From 76048bd0693e30a5abc67aa6dcce9f4973ea208e Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Mon, 4 Nov 2024 13:03:33 +0100 Subject: Check LOOP_VINFO_PEELING_FOR_GAPS on epilog is supported We need to check that an epilogue doesn't require LOOP_VINFO_PEELING_FOR_GAPS in case the main loop didn't (the other way around is OK), the computation whether the epilog is executed or not gets our of sync otherwise. * tree-vect-loop.cc (vect_analyze_loop_2): Move vect_analyze_loop_costing after check whether we can do peeling. Add check on LOOP_VINFO_PEELING_FOR_GAPS for epilogues. --- gcc/tree-vect-loop.cc | 30 ++++++++++++++++++++---------- 1 file changed, 20 insertions(+), 10 deletions(-) (limited to 'gcc') diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc index e6d2414..e91549a 100644 --- a/gcc/tree-vect-loop.cc +++ b/gcc/tree-vect-loop.cc @@ -3143,17 +3143,15 @@ start_over: " epilogue loop.\n"); } - /* Check the costings of the loop make vectorizing worthwhile. */ - res = vect_analyze_loop_costing (loop_vinfo, suggested_unroll_factor); - if (res < 0) - { - ok = opt_result::failure_at (vect_location, - "Loop costings may not be worthwhile.\n"); - goto again; - } - if (!res) + /* If the epilogue needs peeling for gaps but the main loop doesn't give + up on the epilogue. */ + if (LOOP_VINFO_EPILOGUE_P (loop_vinfo) + && LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo) + && (LOOP_VINFO_PEELING_FOR_GAPS (orig_loop_vinfo) + != LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo))) return opt_result::failure_at (vect_location, - "Loop costings not worthwhile.\n"); + "Epilogue loop requires peeling for gaps " + "but main loop does not.\n"); /* If an epilogue loop is required make sure we can create one. */ if (LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo) @@ -3174,6 +3172,18 @@ start_over: } } + /* Check the costings of the loop make vectorizing worthwhile. */ + res = vect_analyze_loop_costing (loop_vinfo, suggested_unroll_factor); + if (res < 0) + { + ok = opt_result::failure_at (vect_location, + "Loop costings may not be worthwhile.\n"); + goto again; + } + if (!res) + return opt_result::failure_at (vect_location, + "Loop costings not worthwhile.\n"); + /* During peeling, we need to check if number of loop iterations is enough for both peeled prolog loop and vector loop. This check can be merged along with threshold check of loop versioning, so -- cgit v1.1