From 6d936684fcf9bbb55837e3a87ae2221d5ec9b5b7 Mon Sep 17 00:00:00 2001 From: Andrew MacLeod Date: Tue, 2 Nov 2021 09:46:53 -0400 Subject: [PATCH] For ranges, PHIs don't need to process arg == def. If an argument of a phi is the same as the DEF of the phi, then the range on the incoming edge doesn't need to be taken into account since it can't be anything other than itself. * gimple-range-fold.cc (fold_using_range::range_of_phi): Don't import a range from edge if arg == phidef. --- gcc/gimple-range-fold.cc | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/gcc/gimple-range-fold.cc b/gcc/gimple-range-fold.cc index 6cc7753..608d98b 100644 --- a/gcc/gimple-range-fold.cc +++ b/gcc/gimple-range-fold.cc @@ -779,6 +779,10 @@ fold_using_range::range_of_phi (irange &r, gphi *phi, fur_source &src) for (x = 0; x < gimple_phi_num_args (phi); x++) { tree arg = gimple_phi_arg_def (phi, x); + // An argument that is the same as the def provides no new range. + if (arg == phi_def) + continue; + edge e = gimple_phi_arg_edge (phi, x); // Get the range of the argument on its edge. -- 2.7.4