RFR: 8285868: x86 intrinsics for floating point methods isNaN, isFinite and isInfinite [v9]

[Vladimir Kozlov]

On Tue, 24 May 2022 20:31:53 GMT, Srinivas Vamsi Parasa <duke at openjdk.java.net> wrote:

>> We develop optimized x86 intrinsics for the floating point class check methods `isNaN()`, `isFinite()` and `IsInfinite()` for Float and Double classes. JMH benchmarks show upto `~70% `improvement using` vfpclasss(s/d)` instructions.
>> 
>> 
>> Benchmark (ns/op)	        Baseline Intrinsic(vfpclasss/d)	Speedup(%)
>> FloatClassCheck.testIsFinite	0.562	          0.406	         28%
>> FloatClassCheck.testIsInfinite	0.815	          0.383	         53%
>> FloatClassCheck.testIsNaN	0.63	          0.382	         39%
>> DoubleClassCheck.testIsFinite	0.565	          0.409	         28%
>> DoubleClassCheck.testIsInfinite	0.812	          0.375	         54%
>> DoubleClassCheck.testIsNaN	0.631	          0.38	         40%
>> FPComparison.isFiniteDouble	332.638	          272.577	 18%
>> FPComparison.isFiniteFloat	413.217	          331.825	 20%
>> FPComparison.isInfiniteDouble	874.897	          240.632	 72%
>> FPComparison.isInfiniteFloat	872.279	          321.269	 63%
>> FPComparison.isNanDouble	286.566	          240.36	 16%
>> FPComparison.isNanFloat	        346.123	          316.923	  8%
>
> Srinivas Vamsi Parasa has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 11 commits:
> 
>  - Remove support for non vfpclasss/d based intrinsics
>  - Merge branch 'master' of https://git.openjdk.java.net/jdk into float
>  - add comment for vfpclasss/d for isFinite()
>  - Merge branch 'master' of https://git.openjdk.java.net/jdk into float
>  - zero out the upper bits not written by setb
>  - use 0x1 to be simpler
>  - remove the redundant temp register
>  - Split the macros using predicate
>  - update jmh tests
>  - Merge branch 'master' into float
>  - ... and 1 more: https://git.openjdk.java.net/jdk/compare/c1db70d8...70bba0fe

Looks good.

Please, adopt @merykitty suggested changes for micro-benchmarks to include `store, cmove, branch` cases. Show performance results for all of them.

Also adapt your regression tests for all 3 cases too.

I assume `Baseline` data includes #8525 changes. Right?

src/hotspot/share/runtime/vmStructs.cpp line 1847:

> 1845:   declare_c2_type(SignumDNode, Node)                                      \
> 1846:   declare_c2_type(SignumFNode, Node)                                      \
> 1847:   declare_c2_type(IsInfiniteFNode, Node)                                  \

Where are other new nodes?

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PR: https://git.openjdk.java.net/jdk/pull/8459