re PR tree-optimization/18527 (cannot determine number of iterations for loops with <=)
PR tree-optimization/18527
* tree-ssa-loop-niter.c (number_of_iterations_cond,
number_of_iterations_special, number_of_iterations_exit):
Move base and step of an iv to a single structure. Add
no_overflow flag, and use it in # of iterations analysis.
* tree-scalar-evolution.c (analyze_scalar_evolution_in_loop): Add
folded_casts argument.
(simple_iv): Pass base and step in a structure. Set no_overflow
flag.
(scev_const_prop): Add argument to analyze_scalar_evolution_in_loop.
Evaluate expensiveness of computing # of iterations instead of
the final expression.
* tree-scalar-evolution.h (affine_iv): New structure.
(simple_iv): Declaration changed.
* tree-chrec.c (chrec_apply): Handle chrecs containing symbols.
* tree-ssa-loop-ivopts.c (determine_biv_step, find_givs_in_stmt_scev,
find_givs_in_stmt): Changed due to simple_iv change.
* gcc.dg/tree-ssa/loop-15.c: New test.
From-SVN: r109427