[Bug debug/103788] New: [9/10/11/12 Regression] '-fcompare-debug' failure (length) w/ -O1

[Bug debug/103788] New: [9/10/11/12 Regression] '-fcompare-debug' failure (length) w/ -O1

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103788

            Bug ID: 103788
           Summary: [9/10/11/12 Regression] '-fcompare-debug' failure
                    (length) w/ -O1
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: debug
          Assignee: unassigned at gcc dot gnu.org
          Reporter: asolokha at gmx dot com
  Target Milestone: ---

gcc 12.0.0 20211219 snapshot (g:fcbf94a5be9e0c1ecad92da773a6632b86b7f70a) fails
-fcompare-debug check when compiling the following testcase w/ -O1:

int
bar (void);

int
foo (int x)
{
  int i;

  for (i = 0; i <= __INT_MAX__; ++i)
    x += bar () < (x ? 2 : 1);

  return x;
}

% gcc-12.0.0 -O1 -fcompare-debug -c ohtuq2al.c
gcc-12.0.0: error: ohtuq2al.c: '-fcompare-debug' failure (length)

--- ohtuq2al.c.gkd      2021-12-21 18:49:49.840375354 +0700
+++ ohtuq2al.gk.c.gkd   2021-12-21 18:49:49.891375611 +0700
@@ -75,7 +75,7 @@
         (expr_list:REG_UNUSED (reg:CC 17 flags)
             (nil))))
 (jump_insn # 0 0 3 (set (pc)
-        (label_ref #)) "ohtuq2al.c":10:17# {jump}
+        (label_ref #)) "ohtuq2al.c":10:5# {jump}
      (nil)
  -> 3)
 (barrier # 0 0)

[Bug debug/103788] [9/10/11/12 Regression] '-fcompare-debug' failure (length) w/ -O1

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103788

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ebotcazou at gcc dot gnu.org,
                   |                            |marxin at gcc dot gnu.org
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2021-12-21
     Ever confirmed|0                           |1

--- Comment #1 from Martin Liška <marxin at gcc dot gnu.org> ---
Likely latent which was exposed with r9-3352-g87bd153645f393a1.

[Bug debug/103788] [9/10/11/12 Regression] '-fcompare-debug' failure (length) w/ -O1

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103788

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |ice-on-valid-code
   Target Milestone|---                         |9.5
                 CC|                            |pinskia at gcc dot gnu.org

[Bug debug/103788] [9/10/11/12 Regression] '-fcompare-debug' failure (length) w/ -O1

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103788

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           See Also|                            |https://gcc.gnu.org/bugzill
                   |                            |a/show_bug.cgi?id=100733

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Martin Liška from comment #1)
> Likely latent which was exposed with r9-3352-g87bd153645f393a1.

[Bug debug/103788] [9/10/11/12 Regression] '-fcompare-debug' failure (length) w/ -O1

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103788

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #2)
> (In reply to Martin Liška from comment #1)
> > Likely latent which was exposed with r9-3352-g87bd153645f393a1.

here is a slightly modified (just line rather than column change) which fails
in GCC 8 also:
int
bar (void);

int
foo (int x)
{
  int i;

  for (i = 0; i <= __INT_MAX__; ++i)
    x += bar () < (
    x ? 2 : 1 );
  return x;
}

[Bug debug/103788] [9/10/11/12 Regression] '-fcompare-debug' failure (length) w/ -O1

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103788

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
In .gimple already:
-g2:
  [/app/example.cpp:11:5] goto <D.1986>;
vs -g0:
  [/app/example.cpp:10:17] goto <D.1986>;


-g2:
  <D.1986>:;
  # DEBUG BEGIN STMT;
  SAVE_EXPR <bar () < (x != 0 ? 2 : 1)>;, x = (SAVE_EXPR <bar () < (x != 0 ? 2
: 1)>) + x;;
  # DEBUG BEGIN STMT;
   ++i;
  # DEBUG BEGIN STMT;
  goto <D.1986>;


vs -g0:
  <D.1986>:;
  SAVE_EXPR <bar () < (x != 0 ? 2 : 1)>;, x = (SAVE_EXPR <bar () < (x != 0 ? 2
: 1)>) + x;;
   ++i;
  goto <D.1986>;

[Bug debug/103788] [9/10/11/12 Regression] '-fcompare-debug' failure (length) w/ -O1

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103788

--- Comment #5 from Arseny Solokha <asolokha at gmx dot com> ---
Can it be related to PR94276?

[Bug debug/103788] [9/10/11/12 Regression] '-fcompare-debug' failure (length) w/ -O1

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103788

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |aoliva at gcc dot gnu.org

--- Comment #6 from Martin Liška <marxin at gcc dot gnu.org> ---
> here is a slightly modified (just line rather than column change) which
> fails in GCC 8 also:
> int
> bar (void);
> 
> int
> foo (int x)
> {
>   int i;
> 
>   for (i = 0; i <= __INT_MAX__; ++i)
>     x += bar () < (
>     x ? 2 : 1 );
>   return x;
> }

This one started with r8-5241-g8697bf9f46f36168 which introduced
-gstatement-frontiers.

[Bug debug/103788] [9/10/11/12 Regression] '-fcompare-debug' failure (length) w/ -O1

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103788

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2

[Bug debug/103788] [9/10/11/12 Regression] '-fcompare-debug' failure (length) w/ -O1

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103788

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Dup of the many -gstatement-frontiers -fcompare-debug issues.  No idea what to
do about those.

[Bug debug/103788] [10/11/12/13 Regression] '-fcompare-debug' failure (length) w/ -O1

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103788

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|9.5                         |10.4

--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 9 branch is being closed

[Bug debug/103788] [10/11/12/13 Regression] '-fcompare-debug' failure (length) w/ -O1

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103788

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|10.4                        |10.5

--- Comment #9 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 10.4 is being released, retargeting bugs to GCC 10.5.

[Bug debug/103788] [11/12/13/14 Regression] '-fcompare-debug' failure (length) w/ -O1

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103788

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|10.5                        |11.5

--- Comment #10 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 10 branch is being closed.