https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105983
Bug ID: 105983
Summary: Failure to optimize (b != 0) && (a >= b) as well as
the same pattern with binary and
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: ---
bool f(unsigned a, unsigned b)
{
return (b != 0) && (a >= b);
}
This can be optimized to `return (b != 0) & (a >= b);`, which is itself
optimized to `return (b - 1) > a;`. GCC outputs code equivalent to `return (b
!= 0) & (a >= b);` (at least on x86) whereas if that code is compiled it would
output `return (b - 1) > a;`, while LLVM has no trouble directly outputting the
optimal code.
