RFR: 8285868: x86_64 intrinsics for floating point methods isNaN, isFinite and isInfinite [v4]

[Quan Anh Mai]

On Tue, 17 May 2022 22:12:38 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 ~8x improvement for isNan(), ~3x improvement for isInfinite() and 15% gain for isFinite().
>> 
>> 
>> 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:
> 
>   Split the macros using predicate

Also, for non `vfpclass` cases, it would be simpler and more efficient to implement in the Java side instead

    static Float::isFinite(float f) {
        return (floatToRawIntBits(f) & SIGN_ELIMINATION) < POS_INFINITY_BITS;
    }

-------------

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