Request for reviews (S): 6910664: C2: java/util/Arrays/Sorting.java fails with DeoptimizeALot flag

[Vladimir Kozlov]

I updated webrev:

http://cr.openjdk.java.net/~kvn/6910664/webrev.03

Thanks,
Vladimir

Tom Rodriguez wrote:
> I was wrong about C1, it already handles this correctly.  It uses float_in_dbl for fpu registers and normal for xmm.
> 
> tom
> 
> On Feb 19, 2010, at 8:46 AM, Vladimir Kozlov wrote:
> 
>> Thank you, Tom
>>
>> Yes, you are right, I did not thought that I can use Location::normal.
>> Then the comment in the .ad files is wrong.
>>
>> I can fix C1 also if you point me the place.
>>
>> Thanks,
>> Vladimir
>>
>> Tom Rodriguez wrote:
>>> I'm not sure that's the right fix.  The whole point of float_in_dbl is to deal with x86 FPU registers so converting it into some platform dependent thing based on UseSSE doesn't seem right.  I think Matcher::float_in_double should be false if UseSSE >= 1 in x86_32.ad and should always be false in x86_64.ad.  In that case it will use Location::normal instead which will do:
>>>      // Just copy all other bits straight through
>>>      union { intptr_t p; jint ji;} value;
>>>      value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
>>>      value.ji = *(jint*)value_addr;
>>>      return new StackValue(value.p);
>>> which is equivalent to your new create_float_stack_value logic.
>>> How did we go for so long with this being broken?  It's totally wrong on 64 bit.  C1 has the same problem too.
>>> tom
>>> On Feb 18, 2010, at 7:08 PM, Vladimir Kozlov wrote:
>>>> http://cr.openjdk.java.net/~kvn/6910664/webrev.02
>>>>
>>>> Fixed 6910664: C2: java/util/Arrays/Sorting.java fails with DeoptimizeALot flag
>>>>
>>>> Problem:
>>>> The test has several java float locals and use XMM registers in debug info.
>>>> But the code which restore these values during deoptimization was not
>>>> updated for XMM registers usage. It assumes that float values were converted
>>>> to double on stack as it was before SSE hardware when FPU was used.
>>>>
>>>> Solution:
>>>> Add platform specific method to get float stack value from compiled frame.
>>>>
>>>> Reviewed by:
>>>>
>>>> Fix verified (y/n): y, test with -XX:UseSSE=0|1|2
>>>>
>>>> Other testing:
>>>> JPRT
>>>>
>