On Thu, 11 Jun 2026 07:37:30 GMT, Eric Fang <[email protected]> wrote:
>> Vector API `lanewise BITWISE_BLEND` on AArch64 is currently lowered to a >> generic vector sequence built from `(XorV(AndV(XorV)))` nodes. AArch64 >> provides a more efficient mapping for this operation through the NEON `BSL` >> and SVE `BSL` (bitwise select) instructions. >> >> This change teaches C2 to recognize the `BITWISE_BLEND` patterns and lower >> them to the dedicated AArch64 instructions for better performance. >> >> The change includes the AArch64 match rules and assembler support, updates >> the AArch64 asm tests, adds IR framework nodes for the new mach >> instructions, introduces a new jtreg IR test and extends the MaskedLogicOpts >> JMH benchmark for 128-bit long type. >> >> JMH results show **11% - 54%** performance improvements for the optimized >> cases, and all jtreg tests (tier1, tier2 and tier3) passe on SVE2, SVE1, and >> NEON configurations. >> >> On a Nvidia Grace (Neoverse-V2) machine with 128-bit SVE2: >> >> Benchmark Unit ARRAYLEN Before Error >> After Error Uplift >> bitwiseBlendOperationInt128 ops/s 256.00 3787.49 5.29 >> 4277.64 8.89 1.13 >> bitwiseBlendOperationInt128 ops/s 512.00 1888.24 11.02 >> 2143.21 6.32 1.14 >> bitwiseBlendOperationInt128 ops/s 1024.00 938.22 6.24 >> 1053.45 14.68 1.12 >> bitwiseBlendOperationLong128 ops/s 256.00 1895.45 13.68 2140.31 >> 3.68 1.13 >> bitwiseBlendOperationLong128 ops/s 512.00 938.71 5.32 1052.16 >> 14.07 1.12 >> bitwiseBlendOperationLong128 ops/s 1024.00 474.15 2.33 526.49 >> 2.62 1.11 >> >> >> On an AWS Graviton3 (Neoverse-V1) machine with 256-bit SVE1: >> >> Benchmark Unit ARRAYLEN Before Error >> After Error Uplift >> bitwiseBlendOperationInt128 ops/s 256.00 2051.52 13.85 >> 2481.44 0.27 1.21 >> bitwiseBlendOperationInt128 ops/s 512.00 995.47 20.77 >> 1235.10 5.70 1.24 >> bitwiseBlendOperationInt128 ops/s 1024.00 507.73 9.83 >> 617.59 2.43 1.22 >> bitwiseBlendOperationLong128 ops/s 256.00 1000.99 21.50 1235.39 >> 5.48 1.23 >> bitwiseBlendOperationLong128 ops/s 512.00 507.73 9.74 617.67 >> 2.32 1.22 >> bitwiseBlendOperationLong128 ops/s 1024.00 258.86 0.01 310.70 >> 0.04 1.20 >> >> >> On a Nvidia Grace (Neoverse-V2) machine with 128-bit NEON: >> >> Benchmark Unit ARRAYLEN Before Error >> After Error Uplift >> bitwiseBlendOperationInt128 ops/s 256.00 2336.17 13.18 >> 3505.19 19.61 1.50 >> bitwiseBlendOperationInt128 ops/s 512.00 1145.50 ... > > Eric Fang has updated the pull request incrementally with one additional > commit since the last revision: > > Add a movprfx optimization entry point for the newly added sve_bsl > instruction I ran a full round of JTreg and JMH tests on this patch locally. All JTReg tests passed. After adding `movprfx` fusion support to the `BSL` instruction, the performance improvement of this PR is even greater. For example, on a 128-bit SVE2 grace machine, the current performance improvement is as follows: <html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns="http://www.w3.org/TR/REC-html40";> <head> <meta name=ProgId content=Excel.Sheet> <meta name=Generator content="Microsoft Excel 15"> <link id=Main-File rel=Main-File href="file:////Users/erfang/Library/Group%20Containers/UBF8T346G9.Office/TemporaryItems/msohtmlclip/clip.htm"> <link rel=File-List href="file:////Users/erfang/Library/Group%20Containers/UBF8T346G9.Office/TemporaryItems/msohtmlclip/clip_filelist.xml"> </head> <body link="#467886" vlink="#96607D"> Benchmark | ARRAYLEN | Unit | Before | Error | After | Error | Uplift -- | -- | -- | -- | -- | -- | -- | -- bitwiseBlendOperationInt128 | 256 | ops/s | 3709.10 | 3.47 | 5801.07 | 3.99 | 1.56 bitwiseBlendOperationInt128 | 512 | ops/s | 1850.16 | 15.67 | 2911.17 | 6.21 | 1.57 bitwiseBlendOperationInt128 | 1024 | ops/s | 913.95 | 8.45 | 1423.66 | 34.04 | 1.56 bitwiseBlendOperationLong128 | 256 | ops/s | 1850.36 | 12.54 | 2913.70 | 2.19 | 1.57 bitwiseBlendOperationLong128 | 512 | ops/s | 920.63 | 5.76 | 1433.99 | 26.71 | 1.56 bitwiseBlendOperationLong128 | 1024 | ops/s | 464.38 | 1.38 | 709.36 | 9.56 | 1.53 </body> </html> ------------- PR Comment: https://git.openjdk.org/jdk/pull/31269#issuecomment-4686625641
