[Bug tree-optimization/60340] New: ICE on valid code with -fcheck-data-deps at -O1 and above on x86_64-linux-gnu

[su at cs dot ucdavis.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60340

            Bug ID: 60340
           Summary: ICE on valid code with -fcheck-data-deps at -O1 and
                    above on x86_64-linux-gnu
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: su at cs dot ucdavis.edu

The following code causes an ICE when compiled by the current gcc trunk with
-fcheck-data-deps at -O1 and above on x86_64-linux-gnu (in both 32-bit and
64-bit modes). 

It also affects 4.7.x and 4.8.x, but not 4.6.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/4.9.0/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 4.9.0 20140225 (experimental) [trunk revision 208111] (GCC) 
$ 
$ gcc-trunk -O1 -c small.c
$ gcc-trunk -O0 -fcheck-data-deps -c small.c
$ gcc-4.6.4 -O1 -fcheck-data-deps -c small.c
$ 
$ gcc-trunk -O1 -fcheck-data-deps -c small.c

(Number of distance vectors differ: Banerjee has 1, Omega has 2.
Banerjee dist vectors:
  0 
Omega dist vectors:
  0 
  1 
data dependence relation:
(Data Dep: 
#(Data Ref: 
#  bb: 4 
#  stmt: a.0_4 ={v} a;
#  ref: a
#  base_object: MEM[(int *)&a];
#)
#(Data Ref: 
#  bb: 4 
#  stmt: a ={v} a.1_5;
#  ref: a
#  base_object: MEM[(int *)&a];
#)
  inner loop index: 0
  loop nest: (1 )
  distance_vector:   0 
  distance_vector:   1 
  direction_vector:     =
  direction_vector:     +
)
)
small.c: In function ‘foo’:
small.c:3:6: internal compiler error: in compute_affine_dependence, at
tree-data-ref.c:4233
 void foo ()
      ^
0xf187fb compute_affine_dependence(data_dependence_relation*, loop*)
    ../../gcc-trunk/gcc/tree-data-ref.c:4232
0xf1908a compute_all_dependences(vec<data_reference*, va_heap, vl_ptr>,
vec<data_dependence_relation*, va_heap, vl_ptr>*, vec<loop*, va_heap, vl_ptr>,
bool)
    ../../gcc-trunk/gcc/tree-data-ref.c:4304
0xf19a20 compute_data_dependences_for_loop(loop*, bool, vec<loop*, va_heap,
vl_ptr>*, vec<data_reference*, va_heap, vl_ptr>*,
vec<data_dependence_relation*, va_heap, vl_ptr>*)
    ../../gcc-trunk/gcc/tree-data-ref.c:4632
0xf19b0e analyze_all_data_dependences
    ../../gcc-trunk/gcc/tree-data-ref.c:4740
0xf19b0e tree_check_data_deps()
    ../../gcc-trunk/gcc/tree-data-ref.c:4787
0xaa51c7 check_data_deps
    ../../gcc-trunk/gcc/tree-ssa-loop.c:209
0xaa51c7 execute
    ../../gcc-trunk/gcc/tree-ssa-loop.c:245
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.
$ 


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


volatile int a;

void foo ()
{
  for (; a < 1; a++)
    ;
}