From 4bf76b5b6db8e68755788ec91012c5a686440720 Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Wed, 28 Jun 2023 11:27:45 +0200 Subject: [PATCH] tree-optimization/110434 - avoid ={v} {CLOBBER} from NRV When NRV replaces a local variable with it also replaces occurences in clobbers. This leads to being clobbered before the return of it which is strictly invalid but harmless in practice since there's no pass after NRV which would remove earlier stores. The following fixes this nevertheless. PR tree-optimization/110434 * tree-nrv.cc (pass_nrv::execute): Remove CLOBBERs of VAR we replace with . --- gcc/tree-nrv.cc | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/gcc/tree-nrv.cc b/gcc/tree-nrv.cc index ff47439647c2..99c4e21a842b 100644 --- a/gcc/tree-nrv.cc +++ b/gcc/tree-nrv.cc @@ -264,7 +264,17 @@ pass_nrv::execute (function *fun) data.modified = 0; walk_gimple_op (stmt, finalize_nrv_r, &wi); if (data.modified) - update_stmt (stmt); + { + /* If this is a CLOBBER of VAR, remove it. */ + if (gimple_clobber_p (stmt)) + { + unlink_stmt_vdef (stmt); + gsi_remove (&gsi, true); + release_defs (stmt); + continue; + } + update_stmt (stmt); + } gsi_next (&gsi); } } -- 2.47.2