review (S) for 6849984: Value methods for platform dependent math functions constant fold incorrectly
Vladimir.Kozlov at Sun.COM
Thu Jan 14 11:32:57 PST 2010
Christian Thalinger wrote:
> On Thu, 2010-01-14 at 09:45 -0800, Vladimir Kozlov wrote:
>>> Maybe I missed the point of this change, but why are we using the much
>>> more complicated C versions for these?
>>> + // The intrinsic version of these seem to return the same value as
>>> + // the strict version.
>>> + StubRoutines::_intrinsic_exp = SharedRuntime::dexp;
>>> + StubRoutines::_intrinsic_pow = SharedRuntime::dpow;
>> There is no implementation of ExpD and PowD in x86_64.ad (which is surprise - we missed it???)
>> And it is also complex code - see it in x86_32.ad
> Tom just explained it to me on the phone (I try to summarize): What I
> missed is that these new intrinsics are used in the compiler to do
> constant folding and aren't used during runtime.
Yes, that is correct but if we had a simple assembler implementation
then we would use it since it would be faster. And we still care about
> -- Christian
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