From 9ff8f041331ef8b56007fb3c4d41d76f9850010d Mon Sep 17 00:00:00 2001 From: Andrew Pinski Date: Sat, 18 May 2024 11:55:58 -0700 Subject: PHIOPT: Don't transform minmax if middle bb contains a phi [PR115143] The problem here is even if last_and_only_stmt returns a statement, the bb might still contain a phi node which defines a ssa name which is used in that statement so we need to add a check to make sure that the phi nodes are empty for the middle bbs in both the `CMP?MINMAX:MINMAX` case and the `CMP?MINMAX:B` cases. Bootstrapped and tested on x86_64_linux-gnu with no regressions. PR tree-optimization/115143 gcc/ChangeLog: * tree-ssa-phiopt.cc (minmax_replacement): Check for empty phi nodes for middle bbs for the case where middle bb is not empty. gcc/testsuite/ChangeLog: * gcc.c-torture/compile/pr115143-1.c: New test. * gcc.c-torture/compile/pr115143-2.c: New test. * gcc.c-torture/compile/pr115143-3.c: New test. Signed-off-by: Andrew Pinski --- gcc/tree-ssa-phiopt.cc | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'gcc/tree-ssa-phiopt.cc') diff --git a/gcc/tree-ssa-phiopt.cc b/gcc/tree-ssa-phiopt.cc index f166c31..918cf50 100644 --- a/gcc/tree-ssa-phiopt.cc +++ b/gcc/tree-ssa-phiopt.cc @@ -1925,6 +1925,10 @@ minmax_replacement (basic_block cond_bb, basic_block middle_bb, basic_block alt_ || gimple_code (assign) != GIMPLE_ASSIGN) return false; + /* There cannot be any phi nodes in the middle bb. */ + if (!gimple_seq_empty_p (phi_nodes (middle_bb))) + return false; + lhs = gimple_assign_lhs (assign); ass_code = gimple_assign_rhs_code (assign); if (ass_code != MAX_EXPR && ass_code != MIN_EXPR) @@ -1938,6 +1942,10 @@ minmax_replacement (basic_block cond_bb, basic_block middle_bb, basic_block alt_ || gimple_code (assign) != GIMPLE_ASSIGN) return false; + /* There cannot be any phi nodes in the alt middle bb. */ + if (!gimple_seq_empty_p (phi_nodes (alt_middle_bb))) + return false; + alt_lhs = gimple_assign_lhs (assign); if (ass_code != gimple_assign_rhs_code (assign)) return false; @@ -2049,6 +2057,10 @@ minmax_replacement (basic_block cond_bb, basic_block middle_bb, basic_block alt_ || gimple_code (assign) != GIMPLE_ASSIGN) return false; + /* There cannot be any phi nodes in the middle bb. */ + if (!gimple_seq_empty_p (phi_nodes (middle_bb))) + return false; + lhs = gimple_assign_lhs (assign); ass_code = gimple_assign_rhs_code (assign); if (ass_code != MAX_EXPR && ass_code != MIN_EXPR) -- cgit v1.1