tree-ssa-loop-im.c: New file.

	* tree-ssa-loop-im.c: New file.
	* Makefile.in (tree-ssa-loop-im.o): Add.
	* cfgloop.c (superloop_at_depth): New function.
	* cfgloop.h (superloop_at_depth): Declare.
	* common.opt (ftree-lim): New flag.
	* expr.c (array_ref_up_bound): New function.
	* params.def (PARAM_LIM_EXPENSIVE): New parameter.
	* timevar.def (TV_LIM): New timevar.
	* tree-dfa.c (compute_immediate_uses): Respect TDFA_USE flags when
	computing immediate uses of a phi node.
	* tree-flow.h (struct tree_ann_common_d): Add aux field.
	(loop_commit_inserts, for_each_index, tree_ssa_lim): Declare.
	* tree-optimize.c (init_tree_optimization_passes): Add pass_lim.
	* tree-pass.h (pass_lim): Declare.
	* tree-ssa-loop.c (tree_ssa_loop_im, gate_tree_ssa_loop_im): New
	functions.
	(pass_lim): New pass structure.
	* tree-eh.c (tree_could_trap_p): Handle ARRAY_REFs correctly.
	* tree.c (in_array_bounds_p): New function.
	* tree.h (TREE_THIS_NOTRAP): Define also for ARRAY_REFs.
	(in_array_bounds_p, array_ref_up_bound): Declare.
	* doc/invoke.texi (-ftree-lim, --param lim-expensive): Document.
	* doc/passes.texi (tree-ssa-loop-im.c): Document.

From-SVN: r84441

1 files changed, 28 insertions, 0 deletions

diff --git a/gcc/tree.c b/gcc/tree.c
index 5e95ab6..033c851 100644
--- a/gcc/tree.c
+++ b/gcc/tree.c
@@ -5650,6 +5650,34 @@ build_empty_stmt (void)
 }
 
 
+/* Returns true if it is possible to prove that the index of
+   an array access REF (an ARRAY_REF expression) falls into the
+   array bounds.  */
+
+bool
+in_array_bounds_p (tree ref)
+{
+  tree idx = TREE_OPERAND (ref, 1);
+  tree min, max;
+
+  if (TREE_CODE (idx) != INTEGER_CST)
+    return false;
+	    
+  min = array_ref_low_bound (ref);
+  max = array_ref_up_bound (ref);
+  if (!min
+      || !max
+      || TREE_CODE (min) != INTEGER_CST
+      || TREE_CODE (max) != INTEGER_CST)
+    return false;
+
+  if (tree_int_cst_lt (idx, min)
+      || tree_int_cst_lt (max, idx))
+    return false;
+
+  return true;
+}
+
 /* Return true if T (assumed to be a DECL) must be assigned a memory
    location.  */