Improve the implementation of `Double/Float.isInfinite` to reduce branching.
Using `>` comparison with `MAX_VALUE` instead of `==` with `POSITIVE_INFINITY`
improves code emission on x86 and produces similar code for arm. This is also
the way gcc implements `std::isinf` on x86 and arm (clang uses the pattern
`Math.abs(v) == POSITIVE_INFINITY` on arm).
`test/micro/org/openjdk/bench/java/lang/FPComparison.java` has been added in
#8525, the results are reshown here:
Benchmark Mode Cnt Score Error Score
Error Unit Ratio
FPComparison.isInfiniteDouble avgt 5 1232.800 ± 31.677 621.185 ±
11.935 ns/op 1.98
FPComparison.isInfiniteFloat avgt 5 1234.708 ± 70.239 623.566 ±
15.206 ns/op 1.98
Thank you very much.
-------------
Commit messages:
- commit
Changes: https://git.openjdk.org/jdk/pull/9238/files
Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9238&range=00
Issue: https://bugs.openjdk.org/browse/JDK-8288933
Stats: 2 lines in 2 files changed: 0 ins; 0 del; 2 mod
Patch: https://git.openjdk.org/jdk/pull/9238.diff
Fetch: git fetch https://git.openjdk.org/jdk pull/9238/head:pull/9238
PR: https://git.openjdk.org/jdk/pull/9238
