http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59121
--- Comment #19 from Mircea Namolaru <mircea.namolaru at inria dot fr> --- The problem for many of these simple cases is with Graphite formulation of memory accesses constraints. For Fortran, or C (if arrays are declared as pointers), a memory access is not constrained enough (basically it is expressed as a function of a single induction variable). This may increase dramatically the number of the constraint solutions. The computation time for them could become prohibitive as well. But even worse, even if the computation finishes, part of the solutions found are false dependencies restricting possible legal transformations. The solution is to constrain more the memory access - as it is done for C arrays (similar code in C as this Fortran example don't create any problem). A possible solution is to express the access in terms of basic induction variable as in the original source code - maybe by modifying the front end. But other solutions are possible. For sure not a work for GCC 4.9.
