X-Git-Url: http://git.sourceforge.jp/view?a=blobdiff_plain;f=gcc%2Floop-doloop.c;h=d1bd28559154bfc2c0bff4ecfd22a540347b68a4;hb=71e7d89442a899c1db36a56329c9c5f01d95417f;hp=6e33a4f9ba014273b7f8199efc18e4418541840f;hpb=7bfc9b7cc90d5fc45847f176852078b1ddd504b1;p=pf3gnuchains%2Fgcc-fork.git

diff --git a/gcc/loop-doloop.c b/gcc/loop-doloop.c
index 6e33a4f9ba0..d1bd2855915 100644
--- a/gcc/loop-doloop.c
+++ b/gcc/loop-doloop.c
@@ -1,5 +1,6 @@
 /* Perform doloop optimizations
-   Copyright (C) 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
+   Copyright (C) 2004, 2005, 2006, 2007, 2008, 2010
+   Free Software Foundation, Inc.
    Based on code by Michael P. Hayes (m.hayes@elec.canterbury.ac.nz)
 
 This file is part of GCC.
@@ -290,7 +291,8 @@ add_test (rtx cond, edge *e, basic_block dest)
   op0 = force_operand (op0, NULL_RTX);
   op1 = force_operand (op1, NULL_RTX);
   label = block_label (dest);
-  do_compare_rtx_and_jump (op0, op1, code, 0, mode, NULL_RTX, NULL_RTX, label);
+  do_compare_rtx_and_jump (op0, op1, code, 0, mode, NULL_RTX,
+			   NULL_RTX, label, -1);
 
   jump = get_last_insn ();
   if (!jump || !JUMP_P (jump))
@@ -316,13 +318,12 @@ add_test (rtx cond, edge *e, basic_block dest)
       redirect_edge_and_branch_force (*e, dest);
       return false;
     }
-      
+
   JUMP_LABEL (jump) = label;
 
   /* The jump is supposed to handle an unlikely special case.  */
-  REG_NOTES (jump)
-	  = gen_rtx_EXPR_LIST (REG_BR_PROB,
-			       const0_rtx, REG_NOTES (jump));
+  add_reg_note (jump, REG_BR_PROB, const0_rtx);
+
   LABEL_NUSES (label)++;
 
   make_edge (bb, dest, (*e)->flags & ~EDGE_FALLTHRU);
@@ -333,11 +334,14 @@ add_test (rtx cond, edge *e, basic_block dest)
    describes the loop, DESC describes the number of iterations of the
    loop, and DOLOOP_INSN is the low-overhead looping insn to emit at the
    end of the loop.  CONDITION is the condition separated from the
-   DOLOOP_SEQ.  COUNT is the number of iterations of the LOOP.  */
+   DOLOOP_SEQ.  COUNT is the number of iterations of the LOOP.
+   ZERO_EXTEND_P says to zero extend COUNT after the increment of it to
+   word_mode from FROM_MODE.  */
 
 static void
 doloop_modify (struct loop *loop, struct niter_desc *desc,
-	       rtx doloop_seq, rtx condition, rtx count)
+	       rtx doloop_seq, rtx condition, rtx count,
+	       bool zero_extend_p, enum machine_mode from_mode)
 {
   rtx counter_reg;
   rtx tmp, noloop = NULL_RTX;
@@ -348,6 +352,7 @@ doloop_modify (struct loop *loop, struct niter_desc *desc,
   bool increment_count;
   basic_block loop_end = desc->out_edge->src;
   enum machine_mode mode;
+  rtx true_prob_val;
 
   jump_insn = BB_END (loop_end);
 
@@ -361,6 +366,10 @@ doloop_modify (struct loop *loop, struct niter_desc *desc,
       fputs (" iterations).\n", dump_file);
     }
 
+  /* Get the probability of the original branch. If it exists we would
+     need to update REG_BR_PROB of the new jump_insn.  */
+  true_prob_val = find_reg_note (jump_insn, REG_BR_PROB, NULL_RTX);
+
   /* Discard original jump to continue loop.  The original compare
      result may still be live, so it cannot be discarded explicitly.  */
   delete_insn (jump_insn);
@@ -406,7 +415,11 @@ doloop_modify (struct loop *loop, struct niter_desc *desc,
     }
 
   if (increment_count)
-    count = simplify_gen_binary (PLUS, mode, count, const1_rtx);
+    count = simplify_gen_binary (PLUS, from_mode, count, const1_rtx);
+
+  if (zero_extend_p)
+    count = simplify_gen_unary (ZERO_EXTEND, word_mode,
+				count, from_mode);
 
   /* Insert initialization of the count register into the loop header.  */
   start_sequence ();
@@ -450,7 +463,7 @@ doloop_modify (struct loop *loop, struct niter_desc *desc,
 	  set_zero->count = preheader->count;
 	  set_zero->frequency = preheader->frequency;
 	}
- 
+
       if (EDGE_COUNT (set_zero->preds) == 0)
 	{
 	  /* All the conditions were simplified to false, remove the
@@ -465,7 +478,7 @@ doloop_modify (struct loop *loop, struct niter_desc *desc,
 	  sequence = get_insns ();
 	  end_sequence ();
 	  emit_insn_after (sequence, BB_END (set_zero));
-      
+
 	  set_immediate_dominator (CDI_DOMINATORS, set_zero,
 				   recompute_dominator (CDI_DOMINATORS,
 							set_zero));
@@ -512,9 +525,14 @@ doloop_modify (struct loop *loop, struct niter_desc *desc,
   /* Add a REG_NONNEG note if the actual or estimated maximum number
      of iterations is non-negative.  */
   if (nonneg)
+    add_reg_note (jump_insn, REG_NONNEG, NULL_RTX);
+
+  /* Update the REG_BR_PROB note.  */
+  if (true_prob_val)
     {
-      REG_NOTES (jump_insn)
-	= gen_rtx_EXPR_LIST (REG_NONNEG, NULL_RTX, REG_NOTES (jump_insn));
+      /* Seems safer to use the branch probability.  */
+      add_reg_note (jump_insn, REG_BR_PROB,
+		    GEN_INT (desc->in_edge->probability));
     }
 }
 
@@ -537,6 +555,7 @@ doloop_optimize (struct loop *loop)
   struct niter_desc *desc;
   unsigned word_mode_size;
   unsigned HOST_WIDE_INT word_mode_max;
+  bool zero_extend_p = false;
 
   if (dump_file)
     fprintf (dump_file, "Doloop: Processing loop %d.\n", loop->num);
@@ -576,7 +595,8 @@ doloop_optimize (struct loop *loop)
 
   max_cost
     = COSTS_N_INSNS (PARAM_VALUE (PARAM_MAX_ITERATIONS_COMPUTATION_COST));
-  if (rtx_cost (desc->niter_expr, SET) > max_cost)
+  if (rtx_cost (desc->niter_expr, SET, optimize_loop_for_speed_p (loop))
+      > max_cost)
     {
       if (dump_file)
 	fprintf (dump_file,
@@ -610,8 +630,7 @@ doloop_optimize (struct loop *loop)
     {
       if (word_mode_size > GET_MODE_BITSIZE (mode))
 	{
-	  count = simplify_gen_unary (ZERO_EXTEND, word_mode,
-				      count, mode);
+	  zero_extend_p = true;
 	  iterations = simplify_gen_unary (ZERO_EXTEND, word_mode,
 					   iterations, mode);
 	  iterations_max = simplify_gen_unary (ZERO_EXTEND, word_mode,
@@ -655,7 +674,8 @@ doloop_optimize (struct loop *loop)
       return false;
     }
 
-  doloop_modify (loop, desc, doloop_seq, condition, count);
+  doloop_modify (loop, desc, doloop_seq, condition, count,
+		 zero_extend_p, mode);
   return true;
 }