SSSE3 population count vs hardware

Peter Kankowski compared speed of SSE4.2 instructions crc32 and popcnt against software implementations. Hardware CRC32 is significantly faster, but population count is slightly slower than my SSSE3 popcount!

Speedup reversing table of bytes

With help of BSWAP instruction or SSE instructions (PSHUFD, PSHUFLW, PSHUFHW) or SSSE3 instruction (PSHUFB) reversing table can be faster. Speedup depends on three factors:

• table size: larger=faster
• table address: aligned=faster/much faster (15.5 speedup - possible! see chart)
• CPU type

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