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* [Bug c/111383] New: Wrong code at -Os on x86_64-linux-gnu since r12-5138-ge82c382971
@ 2023-09-12  7:11 shaohua.li at inf dot ethz.ch
  2023-09-12 11:21 ` [Bug tree-optimization/111383] " xry111 at gcc dot gnu.org
                   ` (8 more replies)
  0 siblings, 9 replies; 10+ messages in thread
From: shaohua.li at inf dot ethz.ch @ 2023-09-12  7:11 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111383

            Bug ID: 111383
           Summary: Wrong code at -Os on x86_64-linux-gnu since
                    r12-5138-ge82c382971
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: shaohua.li at inf dot ethz.ch
                CC: aldyh at redhat dot com
  Target Milestone: ---

gcc at -Os produced the wrong code.

Bisected to r12-5138-ge82c382971

Compiler explorer: https://godbolt.org/z/eYY31rn4d

$ cat a.c
int printf(const char *, ...);
int a, d = 1625015426;
char e;
short b;
short *f = &b, *g = &b;
void h(char *k) {
  char c = *k;
  for (; c;)
    ;
}
int main() {
  *g = 25330;
  int i, j;
  i = 0;
  for (; *f + d - 1625040257 < 7;)
    ;
  for (; i < 4; i++) {
    j = 0;
    for (; (d - 1625015511) + (d - 1625015341) + j < 1; j++)
      h(&e);
  }
  printf("%d\n", a);
}
$
$ gcc -O0 a.c && ./a.out
0
$ gcc -Os a.c && ./a.out
(Timeout)
$
$ gcc -fsanitize=address,undefined a.c && ./a.out
0
$

^ permalink raw reply	[flat|nested] 10+ messages in thread

* [Bug tree-optimization/111383] Wrong code at -Os on x86_64-linux-gnu since r12-5138-ge82c382971
  2023-09-12  7:11 [Bug c/111383] New: Wrong code at -Os on x86_64-linux-gnu since r12-5138-ge82c382971 shaohua.li at inf dot ethz.ch
@ 2023-09-12 11:21 ` xry111 at gcc dot gnu.org
  2023-09-12 12:37 ` [Bug tree-optimization/111383] [12/13/14 Regression] " rguenth at gcc dot gnu.org
                   ` (7 subsequent siblings)
  8 siblings, 0 replies; 10+ messages in thread
From: xry111 at gcc dot gnu.org @ 2023-09-12 11:21 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111383

Xi Ruoyao <xry111 at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|c                           |tree-optimization
                 CC|                            |xry111 at gcc dot gnu.org

--- Comment #1 from Xi Ruoyao <xry111 at gcc dot gnu.org> ---
Please try to set the "component" field correctly.

^ permalink raw reply	[flat|nested] 10+ messages in thread

* [Bug tree-optimization/111383] [12/13/14 Regression] Wrong code at -Os on x86_64-linux-gnu since r12-5138-ge82c382971
  2023-09-12  7:11 [Bug c/111383] New: Wrong code at -Os on x86_64-linux-gnu since r12-5138-ge82c382971 shaohua.li at inf dot ethz.ch
  2023-09-12 11:21 ` [Bug tree-optimization/111383] " xry111 at gcc dot gnu.org
@ 2023-09-12 12:37 ` rguenth at gcc dot gnu.org
  2023-09-12 16:41 ` pinskia at gcc dot gnu.org
                   ` (6 subsequent siblings)
  8 siblings, 0 replies; 10+ messages in thread
From: rguenth at gcc dot gnu.org @ 2023-09-12 12:37 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111383

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |wrong-code
            Summary|Wrong code at -Os on        |[12/13/14 Regression] Wrong
                   |x86_64-linux-gnu since      |code at -Os on
                   |r12-5138-ge82c382971        |x86_64-linux-gnu since
                   |                            |r12-5138-ge82c382971
   Target Milestone|---                         |12.4

^ permalink raw reply	[flat|nested] 10+ messages in thread

* [Bug tree-optimization/111383] [12/13/14 Regression] Wrong code at -Os on x86_64-linux-gnu since r12-5138-ge82c382971
  2023-09-12  7:11 [Bug c/111383] New: Wrong code at -Os on x86_64-linux-gnu since r12-5138-ge82c382971 shaohua.li at inf dot ethz.ch
  2023-09-12 11:21 ` [Bug tree-optimization/111383] " xry111 at gcc dot gnu.org
  2023-09-12 12:37 ` [Bug tree-optimization/111383] [12/13/14 Regression] " rguenth at gcc dot gnu.org
@ 2023-09-12 16:41 ` pinskia at gcc dot gnu.org
  2023-09-12 16:44 ` pinskia at gcc dot gnu.org
                   ` (5 subsequent siblings)
  8 siblings, 0 replies; 10+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-09-12 16:41 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111383

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2023-09-12

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Note -fno-ivopts causes the wrong code to go away ...
So it must be the IR that IV-opts produces causes the wrong code to happen.

^ permalink raw reply	[flat|nested] 10+ messages in thread

* [Bug tree-optimization/111383] [12/13/14 Regression] Wrong code at -Os on x86_64-linux-gnu since r12-5138-ge82c382971
  2023-09-12  7:11 [Bug c/111383] New: Wrong code at -Os on x86_64-linux-gnu since r12-5138-ge82c382971 shaohua.li at inf dot ethz.ch
                   ` (2 preceding siblings ...)
  2023-09-12 16:41 ` pinskia at gcc dot gnu.org
@ 2023-09-12 16:44 ` pinskia at gcc dot gnu.org
  2023-09-12 16:46 ` pinskia at gcc dot gnu.org
                   ` (4 subsequent siblings)
  8 siblings, 0 replies; 10+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-09-12 16:44 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111383

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
-fwrapv also allows causes the correct code to happen.

The difference with/without -fwrapv is:
  _7 = _6 + -1625040257;
  if (_7 <= 6)

vs
  if (_6 <= 1625040263)

^ permalink raw reply	[flat|nested] 10+ messages in thread

* [Bug tree-optimization/111383] [12/13/14 Regression] Wrong code at -Os on x86_64-linux-gnu since r12-5138-ge82c382971
  2023-09-12  7:11 [Bug c/111383] New: Wrong code at -Os on x86_64-linux-gnu since r12-5138-ge82c382971 shaohua.li at inf dot ethz.ch
                   ` (3 preceding siblings ...)
  2023-09-12 16:44 ` pinskia at gcc dot gnu.org
@ 2023-09-12 16:46 ` pinskia at gcc dot gnu.org
  2023-09-17 20:12 ` pinskia at gcc dot gnu.org
                   ` (3 subsequent siblings)
  8 siblings, 0 replies; 10+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-09-12 16:46 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111383

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I think iv-opts is changing:
(d - 1625015511) + (d - 1625015341)

into (2*d - N) which introduces an overflow ...

^ permalink raw reply	[flat|nested] 10+ messages in thread

* [Bug tree-optimization/111383] [12/13/14 Regression] Wrong code at -Os on x86_64-linux-gnu since r12-5138-ge82c382971
  2023-09-12  7:11 [Bug c/111383] New: Wrong code at -Os on x86_64-linux-gnu since r12-5138-ge82c382971 shaohua.li at inf dot ethz.ch
                   ` (4 preceding siblings ...)
  2023-09-12 16:46 ` pinskia at gcc dot gnu.org
@ 2023-09-17 20:12 ` pinskia at gcc dot gnu.org
  2023-10-20 13:50 ` rguenth at gcc dot gnu.org
                   ` (2 subsequent siblings)
  8 siblings, 0 replies; 10+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-09-17 20:12 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111383

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Depends on|                            |110233

--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
PR 110233 is almost likely a dup, where IV-OPTS is doing reassociation
incorrectly.


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110233
[Bug 110233] [12/13/14 Regression] Wrong code at -Os on x86_64-linux-gnu

^ permalink raw reply	[flat|nested] 10+ messages in thread

* [Bug tree-optimization/111383] [12/13/14 Regression] Wrong code at -Os on x86_64-linux-gnu since r12-5138-ge82c382971
  2023-09-12  7:11 [Bug c/111383] New: Wrong code at -Os on x86_64-linux-gnu since r12-5138-ge82c382971 shaohua.li at inf dot ethz.ch
                   ` (5 preceding siblings ...)
  2023-09-17 20:12 ` pinskia at gcc dot gnu.org
@ 2023-10-20 13:50 ` rguenth at gcc dot gnu.org
  2023-10-20 13:54 ` cvs-commit at gcc dot gnu.org
  2023-10-20 13:57 ` rguenth at gcc dot gnu.org
  8 siblings, 0 replies; 10+ messages in thread
From: rguenth at gcc dot gnu.org @ 2023-10-20 13:50 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111383

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |DUPLICATE
             Status|NEW                         |RESOLVED

--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed by r14-4789-g44e7e4498c3cdc.

*** This bug has been marked as a duplicate of bug 110243 ***

^ permalink raw reply	[flat|nested] 10+ messages in thread

* [Bug tree-optimization/111383] [12/13/14 Regression] Wrong code at -Os on x86_64-linux-gnu since r12-5138-ge82c382971
  2023-09-12  7:11 [Bug c/111383] New: Wrong code at -Os on x86_64-linux-gnu since r12-5138-ge82c382971 shaohua.li at inf dot ethz.ch
                   ` (6 preceding siblings ...)
  2023-10-20 13:50 ` rguenth at gcc dot gnu.org
@ 2023-10-20 13:54 ` cvs-commit at gcc dot gnu.org
  2023-10-20 13:57 ` rguenth at gcc dot gnu.org
  8 siblings, 0 replies; 10+ messages in thread
From: cvs-commit at gcc dot gnu.org @ 2023-10-20 13:54 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111383

--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Richard Biener <rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:a1fc2cc0a8a8b97dbc3dc6715fd4f384d9204845

commit r14-4791-ga1fc2cc0a8a8b97dbc3dc6715fd4f384d9204845
Author: Richard Biener <rguenther@suse.de>
Date:   Fri Oct 20 15:52:09 2023 +0200

    tree-optimization/111383 - testcase for fixed PR

            PR tree-optimization/111383
            PR tree-optimization/110243
    gcc/testsuite/
            * gcc.dg/torture/pr111383.c: New testcase.

^ permalink raw reply	[flat|nested] 10+ messages in thread

* [Bug tree-optimization/111383] [12/13/14 Regression] Wrong code at -Os on x86_64-linux-gnu since r12-5138-ge82c382971
  2023-09-12  7:11 [Bug c/111383] New: Wrong code at -Os on x86_64-linux-gnu since r12-5138-ge82c382971 shaohua.li at inf dot ethz.ch
                   ` (7 preceding siblings ...)
  2023-10-20 13:54 ` cvs-commit at gcc dot gnu.org
@ 2023-10-20 13:57 ` rguenth at gcc dot gnu.org
  8 siblings, 0 replies; 10+ messages in thread
From: rguenth at gcc dot gnu.org @ 2023-10-20 13:57 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111383
Bug 111383 depends on bug 110233, which changed state.

Bug 110233 Summary: [12/13/14 Regression] Wrong code at -Os on x86_64-linux-gnu
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110233

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |DUPLICATE

^ permalink raw reply	[flat|nested] 10+ messages in thread

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2023-09-12 11:21 ` [Bug tree-optimization/111383] " xry111 at gcc dot gnu.org
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