http://en.wikipedia.org/wiki/Advanced_Vector_Extensions#CPUs_with_AVX

For what it's worth, bit 28 of ECX indicates whether the CPU has AVX
(for the cpuid instruction).

Regards,
Alex

On Sun, Jan 15, 2012 at 11:04 PM, Walter Bright <walter at digitalmars.com> wrote:
> http://en.wikipedia.org/wiki/Advanced_Vector_Extensions#CPUs_with_AVX
> _______________________________________________
> D-runtime mailing list
> D-runtime at puremagic.com
> http://lists.puremagic.com/mailman/listinfo/d-runtime

There seems to be commented out support for detecting AVX already: https://github.com/D-Programming-Language/druntime/blob/master/src/core/cpuid.d#L275

Any reason this isn't enabled?

Regards,
Alex

On Sun, Jan 15, 2012 at 11:08 PM, Alex <xtzgzorex at gmail.com> wrote:
> For what it's worth, bit 28 of ECX indicates whether the CPU has AVX
> (for the cpuid instruction).
>
> Regards,
> Alex
>
> On Sun, Jan 15, 2012 at 11:04 PM, Walter Bright <walter at digitalmars.com> wrote:
>> http://en.wikipedia.org/wiki/Advanced_Vector_Extensions#CPUs_with_AVX
>> _______________________________________________
>> D-runtime mailing list
>> D-runtime at puremagic.com
>> http://lists.puremagic.com/mailman/listinfo/d-runtime

That's bit 25, but you mentioned bit 28?

On 1/15/2012 2:11 PM, Alex wrote:
> There seems to be commented out support for detecting AVX already: https://github.com/D-Programming-Language/druntime/blob/master/src/core/cpuid.d#L275
>
> Any reason this isn't enabled?
>
> Regards,
> Alex
>
> On Sun, Jan 15, 2012 at 11:08 PM, Alex<xtzgzorex at gmail.com>  wrote:
>> For what it's worth, bit 28 of ECX indicates whether the CPU has AVX
>> (for the cpuid instruction).
>>
>> Regards,
>> Alex
>>
>> On Sun, Jan 15, 2012 at 11:04 PM, Walter Bright<walter at digitalmars.com>  wrote:
>>> http://en.wikipedia.org/wiki/Advanced_Vector_Extensions#CPUs_with_AVX
>>> _______________________________________________
>>> D-runtime mailing list
>>> D-runtime at puremagic.com
>>> http://lists.puremagic.com/mailman/listinfo/d-runtime
> _______________________________________________
> D-runtime mailing list
> D-runtime at puremagic.com
> http://lists.puremagic.com/mailman/listinfo/d-runtime
>
>

Hm, bit 25 is the AES extensions seemingly (at least in ECX).

See: http://en.wikipedia.org/wiki/CPUID#EAX.3D1:_Processor_Info_and_Feature_Bits

Regards,
Alex

On Sun, Jan 15, 2012 at 11:52 PM, Walter Bright <walter at digitalmars.com> wrote:
> That's bit 25, but you mentioned bit 28?
>
>
> On 1/15/2012 2:11 PM, Alex wrote:
>>
>> There seems to be commented out support for detecting AVX already:
>>
>> https://github.com/D-Programming-Language/druntime/blob/master/src/core/cpuid.d#L275
>>
>> Any reason this isn't enabled?
>>
>> Regards,
>> Alex
>>
>> On Sun, Jan 15, 2012 at 11:08 PM, Alex<xtzgzorex at gmail.com> ?wrote:
>>>
>>> For what it's worth, bit 28 of ECX indicates whether the CPU has AVX
>>> (for the cpuid instruction).
>>>
>>> Regards,
>>> Alex
>>>
>>> On Sun, Jan 15, 2012 at 11:04 PM, Walter Bright<walter at digitalmars.com> ?wrote:
>>>>
>>>> http://en.wikipedia.org/wiki/Advanced_Vector_Extensions#CPUs_with_AVX
>>>> _______________________________________________
>>>> D-runtime mailing list
>>>> D-runtime at puremagic.com
>>>> http://lists.puremagic.com/mailman/listinfo/d-runtime
>>
>> _______________________________________________
>> D-runtime mailing list
>> D-runtime at puremagic.com
>> http://lists.puremagic.com/mailman/listinfo/d-runtime
>>
>>
> _______________________________________________
> D-runtime mailing list
> D-runtime at puremagic.com
> http://lists.puremagic.com/mailman/listinfo/d-runtime

On 15 January 2012 22:52, Walter Bright <walter at digitalmars.com> wrote:
> That's bit 25, but you mentioned bit 28?
>
>

A quick look-up, hasAVXinHardware() should check 28 bit in ECX,  Avx()
should check 27 bit and 28.



> On 1/15/2012 2:11 PM, Alex wrote:
>>
>> There seems to be commented out support for detecting AVX already:
>>
>> https://github.com/D-Programming-Language/druntime/blob/master/src/core/cpuid.d#L275
>>
>> Any reason this isn't enabled?
>>
>> Regards,
>> Alex
>>
>> On Sun, Jan 15, 2012 at 11:08 PM, Alex<xtzgzorex at gmail.com> ?wrote:
>>>
>>> For what it's worth, bit 28 of ECX indicates whether the CPU has AVX
>>> (for the cpuid instruction).
>>>
>>> Regards,
>>> Alex
>>>
>>> On Sun, Jan 15, 2012 at 11:04 PM, Walter Bright<walter at digitalmars.com> ?wrote:
>>>>
>>>> http://en.wikipedia.org/wiki/Advanced_Vector_Extensions#CPUs_with_AVX
>>>> _______________________________________________
>>>> D-runtime mailing list
>>>> D-runtime at puremagic.com
>>>> http://lists.puremagic.com/mailman/listinfo/d-runtime
>>
>> _______________________________________________
>> D-runtime mailing list
>> D-runtime at puremagic.com
>> http://lists.puremagic.com/mailman/listinfo/d-runtime
>>
>>
> _______________________________________________
> D-runtime mailing list
> D-runtime at puremagic.com
> http://lists.puremagic.com/mailman/listinfo/d-runtime



-- 
Iain Buclaw

*(p < e ? p++ : p) = (c & 0x0f) + '0';

On Sun, 15 Jan 2012 23:04:09 +0100, Walter Bright <walter at digitalmars.com> wrote:

> http://en.wikipedia.org/wiki/Advanced_Vector_Extensions#CPUs_with_AVX
> _______________________________________________
> D-runtime mailing list
> D-runtime at puremagic.com
> http://lists.puremagic.com/mailman/listinfo/d-runtime

I did wrote that too sometime ago.
DMD is missing the xgetbv instruction to do so.

On Sun, 15 Jan 2012 23:52:01 +0100, Walter Bright <walter at digitalmars.com> wrote:

> That's bit 25, but you mentioned bit 28?
>
> On 1/15/2012 2:11 PM, Alex wrote:
>> There seems to be commented out support for detecting AVX already: https://github.com/D-Programming-Language/druntime/blob/master/src/core/cpuid.d#L275
>>
>> Any reason this isn't enabled?
>>
>> Regards,
>> Alex
>>
>> On Sun, Jan 15, 2012 at 11:08 PM, Alex<xtzgzorex at gmail.com>  wrote:
>>> For what it's worth, bit 28 of ECX indicates whether the CPU has AVX
>>> (for the cpuid instruction).
>>>
>>> Regards,
>>> Alex
>>>
>>> On Sun, Jan 15, 2012 at 11:04 PM, Walter Bright<walter at digitalmars.com>  wrote:
>>>> http://en.wikipedia.org/wiki/Advanced_Vector_Extensions#CPUs_with_AVX
>>>> _______________________________________________
>>>> D-runtime mailing list
>>>> D-runtime at puremagic.com
>>>> http://lists.puremagic.com/mailman/listinfo/d-runtime
>> _______________________________________________
>> D-runtime mailing list
>> D-runtime at puremagic.com
>> http://lists.puremagic.com/mailman/listinfo/d-runtime
>>
>>
> _______________________________________________
> D-runtime mailing list
> D-runtime at puremagic.com
> http://lists.puremagic.com/mailman/listinfo/d-runtime

https://github.com/dawgfoto/druntime/tree/DetectAVX

You need to check cpuid first for miscfeatures & OS_XSAVE (1 << 27).
Must be set or executing xgetbv will cause #GP.
Then xgetbv with index 0 will return the XFEATURES_ENABLED_MASK,
which shows you whether your OS does save YMM registers.
Currently this should work for linux, OSX > 10.6.8, Windows7 SP1.

On 1/15/2012 4:27 PM, Martin Nowak wrote:
>
> DMD is missing the xgetbv instruction to do so.
>

Not no more!

On 15 January 2012 23:11, Alex <xtzgzorex at gmail.com> wrote:
> There seems to be commented out support for detecting AVX already: https://github.com/D-Programming-Language/druntime/blob/master/src/core/cpuid.d#L275
>
> Any reason this isn't enabled?

I actually wrote that code before any AVX processors had ever been released. So it was entirely speculative.

>
> Regards,
> Alex
>
> On Sun, Jan 15, 2012 at 11:08 PM, Alex <xtzgzorex at gmail.com> wrote:
>> For what it's worth, bit 28 of ECX indicates whether the CPU has AVX
>> (for the cpuid instruction).
>>
>> Regards,
>> Alex
>>
>> On Sun, Jan 15, 2012 at 11:04 PM, Walter Bright <walter at digitalmars.com> wrote:
>>> http://en.wikipedia.org/wiki/Advanced_Vector_Extensions#CPUs_with_AVX
>>> _______________________________________________
>>> D-runtime mailing list
>>> D-runtime at puremagic.com
>>> http://lists.puremagic.com/mailman/listinfo/d-runtime
> _______________________________________________
> D-runtime mailing list
> D-runtime at puremagic.com
> http://lists.puremagic.com/mailman/listinfo/d-runtime