From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 118127 invoked by alias); 27 Nov 2017 15:18:42 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 115914 invoked by uid 89); 27 Nov 2017 15:18:40 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-11.2 required=5.0 tests=BAYES_00,GIT_PATCH_2,GIT_PATCH_3,KAM_NUMSUBJECT,KB_WAM_FROM_NAME_SINGLEWORD,SPF_PASS,T_RP_MATCHES_RCVD autolearn=ham version=3.3.2 spammy= X-HELO: mx2.suse.de Received: from mx2.suse.de (HELO mx2.suse.de) (195.135.220.15) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Mon, 27 Nov 2017 15:18:34 +0000 Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id DC2E9AB0C for ; Mon, 27 Nov 2017 15:18:31 +0000 (UTC) Date: Mon, 27 Nov 2017 15:41:00 -0000 From: Richard Biener To: gcc-patches@gcc.gnu.org Subject: [PATCH][2/2] gimple-fold.c part for PR83141 Message-ID: User-Agent: Alpine 2.20 (LSU 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-SW-Source: 2017-11/txt/msg02304.txt.bz2 The following is the truly minimal fix for the middle-end issue with SRA and memcpy folding interaction. I've tried more variants that "make sense" but as they all end up folding slightly more memcpy calls than before we run into optimization testcase regressions in places that look for __builtin_memcpy and do not deal with aggregate copies as MEM[..] = MEM[..]; Bootstrap and regtest running on x86_64-unknown-linux-gnu. GCC 9 is the time we can try dealing with such fallout, it just doesn't feel like the correct time to do now... Richard. 2017-11-27 Richard Biener PR middle-end/83141 * gimple-fold.c (gimple_fold_builtin_memory_op): For aggregate copies generated from memcpy use a character array as reference type. Index: gcc/gimple-fold.c =================================================================== --- gcc/gimple-fold.c (revision 255172) +++ gcc/gimple-fold.c (working copy) @@ -1038,9 +1038,25 @@ gimple_fold_builtin_memory_op (gimple_st gimple_assign_set_lhs (new_stmt, srcvar); gimple_set_vuse (new_stmt, gimple_vuse (stmt)); gsi_insert_before (gsi, new_stmt, GSI_SAME_STMT); + new_stmt = gimple_build_assign (destvar, srcvar); + goto set_vop_and_replace; } } - new_stmt = gimple_build_assign (destvar, srcvar); + + /* We get an aggregate copy. Use an unsigned char[] type to + perform the copying to preserve padding and to avoid any issues + with TREE_ADDRESSABLE types or float modes behavior on copying. */ + desttype = build_array_type_nelts (unsigned_char_type_node, + tree_to_uhwi (len)); + srctype = desttype; + if (src_align > TYPE_ALIGN (srctype)) + srctype = build_aligned_type (srctype, src_align); + if (dest_align > TYPE_ALIGN (desttype)) + desttype = build_aligned_type (desttype, dest_align); + new_stmt + = gimple_build_assign (fold_build2 (MEM_REF, desttype, dest, off0), + fold_build2 (MEM_REF, srctype, src, off0)); +set_vop_and_replace: gimple_set_vuse (new_stmt, gimple_vuse (stmt)); gimple_set_vdef (new_stmt, gimple_vdef (stmt)); if (gimple_vdef (new_stmt)