Avoid "=== true" inside code by calling a function that does this for us.

lib/compiler/implementation/ssa/optimize.dart

Index: lib/compiler/implementation/ssa/optimize.dart
diff --git a/lib/compiler/implementation/ssa/optimize.dart b/lib/compiler/implementation/ssa/optimize.dart
index a1562b535c79efae6f852115688d6281c8b531fc..17ae1297e0b7cacd47b6fcfd205f802be8d149ff 100644
--- a/lib/compiler/implementation/ssa/optimize.dart
+++ b/lib/compiler/implementation/ssa/optimize.dart
@@ -241,6 +241,45 @@ class SsaConstantFolder extends HBaseVisitor implements OptimizationPhase {
     return node;
   }
 
+  HInstruction visitRelational(HRelational node) {
+    if (node.usedBy.length == 1 && node.usedBy[0] is HBoolify) {

[ngeoffray, 2012/04/25 11:48:08]

I'd check if all the users are HBoolify instead.

[floitsch, 2012/04/25 16:01:49]

Done.

+      Interceptors interceptors = compiler.builder.interceptors;
+      HStatic oldTarget = node.target;
+      Element boolifiedInterceptor =
+          interceptors.getBoolifiedVersionOfInterceptor(oldTarget.element);
+      if (boolifiedInterceptor !== null) {
+        HStatic boolifiedTarget = new HStatic(boolifiedInterceptor);
+        // We don't remove the [oldTarget] in case it is used by other
+        // instructions. If it is unused it will be treated as dead code and
+        // discarded.
+        oldTarget.block.addAfter(oldTarget, boolifiedTarget);
+        // Remove us from the usedBy list of the old target.

[ngeoffray, 2012/04/25 11:48:08]

Please move that code into the HInstruction class.

[floitsch, 2012/04/25 16:01:49]

Moved into HBasicBlock class.

+        if (oldTarget.usedBy.length == 1) {
+          oldTarget.usedBy.clear();
+        } else {
+          List<HInstruction> users = oldTarget.usedBy;
+          int length = users.length;
+          for (int i = 0; i < length; i++) {
+            if (users[i] === node) {
+              users[i] = users[length - 1];
+              users.length = length - 1;
+            }
+          }
+        }
+        // Replace old target with boolified target.
+        assert(node.target == node.inputs[0]);
+        node.inputs[0] = boolifiedTarget;
+        boolifiedTarget.usedBy.add(node);
+        node.usesBoolifiedInterceptor = true;
+        node.propagatedType = HType.BOOLEAN;
+      }
+    }
+    // This node stays the same, but the Boolify node will go away.

[ngeoffray, 2012/04/25 11:48:08]

Move that comment one line up (in the if clause).

[floitsch, 2012/04/25 16:01:49]

Done.

+    // Note that we still have to call [super] to make sure that we end up
+    // in the remaining optimizations.
+    return super.visitRelational(node);
+  }
+
   HInstruction visitEquals(HEquals node) {
     HInstruction left = node.left;
     HInstruction right = node.right;
@@ -283,8 +322,10 @@ class SsaConstantFolder extends HBaseVisitor implements OptimizationPhase {
       }
     }
 
-    // All other cases are dealt with by the [visitInvokeBinary].
-    return visitInvokeBinary(node);
+    // All other cases are dealt with by the [visitRelational] and
+    // [visitInvokeBinary], which are visited by invoking the [super]'s
+    // visit method.
+    return super.visitEquals(node);
   }
 
   HInstruction visitTypeGuard(HTypeGuard node) {