[9] RFR(S): 8158214: Crash with "assert(VM_Version::supports_sse4_1()) failed" if UseSSE < 4 is set

[Vladimir Kozlov]

Is it only pinsrd instruction requires sse4.1? I looked on crc32 code 
and we can use pinsrw instruction with shift:

if (supports_sse4_1()) {
   pinsrd(xmm1, crc, 0);
} else {
   pinsrw(xmm1, crc, 0);
   shrl(crc, 16);
   pinsrw(xmm1, crc, 1);
}

Unfortunately UseAESCTRIntrinsics use more sse4.1 instructions so we 
can't do that. And it is already guarded by supports_sse4_1().

Changes which remove UseSSE checks in vm_version_x86.cpp are good.

Thanks,
Vladimir


On 5/31/16 5:48 AM, Tobias Hartmann wrote:
> Hi,
>
> please review the following patch:
>
> https://bugs.openjdk.java.net/browse/JDK-8158214
> http://cr.openjdk.java.net/~thartmann/8158214/webrev.00/
>
> The VM crashes during stub generation if UseSSE = 3 is set. The problem is that even if SSE 4 is not available or disabled, MacroAssembler::kernel_crc32() emits the 'pinsrd' instruction which is a SSE 4.1 instruction.
>
> The solution is to only emit CRC32 intrinsics if SSE 4.1 is available (the UseSSE > 2 check is not strong enough). I also removed the unnecessary UseSSE >= 4 checks because they are included in the supports_sse4_2() check.
>
> Tested with JPRT and RBT (running).
>
> Thanks,
> Tobias
>