Unlike on x86 (see 8285868 and the discussion in review), isFinite intrinsic
turned out to be profitable on RISC-V using the same fclass instruction as for
8293695 (isInfinite instrinsic). Therefore, I'm proposing to have it added on
RISC-V in this PR.
benchmark results:
before:
Benchmark Mode Cnt Score Error Units
DoubleClassCheck.testIsFiniteBranch avgt 15 52.824 ± 1.744 ns/op
DoubleClassCheck.testIsFiniteCMov avgt 15 16.104 ± 0.358 ns/op
DoubleClassCheck.testIsFiniteStore avgt 15 14.366 ± 2.174 ns/op
FloatClassCheck.testIsFiniteBranch avgt 15 49.821 ± 0.330 ns/op
FloatClassCheck.testIsFiniteCMov avgt 15 14.702 ± 0.335 ns/op
FloatClassCheck.testIsFiniteStore avgt 15 14.749 ± 0.496 ns/op
after:
DoubleClassCheck.testIsFiniteBranch avgt 15 48.921 ± 0.557 ns/op
DoubleClassCheck.testIsFiniteCMov avgt 15 13.716 ± 0.304 ns/op
DoubleClassCheck.testIsFiniteStore avgt 15 9.152 ± 0.158 ns/op
FloatClassCheck.testIsFiniteBranch avgt 15 47.740 ± 2.028 ns/op
FloatClassCheck.testIsFiniteCMov avgt 15 13.299 ± 0.282 ns/op
FloatClassCheck.testIsFiniteStore avgt 15 9.185 ± 0.396 ns/op
Existing isInfinite jtreg test was altered to be able to use common code for
isFinite test and fine-grained requires tag filtering. Existing benchmark was
modified to include isFinite case. A typo ("Atleast" -> "At least") was fixed
on the way.
Test passed on both release and fastdebug builds. Hotspot tier1 tests were run
on x86_64 and RISC-V with no issues.
-------------
Commit messages:
- JDK-8294198 implementation
Changes: https://git.openjdk.org/jdk/pull/10391/files
Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10391&range=00
Issue: https://bugs.openjdk.org/browse/JDK-8294198
Stats: 363 lines in 17 files changed: 315 ins; 47 del; 1 mod
Patch: https://git.openjdk.org/jdk/pull/10391.diff
Fetch: git fetch https://git.openjdk.org/jdk pull/10391/head:pull/10391
PR: https://git.openjdk.org/jdk/pull/10391
