFF.

gcc-4.9 emits a .thumb after the extended asm to switch back into
thumb mode just in case.  gcc-5.3 instead emits .syntax unified, which
doesn't change the arm/thumb mode, just the syntax supported.  This is
arguably a bug, but this doesn't immediately help you.  It could take
a little time to get gcc-5.x source fixed, and then the compiler
binary releases.  Or alternatively we could fix the asm to work with
gcc 5.

Jim
_______________________________________________
linaro-toolchain mailing list
linaro-toolchain@lists.linaro.org
https://lists.linaro.org/mailman/listinfo/linaro-toolchain

[prev in list] [next in list] [prev in thread] [next in thread]