RFR(XS): 8194494: SHA-512 stub uses AVX 2 instructions on non-supporting CPUs
tobias.hartmann at oracle.com
Thu Jan 4 07:35:34 UTC 2018
On 03.01.2018 20:44, Vladimir Kozlov wrote:
> Even so sha512 is only implemented for 64-bit I think you should not restrict check with LP64_ONLY(). The only
> implementation uses avx2.
Okay, that makes sense. Here's the new webrev:
> On 1/3/18 8:49 AM, Tobias Hartmann wrote:
>> please review the following patch:
>> The VM crashes with SIGILL on CPUs that have the SHA extension but no AVX 2 support because since JDK-8165381 the
>> SHA-512 stub uses AVX 2 instructions (for example, 'vpblendd'). In addition to UseSHA, we need to check for
>> supports_avx2() && supports_bmi2() on x86.
>> I had no suitable machine available for testing but I was able to trigger the problem by enforcing
>> UseSHA512Intrinsics=true on my machine and disabling AVX 2 support (see comments in the bug for details).
>> This problem was reported by Csaba Mate .
>>  http://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2018-January/028002.html
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