RFR(L): 8081247 AVX 512 extended support code review request

[Nils Eliasson]

Hi Michael,

The patch looks good.

Thanks for contributing,
Nils


On 2015-06-05 06:46, Berg, Michael C wrote:
> Vladimir please find the following webrev with the suggested changes, I have added small signature functions which look like the old versions  in the assembler but manage the problem I need to handle, which is additional state for legacy only instructions. There is a new vm_version function which handles the cpuid checks with a conglomerate approach for the one scenario which had it.
> The loop in the stub generator is now formed to alter the upper bound and execute in one path.
>
> http://cr.openjdk.java.net/~mcberg/8081247/webrev.03/
>
> Regards,
> Michael
>
> -----Original Message-----
> From: Vladimir Kozlov [mailto:vladimir.kozlov at oracle.com]
> Sent: Wednesday, June 03, 2015 6:10 PM
> To: Berg, Michael C; 'hotspot-compiler-dev at openjdk.java.net'
> Subject: Re: RFR(L): 8081247 AVX 512 extended support code review request
>
> Hi, Michael
>
> assembler_x86.cpp:
>
> I don't like that you replaced prefix method with few parameters with method which has a lot of them:
>
> -  int encode = vex_prefix_0F38_and_encode_q(dst, src1, src2);
> +  int encode = vex_prefix_and_encode(dst->encoding(), src1->encoding(),
> src2->encoding(),
> +                                     VEX_SIMD_NONE, VEX_OPCODE_0F_38,
> true, AVX_128bit,
> +                                     true, false);
>
> Why you did that?
>
>
> stubGenerator_x86_64.cpp:
>
> Can we set different loop limit based on UseAVX instead of having 2 loops.
>
> x86.ad:
>
> Instead of long condition expressions like next:
>
> UseAVX > 0 && !VM_Version::supports_avx512vl() &&
> !VM_Version::supports_avx512bw()
>
> May be have one VM_Version finction which does these checks.
>
> Thanks,
> Vladimir
>
> On 6/2/15 9:38 PM, Berg, Michael C wrote:
>> Hi Folks,
>>
>> I would like to contribute more AVX512 enabling to facilitate support
>> for machines which utilize EVEX encoding. I need two reviewers to
>> review this patch and comment as needed:
>>
>> Bug-id: https://bugs.openjdk.java.net/browse/JDK-8081247
>>
>> webrev:
>>
>> http://cr.openjdk.java.net/~mcberg/8081247/webrev.01/
>>
>> This patch enables BMI code on EVEX targets, improves replication
>> patterns to be more efficient on both EVEX enabled and legacy targets,
>> adds more CPUID based rules for correct code generation on various
>> EVEX enabled servers, extends more call save/restore functionality and
>> extends the vector space further for SIMD operations.  Please expedite
>> this review as there is a near term need for the support.
>>
>> Also, as I am not yet a committer, this code needs a sponsor as well.
>>
>> Thanks,
>>
>> Michael
>>