Checking whether the indexes of masked lanes are inside of the valid memory boundary is necessary for masked vector memory access. However, this could be saved if the given offset is inside of the vector range that could make sure no IOOBE (IndexOutOfBoundaryException) happens. The masked load APIs have saved this kind of check for common cases. And this patch did the similar optimization for the masked vector store.
The performance for the new added store masked benchmarks improves about `1.83x ~ 2.62x` on a x86 system: Benchmark Before After Gain Units StoreMaskedBenchmark.byteStoreArrayMask 12757.936 23291.118 1.826 ops/ms StoreMaskedBenchmark.doubleStoreArrayMask 1520.932 3921.616 2.578 ops/ms StoreMaskedBenchmark.floatStoreArrayMask 2713.031 7122.535 2.625 ops/ms StoreMaskedBenchmark.intStoreArrayMask 4113.772 8220.206 1.998 ops/ms StoreMaskedBenchmark.longStoreArrayMask 1993.986 4874.148 2.444 ops/ms StoreMaskedBenchmark.shortStoreArrayMask 8543.593 17821.086 2.086 ops/ms Similar performane gain can also be observed on ARM hardware. ------------- Commit messages: - 8286279: [vectorapi] Only check index of masked lanes if offset is out of array boundary for masked store Changes: https://git.openjdk.java.net/jdk/pull/8620/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=8620&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8286279 Stats: 213 lines in 8 files changed: 188 ins; 0 del; 25 mod Patch: https://git.openjdk.java.net/jdk/pull/8620.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/8620/head:pull/8620 PR: https://git.openjdk.java.net/jdk/pull/8620
