https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85212
Bug ID: 85212 Summary: Parallelizable loop isn't unrolled [regression bug?] Product: gcc Version: 7.3.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: robertw89 at googlemail dot com Target Milestone: --- The compiler fails to unroll the loop (partially). compiled with -O3 -mavx -mavx2 -mfma -fno-math-errno -ffast-math -floop-parallelize-all -ftree-parallelize-loops=8 void testAutoParr(int *x) { for (int i = 0; i < 1000; i++){ x[2*i+1] = x[2*i]; } }