Merge in trunk.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/wide-int@203881 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 58 insertions, 24 deletions

diff --git a/gcc/dojump.c b/gcc/dojump.c
index 700a17c9653..b7b78050217 100644
--- a/gcc/dojump.c
+++ b/gcc/dojump.c
@@ -311,32 +311,66 @@ do_jump_1 (enum tree_code code, tree op0, tree op1,
       break;
 
     case TRUTH_ANDIF_EXPR:
-      if (if_false_label == NULL_RTX)
-        {
-	  drop_through_label = gen_label_rtx ();
-	  do_jump (op0, drop_through_label, NULL_RTX, prob);
-	  do_jump (op1, NULL_RTX, if_true_label, prob);
-	}
-      else
-	{
-	  do_jump (op0, if_false_label, NULL_RTX, prob);
-	  do_jump (op1, if_false_label, if_true_label, prob);
-	}
-      break;
+      {
+        /* Spread the probability that the expression is false evenly between
+           the two conditions. So the first condition is false half the total
+           probability of being false. The second condition is false the other
+           half of the total probability of being false, so its jump has a false
+           probability of half the total, relative to the probability we
+           reached it (i.e. the first condition was true).  */
+        int op0_prob = -1;
+        int op1_prob = -1;
+        if (prob != -1)
+          {
+            int false_prob = inv (prob);
+            int op0_false_prob = false_prob / 2;
+            int op1_false_prob = GCOV_COMPUTE_SCALE ((false_prob / 2),
+                                                     inv (op0_false_prob));
+            /* Get the probability that each jump below is true.  */
+            op0_prob = inv (op0_false_prob);
+            op1_prob = inv (op1_false_prob);
+          }
+        if (if_false_label == NULL_RTX)
+          {
+            drop_through_label = gen_label_rtx ();
+            do_jump (op0, drop_through_label, NULL_RTX, op0_prob);
+            do_jump (op1, NULL_RTX, if_true_label, op1_prob);
+          }
+        else
+          {
+            do_jump (op0, if_false_label, NULL_RTX, op0_prob);
+            do_jump (op1, if_false_label, if_true_label, op1_prob);
+          }
+        break;
+      }
 
     case TRUTH_ORIF_EXPR:
-      if (if_true_label == NULL_RTX)
-	{
-          drop_through_label = gen_label_rtx ();
-	  do_jump (op0, NULL_RTX, drop_through_label, prob);
-	  do_jump (op1, if_false_label, NULL_RTX, prob);
-	}
-      else
-	{
-	  do_jump (op0, NULL_RTX, if_true_label, prob);
-	  do_jump (op1, if_false_label, if_true_label, prob);
-	}
-      break;
+      {
+        /* Spread the probability evenly between the two conditions. So
+           the first condition has half the total probability of being true.
+           The second condition has the other half of the total probability,
+           so its jump has a probability of half the total, relative to
+           the probability we reached it (i.e. the first condition was false).  */
+        int op0_prob = -1;
+        int op1_prob = -1;
+        if (prob != -1)
+          {
+            op0_prob = prob / 2;
+            op1_prob = GCOV_COMPUTE_SCALE ((prob / 2), inv (op0_prob));
+          }
+        if (if_true_label == NULL_RTX)
+          {
+            drop_through_label = gen_label_rtx ();
+            do_jump (op0, NULL_RTX, drop_through_label, op0_prob);
+            do_jump (op1, if_false_label, NULL_RTX, op1_prob);
+          }
+        else
+          {
+            do_jump (op0, NULL_RTX, if_true_label, op0_prob);
+            do_jump (op1, if_false_label, if_true_label, op1_prob);
+          }
+        break;
+      }
 
     default:
       gcc_unreachable ();