https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115306
Bug ID: 115306
Summary: (X + 1) > Y ? -X : 1 pattern does not handle X=~X nor
X = -X;
Product: gcc
Version: 15.0
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: ---
The new pattern:
/* (1 - X) > Y ? X : 1 simplifies to (-X) >= Y ? X : 1 when
X is unsigned for the same logic as above, just replace X with -X. */
(simplify
(cond (gt (minus integer_onep @0) @1) @0 integer_onep@2)
(if (TYPE_UNSIGNED (type))
(cond (ge (negate @0) @1) @0 @2)))
