8350960: RISC-V: Add riscv backend for Float16 operations - vectorization

[Hamlin-Li]

Hi,
Can you help to review this patch?
It's a follow-up of 9a3f999.
Thanks!

Test

Performance data

Benchmark	(vectorDim)	Mode	Cnt	Score - patch	Score - master	Improvement (master/patch)	Error	Units
Float16OperationsBenchmark.addBenchmark	256	avgt	10	382.123	2595.718	6.793	0.631	ns/op
Float16OperationsBenchmark.addBenchmark	512	avgt	10	563.726	5167.687	9.167	0.063	ns/op
Float16OperationsBenchmark.addBenchmark	1024	avgt	10	888.455	9468.714	10.658	0.147	ns/op
Float16OperationsBenchmark.addBenchmark	2048	avgt	10	1540.255	18879.796	12.258	0.396	ns/op
Float16OperationsBenchmark.divBenchmark	256	avgt	10	579.959	4028.335	6.946	0.008	ns/op
Float16OperationsBenchmark.divBenchmark	512	avgt	10	914.634	8034.234	8.784	0.027	ns/op
Float16OperationsBenchmark.divBenchmark	1024	avgt	10	1494.017	15125.924	10.124	0.292	ns/op
Float16OperationsBenchmark.divBenchmark	2048	avgt	10	2728.517	30197.97	11.068	32.869	ns/op
Float16OperationsBenchmark.fmaBenchmark	256	avgt	10	476.764	2817.035	5.909	0.012	ns/op
Float16OperationsBenchmark.fmaBenchmark	512	avgt	10	707.035	5239.438	7.41	0.129	ns/op
Float16OperationsBenchmark.fmaBenchmark	1024	avgt	10	1114.29	7361.105	6.606	0.024	ns/op
Float16OperationsBenchmark.fmaBenchmark	2048	avgt	10	1931.713	14465.602	7.488	1.852	ns/op
Float16OperationsBenchmark.maxBenchmark	256	avgt	10	501.892	3754.563	7.481	0.408	ns/op
Float16OperationsBenchmark.maxBenchmark	512	avgt	10	738.148	7450.666	10.094	1.206	ns/op
Float16OperationsBenchmark.maxBenchmark	1024	avgt	10	1195.262	15463.892	12.938	8.889	ns/op
Float16OperationsBenchmark.maxBenchmark	2048	avgt	10	2253.656	30649.239	13.6	6.154	ns/op
Float16OperationsBenchmark.minBenchmark	256	avgt	10	501.873	3753.9	7.48	0.298	ns/op
Float16OperationsBenchmark.minBenchmark	512	avgt	10	732.16	7445.395	10.169	0.779	ns/op
Float16OperationsBenchmark.minBenchmark	1024	avgt	10	1186.985	15349.186	12.931	1.829	ns/op
Float16OperationsBenchmark.minBenchmark	2048	avgt	10	2264.592	30638.19	13.529	2.077	ns/op
Float16OperationsBenchmark.mulBenchmark	256	avgt	10	382.06	2595.757	6.794	0.228	ns/op
Float16OperationsBenchmark.mulBenchmark	512	avgt	10	565.259	5168.078	9.143	0.516	ns/op
Float16OperationsBenchmark.mulBenchmark	1024	avgt	10	889.168	9468.645	10.649	0.159	ns/op
Float16OperationsBenchmark.mulBenchmark	2048	avgt	10	1542.165	18881.248	12.243	1.791	ns/op
Float16OperationsBenchmark.sqrtBenchmark	256	avgt	10	508.016	3908.87	7.694	0.01	ns/op
Float16OperationsBenchmark.sqrtBenchmark	512	avgt	10	827.056	7775.415	9.401	0.045	ns/op
Float16OperationsBenchmark.sqrtBenchmark	1024	avgt	10	1395.414	15508.686	11.114	0.208	ns/op
Float16OperationsBenchmark.sqrtBenchmark	2048	avgt	10	2531.666	31002.463	12.246	3.48	ns/op
Float16OperationsBenchmark.subBenchmark	256	avgt	10	380.344	2617.333	6.881	0.926	ns/op
Float16OperationsBenchmark.subBenchmark	512	avgt	10	564.335	5170.905	9.163	0.937	ns/op
Float16OperationsBenchmark.subBenchmark	1024	avgt	10	889.011	9469.324	10.652	0.144	ns/op
Float16OperationsBenchmark.subBenchmark	2048	avgt	10	1540.936	18881.797	12.253	0.824	ns/op

---

Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• Change must not contain extraneous whitespace
• Commit message must refer to an issue

Issue

• JDK-8350960: RISC-V: Add riscv backend for Float16 operations - vectorization (Enhancement - P4)

Reviewers

• Fei Yang (@RealFYang - Reviewer)
• Dingli Zhang (@DingliZhang - Author)
• Ludovic Henry (@luhenry - Committer)

Reviewing

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[openjdk]

@Hamlin-Li This change now passes all automated pre-integration checks.

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8350960: RISC-V: Add riscv backend for Float16 operations - vectorization

Reviewed-by: fyang, dzhang, luhenry

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At the time when this comment was updated there had been 186 new commits pushed to the master branch:

• effe40a: 8351843: change test/jdk/com/sun/net/httpserver/simpleserver/RootDirPermissionsTest.java to a manual test
• 2fb3329: 8356846: Remove unnecessary List.contains key from TIFFDirectory.removeTagSet
• 67fb1ee: 8356946: x86: Optimize interpreter profile updates
• ... and 183 more: https://git.openjdk.org/jdk/compare/ca5e0b1848054848fb5e39eebac06f2011cceb2e...master

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[mlbridge]

Webrevs

• 02: Full - Incremental (0e165958)
• 01: Full - Incremental (0ad3b5a9)
• 00: Full (6eb66599)

[RealFYang]

Two comments after a cursory look. Thanks.

[RealFYang]

Updated change looks good. And nice JMH numbers!

[Hamlin-Li]

Updated change looks good. And nice JMH numbers!

Thank you!

[DingliZhang]

LGTM, thanks!

[Hamlin-Li]

Thank you @luhenry @DingliZhang !

[Hamlin-Li]

/integrate

[openjdk]

Going to push as commit 92fd449.
Since your change was applied there have been 193 commits pushed to the master branch:

• 2e26b43: 8356875: RISC-V: extension flag UseZvfh should depends on UseZfh
• 3acfa9e: 8356966: java/awt/Graphics2D/DrawString/IgnoredWhitespaceTest.java fails on Linux after JDK-8350203
• 26cb016: 8350329: C2: Div looses dependency on condition that guarantees divisor not zero in counted loop after peeling
• ... and 190 more: https://git.openjdk.org/jdk/compare/ca5e0b1848054848fb5e39eebac06f2011cceb2e...master

Your commit was automatically rebased without conflicts.

[openjdk]

@Hamlin-Li Pushed as commit 92fd449.

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