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* [Bug c/65357] New: aggressive loop optimization not correct @ 2015-03-09 2:26 weiming at ms1 dot url.com.tw 2015-03-09 4:18 ` [Bug c/65357] " trippels at gcc dot gnu.org ` (5 more replies) 0 siblings, 6 replies; 7+ messages in thread From: weiming at ms1 dot url.com.tw @ 2015-03-09 2:26 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65357 Bug ID: 65357 Summary: aggressive loop optimization not correct Product: gcc Version: unknown Status: UNCONFIRMED Severity: normal Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: weiming at ms1 dot url.com.tw source: #include <stdio.h> #include <stdlib.h> void addlist(int n, int *list) { int i; for (i=0; i<n; i++) { *list++=*list+10; *list++=*list+11; } } int tlist[10]={ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 }; void main(void) { int i; addlist(5, tlist); for (i=0; i<10; i++) { fprintf(stdout, "%d: %d\n", i, tlist[i]); } } makefile: tt.exe: tt.c gcc -O3 -o $@ $< result of gcc 4.7.3: 0: 10 1: 12 2: 12 3: 14 4: 14 5: 16 6: 16 7: 18 8: 18 9: 20 result of gcc 4.8.4 and 4.9.2: 0: 11 1: 13 2: 13 3: 15 4: 15 5: 17 6: 17 7: 19 8: 19 9: 11 which is correct? ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c/65357] aggressive loop optimization not correct 2015-03-09 2:26 [Bug c/65357] New: aggressive loop optimization not correct weiming at ms1 dot url.com.tw @ 2015-03-09 4:18 ` trippels at gcc dot gnu.org 2015-03-09 5:08 ` pinskia at gcc dot gnu.org ` (4 subsequent siblings) 5 siblings, 0 replies; 7+ messages in thread From: trippels at gcc dot gnu.org @ 2015-03-09 4:18 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65357 Markus Trippelsdorf <trippels at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED CC| |trippels at gcc dot gnu.org Resolution|--- |INVALID --- Comment #1 from Markus Trippelsdorf <trippels at gcc dot gnu.org> --- Both, because you invoke undefined behavior. https://gcc.gnu.org/bugs/#nonbugs_c ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c/65357] aggressive loop optimization not correct 2015-03-09 2:26 [Bug c/65357] New: aggressive loop optimization not correct weiming at ms1 dot url.com.tw 2015-03-09 4:18 ` [Bug c/65357] " trippels at gcc dot gnu.org @ 2015-03-09 5:08 ` pinskia at gcc dot gnu.org 2015-03-09 5:47 ` weiming at ms1 dot url.com.tw ` (3 subsequent siblings) 5 siblings, 0 replies; 7+ messages in thread From: pinskia at gcc dot gnu.org @ 2015-03-09 5:08 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65357 --- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- That is addlist goes one past the end of the array tlist. ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c/65357] aggressive loop optimization not correct 2015-03-09 2:26 [Bug c/65357] New: aggressive loop optimization not correct weiming at ms1 dot url.com.tw 2015-03-09 4:18 ` [Bug c/65357] " trippels at gcc dot gnu.org 2015-03-09 5:08 ` pinskia at gcc dot gnu.org @ 2015-03-09 5:47 ` weiming at ms1 dot url.com.tw 2015-03-09 6:14 ` weiming at ms1 dot url.com.tw ` (2 subsequent siblings) 5 siblings, 0 replies; 7+ messages in thread From: weiming at ms1 dot url.com.tw @ 2015-03-09 5:47 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65357 --- Comment #3 from Weiming Shih <weiming at ms1 dot url.com.tw> --- I see. Thank you. ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c/65357] aggressive loop optimization not correct 2015-03-09 2:26 [Bug c/65357] New: aggressive loop optimization not correct weiming at ms1 dot url.com.tw ` (2 preceding siblings ...) 2015-03-09 5:47 ` weiming at ms1 dot url.com.tw @ 2015-03-09 6:14 ` weiming at ms1 dot url.com.tw 2015-03-09 8:33 ` jakub at gcc dot gnu.org 2015-03-09 8:47 ` pinskia at gcc dot gnu.org 5 siblings, 0 replies; 7+ messages in thread From: weiming at ms1 dot url.com.tw @ 2015-03-09 6:14 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65357 --- Comment #4 from Weiming Shih <weiming at ms1 dot url.com.tw> --- How can I get a warning for such an undefined behavior? ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c/65357] aggressive loop optimization not correct 2015-03-09 2:26 [Bug c/65357] New: aggressive loop optimization not correct weiming at ms1 dot url.com.tw ` (3 preceding siblings ...) 2015-03-09 6:14 ` weiming at ms1 dot url.com.tw @ 2015-03-09 8:33 ` jakub at gcc dot gnu.org 2015-03-09 8:47 ` pinskia at gcc dot gnu.org 5 siblings, 0 replies; 7+ messages in thread From: jakub at gcc dot gnu.org @ 2015-03-09 8:33 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65357 Jakub Jelinek <jakub at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |jakub at gcc dot gnu.org --- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Perhaps by enabling warnings? E.g. with -Wall you get all the important warnings: warning: operation on ‘list’ may be undefined [-Wsequence-point] (twice) and warning: return type of ‘main’ is not ‘int’ [-Wmain] >From gcc-bugs-return-479757-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org Mon Mar 09 08:36:55 2015 Return-Path: <gcc-bugs-return-479757-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org> Delivered-To: listarch-gcc-bugs@gcc.gnu.org Received: (qmail 90920 invoked by alias); 9 Mar 2015 08:36:55 -0000 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: <gcc-bugs.gcc.gnu.org> List-Archive: <http://gcc.gnu.org/ml/gcc-bugs/> List-Post: <mailto:gcc-bugs@gcc.gnu.org> List-Help: <mailto:gcc-bugs-help@gcc.gnu.org> Sender: gcc-bugs-owner@gcc.gnu.org Delivered-To: mailing list gcc-bugs@gcc.gnu.org Received: (qmail 90861 invoked by uid 48); 9 Mar 2015 08:36:52 -0000 From: "mikpelinux at gmail dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug target/65358] wrong parameter passing code with tail call optimization on arm Date: Mon, 09 Mar 2015 08:36:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: target X-Bugzilla-Version: 5.0 X-Bugzilla-Keywords: wrong-code X-Bugzilla-Severity: critical X-Bugzilla-Who: mikpelinux at gmail dot com X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: <bug-65358-4-B3qaA3bjeb@http.gcc.gnu.org/bugzilla/> In-Reply-To: <bug-65358-4@http.gcc.gnu.org/bugzilla/> References: <bug-65358-4@http.gcc.gnu.org/bugzilla/> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-SW-Source: 2015-03/txt/msg00901.txt.bz2 Content-length: 305 https://gcc.gnu.org/bugzilla/show_bug.cgi?ide358 --- Comment #6 from Mikael Pettersson <mikpelinux at gmail dot com> --- (In reply to Honggyu Kim from comment #4) > Can I add this testcase with your modification as my first gcc contribution? > :) Sure, just attach it to this PR as a new test case. ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c/65357] aggressive loop optimization not correct 2015-03-09 2:26 [Bug c/65357] New: aggressive loop optimization not correct weiming at ms1 dot url.com.tw ` (4 preceding siblings ...) 2015-03-09 8:33 ` jakub at gcc dot gnu.org @ 2015-03-09 8:47 ` pinskia at gcc dot gnu.org 5 siblings, 0 replies; 7+ messages in thread From: pinskia at gcc dot gnu.org @ 2015-03-09 8:47 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65357 --- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> --- I missed there was a sequence point issue there too :). ^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2015-03-09 8:47 UTC | newest] Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2015-03-09 2:26 [Bug c/65357] New: aggressive loop optimization not correct weiming at ms1 dot url.com.tw 2015-03-09 4:18 ` [Bug c/65357] " trippels at gcc dot gnu.org 2015-03-09 5:08 ` pinskia at gcc dot gnu.org 2015-03-09 5:47 ` weiming at ms1 dot url.com.tw 2015-03-09 6:14 ` weiming at ms1 dot url.com.tw 2015-03-09 8:33 ` jakub at gcc dot gnu.org 2015-03-09 8:47 ` pinskia at gcc dot gnu.org
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