Request for review (S): 7032388: guarantee(VM_Version::supports_cmov()) failed: illegal instruction on i586 after 6919934

[Igor Veresov]

Still looks good.

igor

On 3/30/11 11:30 AM, Christian Thalinger wrote:
> I made two small changes that Paul suggested since #ifdefs are bad and cmovptr makes more sense in the context.
>
> -- Christian
>
> On Mar 30, 2011, at 5:40 PM, Paul Hohensee wrote:
>> Couple of small comments.
>>
>> In assembler_x86.cpp, I'd removed the #ifdef _LP64 and have supports_cmov
>> be the condition that determines whether or not to emit the cmov.  Every 64-bit
>> chip supports cmov, so supports_cmov will return true on every 64-bit platform.
>>
>> In templateTable_x86_32.cpp, you use cmov, which you've made an alias for
>> cmovptr in assembler_x86.hpp.  I'd get use cmovptr directly here instead,
>> esp. since cmpptr is used just before it.
>>
>> Paul
>>
>> On 3/30/11 8:46 AM, Christian Thalinger wrote:
>>> http://cr.openjdk.java.net/~twisti/7032388/
>>>
>>> 7032388: guarantee(VM_Version::supports_cmov()) failed: illegal instruction on i586 after 6919934
>>> Summary: 6919934 added some unguarded cmov instructions which hit a guarantee on older hardware.
>>> Reviewed-by:
>>>
>>> 6919934 added some unguarded cmov instructions which hit a guarantee
>>> on older hardware (pre-i686).
>>>
>>> The fix is to either guard the added cmov instructions with a
>>> supports_cmov() or let the cmov instruction decide itself if the
>>> hardware supports cmov and if not use a branch-mov idiom.  I chose the
>>> latter.
>>>
>>> src/cpu/x86/vm/assembler_x86.cpp
>>> src/cpu/x86/vm/assembler_x86.hpp
>>> src/cpu/x86/vm/c1_LIRAssembler_x86.cpp
>>> src/cpu/x86/vm/c1_Runtime1_x86.cpp
>>> src/cpu/x86/vm/templateTable_x86_32.cpp
>
>