The following adjusts data_dep_in_cycle_p to properly consider the whole loop nest when looking for data dep cycles and exempting zero-distance DDRs instead of just the outermost loop.
Bootstrap & regtest running on x86_64-unknown-linux-gnu. * tree-loop-distribution.cc (loop_distribution::data_dep_in_cycle_p): Consider all loops in the nest when looking for lambda_vector_zerop. --- gcc/tree-loop-distribution.cc | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/gcc/tree-loop-distribution.cc b/gcc/tree-loop-distribution.cc index 8e92af61c57..5ededd97c3d 100644 --- a/gcc/tree-loop-distribution.cc +++ b/gcc/tree-loop-distribution.cc @@ -1440,7 +1440,7 @@ loop_distribution::data_dep_in_cycle_p (struct graph *rdg, else if (DDR_NUM_DIST_VECTS (ddr) > 1) return true; else if (DDR_REVERSED_P (ddr) - || lambda_vector_zerop (DDR_DIST_VECT (ddr, 0), 1)) + || lambda_vector_zerop (DDR_DIST_VECT (ddr, 0), DDR_NB_LOOPS (ddr))) return false; return true; -- 2.35.3