https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121405
--- Comment #10 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Richard Biener <rgue...@gcc.gnu.org>: https://gcc.gnu.org/g:53f491ccd1e59fad77fb2cb30d1a58b9e5e5f63c commit r16-3066-g53f491ccd1e59fad77fb2cb30d1a58b9e5e5f63c Author: Richard Biener <rguent...@suse.de> Date: Wed Aug 6 12:31:13 2025 +0200 tree-optimization/121405 - missed VN with aggregate copy The following handles value-numbering of a BIT_FIELD_REF of a register that's defined by a load by looking up a subset load similar to how we handle bit-and masked loads. This allows the testcase to be simplified by two FRE passes, the first one will create the BIT_FIELD_REF. PR tree-optimization/121405 * tree-ssa-sccvn.cc (visit_nary_op): Handle BIT_FIELD_REF with reference def by looking up a combination of both. * gcc.dg/tree-ssa/ssa-fre-107.c: New testcase. * gcc.target/i386/pr90579.c: Adjust.
