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.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@109427 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 13 insertions, 1 deletions

diff --git a/gcc/tree-scalar-evolution.h b/gcc/tree-scalar-evolution.h
index 60878b1d97e..0fecaee2390 100644
--- a/gcc/tree-scalar-evolution.h
+++ b/gcc/tree-scalar-evolution.h
@@ -32,7 +32,19 @@ extern tree analyze_scalar_evolution (struct loop *, tree);
 extern tree instantiate_parameters (struct loop *, tree);
 extern void gather_stats_on_scev_database (void);
 extern void scev_analysis (void);
-extern bool simple_iv (struct loop *, tree, tree, tree *, tree *, bool);
 void scev_const_prop (void);
 
+/* Affine iv.  */
+
+typedef struct
+{
+  /* Iv = BASE + STEP * i.  */
+  tree base, step;
+
+  /* True if this iv does not overflow.  */
+  bool no_overflow;
+} affine_iv;
+
+extern bool simple_iv (struct loop *, tree, tree, affine_iv *, bool);
+
 #endif  /* GCC_TREE_SCALAR_EVOLUTION_H  */