https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112494
--- Comment #9 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Uros Bizjak <u...@gcc.gnu.org>: https://gcc.gnu.org/g:99db2ce2419245e40808a9fad45113315496a907 commit r14-5933-g99db2ce2419245e40808a9fad45113315496a907 Author: Uros Bizjak <ubiz...@gmail.com> Date: Tue Nov 28 16:56:29 2023 +0100 i386: Improve cmpstrnqi_1 insn pattern [PR112494] REPZ CMPSB instruction does not update FLAGS register when %ecx register equals zero. Improve cmpstrnqi_1 insn pattern to set FLAGS_REG to its previous value instead of (const_int 0) when operand 2 equals zero. PR target/112494 gcc/ChangeLog: * config/i386/i386.md (cmpstrnqi_1): Set FLAGS_REG to its previous value when operand 2 equals zero. (*cmpstrnqi_1): Ditto. (*cmpstrnqi_1 peephole2): Ditto.
