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, 13 insertions, 2 deletions

diff --git a/gcc/tree.h b/gcc/tree.h
index f2cfa21..5c9c048 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -303,7 +303,7 @@ struct tree_common GTY(())
 	   ..._TYPE
 
        TREE_THIS_NOTRAP in
-          INDIRECT_REF
+          INDIRECT_REF, ARRAY_REF, ARRAY_RANGE_REF
 
    deprecated_flag:
 
@@ -798,7 +798,12 @@ extern void tree_operand_check_failed (int, enum tree_code,
 /* Nonzero means this node will not trap.  In an INDIRECT_REF, means
    accessing the memory pointed to won't generate a trap.  However,
    this only applies to an object when used appropriately: it doesn't
-   mean that writing a READONLY mem won't trap.  */
+   mean that writing a READONLY mem won't trap.
+   
+   In ARRAY_REF and ARRAY_RANGE_REF means that we know that the index
+   (or slice of the array) always belongs to the range of the array.
+   I.e. that the access will not trap, provided that the access to
+   the base to the array will not trap.  */
 #define TREE_THIS_NOTRAP(NODE) ((NODE)->common.nothrow_flag)
 
 /* In a VAR_DECL, PARM_DECL or FIELD_DECL, or any kind of ..._REF node,
@@ -2722,6 +2727,7 @@ extern tree build_method_type (tree, tree);
 extern tree build_offset_type (tree, tree);
 extern tree build_complex_type (tree);
 extern tree array_type_nelts (tree);
+extern bool in_array_bounds_p (tree);
 
 extern tree value_member (tree, tree);
 extern tree purpose_member (tree, tree);
@@ -3256,6 +3262,11 @@ extern tree array_ref_element_size (tree);
 
 extern tree array_ref_low_bound (tree);
 
+/* Return a tree representing the upper bound of the array mentioned in
+   EXP, an ARRAY_REF.  */
+
+extern tree array_ref_up_bound (tree);
+
 /* Return a tree representing the offset, in bytes, of the field referenced
    by EXP.  This does not include any offset in DECL_FIELD_BIT_OFFSET.  */