* predict.c (combine_predictions_for_insn): Avoid division by zero.

From-SVN: r48615

* predict.c (combine_predictions_for_insn): Avoid division by zero.
From-SVN: r48615
571a03b8 · Jakub Jelinek · Jakub Jelinek · 2e951384 · 571a03b8 · 571a03b8
Commit 571a03b8 authored Jan 07, 2002 by Jakub Jelinek Committed by Jakub Jelinek Jan 07, 2002
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gcc/ChangeLog
+4 -0

gcc/predict.c
+6 -2

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--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
 2002-01-07  Jakub Jelinek  <jakub@redhat.com>

+	* predict.c (combine_predictions_for_insn): Avoid division by zero.
+
+2002-01-07  Jakub Jelinek  <jakub@redhat.com>
+
 	* simplify-rtx.c (simplify_plus_minus): Bump n_ops for NOT.
 	Don't allow -1 - x -> ~x simplifications in the first pass.


--- a/gcc/predict.c
+++ b/gcc/predict.c
@@ -253,8 +253,12 @@ combine_predictions_for_insn (insn, bb)
 	     * (REG_BR_PROB_BASE - probability));

 	/* Use FP math to avoid overflows of 32bit integers.  */
-	combined_probability = (((double) combined_probability) * probability
-				* REG_BR_PROB_BASE / d + 0.5);
+	if (d == 0)
+	  /* If one probability is 0% and one 100%, avoid division by zero.  */
+	  combined_probability = REG_BR_PROB_BASE / 2;
+	else
+	  combined_probability = (((double) combined_probability) * probability
+				  * REG_BR_PROB_BASE / d + 0.5);
      }

  /* Decide which heuristic to use.  In case we didn't match anything,