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

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

[uttamp at us dot ibm dot com]

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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

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

[uttamp at us dot ibm dot com]

------- Comment #1 from uttamp at us dot ibm dot com  2006-01-24 01:58 -------
fyi: This works till trunk-20060106.


-- 


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

[Bug tree-optimization/25937] ICE with -O2 -ftree-loop-linear

[pinskia at gcc dot gnu dot org]

------- Comment #2 from pinskia at gcc dot gnu dot org  2006-01-24 02:00 -------
Confirmed, for us normal people who cannot copy  and paste without the line
numbers:
int func(float *v1, const float *v2, int l, int e)
{
int i,j, bi=0;
float md=0, d=0, t;
for (i=0;i< e;i--)
{
for (j=0;j<l;j++)
{
t = v1[j]-*v2++;
d += t*t;
}
if ( d > md)
md=d;
}
}


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dberlin at gcc dot gnu dot
                   |                            |org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
           Keywords|                            |ice-on-valid-code
   Last reconfirmed|0000-00-00 00:00:00         |2006-01-24 02:00:48
               date|                            |
            Summary|ICE: Illegal instruction,   |ICE with -O2 -ftree-loop-
                   |with valid code             |linear


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

[Bug tree-optimization/25937] [4.2 Regression] ICE with -O2 -ftree-loop-linear

[pinskia at gcc dot gnu dot org]

------- Comment #3 from pinskia at gcc dot gnu dot org  2006-01-24 02:18 -------
Note I think this is a latent bug, I think improvements to PRE or the
reassociate rewrite cause the ICE.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  GCC build triplet|powerpc64-linux             |
   GCC host triplet|powerpc64-linux             |
 GCC target triplet|powerpc64-linux             |
            Summary|ICE with -O2 -ftree-loop-   |[4.2 Regression] ICE with -
                   |linear                      |O2 -ftree-loop-linear
   Target Milestone|---                         |4.2.0


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

[Bug tree-optimization/25937] ICE with -O2 -ftree-loop-linear

[dberlin at gcc dot gnu dot org]

------- Comment #4 from dberlin at gcc dot gnu dot org  2006-01-24 03:15 -------
These ICE's are very hard to fix without real loop distribution.  They
basically all concern the perfect nest transformation.

I'm not even sure it's worth attempting to fix them by hacking up the perfect
nest transformation further.


-- 

dberlin at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  GCC build triplet|                            |powerpc64-linux
   GCC host triplet|                            |powerpc64-linux
 GCC target triplet|                            |powerpc64-linux
            Summary|[4.2 Regression] ICE with - |ICE with -O2 -ftree-loop-
                   |O2 -ftree-loop-linear       |linear
   Target Milestone|4.2.0                       |---


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

[Bug tree-optimization/25937] ICE with -O2 -ftree-loop-linear

[uttamp at us dot ibm dot com]

------- Comment #5 from uttamp at us dot ibm dot com  2006-01-25 23:14 -------
I put the line numbers in there because I just wanted to point out the
different error messages I get with small changes in code. ;-)


-- 


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

[Bug tree-optimization/25937] ICE with -O2 -ftree-loop-linear

[rguenth at gcc dot gnu dot org]

------- Comment #6 from rguenth at gcc dot gnu dot org  2006-03-23 09:35 -------
Looks related to PR25211


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  BugsThisDependsOn|                            |25211


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

[Bug tree-optimization/25937] ICE with -O2 -ftree-loop-linear

[pinskia at gcc dot gnu dot org]

------- Comment #7 from pinskia at gcc dot gnu dot org  2006-05-18 05:49 -------
Fixed by:
2006-05-17  Sebastian Pop  <pop@cri.ensmp.fr>

        PR middle-end/20256
        PR middle-end/26435
        * tree-loop-linear.c (linear_transform_loops): Don't test
perfect_nest_p.
        Call rewrite_into_loop_closed_ssa only when something changed.
        * lambda.h (gcc_loopnest_to_lambda_loopnest): Update declaration.
        * lambda-code.c (can_convert_to_perfect_nest): Declared.
        (gcc_loopnest_to_lambda_loopnest): Removed need_perfect_nest parameter.
        Test for perfect_nest_p here.  Fix formating.
        (replace_uses_equiv_to_x_with_y): Fix formating.
        (stmt_uses_op): Removed.
        (can_convert_to_perfect_nest): Removed loopivs parameter.
        Complete the test by checking the scalar dependences.
        (perfect_nestify): Remove the test for can_convert_to_perfect_nest.
        Fix formating.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.2.0


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