Revert "dart2js: improve ssa utilization of bool value types"

pkg/compiler/lib/src/ssa/optimize.dart

Index: pkg/compiler/lib/src/ssa/optimize.dart
diff --git a/pkg/compiler/lib/src/ssa/optimize.dart b/pkg/compiler/lib/src/ssa/optimize.dart
index a24b0c16d96c78a23105f4acd5a2d130ccb1af30..07611f654a3292066d02ec241076f47e28dc7c3b 100644
--- a/pkg/compiler/lib/src/ssa/optimize.dart
+++ b/pkg/compiler/lib/src/ssa/optimize.dart
@@ -200,32 +200,6 @@ class SsaInstructionSimplifier extends HBaseVisitor
     return node;
   }
 
-  ConstantValue getConstantFromType(HInstruction node) {
-    if (node.isValue() && !node.canBeNull()) {
-      ValueTypeMask valueMask = node.instructionType;
-      if (valueMask.value.isBool) {
-        return valueMask.value;
-      }
-      // TODO(het): consider supporting other values (short strings?)
-    }
-    return null;
-  }
-
-  void propagateConstantValueToUses(HInstruction known) {
-    if (known.usedBy.isEmpty) return;
-    ConstantValue value = getConstantFromType(known);
-    if (value != null) {
-      for (HInstruction user in known.usedBy.toList()) {
-        user.changeUse(known, graph.addConstant(value, compiler));
-      }
-    }
-  }
-
-  HInstruction visitParameterValue(HParameterValue node) {
-    propagateConstantValueToUses(node);
-    return node;
-  }
-
   HInstruction visitBoolify(HBoolify node) {
     List<HInstruction> inputs = node.inputs;
     assert(inputs.length == 1);
@@ -398,7 +372,6 @@ class SsaInstructionSimplifier extends HBaseVisitor
   }
 
   HInstruction visitInvokeDynamicMethod(HInvokeDynamicMethod node) {
-    propagateConstantValueToUses(node);
     if (node.isInterceptedCall) {
       HInstruction folded = handleInterceptedCall(node);
       if (folded != node) return folded;
@@ -833,7 +806,6 @@ class SsaInstructionSimplifier extends HBaseVisitor
   }
 
   HInstruction visitInvokeDynamicGetter(HInvokeDynamicGetter node) {
-    propagateConstantValueToUses(node);
     if (node.isInterceptedCall) {
       HInstruction folded = handleInterceptedCall(node);
       if (folded != node) return folded;
@@ -895,7 +867,6 @@ class SsaInstructionSimplifier extends HBaseVisitor
   }
 
   HInstruction visitInvokeStatic(HInvokeStatic node) {
-    propagateConstantValueToUses(node);
     if (node.element == backend.getCheckConcurrentModificationError()) {
       if (node.inputs.length == 2) {
         HInstruction firstArgument = node.inputs[0];
@@ -1335,6 +1306,13 @@ class SsaLiveBlockAnalyzer extends HBaseVisitor {
       } else {
         markBlockLive(instruction.elseBlock);
       }
+    } else if (condition.isValue()) {
+      ValueTypeMask valueType = condition.instructionType;
+      if (valueType.value == true) {
+        markBlockLive(instruction.thenBlock);
+      } else {
+        markBlockLive(instruction.elseBlock);
+      }
     } else {
       visitControlFlow(instruction);
     }