Fix a bug in SSA construction.

If a join block does not have an incoming value for a local
from a predecessor block, we should not create a phi. The
verifier has made sure the local is updated before any
following reads after this block.

Change-Id: Id2785efc73c9fb3224826fff2f4b4ad215905ff4

1 files changed, 13 insertions, 0 deletions

diff --git a/test/402-optimizing-control-flow/src/Main.java b/test/402-optimizing-control-flow/src/Main.java
index 3339ef436e..c9c24dd568 100644
--- a/test/402-optimizing-control-flow/src/Main.java
+++ b/test/402-optimizing-control-flow/src/Main.java
@@ -40,6 +40,9 @@ public class Main {
 
     result = $opt$testForLoop(42);
     expectEquals(44, result);
+
+    result = $opt$testIfWithLocal(5);
+    expectEquals(7, result);
   }
 
   static int $opt$testIfEq1(int a) {
@@ -73,4 +76,14 @@ public class Main {
     for (; a != 44; a++) {}
     return a;
   }
+
+  static int $opt$testIfWithLocal(int a) {
+    if (a == 5) {
+      int f = 2;
+      a += f;
+    }
+    // The SSA builder should not create a phi for f.
+
+    return a;
+  }
 }