[Bug tree-optimization/25937] New: ICE: Illegal instruction, with valid code

["uttamp at us dot ibm dot com" <gcc-bugzilla at gcc dot gnu dot org>]

Hi,

Following code causing an ICE with mainline.

elm3b9:/home/pawar> cat test.c
      1 int func(float *v1, const float *v2, int l, int e)
      2 {
      3    int i,j, bi=0;
      4    float md=0, d=0, t;
      5    for (i=0;i< e;i--)
      6    {
      7       for (j=0;j<l;j++)
      8       {
      9          t = v1[j]-*v2++;
     10          d += t*t;
     11       }
     12       if ( d > md)
     13          md=d;
     14    }
     15 }

$ /opt/gcc-nightly/trunk-20060123/bin/gcc  -v -c -O2 -ftree-loop-linear test.c
Using built-in specs.
Target: powerpc64-linux
Configured with: /home/gccbuild/gcc_trunk_anonsvn/trunk/configure
--prefix=/opt/gcc-nightly/trunk-20060123 --build=powerpc64-linux
--host=powerpc64-linux --target=powerpc64-linux --with-cpu=default32
--with-as=/opt/gcc-nightly/trunk-20060123/bin/as
--with-ld=/opt/gcc-nightly/trunk-20060123/bin/ld --enable-threads=posix
--enable-shared --enable-__cxa_atexit --enable-languages=c,c++,f95,java,objc
--enable-checking --with-mpfr=/opt/gcc-nightly/trunk-20060123
Thread model: posix
gcc version 4.2.0 20060123 (experimental)
 /home/gcc-nightly/trunk-20060123/bin/../libexec/gcc/powerpc64-linux/4.2.0/cc1
-quiet -v -iprefix
/home/gcc-nightly/trunk-20060123/bin/../lib/gcc/powerpc64-linux/4.2.0/
-D__unix__ -D__gnu_linux__ -D__linux__ -Dunix -D__unix -Dlinux -D__linux
-Asystem=linux -Asystem=unix -Asystem=posix test.c -quiet -dumpbase test.c
-auxbase test -O2 -version -ftree-loop-linear -o /tmp/cc145sWC.s
ignoring nonexistent directory
"/home/gcc-nightly/trunk-20060123/bin/../lib/gcc/powerpc64-linux/4.2.0/../../../../powerpc64-linux/include"
ignoring duplicate directory
"/opt/gcc-nightly/trunk-20060123/lib/gcc/powerpc64-linux/4.2.0/include"
ignoring nonexistent directory
"/opt/gcc-nightly/trunk-20060123/lib/gcc/powerpc64-linux/4.2.0/../../../../powerpc64-linux/include"
#include "..." search starts here:
#include <...> search starts here:
 /home/gcc-nightly/trunk-20060123/bin/../lib/gcc/powerpc64-linux/4.2.0/include
 /usr/local/include
 /opt/gcc-nightly/trunk-20060123/include
 /usr/include
End of search list.
GNU C version 4.2.0 20060123 (experimental) (powerpc64-linux)
        compiled by GNU C version 4.2.0 20060123 (experimental).
GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
Compiler executable checksum: ab2acf781189b94f37d1814045ecf667
test.c: In function ?func?:
test.c:2: internal compiler error: Illegal instruction
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.

If I remove -v option from the command line, I get following,
$ /opt/gcc-nightly/trunk-20060123/bin/gcc  -c -O2 -ftree-loop-linear test.c
gcc: Internal error: Segmentation fault (program cc1)
Please submit a full bug report.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.

If I remove, declaration bi=0 from line 3, I get following,

$ elm3b11:/home/pawar/reghunt/work> /opt/gcc-nightly/trunk-20060123/bin/gcc  -c
-O2 -ftree-loop-linear test.c
test.c: In function ?func?:
test.c:2: internal compiler error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.

On line 5, if change i-- to i++, I get following (without bi=0),
$ elm3b11:/home/pawar/reghunt/work> /opt/gcc-nightly/trunk-20060123/bin/gcc  -c
-O2 -ftree-loop-linear test.c
test.c: In function ?func?:
test.c:2: error: definition in block 17 does not dominate use in block 6
for SSA_NAME: v2_38 in statement:
v2_42 = PHI <v2_38(6), v2_31(11)>;
PHI argument
v2_38
for PHI node
v2_42 = PHI <v2_38(6), v2_31(11)>;
test.c:2: internal compiler error: verify_ssa failed
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.

and with bi=0, on line 3 I get,
$ elm3b11:/home/pawar/reghunt/work> /opt/gcc-nightly/trunk-20060123/bin/gcc  -c
-O2 -ftree-loop-linear test.c
test.c: In function ?func?:
test.c:2: error: definition in block 17 does not dominate use in block 6
for SSA_NAME: v2_38 in statement:
v2_42 = PHI <v2_38(6), v2_9(11)>;
PHI argument
v2_38
for PHI node
v2_42 = PHI <v2_38(6), v2_9(11)>;
test.c:2: internal compiler error: verify_ssa failed
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.


-- 
           Summary: ICE: Illegal instruction, with valid code
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: uttamp at us dot ibm dot com
 GCC build triplet: powerpc64-linux
  GCC host triplet: powerpc64-linux
GCC target triplet: powerpc64-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25937