On Sun, Dec 30, 2012 at 8:08 PM, Uros Bizjak <ubiz...@gmail.com> wrote:
> On Fri, Dec 28, 2012 at 9:27 PM, Richard Henderson <r...@redhat.com> wrote:
>> On 12/27/2012 12:08 AM, Uros Bizjak wrote:
>>> The alternative approach is changing cpuid definition in cpuid.h (as
>>> in attached patch) to preserve %rbx, but we can't detect various code
>>> model settings there. Since the change depends on the definition of
>>> __PIC__, we unnecessary preserve %rbx also for -mcmodel=small.
>>
>> Certainly we can. We also control the preprocessor defines.
>> All that's needed is that we create one for the code model.
>
> Something like attached?
>
> I have also included all suggestions (earlyclobber and operand prefix
> on temporary register).
>
> 2012-12-30 Uros Bizjak <ubiz...@gmail.com>
>
> PR target/55712
> * config/i386/i386-c.c (ix86_target_macros_internal): Depending on
> selected code model, define __code_mode_small__,
> __code_model_medium__,
> __code_model_large__, __code_model_32__ or __code_model_kernel__.
> * config/i386/cpuid.h (__cpuid, __cpuid_count) [__i386__]: Prefix
> xchg temporary register with %k. Declare temporary register as
> early clobbered.
> [__x86_64__]: For medium and large code models, preserve %rbx
> register.
>
> Tested on x86_64-pc-linux-gnu {,-m32}.
I have committed the patch to mainline SVN. The patch will be
backported to 4.7 branch after a couple of days.
Uros.
