The function CopyCharsUnsigned(uint8_t* dest, const uint8_t* src, size_t chars) is now a specializa…

src/utils.h

Index: src/utils.h
diff --git a/src/utils.h b/src/utils.h
index 8eca39207d4aa55b222870a2e36e7ce53a273bc8..7badfe09b138518d557bc062a2b43d3258c05e63 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -1154,7 +1154,9 @@ Vector<const char> ReadFile(FILE* file,
 template <typename sourcechar, typename sinkchar>
 INLINE(static void CopyCharsUnsigned(sinkchar* dest, const sourcechar* src,
                                      size_t chars));
-#if defined(V8_HOST_ARCH_ARM)
+#if defined(V8_HOST_ARCH_X64)
+INLINE(void CopyCharsUnsigned(uint8_t* dest, const uint8_t* src, size_t chars));
+#elif defined(V8_HOST_ARCH_ARM)
 INLINE(void CopyCharsUnsigned(uint8_t* dest, const uint8_t* src, size_t chars));
 INLINE(void CopyCharsUnsigned(uint16_t* dest, const uint8_t* src,
                               size_t chars));
@@ -1213,7 +1215,16 @@ void CopyCharsUnsigned(sinkchar* dest, const sourcechar* src, size_t chars) {
 }
 
 
-#if defined(V8_HOST_ARCH_ARM)
+#if defined(V8_HOST_ARCH_X64)
+void CopyCharsUnsigned(uint8_t* dest, const uint8_t* src, size_t chars) {
+  uint8_t* limit = dest + chars;
+  if (sizeof(*dest) == sizeof(*src)) {

[Jakob Kummerow, 2016/08/30 13:29:28]

Well, this check is pretty pointless, because always sizeof(*dest) ==
sizeof(*src) == sizeof(uint8_t) == 1.

Comparing this with the function right above, it seems what you really want is
to change the value of kMinComplexMemCopy (to 0?) on x64. Why don't you just do
that?

+    MemCopy(dest, src, chars * sizeof(*dest));
+  } else {
+    while (dest < limit) *dest++ = *src++;
+  }
+}
+#elif defined(V8_HOST_ARCH_ARM)
 void CopyCharsUnsigned(uint8_t* dest, const uint8_t* src, size_t chars) {
   switch (static_cast<unsigned>(chars)) {
     case 0: