https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83857
--- Comment #6 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> --- Author: rsandifo Date: Tue Jan 16 15:13:32 2018 New Revision: 256747 URL: https://gcc.gnu.org/viewcvs?rev=256747&root=gcc&view=rev Log: Two fixes for live-out SLP inductions (PR 83857) vect_analyze_loop_operations was calling vectorizable_live_operation for all live-out phis, which led to a bogus ncopies calculation in the pure SLP case. I think v_a_l_o should only be passing phis that are vectorised using normal loop vectorisation, since vect_slp_analyze_node_operations handles the SLP side (and knows the correct slp_index and slp_node arguments to pass in, via vect_analyze_stmt). With that fixed we hit an older bug that vectorizable_live_operation didn't handle live-out SLP inductions. Fixed by using gimple_phi_result rather than gimple_get_lhs for phis. 2018-01-16 Richard Sandiford <richard.sandif...@linaro.org> gcc/ PR tree-optimization/83857 * tree-vect-loop.c (vect_analyze_loop_operations): Don't call vectorizable_live_operation for pure SLP statements. (vectorizable_live_operation): Handle PHIs. gcc/testsuite/ PR tree-optimization/83857 * gcc.dg/vect/pr83857.c: New test. Added: trunk/gcc/testsuite/gcc.dg/vect/pr83857.c Modified: trunk/gcc/ChangeLog trunk/gcc/testsuite/ChangeLog trunk/gcc/tree-vect-loop.c
