https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105940
--- Comment #9 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Kewen Lin <li...@gcc.gnu.org>: https://gcc.gnu.org/g:86882d9feb6a534325d7162216696266898e36d0 commit r13-1173-g86882d9feb6a534325d7162216696266898e36d0 Author: Kewen Lin <li...@linux.ibm.com> Date: Mon Jun 20 07:44:21 2022 -0500 vect: Respect slp decision when applying suggested uf [PR105940] This follows Richi's suggestion in PR105940, it aims to avoid inconsistent slp decision between when the suggested unroll factor is worked out and when the suggested unroll factor is applied. If the previous slp decision is true when the suggested unroll factor is worked out, when we are applying unroll factor we don't need to start over with slp off if the analysis with slp on fails. On the other hand, if the previous slp decision is false when the suggested unroll factor is worked out, when we are applying unroll factor we can skip the slp handlings. Function vect_is_simple_reduction saves reduction chains for subsequent slp analyses, we have to disable this early otherwise there is an ICE in vectorizable_reduction for below: if (REDUC_GROUP_FIRST_ELEMENT (stmt_info)) gcc_assert (slp_node && REDUC_GROUP_FIRST_ELEMENT (stmt_info) == stmt_info); PR tree-optimization/105940 gcc/ChangeLog: * tree-vect-loop.cc (vect_analyze_loop_2): Add new parameter slp_done_for_suggested_uf and adjust with it accordingly. (vect_analyze_loop_1): Add new variable slp_done_for_suggested_uf, pass it down to vect_analyze_loop_2 for the initial analysis and applying suggested unroll factor. (vect_is_simple_reduction): Add parameter slp and adjust with it. (vect_analyze_scalar_cycles_1): Add parameter slp and pass down. (vect_analyze_scalar_cycles): Likewise.
