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-rw-r--r--gcc/predict.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/gcc/predict.c b/gcc/predict.c
index 0c16b53..67a5f74 100644
--- a/gcc/predict.c
+++ b/gcc/predict.c
@@ -1,6 +1,6 @@
/* Branch prediction routines for the GNU compiler.
Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010,
- 2011, 2012 Free Software Foundation, Inc.
+ 2011, 2012, 2013 Free Software Foundation, Inc.
This file is part of GCC.
@@ -1434,7 +1434,8 @@ predict_loops (void)
if (TREE_CODE (niter) == INTEGER_CST)
{
if (host_integerp (niter, 1)
- && compare_tree_int (niter, max-1) == -1)
+ && max
+ && compare_tree_int (niter, max - 1) == -1)
nitercst = tree_low_cst (niter, 1) + 1;
else
nitercst = max;
@@ -1456,6 +1457,11 @@ predict_loops (void)
else
continue;
+ /* If the prediction for number of iterations is zero, do not
+ predict the exit edges. */
+ if (nitercst == 0)
+ continue;
+
probability = ((REG_BR_PROB_BASE + nitercst / 2) / nitercst);
predict_edge (ex, predictor, probability);
}