Track fields which are known to be always set to integer constants

lib/compiler/implementation/ssa/codegen.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 class SsaCodeGeneratorTask extends CompilerTask {
   final JavaScriptBackend backend;
   SsaCodeGeneratorTask(JavaScriptBackend backend)
       : this.backend = backend,
         super(backend.compiler);
   String get name() => 'SSA code generator';
@@ skipping 1154 matching lines @@
       endExpression(JSPrecedence.EQUALITY_PRECEDENCE);
     } else if (node.element === equalsNullElement ||
                node.element === boolifiedEqualsNullElement) {
       beginExpression(JSPrecedence.CALL_PRECEDENCE);
       use(node.target, JSPrecedence.CALL_PRECEDENCE);
       buffer.add('(');
       use(node.left, JSPrecedence.ASSIGNMENT_PRECEDENCE);
       buffer.add(')');
       endExpression(JSPrecedence.CALL_PRECEDENCE);
     } else {
-      visitInvokeStatic(node);
+      if (node.left is HFieldGet && node.right is HConstant) {

[ngeoffray, 2012/06/14 13:01:21]

This is too late in the game. The node.builtin should be set for what you want
to optimize.

[Søren Gjesse, 2012/06/15 13:19:59]

Removed all this as the SSA optimization phase now updates the guarenteedType of
the HFieldGet instruction causing the builtin === comparison to be generated.

+        HFieldGet left = node.left;
+        HConstant right = node.right;
+        Type type = left.receiver.propagatedType.computeType(compiler);
+        if (left.element != null &&
+            compiler.codegenWorld.hasFieldOnlyIntegerSetters(
+                type, left.element.name)) {
+          switch (compiler.pass) {
+            case 1:
+              visitInvokeStatic(node);
+              break;
+            case 2:
+              if (right.isConstantInteger()) {
+                buffer.add('(');
+                use(node.left, JSPrecedence.EQUALITY_PRECEDENCE);
+                buffer.add(' === ');
+                use(node.right, JSPrecedence.RELATIONAL_PRECEDENCE);
+                buffer.add(')');
+              } else {
+                visitInvokeStatic(node);
+              }
+              break;
+          }
+        } else {
+          visitInvokeStatic(node);
+        }
+      } else {
+        visitInvokeStatic(node);
+      }
     }
   }
 
   visitAdd(HAdd node)               => visitInvokeBinary(node, '+');
   visitDivide(HDivide node)         => visitInvokeBinary(node, '/');
   visitMultiply(HMultiply node)     => visitInvokeBinary(node, '*');
   visitSubtract(HSubtract node)     => visitInvokeBinary(node, '-');
   // Truncating divide does not have a JS equivalent.
   visitTruncatingDivide(HTruncatingDivide node) => visitInvokeStatic(node);
   // Modulo cannot be mapped to the native operator (different semantics).
@@ skipping 535 matching lines @@
   visitFieldSet(HFieldSet node) {
     String name;
     if (!node.isFromActivation()) {
       name = compiler.namer.getName(node.element);
       beginExpression(JSPrecedence.ASSIGNMENT_PRECEDENCE);
       use(node.receiver, JSPrecedence.MEMBER_PRECEDENCE);
       buffer.add('.');
       buffer.add(name);
       Type type = node.receiver.propagatedType.computeType(compiler);
       if (type != null) {
-        world.registerFieldSetter(node.element.name, type);
+        Type valueType = node.value.propagatedType.computeType(compiler);
+        if (valueType.toString() == "int") {

[ngeoffray, 2012/06/14 13:01:21]

You should change that to node.value.isInteger()

[Søren Gjesse, 2012/06/15 13:19:59]

Done.

+          world.registerFieldSetter(node.element.name, type, true);
+        } else {
+          world.registerFieldSetter(node.element.name, type, false);
+        }
       }
     } else {
       declareInstruction(node.receiver);
     }
     buffer.add(' = ');
     use(node.value, JSPrecedence.ASSIGNMENT_PRECEDENCE);
     if (node.receiver !== null) {
       endExpression(JSPrecedence.ASSIGNMENT_PRECEDENCE);
     }
   }
@@ skipping 1143 matching lines @@
       startBailoutSwitch();
     }
   }
 
   void endLabeledBlock(HLabeledBlockInformation labeledBlockInfo) {
     if (labeledBlockInfo.body.start.hasGuards()) {
       endBailoutSwitch();
     }
   }
 }