[Bug c/111734] New: wrong code with '-O3 -fno-inline-functions-called-once -fno-inline-small-functions -fno-omit-frame-pointer -fno-toplevel-reorder -fno-tree-fre'

[Bug c/111734] New: wrong code with '-O3 -fno-inline-functions-called-once -fno-inline-small-functions -fno-omit-frame-pointer -fno-toplevel-reorder -fno-tree-fre'

[19373742 at buaa dot edu.cn]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111734

            Bug ID: 111734
           Summary: wrong code with '-O3 -fno-inline-functions-called-once
                    -fno-inline-small-functions -fno-omit-frame-pointer
                    -fno-toplevel-reorder -fno-tree-fre'
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: 19373742 at buaa dot edu.cn
  Target Milestone: ---

Created attachment 56077
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=56077&action=edit
The preprocessed file

*******************************************************************************
OS and Platform:
Ubuntu 20.04.4 LTS
*******************************************************************************
gcc version:
$ gcc -v
Using built-in specs.
COLLECT_GCC=/home/ctc/gcc-releases/gcc-14/bin/gcc
COLLECT_LTO_WRAPPER=/home/ctc/gcc-releases/gcc-14/libexec/gcc/x86_64-pc-linux-gnu/14.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ./configure --prefix=/home/cuisk/ctc/gcc-releases/gcc-14
--disable-multilib --enable-language=c,c++
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 14.0.0 20231008 (experimental) (GCC) 
*******************************************************************************
Command Lines:
$ /home/ctc/gcc-releases/gcc-14/bin/gcc -O3 -fno-inline-functions-called-once
-fno-inline-small-functions -fno-omit-frame-pointer -fno-toplevel-reorder
-fno-tree-fre -I /home/ctc/csmith/include/csmith-2.3.0/ a.c -o w

$ ./w
checksum = DD7E999B

$ /home/ctc/gcc-releases/gcc-14/bin/gcc -I
/home/ctc/csmith/include/csmith-2.3.0/ a.c -o w

$ ./w
checksum = A876723F

[Bug c/111734] wrong code with '-O3 -fno-inline-functions-called-once -fno-inline-small-functions -fno-omit-frame-pointer -fno-toplevel-reorder -fno-tree-fre'

[19373742 at buaa dot edu.cn]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111734

--- Comment #1 from CTC <19373742 at buaa dot edu.cn> ---
Created attachment 56078
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=56078&action=edit
The compiler output

[Bug c/111734] wrong code with '-O3 -fno-inline-functions-called-once -fno-inline-small-functions -fno-omit-frame-pointer -fno-toplevel-reorder -fno-tree-fre'

[19373742 at buaa dot edu.cn]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111734

--- Comment #2 from CTC <19373742 at buaa dot edu.cn> ---
A reduced testcase:

#include<stdio.h>
#include<inttypes.h>
struct a {};
struct {
  uint32_t b;
  int16_t c;
} d, f = {9, 1};
int32_t e;
static int32_t *g();
static uint32_t h() {
  int32_t *i = &e;
  struct a j;
  g(j, i, &i);
  if (*i)
    f = d;
}
int32_t *g(uint32_t, int32_t, int32_t **m) {
  int32_t *k = &e;
  *m = k;
}
int main() {
  h();
  printf("%d\n", f.c);
}

[Bug tree-optimization/111734] [14 Regression] wrong code with '-O3 -fno-inline-functions-called-once -fno-inline-small-functions -fno-omit-frame-pointer -fno-toplevel-reorder -fno-tree-fre'

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111734

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
            Summary|wrong code with '-O3        |[14 Regression] wrong code
                   |-fno-inline-functions-calle |with '-O3
                   |d-once                      |-fno-inline-functions-calle
                   |-fno-inline-small-functions |d-once
                   |-fno-omit-frame-pointer     |-fno-inline-small-functions
                   |-fno-toplevel-reorder       |-fno-omit-frame-pointer
                   |-fno-tree-fre'              |-fno-toplevel-reorder
                   |                            |-fno-tree-fre'
   Last reconfirmed|                            |2023-10-10
          Component|c                           |tree-optimization
   Target Milestone|---                         |14.0
             Status|UNCONFIRMED                 |NEW

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
PRE does:

Processing block 0: BB2
Value numbering stmt = *m_1(D) = &e;
RHS &e simplified to &e
No store match
Value numbering store *m_1(D) to &e
Setting value number of .MEM_3 to .MEM_

...

Starting insert iteration 1
Deleted redundant store *m_1(D) = &e;
Removing dead stmt *m_1(D) = &e;


Better reduced testcase:
```
struct a {};
struct {
  unsigned b;
  unsigned short c;
} d, f = {9, 1};
int e;
static void g(unsigned, __SIZE_TYPE__, int **m);
static void h() {
  int *i = &e;
  g(0, (__SIZE_TYPE__)i, &i);
  if (*i)
    f = d;
}
void g(unsigned a, __SIZE_TYPE__ b, int **m) {
  *m = &e;
}
int main() {
  h();
  if (f.c != 1)
    __builtin_abort();
}
```

[Bug tree-optimization/111734] [14 Regression] wrong code with '-O3 -fno-inline-functions-called-once -fno-inline-small-functions -fno-omit-frame-pointer -fno-toplevel-reorder -fno-tree-fre'

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111734

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |hubicka at gcc dot gnu.org,
                   |                            |jamborm at gcc dot gnu.org,
                   |                            |rguenth at gcc dot gnu.org
           Priority|P3                          |P1

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
-fno-ipa-modref fixes it.

Fails with -O3 -fno-inline -fno-toplevel-reorder -fno-tree-fre

--- a-t.c.146t.pre 2023-10-17 15:07:52.544953598 +0200
+++ a-t.c.146t.pre.bad 2023-10-17 15:07:45.788953643 +0200
@@ -25,7 +25,6 @@
   int _4;

   <bb 2> [local count: 1073741824]:
-  i = &e;
   g.constprop (&i);
   i.2_3 = i;
   _4 = *i.2_3;

I think this is a duplicate of the modref / IPA-CP issue (failing to remember
the PR number) which IIRC has a patch under review.

[Bug tree-optimization/111734] [14 Regression] wrong code with '-O3 -fno-inline-functions-called-once -fno-inline-small-functions -fno-omit-frame-pointer -fno-toplevel-reorder -fno-tree-fre'

[sjames at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111734

--- Comment #5 from Sam James <sjames at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #4)
> [...]
> I think this is a duplicate of the modref / IPA-CP issue (failing to remember
> the PR number) which IIRC has a patch under review.

PR111157 or maybe PR108007?

[Bug tree-optimization/111734] [14 Regression] wrong code with '-O3 -fno-inline-functions-called-once -fno-inline-small-functions -fno-omit-frame-pointer -fno-toplevel-reorder -fno-tree-fre'

[sjames at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111734

--- Comment #6 from Sam James <sjames at gcc dot gnu.org> ---
-fharden-control-flow-redundancy suppresses it.

[Bug tree-optimization/111734] [14 Regression] wrong code with '-O3 -fno-inline-functions-called-once -fno-inline-small-functions -fno-omit-frame-pointer -fno-toplevel-reorder -fno-tree-fre' since r14-3226-gd073e2d75d9ed4

[sjames at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111734

Sam James <sjames at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[14 Regression] wrong code  |[14 Regression] wrong code
                   |with '-O3                   |with '-O3
                   |-fno-inline-functions-calle |-fno-inline-functions-calle
                   |d-once                      |d-once
                   |-fno-inline-small-functions |-fno-inline-small-functions
                   |-fno-omit-frame-pointer     |-fno-omit-frame-pointer
                   |-fno-toplevel-reorder       |-fno-toplevel-reorder
                   |-fno-tree-fre'              |-fno-tree-fre' since
                   |                            |r14-3226-gd073e2d75d9ed4

--- Comment #7 from Sam James <sjames at gcc dot gnu.org> ---
d073e2d75d9ed492de9a8dc6970e5b69fae20e5a is the first bad commit
commit d073e2d75d9ed492de9a8dc6970e5b69fae20e5a
Author: Martin Jambor <mjambor@suse.cz>
Date:   Tue Aug 15 17:26:13 2023 +0200

    Feed results of IPA-CP into tree value numbering

i.e. r14-3226-gd073e2d75d9ed4.

[Bug tree-optimization/111734] [14 Regression] wrong code with '-O3 -fno-inline-functions-called-once -fno-inline-small-functions -fno-omit-frame-pointer -fno-toplevel-reorder -fno-tree-fre' since r14-3226-gd073e2d75d9ed4

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111734

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

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

--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> ---
PR111157, and indeed, confirmed fixed now.

*** This bug has been marked as a duplicate of bug 111157 ***