diff --git a/js/src/jit-test/tests/jaeger/optimize-globals-1.js b/js/src/jit-test/tests/jaeger/optimize-globals-1.js
new file mode 100644
index 000000000000..4197a271749e
--- /dev/null
+++ b/js/src/jit-test/tests/jaeger/optimize-globals-1.js
@@ -0,0 +1,9 @@
+
+function testLocalNames() {
+    var NaN = 4;
+    var undefined = 5;
+    var Infinity = 6;
+    return NaN + undefined + Infinity;
+}
+assertEq(testLocalNames(), 15);
+
diff --git a/js/src/jit-test/tests/jaeger/optimize-globals-2.js b/js/src/jit-test/tests/jaeger/optimize-globals-2.js
new file mode 100644
index 000000000000..2e01cdcb047f
--- /dev/null
+++ b/js/src/jit-test/tests/jaeger/optimize-globals-2.js
@@ -0,0 +1,20 @@
+
+function testNaN(x) {
+    var x = NaN;
+    assertEq(isNaN(x), true);
+}
+testNaN();
+
+function testInfinity(x) {
+    return (x === Infinity);
+}
+assertEq(testInfinity(Infinity), true);
+assertEq(testInfinity(6), false);
+assertEq(testInfinity(-Infinity), false);
+
+function testUndefined(x) {
+    return (x === undefined);
+}
+assertEq(testUndefined(undefined), true);
+assertEq(testUndefined(), true);
+assertEq(testUndefined(5), false);
diff --git a/js/src/jit-test/tests/jaeger/optimize-globals-3.js b/js/src/jit-test/tests/jaeger/optimize-globals-3.js
new file mode 100644
index 000000000000..eb2474c45bdf
--- /dev/null
+++ b/js/src/jit-test/tests/jaeger/optimize-globals-3.js
@@ -0,0 +1,9 @@
+
+NaN = 4;
+undefined = 5;
+Infinity = 6;
+
+assertEq(isNaN(NaN), true);
+assertEq(Infinity > 100, true);
+assertEq(undefined != 5, true);
+
diff --git a/js/src/jsapi.cpp b/js/src/jsapi.cpp
index f9b5f5eabef7..8858796f0e97 100644
--- a/js/src/jsapi.cpp
+++ b/js/src/jsapi.cpp
@@ -1525,8 +1525,8 @@ static JSStdName standard_class_names[] = {
     {js_InitObjectClass,        EAGER_ATOM(eval), CLASP(Object)},
 
     /* Global properties and functions defined by the Number class. */
-    {js_InitNumberClass,        LAZY_ATOM(NaN), CLASP(Number)},
-    {js_InitNumberClass,        LAZY_ATOM(Infinity), CLASP(Number)},
+    {js_InitNumberClass,        EAGER_ATOM(NaN), CLASP(Number)},
+    {js_InitNumberClass,        EAGER_ATOM(Infinity), CLASP(Number)},
     {js_InitNumberClass,        LAZY_ATOM(isNaN), CLASP(Number)},
     {js_InitNumberClass,        LAZY_ATOM(isFinite), CLASP(Number)},
     {js_InitNumberClass,        LAZY_ATOM(parseFloat), CLASP(Number)},
diff --git a/js/src/jsatom.cpp b/js/src/jsatom.cpp
index 5d4584b94f45..439a58c35040 100644
--- a/js/src/jsatom.cpp
+++ b/js/src/jsatom.cpp
@@ -181,6 +181,8 @@ const char *const js_common_atom_names[] = {
     "use strict",               /* useStrictAtom                */
     "loc",                      /* locAtom                      */
     "line",                     /* lineAtom                     */
+    "Infinity",                 /* InfinityAtom                 */
+    "NaN",                      /* NaNAtom                      */
 
 #if JS_HAS_XML_SUPPORT
     js_etago_str,               /* etagoAtom                    */
diff --git a/js/src/jsatom.h b/js/src/jsatom.h
index 0d3e370911fe..9c6f0a1b4483 100644
--- a/js/src/jsatom.h
+++ b/js/src/jsatom.h
@@ -373,6 +373,8 @@ struct JSAtomState
     JSAtom              *useStrictAtom;
     JSAtom              *locAtom;
     JSAtom              *lineAtom;
+    JSAtom              *InfinityAtom;
+    JSAtom              *NaNAtom;
 
 #if JS_HAS_XML_SUPPORT
     JSAtom              *etagoAtom;
@@ -407,8 +409,6 @@ struct JSAtomState
 
     /* Less frequently used atoms, pinned lazily by JS_ResolveStandardClass. */
     struct {
-        JSAtom          *InfinityAtom;
-        JSAtom          *NaNAtom;
         JSAtom          *XMLListAtom;
         JSAtom          *decodeURIAtom;
         JSAtom          *decodeURIComponentAtom;
diff --git a/js/src/methodjit/Compiler.cpp b/js/src/methodjit/Compiler.cpp
index 8e32d6b69808..b074daeb9601 100644
--- a/js/src/methodjit/Compiler.cpp
+++ b/js/src/methodjit/Compiler.cpp
@@ -4336,6 +4336,20 @@ mjit::Compiler::jsop_bindgname()
 void
 mjit::Compiler::jsop_getgname(uint32 index)
 {
+    /* Optimize undefined, NaN and Infinity. */
+    JSAtom *atom = script->getAtom(index);
+    if (atom == cx->runtime->atomState.typeAtoms[JSTYPE_VOID]) {
+        frame.push(UndefinedValue());
+        return;
+    }
+    if (atom == cx->runtime->atomState.NaNAtom) {
+        frame.push(cx->runtime->NaNValue);
+        return;
+    }
+    if (atom == cx->runtime->atomState.InfinityAtom) {
+        frame.push(cx->runtime->positiveInfinityValue);
+        return;
+    }
 #if defined JS_MONOIC
     jsop_bindgname();