* predict.c (estimate_probability): If no prediction was found, then

        predict the successor that is the next physical block (if such a
        successor exists).


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@33683 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 13 insertions, 0 deletions

diff --git a/gcc/predict.c b/gcc/predict.c
index b957e5f6050..148d46bb1e6 100644
--- a/gcc/predict.c
+++ b/gcc/predict.c
@@ -202,6 +202,19 @@ estimate_probability (loops_info)
 	  break;
 	}
 
+      /* If one of the blocks already directly follows the current
+	 block, then predict it as the taken path.  This reduces
+	 random block movement.  */
+      for (e = BASIC_BLOCK (i)->succ; e; e = e->succ_next)
+        if (e->dest->index == i + 1)
+          {
+            if (e->flags & EDGE_FALLTHRU)
+              prob = 0;
+            else
+              prob = REG_BR_PROB_BASE;
+            goto emitnote;
+          }
+
       /* If we havn't chosen something by now, predict 50-50.  */
       prob = REG_BR_PROB_BASE / 2;