hiscoa-compress: faster msb calculation#48
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Feb 28, 2026
Performance:
- try_match: precompute match limit (buffer end, max length, line
boundary) instead of checking 3 conditions per byte in inner loop
- push_bits: defer XOR obfuscation to a single final pass instead of
2 XOR operations per byte during bit writing
- Remove xorval field from compressor state (no longer needed)
Bug fix:
- Fix 32-bit alignment padding: when already aligned, the expression
32 - (bitpos % 32) evaluated to 32, adding 4 unnecessary bytes per
band. Use (32 - (bitpos % 32)) % 32 to correctly produce 0 when
already aligned. This also fixes the pre-existing roundtrip test
failures ("band not fully decompressed: 4 bytes left").
Covers the same __builtin_clz optimization as upstream PR mounaiban#48, but
with a portable fallback for non-GCC/Clang compilers.
https://claude.ai/code/session_01HbeKJzNreDZgAHFz32FMfE
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