[Bug rtl-optimization/47157] New: [4.6 Regression] ICE: in calc_dfs_tree, at dominance.c:395 with -O

[Bug rtl-optimization/47157] New: [4.6 Regression] ICE: in calc_dfs_tree, at dominance.c:395 with -O

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47157

           Summary: [4.6 Regression] ICE: in calc_dfs_tree, at
                    dominance.c:395 with -O
           Product: gcc
           Version: 4.6.0
               URL: http://gcc.gnu.org/ml/gcc-patches/2010-12/msg01416.htm
                    l
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code, patch
          Severity: normal
          Priority: P3
         Component: rtl-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: jakub@gcc.gnu.org
                CC: jakub@gcc.gnu.org, steven@gcc.gnu.org,
                    regehr@cs.utah.edu, zsojka@seznam.cz
        Depends on: 46755
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu


+++ This bug was initially created as a clone of Bug #46755 +++

PR46755#c8 is unrelated bug to the original one, so creating a separate PR for
it:

Not sure if this is still useful, but here's a fairly small failure-inducing
testcase for this bug for today's GCC.

[regehr@gamow tmp437]$ current-gcc -O2 -c small.c

small.c: In function 'func':
small.c:32:1: internal compiler error: in calc_dfs_tree, at dominance.c:395
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

[regehr@gamow tmp437]$ current-gcc -v

Using built-in specs.
COLLECT_GCC=current-gcc
COLLECT_LTO_WRAPPER=/uusoc/exports/scratch/regehr/z/compiler-install/gcc-r168402-install/bin/../libexec/gcc/x86_64-unknown-linux-gnu/4.6.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: ../configure --with-libelf=/usr/local --enable-lto
--prefix=/home/regehr/z/compiler-install/gcc-r168402-install
--program-prefix=r168402- --enable-languages=c,c++
Thread model: posix
gcc version 4.6.0 20110102 (experimental) (GCC) 

[regehr@gamow tmp437]$ cat small.c


static int
foo (int si1, short si2)
{
  return ((si1 ^ si2) & ((si1 ^ (si1 ^ si2) & ~2147483647) - si2 ^ si2)) <
    0 ? si1 : si1 - si2;
}

struct S0
{
  const unsigned f3:1;
  const unsigned f8:1;
};
struct S0 g_111 = {
  1
};

struct S0 g_139 = {
  1
};

unsigned long int g_22;

void safe (int);
int func_42 (void);

void func (void)
{
  safe (foo (func_42 () != (g_139.f3 | g_111.f8), -1L));
  for (g_22 = 0; g_22; g_22 = 1)
    {
    }
}

This is caused by revision 164431:

http://gcc.gnu.org/ml/gcc-cvs/2010-09/msg00727.html

[Bug rtl-optimization/47157] [4.6 Regression] ICE: in calc_dfs_tree, at dominance.c:395 with -O

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47157

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2011.01.03 10:33:41
         AssignedTo|unassigned at gcc dot       |jakub at gcc dot gnu.org
                   |gnu.org                     |
     Ever Confirmed|0                           |1

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-01-03 10:33:40 UTC ---
Created attachment 22885
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=22885
gcc46-pr47157.patch

Untested fix.

[Bug rtl-optimization/47157] [4.6 Regression] ICE: in calc_dfs_tree, at dominance.c:395 with -O

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47157

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.6.0

[Bug rtl-optimization/47157] [4.6 Regression] ICE: in calc_dfs_tree, at dominance.c:395 with -O

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47157

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-01-03 20:59:25 UTC ---
Author: jakub
Date: Mon Jan  3 20:59:20 2011
New Revision: 168439

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=168439
Log:
    PR rtl-optimization/47157
    * combine.c (try_combine): If undobuf.other_insn becomes
    (set (pc) (pc)) jump, call update_cfg_for_uncondjump on it
    and set *new_direct_jump_p too.

    * gcc.c-torture/compile/pr47157.c: New test.

Added:
    trunk/gcc/testsuite/gcc.c-torture/compile/pr47157.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/combine.c
    trunk/gcc/testsuite/ChangeLog

[Bug rtl-optimization/47157] [4.6 Regression] ICE: in calc_dfs_tree, at dominance.c:395 with -O

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47157

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

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

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-01-03 21:11:29 UTC ---
Fixed.