https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105777
Bug ID: 105777 Summary: Failure to optimize __builtin_mul_overflow with constant operand to add+cmp check Product: gcc Version: 13.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: gabravier at gmail dot com Target Milestone: --- int f17(unsigned x) { int z; return __builtin_mul_overflow((int)x, 35, &z); } This can be optimized to `return (x + 0xFC57C57C) < 0xF8AF8AF9;` (and I'd assume the same pattern with other constants than 35 should be optimizable in the same way). LLVM does this transformation, but GCC does not.