Re: Cygwin 32bit: Can't use gcc -mfpmath=sse

[HK <hk1020@t-online.de>]

On Fri, 11 Sep 2015 10:16:56 +0200, Evgeny Grin <k2k@yandex.ru> wrote:

> 10.09.2015, 23:52, "HK" <hk1020@t-online.de>:
>> On Thu, 10 Sep 2015 13:19:04 +0200, V?clav_Haisman wrote:
>>>  On 10 September 2015 at 01:30, HK wrote:
>>>>  hello.c:1:0: warning: SSE instruction set disabled, using 387
>>>>  arithmetics
>>>
>>>  Does it help to use `-march=native`? My hunch is that this is because
>>>  the default CPU type is set to such that does not have SSE.
>>
>> Yep, that did the trick. Thanks for the suggestion. Now, is this a gcc
>> build
>> build problem? The 64bit version doesn't need -march=native and that is  
>> on
>> the same computer.
>
> It's not a problem as by default GCC generate code compatible with  
> maximum number of CPU models.
> If you need to generate an SSE instructions, you have to use at lest  
> -march=pentium3.
> For x86-64 version, SSE is always enabled as all x86-64 CPUs support SSE  
> and SSE2.
> See http://gcc.gnu.org/onlinedocs/gcc/x86-Options.html#x86-Options

Thanks. While I don't quite agree with the choice of defaults it makes  
sense.
So does my 32bit window next to the 64bit window on the same computer  
really
have a different instruction set? Anyway, case closed.

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