RISC-V: Optimize decompression with branchless AdvanceToNextTagRVOptimized +13.7%#234
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anthony-zy wants to merge 1 commit intogoogle:mainfrom
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RISC-V: Optimize decompression with branchless AdvanceToNextTagRVOptimized +13.7%#234anthony-zy wants to merge 1 commit intogoogle:mainfrom
anthony-zy wants to merge 1 commit intogoogle:mainfrom
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…Optimized) for +4% throughput
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PR Title
Optimize decompression for RISC-V with branchless tag advancement
Summary
Introduces
AdvanceToNextTagRVOptimized, a branchless helper for the decompression hot path. By replacing conditional branches with ternary selections, it allows the compiler to generate efficient branchless sequences (e.g., using RISC-V Zicond extensionczero.eqz/czero.nez).This optimization significantly reduces branch misprediction penalties on RISC-V architectures like the Spacemit(R) X60.
Performance
Tested with lzbench on Spacemit(R) X60:
Verification
lzbench