在 2019/2/25 22:41, Liu Hao 写道:
> 在 2019/2/25 19:27, Zidane Sama 写道:
>> After this commit:
>>
>> [e98d80] (2.0 kB) by Kai Tietz
>> Add a fix for working fesetenv in libquadmath-library
>>
>> fesetenv was broken and do not sets new fpu state because it's now
>> overwrites new env state by fnstenv.
>>
>> And this patch must fix it by store only mxcsr and load its afterwards:
>>
>> diff --git a/mingw-w64-crt/misc/fesetenv.c b/mingw-w64-crt/misc/fesetenv.c
>> index f998017b..07035c66 100644
>> --- a/mingw-w64-crt/misc/fesetenv.c
>> +++ b/mingw-w64-crt/misc/fesetenv.c
>> @@ -66,8 +66,7 @@ int fesetenv (const fenv_t * envp)
>> {
>> fenv_t env = *envp;
>> int _mxcsr;
>> - __asm__ ("fnstenv %0\n"
>> - "stmxcsr %1" : "=m" (*&env), "=m" (*&_mxcsr));
>> + __asm__ ("stmxcsr %0" : "=m" (*&_mxcsr));
>> /*_mxcsr = ((int)envp->__unused0 << 16) | (int)envp->__unused1;
>> *//* mxcsr low and high */
>> env.__unused0 = 0xffff;
>> env.__unused1 = 0xffff;
>>
>>
>>
>
> This seems a good catch.
>
> However I think the `STMXCSR` instruction should follow
> `__mingw_has_sse()`, although CPUs without SSE are rare. I propose
> another patch to address this issue.
>
>
>Ping? Do you have any testcases related to this issue? Please notice that without any response we will not act on this. -- Best regards, LH_Mouse
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