Prevent errorneous floating point expression optimization.

Negations of floating point comparison expressions where incorrectly
transformed changing its value if operands where NaNs.

Comparison operations on floating point numbers do not statisfy arithmetic
laws like  !(a > b) == (a <= b).

Bug: #9463
Bug-Link: #9463
Change-Id: Id8a5c4e060410ab513eea5c27168eb367d645c2b

dev/core/src/com/google/gwt/dev/jjs/ast/JBlock.java

@@ -18,6 +18,7 @@
 import com.google.gwt.dev.jjs.SourceInfo;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 
 /**
@@ -27,8 +28,9 @@ public class JBlock extends JStatement {
 
   private final List<JStatement> statements = new ArrayList<JStatement>();
 
-  public JBlock(SourceInfo info) {
+  public JBlock(SourceInfo info, JStatement... statements) {
     super(info);
+    this.statements.addAll(Arrays.asList(statements));
   }
 
   /**

dev/core/src/com/google/gwt/dev/jjs/impl/DeadCodeElimination.java

@@ -202,10 +202,10 @@ public void endVisit(JBinaryOperation x, Context ctx) {
 
       switch (op) {
         case AND:
-          maybeReplaceMe(x, Simplifier.and(x), ctx);
+          maybeReplaceMe(x, Simplifier.simplifyAnd(x), ctx);
           break;
         case OR:
-          maybeReplaceMe(x, Simplifier.or(x), ctx);
+          maybeReplaceMe(x, Simplifier.simplifyOr(x), ctx);
           break;
         case BIT_XOR:
           simplifyXor(lhs, rhs, ctx);
@@ -315,12 +315,12 @@ public void endVisit(JBlock x, Context ctx) {
 
     @Override
     public void endVisit(JCastOperation x, Context ctx) {
-      maybeReplaceMe(x, Simplifier.cast(x), ctx);
+      maybeReplaceMe(x, Simplifier.simplifyCast(x), ctx);
     }
 
     @Override
     public void endVisit(JConditional x, Context ctx) {
-      maybeReplaceMe(x, Simplifier.conditional(x), ctx);
+      maybeReplaceMe(x, Simplifier.simplifyConditional(x), ctx);
     }
 
     @Override
@@ -340,7 +340,7 @@ public void endVisit(JDoStatement x, Context ctx) {
 
         // If false, replace do with do's body
         if (!booleanLiteral.getValue()) {
-          if (Simplifier.isEmpty(x.getBody())) {
+          if (JjsUtils.isEmptyBlock(x.getBody())) {
             ctx.removeMe();
           } else { // Unless it contains break/continue statements
             FindBreakContinueStatementsVisitor visitor = new FindBreakContinueStatementsVisitor();
@@ -429,7 +429,8 @@ public void endVisit(JForStatement x, Context ctx) {
      */
     @Override
     public void endVisit(JIfStatement x, Context ctx) {
-      maybeReplaceMe(x, Simplifier.ifStatement(x, getCurrentMethod()), ctx);
+      JType methodReturnType = getCurrentMethod() != null ? getCurrentMethod().getType() : null;
+      maybeReplaceMe(x, Simplifier.simplifyIfStatement(x, methodReturnType), ctx);
     }
 
     /**
@@ -651,7 +652,7 @@ public void endVisit(JPrefixOperation x, Context ctx) {
       }
 
       if (x.getOp() == JUnaryOperator.NOT) {
-        maybeReplaceMe(x, Simplifier.not(x), ctx);
+        maybeReplaceMe(x, Simplifier.simplifyNot(x), ctx);
         return;
       } else if (x.getOp() == JUnaryOperator.NEG) {
         maybeReplaceMe(x, simplifyNegate(x, x.getArg()), ctx);
@@ -708,9 +709,9 @@ public void endVisit(JTryStatement x, Context ctx) {
       }
 
       // Compute properties regarding the state of this try statement
-      boolean noTry = Simplifier.isEmpty(x.getTryBlock());
+      boolean noTry = JjsUtils.isEmptyBlock(x.getTryBlock());
       boolean noCatch = catchClauses.size() == 0;
-      boolean noFinally = Simplifier.isEmpty(x.getFinallyBlock());
+      boolean noFinally = JjsUtils.isEmptyBlock(x.getFinallyBlock());
 
       if (noTry) {
         // 2) Prune try statements with no body.

dev/core/src/com/google/gwt/dev/jjs/impl/JjsUtils.java

@@ -453,6 +453,16 @@ static void synthesizeStaticInitializerChain(
           .put(JStringLiteral.class, LiteralTranslators.STRING_LITERAL_TRANSLATOR)
           .build();
 
+  /**
+   * Return true if the statement is an empty block.
+   */
+  public static boolean isEmptyBlock(JStatement stmt) {
+    if (stmt == null) {
+      return true;
+    }
+    return (stmt instanceof JBlock && ((JBlock) stmt).getStatements().isEmpty());
+  }
+
   private enum LiteralTranslators {
     BOOLEAN_LITERAL_TRANSLATOR() {
       @Override