From ff7463172e564c5dd2432d7af8eaa0124cbd4af7 Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Thu, 27 Aug 2020 10:02:22 +0200 Subject: tree-optimization/96579 - another special-operands fix in reassoc This makes sure to put special-ops expanded rhs left where expression rewrite expects it. 2020-08-27 Richard Biener PR tree-optimization/96579 * tree-ssa-reassoc.c (linearize_expr_tree): If we expand rhs via special ops make sure to swap operands. * gcc.dg/pr96579.c: New testcase. --- gcc/tree-ssa-reassoc.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) (limited to 'gcc/tree-ssa-reassoc.c') diff --git a/gcc/tree-ssa-reassoc.c b/gcc/tree-ssa-reassoc.c index fed463b..a5f5d52 100644 --- a/gcc/tree-ssa-reassoc.c +++ b/gcc/tree-ssa-reassoc.c @@ -5651,13 +5651,20 @@ linearize_expr_tree (vec *ops, gimple *stmt, if (!binrhsisreassoc) { - if (!try_special_add_to_ops (ops, rhscode, binrhs, binrhsdef)) + bool swap = false; + if (try_special_add_to_ops (ops, rhscode, binrhs, binrhsdef)) + /* If we add ops for the rhs we expect to be able to recurse + to it via the lhs during expression rewrite so swap + operands. */ + swap = true; + else add_to_ops_vec (ops, binrhs); if (!try_special_add_to_ops (ops, rhscode, binlhs, binlhsdef)) add_to_ops_vec (ops, binlhs); - return; + if (!swap) + return; } if (dump_file && (dump_flags & TDF_DETAILS)) @@ -5676,6 +5683,8 @@ linearize_expr_tree (vec *ops, gimple *stmt, fprintf (dump_file, " is now "); print_gimple_stmt (dump_file, stmt, 0); } + if (!binrhsisreassoc) + return; /* We want to make it so the lhs is always the reassociative op, so swap. */ -- cgit v1.1