diff options
Diffstat (limited to 'src/liblzma/check/crc32_fast.c')
| -rw-r--r-- | src/liblzma/check/crc32_fast.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/src/liblzma/check/crc32_fast.c b/src/liblzma/check/crc32_fast.c index 7157e2f4..cf7d75da 100644 --- a/src/liblzma/check/crc32_fast.c +++ b/src/liblzma/check/crc32_fast.c @@ -93,10 +93,10 @@ crc32_generic(const uint8_t *buf, size_t size, uint32_t crc) // Function dispatching // ////////////////////////// -// If both the generic and CLMUL implementations are built, then the -// function to use is selected at runtime since system running the -// binary may not have the CLMUL instructions. -// The three dispatch methods in order of priority: +// If both the generic and arch-optimized implementations are built, then +// the function to use is selected at runtime because the system running +// the binary might not have the arch-specific instruction set extension(s) +// available. The three dispatch methods in order of priority: // // 1. Indirect function (ifunc). This method is slightly more efficient // than the constructor method because it will change the entry in the @@ -195,10 +195,10 @@ extern LZMA_API(uint32_t) lzma_crc32(const uint8_t *buf, size_t size, uint32_t crc) { #if defined(CRC_GENERIC) && defined(CRC_ARCH_OPTIMIZED) - // If CLMUL is available, it is the best for non-tiny inputs, - // being over twice as fast as the generic slice-by-four version. - // However, for size <= 16 it's different. In the extreme case - // of size == 1 the generic version can be five times faster. + // On x86-64, if CLMUL is available, it is the best for non-tiny + // inputs, being over twice as fast as the generic slice-by-four + // version. However, for size <= 16 it's different. In the extreme + // case of size == 1 the generic version can be five times faster. // At size >= 8 the CLMUL starts to become reasonable. It // varies depending on the alignment of buf too. // |