https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126433
--- Comment #4 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:baf658d80576de061320f136945fff90359ff7fd commit r17-2740-gbaf658d80576de061320f136945fff90359ff7fd Author: Uros Bizjak <[email protected]> Date: Tue Jul 28 08:41:57 2026 +0200 i386: Avoid XCHGB %rH, %rL in bswaphi2 on non-pentium4 targets [PR126433] XCHGB has higher latency than ROLW for non-pentium4 targets, so it should be avoided. Switch from the preferred_for_size/preferred_for_speed attributes to the "enabled" attribute to hard-disable unwanted alternatives. PR target/126433 gcc/ChangeLog: * config/i386/i386.md (*bswaphi2_movbe) Use enabled attribute. Remove preferred_for_speed and preferred_for_size attributes. (*bswaphi2): Ditto. (*bswaphisi2_lowpart): Ditto. gcc/testsuite/ChangeLog: * gcc.target/i386/xchg-1.c: Scan for ROL instead of XCHG. * gcc.target/i386/xchg-2.c: Use -O2 -march=pentium4 to emit XCHG.
