diff --git a/mozilla/js/js2/icodegenerator.cpp b/mozilla/js/js2/icodegenerator.cpp
index d0c86871f5e..b12d9201e19 100644
--- a/mozilla/js/js2/icodegenerator.cpp
+++ b/mozilla/js/js2/icodegenerator.cpp
@@ -1442,12 +1442,12 @@ TypedRegister ICodeGenerator::genExpr(ExprNode *p,
             BinaryExprNode *b = static_cast<BinaryExprNode *>(p);
             TypedRegister r1 = genExpr(b->op1);
             TypedRegister r2 = genExpr(b->op2);
-            ret = binaryOp(mapExprNodeToICodeOp(p->getKind()), r2, r1);
+            ret = binaryOp(mapExprNodeToICodeOp(p->getKind()), r1, r2);     // will generate equal/identical code
             if (trueBranch || falseBranch) {
                 if (trueBranch == NULL)
-                    branchFalse(falseBranch, ret);
+                    branchTrue(falseBranch, ret);
                 else {
-                    branchTrue(trueBranch, ret);
+                    branchFalse(trueBranch, ret);
                     if (falseBranch)
                         branch(falseBranch);
                 }
@@ -2104,11 +2104,13 @@ TypedRegister ICodeGenerator::genStmt(StmtNode *p, LabelSet *currentLabelSet)
     case StmtNode::IfElse:
         {
             Label *falseLabel = getLabel();
+            Label *trueLabel = getLabel();
             Label *beyondLabel = getLabel();
             BinaryStmtNode *i = static_cast<BinaryStmtNode *>(p);
-            TypedRegister c = genExpr(i->expr, false, NULL, falseLabel);
+            TypedRegister c = genExpr(i->expr, false, trueLabel, falseLabel);
             if (!generatedBoolean(i->expr))
                 branchFalse(falseLabel, test(c));
+            setLabel(trueLabel);
             genStmt(i->stmt);
             branch(beyondLabel);
             setLabel(falseLabel);
diff --git a/mozilla/js/js2/interpreter.cpp b/mozilla/js/js2/interpreter.cpp
index 80185b04ff8..ab07962d6b5 100644
--- a/mozilla/js/js2/interpreter.cpp
+++ b/mozilla/js/js2/interpreter.cpp
@@ -372,7 +372,7 @@ static JSValue less_Default(const JSValue& r1, const JSValue& r2)
         lv = lv.toNumber();
         rv = rv.toNumber();
         if (lv.isNaN() || rv.isNaN())
-            return JSValue();
+            return kFalseValue;
         else
             return JSValue(lv.f64 < rv.f64);
     }
@@ -388,26 +388,48 @@ static JSValue lessOrEqual_Default(const JSValue& r1, const JSValue& r2)
         lv = lv.toNumber();
         rv = rv.toNumber();
         if (lv.isNaN() || rv.isNaN())
-            return JSValue();
+            return kFalseValue;
         else
             return JSValue(lv.f64 <= rv.f64);
     }
 }
 static JSValue equal_Default(const JSValue& r1, const JSValue& r2)
 {
-    JSValue lv = r1.toPrimitive(JSValue::Number);
-    JSValue rv = r2.toPrimitive(JSValue::Number);
-    if (lv.isString() && rv.isString()) {
-        return JSValue(bool(lv.string->compare(*rv.string) == 0));
+    if (r1.isSameType(r2)) {
+        if (r1.isUndefined()) return kTrueValue;
+        if (r1.isNull()) return kTrueValue;
+        if (r1.isNumber()) {
+            JSValue lv = r1.toNumber(); // make sure we have f64's
+            JSValue rv = r2.toNumber();
+            if (lv.isNaN() || rv.isNaN())
+                return kFalseValue;
+            else
+                return JSValue(lv.f64 == rv.f64);   // does the right thing for +/- 0
+        }
+        if (r1.isString())
+            return JSValue(bool(r1.string->compare(*r2.string) == 0));
+        if (r1.isBoolean())
+            return JSValue(bool(r1.boolean == r2.boolean));
+        if (r1.isObject())
+            return JSValue(bool(r1.object == r2.object));
     }
-    else {
-        lv = lv.toNumber();
-        rv = rv.toNumber();
-        if (lv.isNaN() || rv.isNaN())
-            return JSValue();
-        else
-            return JSValue(lv.f64 == rv.f64);
+    else {  // different types
+        if (r1.isNull() && r2.isUndefined()) return kTrueValue;
+        if (r2.isNull() && r1.isUndefined()) return kTrueValue;
+        if (r1.isNumber() && r2.isString())
+            return equal_Default(r1, r2.toNumber());
+        if (r2.isNumber() && r1.isString())
+            return equal_Default(r1.toNumber(), r2);
+        if (r1.isBoolean())
+            return equal_Default(r1.toNumber(), r2);
+        if (r2.isBoolean())
+            return equal_Default(r1, r2.toNumber());
+        if ((r1.isString() || r1.isNumber()) && r2.isObject())
+            return equal_Default(r1, r2.toPrimitive());
+        if ((r2.isString() || r2.isNumber()) && r1.isObject())
+            return equal_Default(r1.toPrimitive(), r2);
     }
+    return kFalseValue;
 }
 static JSValue identical_Default(const JSValue& r1, const JSValue& r2)
 {
diff --git a/mozilla/js/js2/js2.cpp b/mozilla/js/js2/js2.cpp
index d16177044df..8a999d71cf0 100644
--- a/mozilla/js/js2/js2.cpp
+++ b/mozilla/js/js2/js2.cpp
@@ -347,7 +347,8 @@ static void testCompile()
             icg.genStmt(s);
             s = s->next;
         }
-        cx.interpret(icg.complete(&Void_Type), JSValues());
+        JSValue result = cx.interpret(icg.complete(&Void_Type), JSValues());
+        stdOut << "result = " << result << "\n";
     }
 }
 
diff --git a/mozilla/js/js2/jstypes.cpp b/mozilla/js/js2/jstypes.cpp
index e85fb4d0a38..f36d2fee532 100644
--- a/mozilla/js/js2/jstypes.cpp
+++ b/mozilla/js/js2/jstypes.cpp
@@ -267,7 +267,7 @@ static JSValue array_constructor(Context *, const JSValues& argv)
             return JSValue(result);
         }
         else
-            return JSValue(new JSArray(JSValue::valueToInteger(argv[1]).i32));
+            return JSValue(new JSArray(JSValue::valueToInt32(argv[1]).i32));
     else
         return JSValue(new JSArray());
 }
@@ -358,15 +358,6 @@ JSType Date_Type = JSType(widenCString("Date"), NULL, new JSNativeFunction(date_
 
 
 // the canonical undefined value, etc.
-const JSValue kUndefinedValue;
-const JSValue kNaNValue = JSValue(nan);
-const JSValue kTrueValue = JSValue(true);
-const JSValue kFalseValue = JSValue(false);
-const JSValue kNullValue = JSValue((JSObject*)NULL);
-const JSValue kNegativeZero = JSValue(-0.0);
-const JSValue kPositiveZero = JSValue(0.0);
-const JSValue kNegativeInfinity = JSValue(negativeInfinity);
-const JSValue kPositiveInfinity = JSValue(positiveInfinity);
 
 
 const JSType *JSValue::getType() const
@@ -712,10 +703,10 @@ JSValue JSValue::valueToInteger(const JSValue& value)
 {
     JSValue result = valueToNumber(value);
     ASSERT(result.tag == f64_tag);
-    result.tag = i32_tag;
+    result.tag = integer_tag;
     bool neg = (result.f64 < 0);
-    result.i32 = (int32)floor((neg) ? -result.f64 : result.f64);
-    result.i32 = (neg) ? -result.i32 : result.i32;
+    result.f64 = floor((neg) ? -result.f64 : result.f64);
+    result.f64 = (neg) ? -result.f64 : result.f64;
     return result;
 }
 
diff --git a/mozilla/js/js2/jstypes.h b/mozilla/js/js2/jstypes.h
index ecbed79258d..70bc6a4d495 100644
--- a/mozilla/js/js2/jstypes.h
+++ b/mozilla/js/js2/jstypes.h
@@ -105,7 +105,7 @@ namespace JSTypes {
             f32_tag, f64_tag,
             integer_tag,
             object_tag, array_tag, function_tag, string_tag, boolean_tag, type_tag,
-            undefined_tag,
+            undefined_tag, null_tag,
             uninitialized_tag
         } Tag;
         Tag tag;
@@ -145,7 +145,7 @@ namespace JSTypes {
 
         bool isInitialized() const                      { return (tag != uninitialized_tag); }
         bool isUndefined() const                        { return (tag == undefined_tag); }
-        bool isNull() const                             { return ((tag == object_tag) && (this->object == NULL)); }
+        bool isNull() const                             { return (tag == null_tag); }
         bool isNaN() const;
         bool isNegativeInfinity() const;
         bool isPositiveInfinity() const;
@@ -173,6 +173,16 @@ namespace JSTypes {
 
 
         const JSType *getType() const;                  // map from tag type to JS2 type
+        bool isSameType(const JSValue &other) const
+        {
+            const JSType *thisType = getType();
+            const JSType *otherType = other.getType();
+            if (thisType == otherType)
+                return true;
+            if (isNumber() && other.isNumber())
+                return true;
+            return false;
+        }
 
         int operator==(const JSValue& value) const;
     };
diff --git a/mozilla/js/js2/numerics.cpp b/mozilla/js/js2/numerics.cpp
index 58d4edbddf5..f7a6088bf99 100644
--- a/mozilla/js/js2/numerics.cpp
+++ b/mozilla/js/js2/numerics.cpp
@@ -22,9 +22,11 @@
 #include <cstring>
 #include <cfloat>
 #include "numerics.h"
+#include "jstypes.h"
 
 namespace JS = JavaScript;
 using namespace JavaScript;
+using namespace JSTypes;
 
 
 //
@@ -225,6 +227,15 @@ InitNumerics::InitNumerics()
 	word1(nan) = 0xFFFFFFFF;
 }
 
+const JSValue JSTypes::kUndefinedValue;
+const JSValue JSTypes::kNaNValue = JSValue(nan);
+const JSValue JSTypes::kTrueValue = JSValue(true);
+const JSValue JSTypes::kFalseValue = JSValue(false);
+const JSValue JSTypes::kNullValue = JSValue(JSValue::Tag::null_tag);
+const JSValue JSTypes::kNegativeZero = JSValue(-0.0);
+const JSValue JSTypes::kPositiveZero = JSValue(0.0);
+const JSValue JSTypes::kNegativeInfinity = JSValue(negativeInfinity);
+const JSValue JSTypes::kPositiveInfinity = JSValue(positiveInfinity);
 
 //
 // Portable double-precision floating point to string and back conversions
diff --git a/mozilla/js2/src/icodegenerator.cpp b/mozilla/js2/src/icodegenerator.cpp
index d0c86871f5e..b12d9201e19 100644
--- a/mozilla/js2/src/icodegenerator.cpp
+++ b/mozilla/js2/src/icodegenerator.cpp
@@ -1442,12 +1442,12 @@ TypedRegister ICodeGenerator::genExpr(ExprNode *p,
             BinaryExprNode *b = static_cast<BinaryExprNode *>(p);
             TypedRegister r1 = genExpr(b->op1);
             TypedRegister r2 = genExpr(b->op2);
-            ret = binaryOp(mapExprNodeToICodeOp(p->getKind()), r2, r1);
+            ret = binaryOp(mapExprNodeToICodeOp(p->getKind()), r1, r2);     // will generate equal/identical code
             if (trueBranch || falseBranch) {
                 if (trueBranch == NULL)
-                    branchFalse(falseBranch, ret);
+                    branchTrue(falseBranch, ret);
                 else {
-                    branchTrue(trueBranch, ret);
+                    branchFalse(trueBranch, ret);
                     if (falseBranch)
                         branch(falseBranch);
                 }
@@ -2104,11 +2104,13 @@ TypedRegister ICodeGenerator::genStmt(StmtNode *p, LabelSet *currentLabelSet)
     case StmtNode::IfElse:
         {
             Label *falseLabel = getLabel();
+            Label *trueLabel = getLabel();
             Label *beyondLabel = getLabel();
             BinaryStmtNode *i = static_cast<BinaryStmtNode *>(p);
-            TypedRegister c = genExpr(i->expr, false, NULL, falseLabel);
+            TypedRegister c = genExpr(i->expr, false, trueLabel, falseLabel);
             if (!generatedBoolean(i->expr))
                 branchFalse(falseLabel, test(c));
+            setLabel(trueLabel);
             genStmt(i->stmt);
             branch(beyondLabel);
             setLabel(falseLabel);
diff --git a/mozilla/js2/src/interpreter.cpp b/mozilla/js2/src/interpreter.cpp
index 80185b04ff8..ab07962d6b5 100644
--- a/mozilla/js2/src/interpreter.cpp
+++ b/mozilla/js2/src/interpreter.cpp
@@ -372,7 +372,7 @@ static JSValue less_Default(const JSValue& r1, const JSValue& r2)
         lv = lv.toNumber();
         rv = rv.toNumber();
         if (lv.isNaN() || rv.isNaN())
-            return JSValue();
+            return kFalseValue;
         else
             return JSValue(lv.f64 < rv.f64);
     }
@@ -388,26 +388,48 @@ static JSValue lessOrEqual_Default(const JSValue& r1, const JSValue& r2)
         lv = lv.toNumber();
         rv = rv.toNumber();
         if (lv.isNaN() || rv.isNaN())
-            return JSValue();
+            return kFalseValue;
         else
             return JSValue(lv.f64 <= rv.f64);
     }
 }
 static JSValue equal_Default(const JSValue& r1, const JSValue& r2)
 {
-    JSValue lv = r1.toPrimitive(JSValue::Number);
-    JSValue rv = r2.toPrimitive(JSValue::Number);
-    if (lv.isString() && rv.isString()) {
-        return JSValue(bool(lv.string->compare(*rv.string) == 0));
+    if (r1.isSameType(r2)) {
+        if (r1.isUndefined()) return kTrueValue;
+        if (r1.isNull()) return kTrueValue;
+        if (r1.isNumber()) {
+            JSValue lv = r1.toNumber(); // make sure we have f64's
+            JSValue rv = r2.toNumber();
+            if (lv.isNaN() || rv.isNaN())
+                return kFalseValue;
+            else
+                return JSValue(lv.f64 == rv.f64);   // does the right thing for +/- 0
+        }
+        if (r1.isString())
+            return JSValue(bool(r1.string->compare(*r2.string) == 0));
+        if (r1.isBoolean())
+            return JSValue(bool(r1.boolean == r2.boolean));
+        if (r1.isObject())
+            return JSValue(bool(r1.object == r2.object));
     }
-    else {
-        lv = lv.toNumber();
-        rv = rv.toNumber();
-        if (lv.isNaN() || rv.isNaN())
-            return JSValue();
-        else
-            return JSValue(lv.f64 == rv.f64);
+    else {  // different types
+        if (r1.isNull() && r2.isUndefined()) return kTrueValue;
+        if (r2.isNull() && r1.isUndefined()) return kTrueValue;
+        if (r1.isNumber() && r2.isString())
+            return equal_Default(r1, r2.toNumber());
+        if (r2.isNumber() && r1.isString())
+            return equal_Default(r1.toNumber(), r2);
+        if (r1.isBoolean())
+            return equal_Default(r1.toNumber(), r2);
+        if (r2.isBoolean())
+            return equal_Default(r1, r2.toNumber());
+        if ((r1.isString() || r1.isNumber()) && r2.isObject())
+            return equal_Default(r1, r2.toPrimitive());
+        if ((r2.isString() || r2.isNumber()) && r1.isObject())
+            return equal_Default(r1.toPrimitive(), r2);
     }
+    return kFalseValue;
 }
 static JSValue identical_Default(const JSValue& r1, const JSValue& r2)
 {
diff --git a/mozilla/js2/src/jstypes.cpp b/mozilla/js2/src/jstypes.cpp
index e85fb4d0a38..f36d2fee532 100644
--- a/mozilla/js2/src/jstypes.cpp
+++ b/mozilla/js2/src/jstypes.cpp
@@ -267,7 +267,7 @@ static JSValue array_constructor(Context *, const JSValues& argv)
             return JSValue(result);
         }
         else
-            return JSValue(new JSArray(JSValue::valueToInteger(argv[1]).i32));
+            return JSValue(new JSArray(JSValue::valueToInt32(argv[1]).i32));
     else
         return JSValue(new JSArray());
 }
@@ -358,15 +358,6 @@ JSType Date_Type = JSType(widenCString("Date"), NULL, new JSNativeFunction(date_
 
 
 // the canonical undefined value, etc.
-const JSValue kUndefinedValue;
-const JSValue kNaNValue = JSValue(nan);
-const JSValue kTrueValue = JSValue(true);
-const JSValue kFalseValue = JSValue(false);
-const JSValue kNullValue = JSValue((JSObject*)NULL);
-const JSValue kNegativeZero = JSValue(-0.0);
-const JSValue kPositiveZero = JSValue(0.0);
-const JSValue kNegativeInfinity = JSValue(negativeInfinity);
-const JSValue kPositiveInfinity = JSValue(positiveInfinity);
 
 
 const JSType *JSValue::getType() const
@@ -712,10 +703,10 @@ JSValue JSValue::valueToInteger(const JSValue& value)
 {
     JSValue result = valueToNumber(value);
     ASSERT(result.tag == f64_tag);
-    result.tag = i32_tag;
+    result.tag = integer_tag;
     bool neg = (result.f64 < 0);
-    result.i32 = (int32)floor((neg) ? -result.f64 : result.f64);
-    result.i32 = (neg) ? -result.i32 : result.i32;
+    result.f64 = floor((neg) ? -result.f64 : result.f64);
+    result.f64 = (neg) ? -result.f64 : result.f64;
     return result;
 }
 
diff --git a/mozilla/js2/src/jstypes.h b/mozilla/js2/src/jstypes.h
index ecbed79258d..70bc6a4d495 100644
--- a/mozilla/js2/src/jstypes.h
+++ b/mozilla/js2/src/jstypes.h
@@ -105,7 +105,7 @@ namespace JSTypes {
             f32_tag, f64_tag,
             integer_tag,
             object_tag, array_tag, function_tag, string_tag, boolean_tag, type_tag,
-            undefined_tag,
+            undefined_tag, null_tag,
             uninitialized_tag
         } Tag;
         Tag tag;
@@ -145,7 +145,7 @@ namespace JSTypes {
 
         bool isInitialized() const                      { return (tag != uninitialized_tag); }
         bool isUndefined() const                        { return (tag == undefined_tag); }
-        bool isNull() const                             { return ((tag == object_tag) && (this->object == NULL)); }
+        bool isNull() const                             { return (tag == null_tag); }
         bool isNaN() const;
         bool isNegativeInfinity() const;
         bool isPositiveInfinity() const;
@@ -173,6 +173,16 @@ namespace JSTypes {
 
 
         const JSType *getType() const;                  // map from tag type to JS2 type
+        bool isSameType(const JSValue &other) const
+        {
+            const JSType *thisType = getType();
+            const JSType *otherType = other.getType();
+            if (thisType == otherType)
+                return true;
+            if (isNumber() && other.isNumber())
+                return true;
+            return false;
+        }
 
         int operator==(const JSValue& value) const;
     };
diff --git a/mozilla/js2/src/numerics.cpp b/mozilla/js2/src/numerics.cpp
index 58d4edbddf5..f7a6088bf99 100644
--- a/mozilla/js2/src/numerics.cpp
+++ b/mozilla/js2/src/numerics.cpp
@@ -22,9 +22,11 @@
 #include <cstring>
 #include <cfloat>
 #include "numerics.h"
+#include "jstypes.h"
 
 namespace JS = JavaScript;
 using namespace JavaScript;
+using namespace JSTypes;
 
 
 //
@@ -225,6 +227,15 @@ InitNumerics::InitNumerics()
 	word1(nan) = 0xFFFFFFFF;
 }
 
+const JSValue JSTypes::kUndefinedValue;
+const JSValue JSTypes::kNaNValue = JSValue(nan);
+const JSValue JSTypes::kTrueValue = JSValue(true);
+const JSValue JSTypes::kFalseValue = JSValue(false);
+const JSValue JSTypes::kNullValue = JSValue(JSValue::Tag::null_tag);
+const JSValue JSTypes::kNegativeZero = JSValue(-0.0);
+const JSValue JSTypes::kPositiveZero = JSValue(0.0);
+const JSValue JSTypes::kNegativeInfinity = JSValue(negativeInfinity);
+const JSValue JSTypes::kPositiveInfinity = JSValue(positiveInfinity);
 
 //
 // Portable double-precision floating point to string and back conversions
diff --git a/mozilla/js2/tests/cpp/js2_shell.cpp b/mozilla/js2/tests/cpp/js2_shell.cpp
index d16177044df..8a999d71cf0 100644
--- a/mozilla/js2/tests/cpp/js2_shell.cpp
+++ b/mozilla/js2/tests/cpp/js2_shell.cpp
@@ -347,7 +347,8 @@ static void testCompile()
             icg.genStmt(s);
             s = s->next;
         }
-        cx.interpret(icg.complete(&Void_Type), JSValues());
+        JSValue result = cx.interpret(icg.complete(&Void_Type), JSValues());
+        stdOut << "result = " << result << "\n";
     }
 }