From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 1774C3858D1E; Tue, 24 Jan 2023 17:10:12 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 1774C3858D1E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1674580212; bh=sXMTetSd0AgGB78XSz2qi34HiT1EVvu560iHXnShLI8=; h=From:To:Subject:Date:In-Reply-To:References:From; b=hSshuDwnGGiTLBpV//TklvN5c3QOHfUozQa6M/3ipThEUOkF0dcRHclNnT0mKnrQM YdxPF8LrG+346XSdzwiTJfVXQqDbr+Ln+Zzy/BPZyEYSFm4pFAMeTzO3zpbJwZPswS 94GewaOQDy7XE8Ub2pUZjtBSWwR+3k42fLT+T2+w= From: "jakub at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/108498] [11/12/13 Regression] ppc64 big endian generates uninitialized reads with -fstore-merging Date: Tue, 24 Jan 2023 17:10:11 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: tree-optimization X-Bugzilla-Version: 12.0 X-Bugzilla-Keywords: wrong-code X-Bugzilla-Severity: normal X-Bugzilla-Who: jakub at gcc dot gnu.org X-Bugzilla-Status: ASSIGNED X-Bugzilla-Resolution: X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: jakub at gcc dot gnu.org X-Bugzilla-Target-Milestone: 11.4 X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 List-Id: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D108498 --- Comment #22 from Jakub Jelinek --- The C/C++ FEs since r9-6625-gbec1da64aec26a490 turn some array initializers into strings. Anyway, I wonder if for GCC 14 we couldn't just treat STRING_CST the same as INTEGER_CST during the merging into groups and instead deal with all of that during split_group. I.e. only at that time see that for this subset of stores we want to merge = them into one STRING_CST store, these others handle differently, etc. And the preconditions for handling something the STRING_CST way would be contiguous chunk with byte aligned start/end containg at least one longer STRING_CST. = So, we wouldn't give up e.g. in the second testcase, but merge the STRING_CSTs stores with the 4 byte INTEGER_CST store in between them, while handling the bitfield stuff at the start and/or the end to separate stores.=