From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by sourceware.org (Postfix) with ESMTPS id E29A23858D1E for ; Fri, 11 Feb 2022 12:19:32 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org E29A23858D1E Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id B618F1F385; Fri, 11 Feb 2022 12:19:31 +0000 (UTC) Received: from murzim.suse.de (murzim.suse.de [10.160.4.192]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 9A359A3B8A; Fri, 11 Feb 2022 12:19:31 +0000 (UTC) Date: Fri, 11 Feb 2022 13:19:31 +0100 (CET) From: Richard Biener To: Jakub Jelinek cc: gcc-patches@gcc.gnu.org Subject: Re: [PATCH] middle-end: Small __builtin_clear_padding improvements In-Reply-To: <20220211113613.GQ2646553@tucnak> Message-ID: References: <20220211113613.GQ2646553@tucnak> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Spam-Status: No, score=-5.3 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_LOW, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 11 Feb 2022 12:19:34 -0000 On Fri, 11 Feb 2022, Jakub Jelinek wrote: > Hi! > > When looking at __builtin_clear_padding today, I've noticed that > it is quite wasteful to extend the original user one argument to 3, > 2 is enough. We need to encode the original type of the first argument > because pointer conversions are useless in GIMPLE, and we need to record > a boolean whether it is for -ftrivial-auto-var-init=* or not. > But for recording the type we don't need the value (we've always used > zero) and for recording the boolean we don't need the type (we've always > used integer_type_node). > So, this patch merges the two into one. > > Ok for trunk if it passes full bootstrap/regtest? OK. Thanks, Richard. > 2022-02-11 Jakub Jelinek > > * tree.cc (build_common_builtin_nodes): Fix up formatting in > __builtin_clear_padding decl creation. > * gimplify.cc (gimple_add_padding_init_for_auto_var): Encode > for_auto_init in the value of 2nd BUILT_IN_CLEAR_PADDING > argument rather than in 3rd argument. > (gimplify_call_expr): Likewise. Fix up comment formatting. > * gimple-fold.cc (gimple_fold_builtin_clear_padding): Expect > 2 arguments instead of 3, take for_auto_init from the value > of 2nd argument. > > --- gcc/tree.cc.jj 2022-02-11 00:19:22.436063200 +0100 > +++ gcc/tree.cc 2022-02-11 12:15:00.929134203 +0100 > @@ -9520,7 +9520,7 @@ build_common_builtin_nodes (void) > local_define_builtin ("__builtin_clear_padding", ftype, > BUILT_IN_CLEAR_PADDING, > "__builtin_clear_padding", > - ECF_LEAF | ECF_NOTHROW); > + ECF_LEAF | ECF_NOTHROW); > } > > if (!builtin_decl_explicit_p (BUILT_IN_UNREACHABLE) > --- gcc/gimplify.cc.jj 2022-02-11 00:19:22.305064981 +0100 > +++ gcc/gimplify.cc 2022-02-11 12:17:22.679180223 +0100 > @@ -1804,7 +1804,6 @@ gimple_add_padding_init_for_auto_var (tr > gimple_seq *seq_p) > { > tree addr_of_decl = NULL_TREE; > - bool for_auto_init = true; > tree fn = builtin_decl_explicit (BUILT_IN_CLEAR_PADDING); > > if (is_vla) > @@ -1821,11 +1820,8 @@ gimple_add_padding_init_for_auto_var (tr > addr_of_decl = build_fold_addr_expr (decl); > } > > - gimple *call = gimple_build_call (fn, > - 3, addr_of_decl, > - build_zero_cst (TREE_TYPE (addr_of_decl)), > - build_int_cst (integer_type_node, > - (int) for_auto_init)); > + gimple *call = gimple_build_call (fn, 2, addr_of_decl, > + build_one_cst (TREE_TYPE (addr_of_decl))); > gimplify_seq_add_stmt (seq_p, call); > } > > @@ -3536,15 +3532,12 @@ gimplify_call_expr (tree *expr_p, gimple > { > /* Remember the original type of the argument in an internal > dummy second argument, as in GIMPLE pointer conversions are > - useless. also mark this call as not for automatic initialization > - in the internal dummy third argument. */ > + useless. Also mark this call as not for automatic > + initialization in the internal dummy third argument. */ > p = CALL_EXPR_ARG (*expr_p, 0); > - bool for_auto_init = false; > *expr_p > - = build_call_expr_loc (EXPR_LOCATION (*expr_p), fndecl, 3, p, > - build_zero_cst (TREE_TYPE (p)), > - build_int_cst (integer_type_node, > - (int) for_auto_init)); > + = build_call_expr_loc (EXPR_LOCATION (*expr_p), fndecl, 2, p, > + build_zero_cst (TREE_TYPE (p))); > return GS_OK; > } > break; > --- gcc/gimple-fold.cc.jj 2022-02-11 00:18:54.799439055 +0100 > +++ gcc/gimple-fold.cc 2022-02-11 12:13:27.869417000 +0100 > @@ -4879,10 +4879,10 @@ gimple_fold_builtin_clear_padding (gimpl > gcc_assert (gimple_call_num_args (stmt) == 3); > tree ptr = gimple_call_arg (stmt, 0); > tree typearg = gimple_call_arg (stmt, 1); > - /* the 3rd argument of __builtin_clear_padding is to distinguish whether > - this call is made by the user or by the compiler for automatic variable > - initialization. */ > - bool for_auto_init = (bool) TREE_INT_CST_LOW (gimple_call_arg (stmt, 2)); > + /* The 2nd argument of __builtin_clear_padding's value is used to > + distinguish whether this call is made by the user or by the compiler > + for automatic variable initialization. */ > + bool for_auto_init = (bool) TREE_INT_CST_LOW (typearg); > tree type = TREE_TYPE (TREE_TYPE (typearg)); > location_t loc = gimple_location (stmt); > clear_padding_struct buf; > > Jakub > > -- Richard Biener SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg, Germany; GF: Ivo Totev; HRB 36809 (AG Nuernberg)