RFR(S): 8063086: Math.pow yields different results upon repeated calls

[Vladimir Kozlov]

Okay.

Thanks,
Vladimir

On 1/8/15 1:26 AM, Roland Westrelin wrote:
> When trying to push this through jprt I had an assert failure due to an unreachable address. Here is a new webrev:
>
> http://cr.openjdk.java.net/~roland/8063086/webrev.01/
>
> with the following change:
>
> --- a/src/cpu/x86/vm/macroAssembler_x86.cpp
> +++ b/src/cpu/x86/vm/macroAssembler_x86.cpp
> @@ -3189,7 +3189,9 @@
>       static double two = 2.0;
>       ExternalAddress two_addr((address)&two);
>
> -    fld_d(two_addr);            // Stack: 2 X Y
> +    // constant maybe too far on 64 bit
> +    lea(tmp2, two_addr);
> +    fld_d(Address(tmp2, 0));    // Stack: 2 X Y
>       fcmp(tmp, 2, true, false);  // Stack: X Y
>       jcc(Assembler::parity, y_not_2);
>       jcc(Assembler::notEqual, y_not_2);
>
> Roland.
>
>> On Jan 7, 2015, at 2:20 PM, Roland Westrelin <roland.westrelin at oracle.com> wrote:
>>
>>> Looks good. Make sure to run new test with -Xcomp and -XX:-TieredCompilation and Client VM.
>>
>> Thanks for the review. I checked the test runs fine in these cases.
>>
>> Roland.
>>
>>>
>>> Thanks,
>>> Vladimir
>>>
>>> On 1/5/15 8:38 AM, Roland Westrelin wrote:
>>>> http://cr.openjdk.java.net/~roland/8063086/webrev.00/
>>>>
>>>> With 8029302, C2 computes x^2 as x*x. The interpreter and C1 code don’t have the special case code and as a result an application can see different result for the same computation whether it’s executed by the interpreter/c1 or c2. Fixed by adding the special case to the interpreter and C1.
>>>>
>>>> Roland.
>>>>
>>
>