diff --git a/Source/JavaScriptCore/ChangeLog b/Source/JavaScriptCore/ChangeLog
index 5f477ee..88e9523 100644
--- a/Source/JavaScriptCore/ChangeLog
+++ b/Source/JavaScriptCore/ChangeLog
@@ -1,3 +1,18 @@
+2019-07-15  Saagar Jha  <saagarjha@apple.com>
+
+        Keyword lookup can use memcmp to get around unaligned load undefined behavior
+        https://bugs.webkit.org/show_bug.cgi?id=199650
+
+        Reviewed by Yusuke Suzuki.
+
+        Replace KeywordLookup's hand-rolled "memcmp" with the standard version, which reduces the need to deal with
+        endianness and unaligned loads.
+
+        * KeywordLookupGenerator.py:
+        (Trie.printSubTreeAsC): Use memcmp instead of macros to test for matches.
+        (Trie.printAsC): Unspecialize Lexer::parseKeyword as templating over the character type reduces the amount of
+        code we need to generate and moves this task out of the Python script and into the C++ compiler.
+
 2019-07-15  Yusuke Suzuki  <ysuzuki@apple.com>
 
         [JSC] Improve wasm wpt test results by fixing miscellaneous issues
diff --git a/Source/JavaScriptCore/KeywordLookupGenerator.py b/Source/JavaScriptCore/KeywordLookupGenerator.py
index d13daba..f640d5a 100644
--- a/Source/JavaScriptCore/KeywordLookupGenerator.py
+++ b/Source/JavaScriptCore/KeywordLookupGenerator.py
@@ -137,11 +137,11 @@
         self.keys = [(trie.prefix, trie) for trie in sorted(self.keys.values(), key=operator.attrgetter('weight'), reverse=True)]
         self.weight = weight
 
-    def printSubTreeAsC(self, typeName, indent):
+    def printSubTreeAsC(self, indent):
         str = makePadding(indent)
 
         if self.value != None:
-            print(str + "if (!isIdentPartIncludingEscape(code+%d, m_codeEnd)) {" % (len(self.fullPrefix)))
+            print(str + "if (!isIdentPartIncludingEscape(code + %d, m_codeEnd)) {" % (len(self.fullPrefix)))
             print(str + "    internalShift<%d>();" % len(self.fullPrefix))
             print(str + "    if (shouldCreateIdentifier)")
             print(str + ("        data->ident = &m_vm->propertyNames->%sKeyword;" % self.fullPrefix))
@@ -155,19 +155,16 @@
                 baseIndex = baseIndex - 1
                 k = trie.fullPrefix[baseIndex] + k
             test = [("'%s'" % c) for c in k]
-            if len(test) == 1:
-                comparison = "code[%d] == %s" % (baseIndex, test[0])
-            else:
-                base = "code"
-                if baseIndex > 0:
-                    base = "code + %d" % baseIndex
-                comparison = ("COMPARE_%d%sS(%s, " % (len(test), typeName, base)) + ", ".join(test) + ")"
+            base = "code + %d" % baseIndex
+            length = __builtins__.str(len(test))
+            needle = "(std::array<Char, " + length + ">{{" + ", ".join(test) + "}}).data()"
+            comparison = ("!memcmp(%s, " % (base)) + needle + ", " + length + " * sizeof(Char))"
             if itemCount == 0:
                 print(str + "if (" + comparison + ") {")
             else:
                 print(str + "} else if (" + comparison + ") {")
 
-            trie.printSubTreeAsC(typeName, indent + 4)
+            trie.printSubTreeAsC(indent + 4)
             itemCount = itemCount + 1
 
             if itemCount == len(self.keys):
@@ -189,23 +186,13 @@
         # max length + 1 so we don't need to do any bounds checking at all
         print("static const int maxTokenLength = %d;" % (self.maxLength() + 1))
         print("")
-        print("template <>")
-        print("template <bool shouldCreateIdentifier> ALWAYS_INLINE JSTokenType Lexer<UChar>::parseKeyword(JSTokenData* data)")
+        print("template <typename Char>")
+        print("template <bool shouldCreateIdentifier> ALWAYS_INLINE JSTokenType Lexer<Char>::parseKeyword(JSTokenData* data)")
         print("{")
         print("    ASSERT(m_codeEnd - m_code >= maxTokenLength);")
         print("")
-        print("    const UChar* code = m_code;")
-        self.printSubTreeAsC("UCHAR", 4)
-        print("    return IDENT;")
-        print("}")
-        print("")
-        print("template <>")
-        print("template <bool shouldCreateIdentifier> ALWAYS_INLINE JSTokenType Lexer<LChar>::parseKeyword(JSTokenData* data)")
-        print("{")
-        print("    ASSERT(m_codeEnd - m_code >= maxTokenLength);")
-        print("")
-        print("    const LChar* code = m_code;")
-        self.printSubTreeAsC("CHAR", 4)
+        print("    const Char* code = m_code;")
+        self.printSubTreeAsC(4)
         print("    return IDENT;")
         print("}")
         print("")
@@ -218,89 +205,6 @@
 trie.coalesce()
 trie.fillOut()
 print("// This file was generated by KeywordLookupGenerator.py.  Do not edit.")
-print("""
-#if CPU(NEEDS_ALIGNED_ACCESS)
-
-#define COMPARE_2CHARS(address, char1, char2) \\
-    (((address)[0] == char1) && ((address)[1] == char2))
-#define COMPARE_4CHARS(address, char1, char2, char3, char4) \\
-    (COMPARE_2CHARS(address, char1, char2) && COMPARE_2CHARS((address) + 2, char3, char4))
-#define COMPARE_2UCHARS(address, char1, char2) \\
-    (((address)[0] == char1) && ((address)[1] == char2))
-#define COMPARE_4UCHARS(address, char1, char2, char3, char4) \\
-    (COMPARE_2UCHARS(address, char1, char2) && COMPARE_2UCHARS((address) + 2, char3, char4))
-
-#else // CPU(NEEDS_ALIGNED_ACCESS)
-
-#if CPU(BIG_ENDIAN)
-
-#define CHARPAIR_TOUINT16(a, b) \\
-    ((((uint16_t)(a)) << 8) + (uint16_t)(b))
-#define CHARQUAD_TOUINT32(a, b, c, d) \\
-    ((((uint32_t)(CHARPAIR_TOUINT16(a, b))) << 16) + CHARPAIR_TOUINT16(c, d))
-#define UCHARPAIR_TOUINT32(a, b) \\
-    ((((uint32_t)(a)) << 16) + (uint32_t)(b))
-#define UCHARQUAD_TOUINT64(a, b, c, d) \\
-    ((((uint64_t)(UCHARQUAD_TOUINT64(a, b))) << 32) + UCHARPAIR_TOUINT32(c, d))
-
-#else // CPU(BIG_ENDIAN)
-
-#define CHARPAIR_TOUINT16(a, b) \\
-    ((((uint16_t)(b)) << 8) + (uint16_t)(a))
-#define CHARQUAD_TOUINT32(a, b, c, d) \\
-    ((((uint32_t)(CHARPAIR_TOUINT16(c, d))) << 16) + CHARPAIR_TOUINT16(a, b))
-#define UCHARPAIR_TOUINT32(a, b) \\
-    ((((uint32_t)(b)) << 16) + (uint32_t)(a))
-#define UCHARQUAD_TOUINT64(a, b, c, d) \\
-    ((((uint64_t)(UCHARPAIR_TOUINT32(c, d))) << 32) + UCHARPAIR_TOUINT32(a, b))
-
-#endif // CPU(BIG_ENDIAN)
-
-
-#define COMPARE_2CHARS(address, char1, char2) \\
-    ((reinterpret_cast<const uint16_t*>(address))[0] == CHARPAIR_TOUINT16(char1, char2))
-#define COMPARE_2UCHARS(address, char1, char2) \\
-    ((reinterpret_cast<const uint32_t*>(address))[0] == UCHARPAIR_TOUINT32(char1, char2))
-
-#if CPU(X86_64)
-
-#define COMPARE_4CHARS(address, char1, char2, char3, char4) \\
-    ((reinterpret_cast<const uint32_t*>(address))[0] == CHARQUAD_TOUINT32(char1, char2, char3, char4))
-#define COMPARE_4UCHARS(address, char1, char2, char3, char4) \\
-    ((reinterpret_cast<const uint64_t*>(address))[0] == UCHARQUAD_TOUINT64(char1, char2, char3, char4))
-
-#else // CPU(X86_64)
-
-#define COMPARE_4CHARS(address, char1, char2, char3, char4) \\
-    (COMPARE_2CHARS(address, char1, char2) && COMPARE_2CHARS((address) + 2, char3, char4))
-#define COMPARE_4UCHARS(address, char1, char2, char3, char4) \\
-    (COMPARE_2UCHARS(address, char1, char2) && COMPARE_2UCHARS((address) + 2, char3, char4))
-
-#endif // CPU(X86_64)
-
-#endif // CPU(NEEDS_ALIGNED_ACCESS)
-
-#define COMPARE_3CHARS(address, char1, char2, char3) \\
-    (COMPARE_2CHARS(address, char1, char2) && ((address)[2] == (char3)))
-#define COMPARE_3UCHARS(address, char1, char2, char3) \\
-    (COMPARE_2UCHARS(address, char1, char2) && ((address)[2] == (char3)))
-#define COMPARE_5CHARS(address, char1, char2, char3, char4, char5) \\
-    (COMPARE_4CHARS(address, char1, char2, char3, char4) && ((address)[4] == (char5)))
-#define COMPARE_5UCHARS(address, char1, char2, char3, char4, char5) \\
-    (COMPARE_4UCHARS(address, char1, char2, char3, char4) && ((address)[4] == (char5)))
-#define COMPARE_6CHARS(address, char1, char2, char3, char4, char5, char6) \\
-    (COMPARE_4CHARS(address, char1, char2, char3, char4) && COMPARE_2CHARS(address + 4, char5, char6))
-#define COMPARE_6UCHARS(address, char1, char2, char3, char4, char5, char6) \\
-    (COMPARE_4UCHARS(address, char1, char2, char3, char4) && COMPARE_2UCHARS(address + 4, char5, char6))
-#define COMPARE_7CHARS(address, char1, char2, char3, char4, char5, char6, char7) \\
-    (COMPARE_4CHARS(address, char1, char2, char3, char4) && COMPARE_4CHARS(address + 3, char4, char5, char6, char7))
-#define COMPARE_7UCHARS(address, char1, char2, char3, char4, char5, char6, char7) \\
-    (COMPARE_4UCHARS(address, char1, char2, char3, char4) && COMPARE_4UCHARS(address + 3, char4, char5, char6, char7))
-#define COMPARE_8CHARS(address, char1, char2, char3, char4, char5, char6, char7, char8) \\
-    (COMPARE_4CHARS(address, char1, char2, char3, char4) && COMPARE_4CHARS(address + 4, char5, char6, char7, char8))
-#define COMPARE_8UCHARS(address, char1, char2, char3, char4, char5, char6, char7, char8) \\
-    (COMPARE_4UCHARS(address, char1, char2, char3, char4) && COMPARE_4UCHARS(address + 4, char5, char6, char7, char8))
-""")
 
 trie.printAsC()