Bug#492505: gcc-4.3: regression from 4.2, ICE in set_lattice_value, at tree-ssa-ccp.c:487

[Nick Lewycky <nicholas@mxc.ca>]

Package: gcc-4.3
Version: 4.3.1-6
Severity: normal

The attached delta-reduced code crashes GCC 4.3 with -O1, but not -O0 or GCC
4.2.4 (Debian 4.2.4-3).

# gcc-4.3 000.c -c -O1
000.c: In function ‘_ov_64_seek_lap’:
000.c:33: internal compiler error: in set_lattice_value, at tree-ssa-ccp.c:487
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-4.3/README.Bugs> for instructions.

-- System Information:
Debian Release: lenny/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (500, 'testing'), (1, 'experimental')
Architecture: i386 (x86_64)

Kernel: Linux 2.6.25.9 (PREEMPT)
Locale: LANG=en_CA.UTF-8, LC_CTYPE=en_CA.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash

Versions of packages gcc-4.3 depends on:
hi  binutils              2.18.50.20080507-1 The GNU assembler, linker and bina
ii  cpp-4.3               4.3.1-6            The GNU C preprocessor
ii  gcc-4.3-base          4.3.1-6            The GNU Compiler Collection (base 
ii  libc6                 2.7-12             GNU C Library: Shared libraries
ii  libgcc1               1:4.3.1-6          GCC support library
ii  libgomp1              4.3.1-6            GCC OpenMP (GOMP) support library

Versions of packages gcc-4.3 recommends:
ii  libc6-dev                     2.7-12     GNU C Library: Development Librari

Versions of packages gcc-4.3 suggests:
pn  gcc-4.3-doc                   <none>     (no description available)
pn  gcc-4.3-locales               <none>     (no description available)
pn  gcc-4.3-multilib              <none>     (no description available)
ii  libgcc1-dbg                   1:4.3.1-6  GCC support library (debug symbols
pn  libgomp1-dbg                  <none>     (no description available)
pn  libmudflap0-4.3-dev           <none>     (no description available)
pn  libmudflap0-dbg               <none>     (no description available)

-- no debconf information

void _ov_64_seek_lap (void)
{
  unsigned x1, x2, x3;
  unsigned ltmp_3978_7;
  unsigned ltmp_3978_7__PHI_TEMPORARY;
  unsigned ltmp_4011_7__PHI_TEMPORARY;
  unsigned ltmp_4012_7;
  signed ltmp_4011_7;

  if (x1)
  {
    if (x2)
    {
      goto llvm_cbe__ov_initset_2e_exit;
    }
  }
  while (1)
    ;

llvm_cbe__ov_initset_2e_exit:
  if (x3)
  {
    ltmp_3978_7__PHI_TEMPORARY = 0xffffff7e;
    goto llvm_cbe_ov_halfrate_p_2e_exit;
  }
  ltmp_3978_7__PHI_TEMPORARY = 1;

llvm_cbe_ov_halfrate_p_2e_exit:
  ltmp_3978_7 = ltmp_3978_7__PHI_TEMPORARY;
  ltmp_4011_7__PHI_TEMPORARY = 0xffffffff;
  ltmp_4011_7 = ltmp_4011_7__PHI_TEMPORARY;
  ltmp_4012_7 = ltmp_4011_7 >> ltmp_3978_7;
}