https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112472
Bug ID: 112472 Summary: (trunc)copysign((extend)x, CST) is not optimized to just copysign(x, CST') Product: gcc Version: 14.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: enhancement Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: pinskia at gcc dot gnu.org Target Milestone: --- Take: ``` float f(float a, float b) { return (float)__builtin_copysign(a,-3.0); } ``` This should be optimized to just: ``` _tmp = .COPYSIGN(a, -1.0) return _tmp; ``` The pattern for that does this for the non-constant second argument case is: ``` /* Simplify (trunc)copysign ((extend)x, (extend)y) to copysignf (x, y), x,y is float value, similar for _Float16/double. */ (for copysigns (COPYSIGN_ALL) (simplify (convert (copysigns (convert@2 @0) (convert @1))) (if (optimize && !HONOR_SNANS (@2) && types_match (type, TREE_TYPE (@0)) && types_match (type, TREE_TYPE (@1)) && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (@2)) && direct_internal_fn_supported_p (IFN_COPYSIGN, type, OPTIMIZE_FOR_BOTH)) (IFN_COPYSIGN @0 @1)))) ``` We should be able to handle (convert @1) as a constant ...