https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97707
Bug ID: 97707
Summary: avx12 math function invoked even if
-mprefer-vector-width=256 specified
Product: gcc
Version: 10.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: vincenzo.innocente at cern dot ch
Target Milestone: ---
this code will invoke _ZGVeN8v_sin instead of _ZGVdN4v_sin making use of zmm
registers
#include<cmath>
int main() {
double res=0;
for (int x=0; x<1024;x++) {
double y = x;
res += std::sin(y);
}
return res > 0.5;
}
NOTE if I specify
for (long long x=0; x<1024;x++) {
it will correcty invoke _ZGVdN4v_sin (no zmm)
compiler options
-Ofast -march=skylake-avx512 -mprefer-vector-width=256
