From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by sourceware.org (Postfix) with ESMTPS id 1D652395543A for ; Mon, 10 May 2021 09:42:01 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 1D652395543A Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=rguenther@suse.de X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 41542B034; Mon, 10 May 2021 09:42:00 +0000 (UTC) Date: Mon, 10 May 2021 11:41:59 +0200 (CEST) From: Richard Biener To: Jason Merrill cc: Richard Biener , GCC Patches Subject: Re: [PATCH] middle-end/100464 - avoid spurious TREE_ADDRESSABLE in folding debug stmts In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Spam-Status: No, score=-11.4 required=5.0 tests=BAYES_00, GIT_PATCH_0, KAM_DMARC_STATUS, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) 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: Mon, 10 May 2021 09:42:02 -0000 On Sun, 9 May 2021, Jason Merrill wrote: > On 5/7/21 6:21 AM, Richard Biener wrote: > > On Fri, May 7, 2021 at 12:17 PM Richard Biener wrote: > >> > >> canonicalize_constructor_val was setting TREE_ADDRESSABLE on bases > >> of ADDR_EXPRs but that's futile when we're dealing with CTOR values > >> in debug stmts. This rips out the code which was added for Java > >> and should have been an assertion when we didn't have debug stmts. > >> > >> Bootstrapped and tested on x86_64-unknown-linux-gnu for all languages > >> which revealed PR100468 for which I added the cp/class.c hunk below. > >> Re-testing with that in progress. > >> > >> OK for trunk and branch? It looks like this C++ code is new in GCC 11. > > > > I mislooked, the code is old. > > > > This hunk also breaks (or fixes) g++.dg/tree-ssa/array-temp1.C where > > the gimplifier previously passes the > > > > && (flag_merge_constants >= 2 || !TREE_ADDRESSABLE (object)) > > > > check guarding it against unifying addresses of different instances > > of variables. Clearly in the case of the testcase there are addresses to > > this variable as part of the initializer list construction. So the hunk > > fixes > > wrong-code, but it breaks the testcase. > > > > Any comments? I can of course change the testcase accordingly. > > Hmm, I suppose if the optimization is wrong for PR38615, it's also wrong for > the initializer_list variant: > > extern "C" void abort (void); > #include > > int f(int t, const int *a) > { > std::initializer_list b = { 1, 2, 3 }; > const int *p = b.begin(); > if (!t) > return f (1, p); > return p == a; > } > > int main(void) > { > if (f(0, 0)) > abort (); > return 0; > } > > so adjusting the array-temp testcase seems like the right answer. Done as follows. Bootstrapped / tested on x86_64-unknown-linux-gnu, pushed to trunk sofar. Richard. >From a076632e274abe344ca7648b7c7f299273d4cbe0 Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Fri, 7 May 2021 09:51:18 +0200 Subject: [PATCH] middle-end/100464 - avoid spurious TREE_ADDRESSABLE in folding debug stmts To: gcc-patches@gcc.gnu.org canonicalize_constructor_val was setting TREE_ADDRESSABLE on bases of ADDR_EXPRs but that's futile when we're dealing with CTOR values in debug stmts. This rips out the code which was added for Java and should have been an assertion when we didn't have debug stmts. To not regress g++.dg/tree-ssa/array-temp1.C we have to adjust the testcase to not look for a no longer applied invalid optimization. 2021-05-10 Richard Biener PR middle-end/100464 PR c++/100468 gcc/ * gimple-fold.c (canonicalize_constructor_val): Do not set TREE_ADDRESSABLE. gcc/cp/ * call.c (set_up_extended_ref_temp): Mark the temporary addressable if the TARGET_EXPR was. gcc/testsuite/ * gcc.dg/pr100464.c: New testcase. * g++.dg/tree-ssa/array-temp1.C: Adjust. --- gcc/cp/call.c | 2 ++ gcc/gimple-fold.c | 4 +++- gcc/testsuite/g++.dg/tree-ssa/array-temp1.C | 6 ------ gcc/testsuite/gcc.dg/pr100464.c | 16 ++++++++++++++++ 4 files changed, 21 insertions(+), 7 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/pr100464.c diff --git a/gcc/cp/call.c b/gcc/cp/call.c index d985e4e8eda..f07e09a36d1 100644 --- a/gcc/cp/call.c +++ b/gcc/cp/call.c @@ -12478,6 +12478,8 @@ set_up_extended_ref_temp (tree decl, tree expr, vec **cleanups, VAR. */ if (TREE_CODE (expr) != TARGET_EXPR) expr = get_target_expr (expr); + else if (TREE_ADDRESSABLE (expr)) + TREE_ADDRESSABLE (var) = 1; if (TREE_CODE (decl) == FIELD_DECL && extra_warnings && !TREE_NO_WARNING (decl)) diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c index aa33779b753..768ef89d876 100644 --- a/gcc/gimple-fold.c +++ b/gcc/gimple-fold.c @@ -245,7 +245,9 @@ canonicalize_constructor_val (tree cval, tree from_decl) if (TREE_TYPE (base) == error_mark_node) return NULL_TREE; if (VAR_P (base)) - TREE_ADDRESSABLE (base) = 1; + /* ??? We should be able to assert that TREE_ADDRESSABLE is set, + but since the use can be in a debug stmt we can't. */ + ; else if (TREE_CODE (base) == FUNCTION_DECL) { /* Make sure we create a cgraph node for functions we'll reference. diff --git a/gcc/testsuite/g++.dg/tree-ssa/array-temp1.C b/gcc/testsuite/g++.dg/tree-ssa/array-temp1.C index 97c2e0521c9..3df7aadd30a 100644 --- a/gcc/testsuite/g++.dg/tree-ssa/array-temp1.C +++ b/gcc/testsuite/g++.dg/tree-ssa/array-temp1.C @@ -13,9 +13,3 @@ int f() using AR = const int[]; return AR{ 1,42,3,4,5,6,7,8,9,0 }[5]; } - -int g() -{ - std::initializer_list a = {1,42,3}; - return a.begin()[0]; -} diff --git a/gcc/testsuite/gcc.dg/pr100464.c b/gcc/testsuite/gcc.dg/pr100464.c new file mode 100644 index 00000000000..46cc37dff54 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr100464.c @@ -0,0 +1,16 @@ +/* { dg-do compile } */ +/* { dg-options "-O3 -fcompare-debug" } */ + +int *a; +static int b, c, d, e, g, h; +int f; +void i() { + int *j[] = {&e, &b, &b, &d, &b, &b, &g, &e, &g, &b, &b, + &b, &b, &g, &e, &e, &b, &b, &d, &b, &b, &e, + &e, &g, &b, &b, &b, &b, &g, &e, &g, &c, &e}; + int **k = &j[5]; + for (; f;) + b |= *a; + *k = &h; +} +int main() {} -- 2.26.2