* tree-ssa.h: Don't include gimple-low.h, tree-ssa-address.h, sbitmap.h,

	tree-ssa-threadedge.h, tree-ssa-dom.h, and tree-cfgcleanup.h.
	* gimple-low.c (gimple_check_call_arg,
	gimple_check_call_matching_types): Move to cgraph.c.
	* gimple-low.h: Remove prototype.
	* cgraph.c: (gimple_check_call_arg, gimple_check_call_matching_types):
	Relocate from gimple-low.c.
	* cgraph.h: Add prototype.  Don't include basic-block.h.
	* gimplify.c: Add gimple-low to include list.
	* omp-low.c: Add gimple-low and tree-cfgcleanup.h to include list.
	* tree-eh.c: Add gimple-low to include list.
	* tree-nested.c: Likewise.
	* cfgexpand.c: Add tree-ssa-address.h to include list.
	* expr.c: Likewise.
	* gimple-fold.c: Likewise.
	* gimple-ssa-strength-reduction.c: Likewise.
	* trans-mem.c: Likewise.
	* tree-mudflap.c: Likewise.
	* tree-ssa-loop-ivopts.c: Likewise.
	* tree-ssa-dom.c: Include tree-ssa-threadedge.h and tree-ssa-dom.h.
	(degenerate_phi_result): Move to tree-phinodes.c.
	* tree-ssa-loop-ch.c: Include tree-ssa-threadedge.h.
	* tree-ssa-threadedge.c: Likewise.
	* tree-vrp.c: Likewise.
	* tree-phinodes.c (degenerate_phi_result): Relocate here.
	* tree-ssa-dom.h (degenerate_phi_result): Remove Prototype.
	* tree-phinodes.h (degenerate_phi_result): Add prototype.
	* tree-ssa-copy.c: Include tree-ssa-dom.h.
	* tree-ssa-forwprop.c: Likewise.
	* tree-cfgcleanup.c (execute_cleanup_cfg_post_optimizing,
	pass_data_cleanup_cfg_post_optimizing,
	make_pass_cleanup_cfg_post_optimizing): Relocate from tree-optimize.c.
	* tree-optimize.c: Delete File.
	* graphite.c: Include tree-cfgcleanup.h.
	* passes.c: Likewise.
	* tree-cfg.c: Likewise.
	* tree-profile.c: Likewise.
	* tree-ssa-dse.c: Likewise.
	* tree-ssa-loop-ivcanon.c: Likewise.
	* tree-switch-conversion.c: Don't include tree-ssa-operands.h.
	* tree-outof-ssa.c: Include sbitmap.h.
	* tree-ssa-live.c: Likewise.
	* tree-ssa-propagate.c: Likewise.
	* tree-ssa-structalias.c: Likewise.
	* tree-stdarg.c: Likewise.
	* Makefile.in (OBJS): Delete tree-optimize.o.
	* basic-block.h (gcov_type, gcov_type_unsigned): Move to coretypes.h.
	* coretypes.h (gcov_type, gcov_type_unsigned): Relocate here.
	* varasm.c: Include basic-block.h.
	* cfgloop.h: Include function.h instead of basic-block.h
	(bb_loop_depth): Move to cfgloop.c.
	* cfgloop.c (bb_loop_depth): Relocate from cfgloop.h.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@203833 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 37 insertions, 0 deletions

diff --git a/gcc/tree-phinodes.c b/gcc/tree-phinodes.c
index 0bd5085ba99..f96dafa476c 100644
--- a/gcc/tree-phinodes.c
+++ b/gcc/tree-phinodes.c
@@ -464,4 +464,41 @@ remove_phi_nodes (basic_block bb)
   set_phi_nodes (bb, NULL);
 }
 
+/* Given PHI, return its RHS if the PHI is a degenerate, otherwise return
+   NULL.  */
+
+tree
+degenerate_phi_result (gimple phi)
+{
+  tree lhs = gimple_phi_result (phi);
+  tree val = NULL;
+  size_t i;
+
+  /* Ignoring arguments which are the same as LHS, if all the remaining
+     arguments are the same, then the PHI is a degenerate and has the
+     value of that common argument.  */
+  for (i = 0; i < gimple_phi_num_args (phi); i++)
+    {
+      tree arg = gimple_phi_arg_def (phi, i);
+
+      if (arg == lhs)
+	continue;
+      else if (!arg)
+	break;
+      else if (!val)
+	val = arg;
+      else if (arg == val)
+	continue;
+      /* We bring in some of operand_equal_p not only to speed things
+	 up, but also to avoid crashing when dereferencing the type of
+	 a released SSA name.  */
+      else if (TREE_CODE (val) != TREE_CODE (arg)
+	       || TREE_CODE (val) == SSA_NAME
+	       || !operand_equal_p (arg, val, 0))
+	break;
+    }
+  return (i == gimple_phi_num_args (phi) ? val : NULL);
+}
+
+
 #include "gt-tree-phinodes.h"