* unroll.c: Include predict.h.

	(unroll_loop): Drop prediction notes on preconditioning.
	* predict.def (PRED_LOOP_PRECONDITIONG, PRED_LOOP_CONDITION):
	New; add comments on the others.
	* Makefile.in: (unroll.o): Add dependancy on predict.h.
	* loop.c (strength_reduce): Fix branch prediction.

	* stmt.c (emit_case_nodes): Optimize test whether index is in given
	interval.

	* predict.c (estimate_probability): Do not bail out early
	when note is present.
	(combine_predictions_for_insn): Fix note removal code.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@43441 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 22 insertions, 2 deletions

diff --git a/gcc/stmt.c b/gcc/stmt.c
index 3cefc7ce3ee..ee4523c33c5 100644
--- a/gcc/stmt.c
+++ b/gcc/stmt.c
@@ -6293,8 +6293,10 @@ emit_case_nodes (index, node, default_label, index_type)
 	  /* Node has no children so we check low and high bounds to remove
 	     redundant tests.  Only one of the bounds can exist,
 	     since otherwise this node is bounded--a case tested already.  */
+	  int high_bound = node_has_high_bound (node, index_type);
+	  int low_bound = node_has_low_bound (node, index_type);
 
-	  if (!node_has_high_bound (node, index_type))
+	  if (!high_bound && low_bound)
 	    {
 	      emit_cmp_and_jump_insns (index,
 				       convert_modes
@@ -6306,7 +6308,7 @@ emit_case_nodes (index, node, default_label, index_type)
 				       default_label);
 	    }
 
-	  if (!node_has_low_bound (node, index_type))
+	  else if (!low_bound && high_bound)
 	    {
 	      emit_cmp_and_jump_insns (index,
 				       convert_modes
@@ -6317,6 +6319,24 @@ emit_case_nodes (index, node, default_label, index_type)
 				       LT, NULL_RTX, mode, unsignedp, 0,
 				       default_label);
 	    }
+	  else if (!low_bound && !high_bound)
+	    {
+	      /* Instead of doing two branches emit test (index-low) <= (high-low).  */
+	      tree new_bound = fold (build (MINUS_EXPR, index_type, node->high,
+					    node->low));
+	      rtx new_index;
+	      
+	      new_index = expand_binop (mode, sub_optab, index,
+			      		expand_expr (node->low, NULL_RTX,
+						     VOIDmode, 0),
+				        NULL_RTX, 0, OPTAB_WIDEN);
+				
+	      emit_cmp_and_jump_insns (new_index,
+				       expand_expr (new_bound, NULL_RTX,
+						    VOIDmode, 0),
+				       GT, NULL_RTX, mode, 1, 0,
+				       default_label);
+	    }
 
 	  emit_jump (label_rtx (node->code_label));
 	}