https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70547
Bug ID: 70547
Summary: Optimize multiplication of booleans to bit_and
Product: gcc
Version: 6.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: enhancement
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: glisse at gcc dot gnu.org
Target Milestone: ---
int f(int a,int b,int c,int d){
return (a<b)*(c<d);
}
produces
_3 = a_1(D) < b_2(D);
_4 = (int) _3;
_7 = c_5(D) < d_6(D);
_8 = (int) _7;
_9 = _4 * _8;
return _9;
Since we know that _4 and _8 are in the range [0, 1], we could replace the
multiplication with a cheaper AND.
