https://gcc.gnu.org/bugzilla/show_bug.cgi?id=128310
--- Comment #3 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Uros Bizjak <[email protected]>: https://gcc.gnu.org/g:cdc06c5d808d338b240b4f50ae33cb43b71ccb40 commit r17-5754-gcdc06c5d808d338b240b4f50ae33cb43b71ccb40 Author: Uros Bizjak <[email protected]> Date: Fri Oct 30 10:16:50 2026 +0100 i386: Use separate unspecs for CRC32 widths [PR128310] The CRC32 insns used a single UNSPEC_CRC32 for all operand widths. When the second operand is a constant, which carries no mode, the QI, HI and SI forms become identical unspec expressions, so CSE merges crc32 results of different widths and e.g. _mm_crc32_u16 (c, 0x7f) == _mm_crc32_u32 (c, 0x7f) folds to 1. Use a distinct unspec for each width. Also add the 64-bit zero-extended form of crc32b. Assisted-by: Claude Sonnet 5.5 PR target/128310 gcc/ChangeLog: * config/i386/i386.md (UNSPEC_CRC32): Remove. (UNSPEC_CRC32B, UNSPEC_CRC32W) (UNSPEC_CRC32L, UNSPEC_CRC32Q): New. (sse4_2_crc32qi): Rename from sse4_2_crc32<mode>. Use UNSPEC_CRC32B. (*sse4_2_crc32qi_zext): New insn. (sse4_2_crc32hi): New insn. (sse4_2_crc32si): Ditto. (sse4_2_crc32di): Use UNSPEC_CRC32Q. gcc/testsuite/ChangeLog: * gcc.target/i386/pr128310.c: New test.
