https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65207
Bug ID: 65207 Summary: [5 regression] performance: tree level loop optimization does not peel SpecCPU href loop Product: gcc Version: 5.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: krebbel at gcc dot gnu.org mv-search.c SetupFastFullPelSearch for (blky = 0; blky < 4; blky++) { LineSadBlk0 = LineSadBlk1 = LineSadBlk2 = LineSadBlk3 = 0; for (y = 0; y < 4; y++) { refptr = PelYline_11 (ref_pic, abs_y++, abs_x, img_height, img_width); ... After the loop peeling has been removed from RTL level this loop does not get peeled completely as before on S/390 which results in a performance regression (-5%). https://gcc.gnu.org/ml/gcc-patches/2014-10/msg01211.html The tree level loop peeling refuses to peel the loop because it contains a function call.