https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114702
Bug ID: 114702 Summary: Missed optimization: fail to infer c - b != if a + b != c Product: gcc Version: 14.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: xxs_chy at outlook dot com Target Milestone: --- Godbolt link: https://godbolt.org/z/58rxGaabW ``` void src(int a, int b){ if(b + a == 32){ return; }else{ if(32 - b == a) dummy(); else dummy1(); } } ``` Obviously, "32 - b == a" is false. We can get: ``` void tgt(int a, int b){ if(b + a == 32){ return; }else{ dummy1(); } } ``` This is a real-world dead code after inlining functions in QEMU.