[Bug middle-end/38932] New: ICE in set_value_range, at tree-vrp.c:398

[Bug middle-end/38932] New: ICE in set_value_range, at tree-vrp.c:398

[bonzini at gnu dot org]

>From PR38572, but unrelated to it:

void f (long long int p)
{
  int x;
  static unsigned char g;
  long long int min = -9223372036854775807LL - 1;
  g = 1;
  x = (signed char) (g | 249) / 4;
  if (p >= min - (long long int) x)
    p = 1;

  if (p)
    abort ();
}

gives

small.c: In function 'f':
small.c:3: internal compiler error: in set_value_range, at tree-vrp.c:398

Note that after FRE the code becomes the simpler

void f (long long int p)
{
  long long int min = 9223372036854775807LL + 2; /*0x7fffffffffffffff */
  if (min <= p)
    p = 1;

  if (p)
    abort ();
}

but this does not ICE because in this testcase the "min <= p" is changed to "p
!= min - 1" by the first CCP pass, so this is also a missed folding in FRE.

I'm looking at the VRP failure though.


-- 
           Summary: ICE in set_value_range, at tree-vrp.c:398
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: bonzini at gnu dot org
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38932

[Bug middle-end/38932] ICE in set_value_range, at tree-vrp.c:398

[bonzini at gnu dot org]

-- 

bonzini at gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2009-01-22 08:08:36
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38932

[Bug middle-end/38932] ICE in set_value_range, at tree-vrp.c:398

[bonzini at gnu dot org]

------- Comment #1 from bonzini at gnu dot org  2009-01-22 08:09 -------
Can anyone check if this is a regression, and if so from which version?


-- 

bonzini at gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |hjl dot tools at gmail dot
                   |                            |com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38932

[Bug middle-end/38932] ICE in set_value_range, at tree-vrp.c:398

[bonzini at gnu dot org]

------- Comment #2 from bonzini at gnu dot org  2009-01-22 08:17 -------
Actually, there is no overflow in -9223372036854775807LL - 1 so this is a third
bug. :-)


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38932

[Bug middle-end/38932] ICE in set_value_range, at tree-vrp.c:398

[bonzini at gnu dot org]

------- Comment #3 from bonzini at gnu dot org  2009-01-22 08:23 -------
ah no there's no overflow bit on min


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38932

[Bug middle-end/38932] ICE in set_value_range, at tree-vrp.c:398

[bonzini at gnu dot org]

------- Comment #4 from bonzini at gnu dot org  2009-01-22 09:00 -------
In PRE there is a fold_convert_const_int_from_int call simplifying "(signed
char) 249"  to -7, but setting the TREE_OVERFLOW flag in the meanwhile.  I
don't think it makes sense to set the overflow flag on a NOP:

   * `The result of, or the signal raised by, converting an integer to a
     signed integer type when the value cannot be represented in an
     object of that type (C90 6.2.1.2, C99 6.3.1.3).'

     For conversion to a type of width N, the value is reduced modulo
     2^N to be within range of the type; no signal is raised.

(Integers implementation, from the gcc manual).


-- 

bonzini at gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rguenth at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38932

Re: [Bug middle-end/38932] ICE in set_value_range, at tree-vrp.c:398

[Andrew Thomas Pinski]

Sent from my iPhone

On Jan 22, 2009, at 1:00 AM, "bonzini at gnu dot org" <gcc-bugzilla@gcc.gnu.org 
 > wrote:

>
>
> ------- Comment #4 from bonzini at gnu dot org  2009-01-22 09:00  
> -------
> In PRE there is a fold_convert_const_int_from_int call simplifying  
> "(signed
> char) 249"  to -7, but setting the TREE_OVERFLOW flag in the  
> meanwhile.  I
> don't think it makes sense to set the overflow flag on a NOP:

Yes but changing that right now opens lots of bags of worms.  It has  
been tried before.  The simple way to fix this is in pre unset  
TREE_OVERFLOW because at this point in the IR it does not matter.  I  
hope someone would change vrp to do the correct thing but I guess that  
won't happen any time soon.


Thanks,
Andrew Pinski

>
>
>   * `The result of, or the signal raised by, converting an integer  
> to a
>     signed integer type when the value cannot be represented in an
>     object of that type (C90 6.2.1.2, C99 6.3.1.3).'
>
>     For conversion to a type of width N, the value is reduced modulo
>     2^N to be within range of the type; no signal is raised.
>
> (Integers implementation, from the gcc manual).
>
>
> -- 
>
> bonzini at gnu dot org changed:
>
>           What    |Removed                     |Added
> --- 
> --- 
> ----------------------------------------------------------------------
>                 CC|                            |rguenth at gcc dot  
> gnu dot
>                   |                            |org
>
>
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38932
>

[Bug middle-end/38932] ICE in set_value_range, at tree-vrp.c:398

[pinskia at gmail dot com]

------- Comment #5 from pinskia at gmail dot com  2009-01-22 09:17 -------
Subject: Re:  ICE in set_value_range, at tree-vrp.c:398



Sent from my iPhone

On Jan 22, 2009, at 1:00 AM, "bonzini at gnu dot org" <gcc-bugzilla@gcc.gnu.org 
 > wrote:

>
>
> ------- Comment #4 from bonzini at gnu dot org  2009-01-22 09:00  
> -------
> In PRE there is a fold_convert_const_int_from_int call simplifying  
> "(signed
> char) 249"  to -7, but setting the TREE_OVERFLOW flag in the  
> meanwhile.  I
> don't think it makes sense to set the overflow flag on a NOP:

Yes but changing that right now opens lots of bags of worms.  It has  
been tried before.  The simple way to fix this is in pre unset  
TREE_OVERFLOW because at this point in the IR it does not matter.  I  
hope someone would change vrp to do the correct thing but I guess that  
won't happen any time soon.


Thanks,
Andrew Pinski

>
>
>   * `The result of, or the signal raised by, converting an integer  
> to a
>     signed integer type when the value cannot be represented in an
>     object of that type (C90 6.2.1.2, C99 6.3.1.3).'
>
>     For conversion to a type of width N, the value is reduced modulo
>     2^N to be within range of the type; no signal is raised.
>
> (Integers implementation, from the gcc manual).
>
>
> -- 
>
> bonzini at gnu dot org changed:
>
>           What    |Removed                     |Added
> --- 
> --- 
> ----------------------------------------------------------------------
>                 CC|                            |rguenth at gcc dot  
> gnu dot
>                   |                            |org
>
>
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38932
>


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38932

[Bug middle-end/38932] ICE in set_value_range, at tree-vrp.c:398

[rguenther at suse dot de]

------- Comment #6 from rguenther at suse dot de  2009-01-22 09:29 -------
Subject: Re:  ICE in set_value_range, at
 tree-vrp.c:398

On Thu, 22 Jan 2009, bonzini at gnu dot org wrote:

> ------- Comment #4 from bonzini at gnu dot org  2009-01-22 09:00 -------
> In PRE there is a fold_convert_const_int_from_int call simplifying "(signed
> char) 249"  to -7, but setting the TREE_OVERFLOW flag in the meanwhile.  I
> don't think it makes sense to set the overflow flag on a NOP:
> 
>    * `The result of, or the signal raised by, converting an integer to a
>      signed integer type when the value cannot be represented in an
>      object of that type (C90 6.2.1.2, C99 6.3.1.3).'
> 
>      For conversion to a type of width N, the value is reduced modulo
>      2^N to be within range of the type; no signal is raised.
> 
> (Integers implementation, from the gcc manual).

Correct.  PRE should make sure to clear TREE_OVERFLOW, like CCP for
example does.  A more general solution unfortunately opens too many
cans of worms.

Richard.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38932

[Bug middle-end/38932] [4.4 Regression] ICE in set_value_range, at tree-vrp.c:398

[bonzini at gnu dot org]

------- Comment #7 from bonzini at gnu dot org  2009-01-22 11:04 -------
mine.


-- 

bonzini at gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |bonzini at gnu dot org
                   |dot org                     |
           Severity|normal                      |critical
             Status|NEW                         |ASSIGNED
      Known to fail|                            |4.4.0
      Known to work|                            |4.2.3
           Priority|P3                          |P1
   Last reconfirmed|2009-01-22 08:08:36         |2009-01-22 11:04:08
               date|                            |
            Summary|ICE in set_value_range, at  |[4.4 Regression] ICE in
                   |tree-vrp.c:398              |set_value_range, at tree-
                   |                            |vrp.c:398
            Version|unknown                     |4.4.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38932

[Bug middle-end/38932] [4.4 Regression] ICE in set_value_range, at tree-vrp.c:398

[bonzini at gnu dot org]

------- Comment #8 from bonzini at gnu dot org  2009-01-22 12:10 -------
Fixing FRE still causes an ICE for this:

/* { dg-do compile } */
/* { dg-options "-O2 --std=gnu99" } */

/* This variable needed only to exercise FRE instead of CCP.  */
unsigned char g;

extern void abort();

void f (long long int p)
{
  g = 255;
  /* { dg-warning "constant is" "" { target *-*-* } 14 } */
  /* { dg-warning "overflow" "" { target *-*-* } 14 } */
  if (p >= -9223372036854775808LL - (signed char) g)
    p = 1;

  if (p)
    abort ();
}

Should I create a separate bug and submit what I have?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38932

[Bug middle-end/38932] [4.4 Regression] ICE in set_value_range, at tree-vrp.c:398

[rguenther at suse dot de]

------- Comment #9 from rguenther at suse dot de  2009-01-22 12:28 -------
Subject: Re:  [4.4 Regression] ICE in set_value_range,
 at tree-vrp.c:398

On Thu, 22 Jan 2009, bonzini at gnu dot org wrote:

> ------- Comment #8 from bonzini at gnu dot org  2009-01-22 12:10 -------
> Fixing FRE still causes an ICE for this:
> 
> /* { dg-do compile } */
> /* { dg-options "-O2 --std=gnu99" } */
> 
> /* This variable needed only to exercise FRE instead of CCP.  */
> unsigned char g;
> 
> extern void abort();
> 
> void f (long long int p)
> {
>   g = 255;
>   /* { dg-warning "constant is" "" { target *-*-* } 14 } */
>   /* { dg-warning "overflow" "" { target *-*-* } 14 } */
>   if (p >= -9223372036854775808LL - (signed char) g)
>     p = 1;
> 
>   if (p)
>     abort ();
> }
> 
> Should I create a separate bug and submit what I have?

Yes.

Thanks,
Richard.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38932

[Bug middle-end/38932] [4.3/4.4 Regression] ICE in set_value_range, at tree-vrp.c:398

[hjl dot tools at gmail dot com]

------- Comment #10 from hjl dot tools at gmail dot com  2009-01-22 16:09 -------
It is caused by revision 126434:

http://gcc.gnu.org/ml/gcc-cvs/2007-07/msg00290.html


-- 

hjl dot tools at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dberlin at gcc dot gnu dot
                   |                            |org
      Known to fail|4.4.0                       |4.3.3 4.4.0
            Summary|[4.4 Regression] ICE in     |[4.3/4.4 Regression] ICE in
                   |set_value_range, at tree-   |set_value_range, at tree-
                   |vrp.c:398                   |vrp.c:398


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38932

[Bug middle-end/38932] [4.3/4.4 Regression] ICE in set_value_range, at tree-vrp.c:398

[dberlin at dberlin dot org]

------- Comment #11 from dberlin at gcc dot gnu dot org  2009-01-22 17:12 -------
Subject: Re:  [4.3/4.4 Regression] ICE in 
        set_value_range, at tree-vrp.c:398

Uh, well, that would be tricky since none of this code still exists in 4.4.0

On Thu, Jan 22, 2009 at 11:09 AM, hjl dot tools at gmail dot com
<gcc-bugzilla@gcc.gnu.org> wrote:
>
>
> ------- Comment #10 from hjl dot tools at gmail dot com  2009-01-22 16:09 -------
> It is caused by revision 126434:
>
> http://gcc.gnu.org/ml/gcc-cvs/2007-07/msg00290.html
>
>
> --
>
> hjl dot tools at gmail dot com changed:
>
>           What    |Removed                     |Added
> ----------------------------------------------------------------------------
>                 CC|                            |dberlin at gcc dot gnu dot
>                   |                            |org
>      Known to fail|4.4.0                       |4.3.3 4.4.0
>            Summary|[4.4 Regression] ICE in     |[4.3/4.4 Regression] ICE in
>                   |set_value_range, at tree-   |set_value_range, at tree-
>                   |vrp.c:398                   |vrp.c:398
>
>
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38932
>
> ------- You are receiving this mail because: -------
> You are on the CC list for the bug, or are watching someone who is.
>


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38932

[Bug middle-end/38932] [4.3/4.4 Regression] ICE in set_value_range, at tree-vrp.c:398

[bonzini at gcc dot gnu dot org]

------- Comment #12 from bonzini at gnu dot org  2009-01-23 15:57 -------
Subject: Bug 38932

Author: bonzini
Date: Fri Jan 23 15:57:19 2009
New Revision: 143588

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=143588
Log:
2008-01-23  Paolo Bonzini  <bonzini@gnu.org>

        PR tree-optimization/38932
        * fold-const.c (fold_unary_no_overflow): New.
        * tree.h (fold_unary_no_overflow): Declare.
        * tree-ssa-ccp.c (ccp_fold): Use fold_unary_no_overflow.
        * tree-ssa-sccvn.c (visit_reference_op_load,
        simplify_unary_expression): Likewise.

testsuite:
2008-01-23  Paolo Bonzini  <bonzini@gnu.org>

        PR tree-optimization/38932
        * gcc.dg/pr38932.c: New.


Added:
    trunk/gcc/testsuite/gcc.dg/pr38932.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/fold-const.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-ccp.c
    trunk/gcc/tree-ssa-sccvn.c
    trunk/gcc/tree.h


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38932

[Bug middle-end/38932] [4.3 Regression] ICE in set_value_range, at tree-vrp.c:398

[rguenth at gcc dot gnu dot org]

------- Comment #13 from rguenth at gcc dot gnu dot org  2009-01-23 16:18 -------
Fixed on the trunk.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to fail|4.3.3 4.4.0                 |4.3.3
      Known to work|4.2.3                       |4.2.3 4.4.0
           Priority|P1                          |P2
            Summary|[4.3/4.4 Regression] ICE in |[4.3 Regression] ICE in
                   |set_value_range, at tree-   |set_value_range, at tree-
                   |vrp.c:398                   |vrp.c:398
   Target Milestone|---                         |4.3.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38932

[Bug middle-end/38932] [4.3 Regression] ICE in set_value_range, at tree-vrp.c:398

[bonzini at gnu dot org]

------- Comment #14 from bonzini at gnu dot org  2009-01-24 08:59 -------
Regarding the target milestone, you mean I should apply a 4.3 patch before the
release goes out, too? (I'm currently regtesting it).


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38932

[Bug middle-end/38932] [4.3 Regression] ICE in set_value_range, at tree-vrp.c:398

[rguenther at suse dot de]

------- Comment #15 from rguenther at suse dot de  2009-01-24 09:34 -------
Subject: Re:  [4.3 Regression] ICE in set_value_range,
 at tree-vrp.c:398

On Sat, 24 Jan 2009, bonzini at gnu dot org wrote:

> ------- Comment #14 from bonzini at gnu dot org  2009-01-24 08:59 -------
> Regarding the target milestone, you mean I should apply a 4.3 patch before the
> release goes out, too? (I'm currently regtesting it).

No.

Richard.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38932

[Bug middle-end/38932] [4.3 Regression] ICE in set_value_range, at tree-vrp.c:398

[bonzini at gnu dot org]

------- Comment #16 from bonzini at gnu dot org  2009-01-24 09:54 -------
changing milestone appropriately then, it did sound strange.


-- 

bonzini at gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.3.3                       |4.3.4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38932

[Bug middle-end/38932] [4.3 Regression] ICE in set_value_range, at tree-vrp.c:398

[rguenther at suse dot de]

------- Comment #17 from rguenther at suse dot de  2009-01-24 09:55 -------
Subject: Re:  [4.3 Regression] ICE in set_value_range,
 at tree-vrp.c:398

On Sat, 24 Jan 2009, bonzini at gnu dot org wrote:

> ------- Comment #16 from bonzini at gnu dot org  2009-01-24 09:54 -------
> changing milestone appropriately then, it did sound strange.

Well, we will bump the target milestone of all bugs appropriately
after the release.  So it wasn't inappropriate but just followed
policy.

Richard.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38932

[Bug middle-end/38932] [4.3 Regression] ICE in set_value_range, at tree-vrp.c:398

[bonzini at gnu dot org]

------- Comment #19 from bonzini at gnu dot org  2009-01-26 15:54 -------
fixed on 4.3 branch too.


-- 

bonzini at gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
      Known to work|4.2.3 4.4.0                 |4.2.3 4.4.0 4.3.4
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38932

[Bug middle-end/38932] [4.3 Regression] ICE in set_value_range, at tree-vrp.c:398

[bonzini at gcc dot gnu dot org]

------- Comment #18 from bonzini at gnu dot org  2009-01-26 15:54 -------
Subject: Bug 38932

Author: bonzini
Date: Mon Jan 26 15:54:18 2009
New Revision: 143677

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=143677
Log:
gcc:
2008-01-26  Paolo Bonzini  <bonzini@gnu.org>

        PR tree-optimization/38932
        * fold-const.c (fold_unary_ignore_overflow): New.
        * tree.h (fold_unary_ignore_overflow): Declare.
        * tree-ssa-ccp.c (ccp_fold): Use fold_unary_ignore_overflow.
        * tree-ssa-sccvn.c (simplify_unary_expression): Likewise.

gcc/testsuite:
2008-01-26  Paolo Bonzini  <bonzini@gnu.org>

        PR tree-optimization/38932
        * gcc.dg/pr38932.c: New.


Added:
    branches/gcc-4_3-branch/gcc/testsuite/gcc.dg/pr38932.c
      - copied unchanged from r143588, trunk/gcc/testsuite/gcc.dg/pr38932.c
Modified:
    branches/gcc-4_3-branch/gcc/ChangeLog
    branches/gcc-4_3-branch/gcc/fold-const.c
    branches/gcc-4_3-branch/gcc/testsuite/ChangeLog
    branches/gcc-4_3-branch/gcc/tree-ssa-ccp.c
    branches/gcc-4_3-branch/gcc/tree-ssa-sccvn.c
    branches/gcc-4_3-branch/gcc/tree.h


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38932