unroll.c: Include predict.h.

	* 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.

From-SVN: r43441

7 files changed, 82 insertions, 9 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c45255a..51c11e7 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,23 @@
+Mon Jun 18 17:27:24 CEST 2001  Jan Hubicka  <jh@suse.cz>
+
+	* 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.
+
+Mon Jun 18 17:26:56 CEST 2001  Jan Hubicka  <jh@suse.cz>
+
+	* stmt.c (emit_case_nodes): Optimize test whether index is in given
+	interval.
+
+Mon Jun 18 15:43:10 CEST 2001  Jan Hubicka  <jh@suse.cz>
+
+	* predict.c (estimate_probability): Do not bail out early
+	when note is present.
+	(combine_predictions_for_insn): Fix note removal code.
+
 2001-06-18  Ben Elliston  <bje@redhat.com>
 
 	* except.c (resolve_fixup_regions): Initialise "cleanup".
diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index 6606cab..75b3dbc 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -1450,7 +1450,7 @@ doloop.o : doloop.c $(CONFIG_H) $(SYSTEM_H) $(RTL_H) flags.h $(LOOP_H) \
    $(EXPR_H) hard-reg-set.h $(BASIC_BLOCK_H) $(TM_P_H) toplev.h
 unroll.o : unroll.c $(CONFIG_H) $(SYSTEM_H) $(RTL_H) insn-config.h function.h \
    $(INTEGRATE_H) $(REGS_H) $(RECOG_H) flags.h $(EXPR_H) $(LOOP_H) toplev.h \
-   hard-reg-set.h varray.h $(BASIC_BLOCK_H) $(TM_P_H)
+   hard-reg-set.h varray.h $(BASIC_BLOCK_H) $(TM_P_H) $(PREDICT_H)
 flow.o : flow.c $(CONFIG_H) $(SYSTEM_H) $(RTL_H) $(TREE_H) flags.h insn-config.h \
    $(BASIC_BLOCK_H) $(REGS_H) hard-reg-set.h output.h toplev.h $(RECOG_H) \
    function.h except.h $(EXPR_H) ssa.h $(GGC_H) $(TM_P_H)
diff --git a/gcc/loop.c b/gcc/loop.c
index ec8dc0a..82f09f3 100644
--- a/gcc/loop.c
+++ b/gcc/loop.c
@@ -4505,7 +4505,7 @@ strength_reduce (loop, flags)
   if ((flags & LOOP_BCT)
       && loop_info->n_iterations / loop_info->unroll_number > 1)
     {
-      int n = loop_info->n_iterations / loop_info->unroll_number - 1;
+      int n = loop_info->n_iterations / loop_info->unroll_number;
       predict_insn (PREV_INSN (loop->end),
 		    PRED_LOOP_ITERATIONS,
 		    REG_BR_PROB_BASE - REG_BR_PROB_BASE / n);
diff --git a/gcc/predict.c b/gcc/predict.c
index 21c7149..38818cb 100644
--- a/gcc/predict.c
+++ b/gcc/predict.c
@@ -208,7 +208,6 @@ combine_predictions_for_insn (insn, bb)
      probability combination techniques.  */
   while (*pnote)
     {
-      rtx *next_pnote = &XEXP (*pnote, 1);
       if (REG_NOTE_KIND (*pnote) == REG_BR_PRED)
 	{
 	  int predictor = INTVAL (XEXP (XEXP (*pnote, 0), 0));
@@ -219,7 +218,8 @@ combine_predictions_for_insn (insn, bb)
 	    best_probability = probability, best_predictor = predictor;
 	  *pnote = XEXP (*pnote, 1);
 	}
-      pnote = next_pnote;
+      else
+        pnote = &XEXP (*pnote, 1);
     }
   dump_prediction (PRED_FIRST_MATCH, best_probability, bb);
   if (!prob_note)
@@ -313,9 +313,6 @@ estimate_probability (loops_info)
 	  || ! any_condjump_p (last_insn))
 	continue;
 
-      if (find_reg_note (last_insn, REG_BR_PROB, 0))
-	continue;
-
       for (e = bb->succ; e; e = e->succ_next)
 	{
 	  /* Predict edges to blocks that return immediately to be
diff --git a/gcc/predict.def b/gcc/predict.def
index 01d87a4..ff8171b 100644
--- a/gcc/predict.def
+++ b/gcc/predict.def
@@ -36,15 +36,47 @@ Boston, MA 02111-1307, USA.  */
    REG_BR_PROB_BASE / 2).  */
    
 
+/* An combined heuristics using probability determined by first
+   matching heuristics from this list.  */
 DEF_PREDICTOR (PRED_FIRST_MATCH, "first match", PROB_ALWAYS)
+
+/* Mark unconditional jump as taken.  */
 DEF_PREDICTOR (PRED_UNCONDITIONAL, "unconditional jump", PROB_ALWAYS)
+
+/* Use number of loop iterations determined by loop unroller to set
+   probability.  */
 DEF_PREDICTOR (PRED_LOOP_ITERATIONS, "loop iterations", PROB_ALWAYS)
+
+/* Hints dropped by user via __builtin_expect feature.  */
 DEF_PREDICTOR (PRED_BUILTIN_EXPECT, "__builtin_expect", PROB_VERY_LIKELY)
+
+/* Branch to basic block containing call marked by noreturn attribute.  */
 DEF_PREDICTOR (PRED_NORETURN, "noreturn call", PROB_ALWAYS)
+
+/* Loopback edge is taken.  */
 DEF_PREDICTOR (PRED_LOOP_BRANCH, "loop branch", PROB_VERY_LIKELY)
+
+/* Edge causing loop to terminate is probably not taken. */
 DEF_PREDICTOR (PRED_LOOP_EXIT, "loop exit", PROB_LIKELY)
+
+/* Condition emitted by preconditiong code to ensure that variable
+   setting number of iterations is greater than initial value of iterator.  */
+DEF_PREDICTOR (PRED_LOOP_CONDITION, "loop condition", PROB_VERY_LIKELY)
+
+/* Preconditioning makes linear list of branches.  */
+DEF_PREDICTOR (PRED_LOOP_PRECONDITIONING, "loop preconditioning", PROB_VERY_LIKELY)
+
+/* Copied condition for the first iteration of loop is probably true.  */
 DEF_PREDICTOR (PRED_LOOP_HEADER, "loop header", PROB_LIKELY)
+
+/* Pointers are usually not NULL.  */
 DEF_PREDICTOR (PRED_POINTER, "pointer", PROB_LIKELY)
+
+/* NE is probable, EQ not etc...  */
 DEF_PREDICTOR (PRED_OPCODE, "opcode", PROB_LIKELY)
+
+/* Branch guarding call is probably taken.  */
 DEF_PREDICTOR (PRED_CALL, "call", PROB_LIKELY)
+
+/* Branch causing function to terminate is probably not taken.  */
 DEF_PREDICTOR (PRED_ERROR_RETURN, "error return", PROB_LIKELY)
diff --git a/gcc/stmt.c b/gcc/stmt.c
index 3cefc7c..ee4523c 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));
 	}
diff --git a/gcc/unroll.c b/gcc/unroll.c
index 94c58cd..9a09f5d 100644
--- a/gcc/unroll.c
+++ b/gcc/unroll.c
@@ -167,6 +167,7 @@ enum unroll_types
 #include "toplev.h"
 #include "hard-reg-set.h"
 #include "basic-block.h"
+#include "predict.h"
 
 /* This controls which loops are unrolled, and by how much we unroll
    them.  */
@@ -962,6 +963,7 @@ unroll_loop (loop, insn_count, strength_reduce_p)
 	      emit_cmp_and_jump_insns (initial_value, final_value,
 				       neg_inc ? LE : GE,
 				       NULL_RTX, mode, 0, 0, labels[1]);
+	      predict_insn_def (get_last_insn (), PRED_LOOP_CONDITION, NOT_TAKEN);
 	      JUMP_LABEL (get_last_insn ()) = labels[1];
 	      LABEL_NUSES (labels[1])++;
 	    }
@@ -1007,6 +1009,8 @@ unroll_loop (loop, insn_count, strength_reduce_p)
 				       labels[i]);
 	      JUMP_LABEL (get_last_insn ()) = labels[i];
 	      LABEL_NUSES (labels[i])++;
+	      predict_insn (get_last_insn (), PRED_LOOP_PRECONDITIONING,
+			    REG_BR_PROB_BASE / (unroll_number - i));
 	    }
 
 	  /* If the increment is greater than one, then we need another branch,