RFR: 8285868: x86_64 intrinsics for floating point methods isNaN, isFinite and isInfinite [v6]

[Jatin Bhateja]

On Wed, 18 May 2022 05:17:44 GMT, Srinivas Vamsi Parasa <duke at openjdk.java.net> wrote:

>> We develop optimized x86_64 intrinsics for the floating point class check methods `isNaN()`, `isFinite()` and `IsInfinite()` for Float and Double classes. JMH benchmarks show ~6x improvement for `isNan()`, ~2x improvement for `isInfinite()` and 40% gain for `isFinite()` using` vfpclasss(s/d)` instructions.
>> 
>> 
>> JMH Benchmark (ns/op)	              Baseline	  This PR (WITH vfpclassss/sd)                      Speedup
>> 		                               
>> FloatClassCheck.testIsFinite	      0.559	                  0.4	                            1.4x
>> FloatClassCheck.testIsInfinite	      0.828	                  0.386	                            2.15x
>> FloatClassCheck.testIsNaN	      2.589	                  0.387	                            6.7x
>> DoubleClassCheck.testIsFinite         0.568	                  0.414	                            1.37x
>> DoubleClassCheck.testIsInfinite       0.836	                  0.395	                            2.11x
>> DoubleClassCheck.testIsNaN	      2.592	                  0.393	                            6.6x
>> 
>> JMH Benchmark (ns/op)	              Baseline	  This PR (WITHOUT vfpclassss/sd)                   Speedup
>> FloatClassCheck.testIsFinite	      0.561	                 0.468	                             1.2x
>> FloatClassCheck.testIsInfinite	      0.793	                 0.491	                             1.61x
>> FloatClassCheck.testIsNaN	      2.587	                 0.469	                             5.5x
>> DoubleClassCheck.testIsFinite         0.561	                 0.592	                             0.94x
>> DoubleClassCheck.testIsInfinite       0.828	                 0.592	                             1.4x
>> DoubleClassCheck.testIsNaN	      2.593	                 0.594	                             4.4x
>
> Srinivas Vamsi Parasa has updated the pull request incrementally with one additional commit since the last revision:
> 
>   use 0x1 to be simpler

src/hotspot/share/opto/fpclassnode.hpp line 86:

> 84: };
> 85: 
> 86: #endif // SHARE_OPTO_FPCLASSNODE_HPP

You can move these to src/hotspot/share/opto/intrinsicnode.hpp

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