[Bug c/48742] New: Internal error in glimplify_expr

[Bug c/48742] New: Internal error in glimplify_expr

[derek at knosof dot co.uk]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48742

           Summary: Internal error in glimplify_expr
           Product: gcc
           Version: 4.5.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: derek@knosof.co.uk


The code below generates the message (also occurs in 4.5.0):

internal compiler error: in gimplify_expr, at gimplify.c: 7153

void f(void)
{
func( 1<=2%(3>>1> 5/6==3) );
}

The following outstanding report lists the same error message:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47197

I am running under Suse 11.3 on an AMD Athon x2.

[Bug c/48742] [4.5/4.6/4.7 Regression] Internal error in glimplify_expr

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48742

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2011.04.26 09:39:19
     Ever Confirmed|0                           |1

[Bug c/48742] [4.5/4.6/4.7 Regression] Internal error in glimplify_expr

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48742

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |4.4.4
   Target Milestone|---                         |4.5.4
            Summary|Internal error in           |[4.5/4.6/4.7 Regression]
                   |glimplify_expr              |Internal error in
                   |                            |glimplify_expr

[Bug c/48742] [4.5/4.6/4.7 Regression] Internal error in glimplify_expr

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48742

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

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

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-04-26 11:03:50 UTC ---
Shorter testcase:

int
foo (void)
{
  return 1 / 0 > 0;
}

Started with http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=145254
C_MAYBE_CONST_EXPR leaking to gimplification.

[Bug c/48742] [4.5/4.6/4.7 Regression] Internal error in glimplify_expr

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48742

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jsm28 at gcc dot gnu.org

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-04-26 11:27:10 UTC ---
The problem is that first build_binary_op wraps 1 / 0 into C_MAYBE_CONST_EXPR,
              if (!in_late_binary_op)
                {
                  if (!op0_maybe_const || TREE_CODE (op0) != INTEGER_CST)
                    op0 = c_wrap_maybe_const (op0, !op0_maybe_const);
                  if (!op1_maybe_const || TREE_CODE (op1) != INTEGER_CST)
                    op1 = c_wrap_maybe_const (op1, !op1_maybe_const);
                }
and later on the whole GT_EXPR with C_MAYBE_CONST_EXPR op0 and INTEGER_CST op1
is wrapped in yet another C_MAYBE_CONST_EXPR:
  else if (TREE_CODE (ret) != INTEGER_CST && int_operands
           && !in_late_binary_op)
    ret = note_integer_operands (ret);
Apparently, c_fully_fold_internal doesn't handle nested C_MAYBE_CONST_EXPRs
though, if it finds one, it doesn't recurse on the content and just returns it.

Joseph?

[Bug c/48742] [4.5/4.6/4.7 Regression] Internal error in glimplify_expr

[joseph at codesourcery dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48742

--- Comment #3 from joseph at codesourcery dot com <joseph at codesourcery dot com> 2011-04-26 14:50:47 UTC ---
There shouldn't be nested C_MAYBE_CONST_EXPR.  The code you quote

>               if (!in_late_binary_op)
>                 {
>                   if (!op0_maybe_const || TREE_CODE (op0) != INTEGER_CST)
>                     op0 = c_wrap_maybe_const (op0, !op0_maybe_const);
>                   if (!op1_maybe_const || TREE_CODE (op1) != INTEGER_CST)
>                     op1 = c_wrap_maybe_const (op1, !op1_maybe_const);
>                 }

is to avoid the result of folding getting folded again and to track how 
constant that result is.  But if int_operands I don't think this wrapping 
of the operands is needed because the code after return_build_binary_op: 
will deal with wrapping the result.

[Bug c/48742] [4.5/4.6/4.7 Regression] Internal error in glimplify_expr

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48742

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-04-26 15:16:05 UTC ---
Created attachment 24104
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24104
gcc46-pr48742.patch

So do you mean something like this?  Haven't bootstrapped/regtested it yet...

[Bug c/48742] [4.5/4.6/4.7 Regression] Internal error in gimplify_expr

[joseph at codesourcery dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48742

--- Comment #5 from joseph at codesourcery dot com <joseph at codesourcery dot com> 2011-04-26 15:24:13 UTC ---
On Tue, 26 Apr 2011, jakub at gcc dot gnu.org wrote:

> Created attachment 24104
>   --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24104
> gcc46-pr48742.patch
> 
> So do you mean something like this?  Haven't bootstrapped/regtested it yet...

Yes, that patch looks right.

[Bug c/48742] [4.5/4.6/4.7 Regression] Internal error in gimplify_expr

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48742

--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-04-27 07:04:29 UTC ---
Author: jakub
Date: Wed Apr 27 07:04:25 2011
New Revision: 173011

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=173011
Log:
    PR c/48742
    * c-typeck.c (build_binary_op): Don't wrap arguments if
    int_operands is true.

    * gcc.c-torture/compile/pr48742.c: New test.

Added:
    trunk/gcc/testsuite/gcc.c-torture/compile/pr48742.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/c-typeck.c
    trunk/gcc/testsuite/ChangeLog

[Bug c/48742] [4.5/4.6/4.7 Regression] Internal error in gimplify_expr

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48742

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-04-27 07:05:56 UTC ---
Author: jakub
Date: Wed Apr 27 07:05:54 2011
New Revision: 173012

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=173012
Log:
    PR c/48742
    * c-typeck.c (build_binary_op): Don't wrap arguments if
    int_operands is true.

    * gcc.c-torture/compile/pr48742.c: New test.

Added:
    branches/gcc-4_6-branch/gcc/testsuite/gcc.c-torture/compile/pr48742.c
Modified:
    branches/gcc-4_6-branch/gcc/ChangeLog
    branches/gcc-4_6-branch/gcc/c-typeck.c
    branches/gcc-4_6-branch/gcc/testsuite/ChangeLog

[Bug c/48742] [4.5 Regression] Internal error in gimplify_expr

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48742

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
      Known to work|                            |4.6.1, 4.7.0
         AssignedTo|unassigned at gcc dot       |jakub at gcc dot gnu.org
                   |gnu.org                     |
            Summary|[4.5/4.6/4.7 Regression]    |[4.5 Regression] Internal
                   |Internal error in           |error in gimplify_expr
                   |gimplify_expr               |
      Known to fail|                            |4.5.2

--- Comment #8 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-04-27 07:17:27 UTC ---
Fixed for 4.6+ so far.

[Bug c/48742] [4.5 Regression] Internal error in gimplify_expr

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48742

--- Comment #9 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-05-03 16:34:37 UTC ---
Author: jakub
Date: Tue May  3 16:34:32 2011
New Revision: 173326

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=173326
Log:
    Backport from mainline
    2011-04-27  Jakub Jelinek  <jakub@redhat.com>

    PR c/48742
    * c-typeck.c (build_binary_op): Don't wrap arguments if
    int_operands is true.

    * gcc.c-torture/compile/pr48742.c: New test.

Added:
    branches/gcc-4_5-branch/gcc/testsuite/gcc.c-torture/compile/pr48742.c
Modified:
    branches/gcc-4_5-branch/gcc/ChangeLog
    branches/gcc-4_5-branch/gcc/c-typeck.c
    branches/gcc-4_5-branch/gcc/testsuite/ChangeLog

[Bug c/48742] [4.5 Regression] Internal error in gimplify_expr

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48742

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED

--- Comment #10 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-05-03 17:18:36 UTC ---
Fixed.