[Bug tree-optimization/46194] [4.5/4.6 Regression] gcc.dg/graphite/block-0.c FAILs with -ftree-parallelize-loops

["jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46194

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org,
                   |                            |spop at gcc dot gnu.org

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> 2010-12-31 12:01:51 UTC ---
This shouldn't be parallelized, the loop clearly is not parallelizable.  But we
have:
(Data Dep: 
#(Data Ref: 
#  stmt: D.2709_5 = a[i_16];
#  ref: a[i_16];
#  base_object: a
#  Access function 0: {0, +, 1}_1
#)
#(Data Ref: 
#  stmt: a[j_20] = D.2710_6;
#  ref: a[j_20];
#  base_object: a
#  Access function 0: {0, +, 1}_2
#)
  access_fn_A: {0, +, 1}_1
  access_fn_B: {0, +, 1}_2

 (subscript 
  iterations_that_access_an_element_twice_in_A: [0 + 1 * x_1]
  last_conflict: 1000
  iterations_that_access_an_element_twice_in_B: [0 + 1 * x_1]
  last_conflict: 1000
  (Subscript distance: 0
  )
 )
  inner loop index: 0
  loop nest: (1 2 )
  distance_vector:   0   0 
  direction_vector:     =    =
)
(Data Dep: 
#(Data Ref: 
#  stmt: D.2709_5 = a[i_16];
#  ref: a[i_16];
#  base_object: a
#  Access function 0: {0, +, 1}_1
#)
#(Data Ref: 
#  stmt: D.2709_5 = a[i_16];
#  ref: a[i_16];
#  base_object: a
#  Access function 0: {0, +, 1}_1
#)
  inner loop index: 0
  loop nest: (1 2 )
  distance_vector:   0   0 
  direction_vector:     +    +
)
(Data Dep: 
#(Data Ref: 
#  stmt: a[j_20] = D.2710_6;
#  ref: a[j_20];
#  base_object: a
#  Access function 0: {0, +, 1}_2
#)
#(Data Ref: 
#  stmt: a[j_20] = D.2710_6;
#  ref: a[j_20];
#  base_object: a
#  Access function 0: {0, +, 1}_2
#)
  inner loop index: 0
  loop nest: (1 2 )
  distance_vector:   0   0 
  direction_vector:     +    +
)
  SUCCESS: may be parallelized