[Bug c/63770] New: ICE on valid code at all optimization levels on x86_64-linux-gnu

[Bug c/63770] New: ICE on valid code at all optimization levels on x86_64-linux-gnu

[su at cs dot ucdavis.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63770

            Bug ID: 63770
           Summary: ICE on valid code at all optimization levels on
                    x86_64-linux-gnu
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: su at cs dot ucdavis.edu

The following code causes an ICE when compiled with the current gcc trunk at
all the optimization levels on x86_64-linux-gnu in both 32-bit and 64-bit
modes. 

It is a regression from 4.9.x. 

$ gcc-trunk -v
Using built-in specs.
COLLECT_GCC=gcc-trunk
COLLECT_LTO_WRAPPER=/usr/local/gcc-trunk/libexec/gcc/x86_64-unknown-linux-gnu/5.0.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: ../gcc-trunk/configure --prefix=/usr/local/gcc-trunk
--enable-languages=c,c++ --disable-werror --enable-multilib
Thread model: posix
gcc version 5.0.0 20141106 (experimental) [trunk revision 217200] (GCC) 

$ 
$ gcc-4.9 -O0 -c small.c
$ 
$ gcc-trunk -O0 -c small.c
gcc-trunk: internal compiler error: Segmentation fault (program cc1)
0x40bccc execute
    ../../gcc-trunk/gcc/gcc.c:2908
0x40bfb9 do_spec_1
    ../../gcc-trunk/gcc/gcc.c:4724
0x40ea2b process_brace_body
    ../../gcc-trunk/gcc/gcc.c:6007
0x40ea2b handle_braces
    ../../gcc-trunk/gcc/gcc.c:5921
0x40cb17 do_spec_1
    ../../gcc-trunk/gcc/gcc.c:5378
0x40ea2b process_brace_body
    ../../gcc-trunk/gcc/gcc.c:6007
0x40ea2b handle_braces
    ../../gcc-trunk/gcc/gcc.c:5921
0x40cb17 do_spec_1
    ../../gcc-trunk/gcc/gcc.c:5378
0x40c443 do_spec_1
    ../../gcc-trunk/gcc/gcc.c:5493
0x40ea2b process_brace_body
    ../../gcc-trunk/gcc/gcc.c:6007
0x40ea2b handle_braces
    ../../gcc-trunk/gcc/gcc.c:5921
0x40cb17 do_spec_1
    ../../gcc-trunk/gcc/gcc.c:5378
0x40ea2b process_brace_body
    ../../gcc-trunk/gcc/gcc.c:6007
0x40ea2b handle_braces
    ../../gcc-trunk/gcc/gcc.c:5921
0x40cb17 do_spec_1
    ../../gcc-trunk/gcc/gcc.c:5378
0x40ea2b process_brace_body
    ../../gcc-trunk/gcc/gcc.c:6007
0x40ea2b handle_braces
    ../../gcc-trunk/gcc/gcc.c:5921
0x40cb17 do_spec_1
    ../../gcc-trunk/gcc/gcc.c:5378
0x40ea2b process_brace_body
    ../../gcc-trunk/gcc/gcc.c:6007
0x40ea2b handle_braces
    ../../gcc-trunk/gcc/gcc.c:5921
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <http://gcc.gnu.org/bugs.html> for instructions.
$ 


-----------------------


char a;

struct S
{
  int f0:9;
};

volatile struct S b;

int
fn1 ()
{
  return (1 & b.f0) < a;
}

[Bug middle-end/63770] [5 Regression] ICE on valid code at all optimization levels on x86_64-linux-gnu

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63770

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2014-11-07
          Component|c                           |middle-end
           Assignee|unassigned at gcc dot gnu.org      |rguenth at gcc dot gnu.org
   Target Milestone|---                         |5.0
            Summary|ICE on valid code at all    |[5 Regression] ICE on valid
                   |optimization levels on      |code at all optimization
                   |x86_64-linux-gnu            |levels on x86_64-linux-gnu
     Ever confirmed|0                           |1

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed.  Possibly similar as PR63767.

Mine.

[Bug middle-end/63770] [5 Regression] ICE on valid code at all optimization levels on x86_64-linux-gnu

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63770

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
from a match.pd pattern

/* Try to fold (type) X op CST -> (type) (X op ((type-x) CST))
   when profitable.
   For bitwise binary operations apply operand conversions to the
   binary operation result instead of to the operands.  This allows
   to combine successive conversions and bitwise binary operations.
   We combine the above two cases by using a conditional convert.  */

(<unnamed-signed:9>) b.f0 & 1 -> (<unnamed-signed:9>) (b.f0 & 1)

then from fold_unary

7825          /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
7826             constants (if x has signed type, the sign bit cannot be set
7827             in c).  This folds extension into the BIT_AND_EXPR.
...

The existing measure against this recursion doesn't apply.  I have a fix.

[Bug middle-end/63770] [5 Regression] ICE on valid code at all optimization levels on x86_64-linux-gnu

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63770

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |sasha.levin at oracle dot com

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
*** Bug 63767 has been marked as a duplicate of this bug. ***

[Bug middle-end/63770] [5 Regression] ICE on valid code at all optimization levels on x86_64-linux-gnu

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63770

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Fri Nov  7 10:51:06 2014
New Revision: 217214

URL: https://gcc.gnu.org/viewcvs?rev=217214&root=gcc&view=rev
Log:
2014-11-07  Richard Biener  <rguenther@suse.de>

    PR middle-end/63770
    * match.pd: Guard conflicting GENERIC pattern properly.

    * gcc.dg/pr63770.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.dg/pr63770.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/match.pd
    trunk/gcc/testsuite/ChangeLog

[Bug middle-end/63770] [5 Regression] ICE on valid code at all optimization levels on x86_64-linux-gnu

[trippels at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63770

Markus Trippelsdorf <trippels at gcc dot gnu.org> changed:

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

--- Comment #6 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
Richard, can you take a look at PR63244?
Maybe a backport of your patch to 4.9 could help?