[cleanup] De-templatize CopyWords, drop MoveWords

CopyWords, as the name implies, copies raw words anyway, so there
is no need for type specialization.
MoveWords was dead code.

Bug: v8:8238
Change-Id: Ib497cfbabdcf8bac672ac74ef69f679b50ddfd6e
Reviewed-on: https://chromium-review.googlesource.com/c/1316609Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57226}

src/elements.cc

@@ -293,8 +293,7 @@ static void CopyDoubleToDoubleElements(FixedArrayBase* from_base,
   to_address += kDoubleSize * to_start;
   from_address += kDoubleSize * from_start;
   int words_per_double = (kDoubleSize / kPointerSize);
-  CopyWords(reinterpret_cast<Address*>(to_address),
-            reinterpret_cast<Address*>(from_address),
+  CopyWords(to_address, from_address,
             static_cast<size_t>(words_per_double * copy_size));
 }
 

src/heap/heap-inl.h

@@ -503,8 +503,7 @@ bool Heap::ShouldBePromoted(Address old_address) {
 }
 
 void Heap::CopyBlock(Address dst, Address src, int byte_size) {
-  CopyWords(reinterpret_cast<Object**>(dst), reinterpret_cast<Object**>(src),
-            static_cast<size_t>(byte_size / kPointerSize));
+  CopyWords(dst, src, static_cast<size_t>(byte_size / kPointerSize));
 }
 
 template <Heap::FindMementoMode mode>

src/utils.h

@@ -1114,51 +1114,29 @@ int WriteAsCFile(const char* filename, const char* varname,
 // Memory
 
 // Copies words from |src| to |dst|. The data spans must not overlap.
-template <typename T>
-inline void CopyWords(T* dst, const T* src, size_t num_words) {
-  STATIC_ASSERT(sizeof(T) == kPointerSize);
-  DCHECK(Min(dst, const_cast<T*>(src)) + num_words <=
-         Max(dst, const_cast<T*>(src)));
+// |src| and |dst| must be kPointerSize-aligned.
+inline void CopyWords(Address dst, const Address src, size_t num_words) {
+  DCHECK(IsAligned(dst, kPointerSize));
+  DCHECK(IsAligned(src, kPointerSize));
+  DCHECK(Min(dst, src) + num_words * kPointerSize <= Max(dst, src));
   DCHECK_GT(num_words, 0);
 
   // Use block copying MemCopy if the segment we're copying is
   // enough to justify the extra call/setup overhead.
   static const size_t kBlockCopyLimit = 16;
 
+  Address* dst_ptr = reinterpret_cast<Address*>(dst);
+  Address* src_ptr = reinterpret_cast<Address*>(src);
   if (num_words < kBlockCopyLimit) {
     do {
       num_words--;
-      *dst++ = *src++;
-    } while (num_words > 0);
-  } else {
-    MemCopy(dst, src, num_words * kPointerSize);
-  }
-}
-
-
-// Copies words from |src| to |dst|. No restrictions.
-template <typename T>
-inline void MoveWords(T* dst, const T* src, size_t num_words) {
-  STATIC_ASSERT(sizeof(T) == kPointerSize);
-  DCHECK_GT(num_words, 0);
-
-  // Use block copying MemCopy if the segment we're copying is
-  // enough to justify the extra call/setup overhead.
-  static const size_t kBlockCopyLimit = 16;
-
-  if (num_words < kBlockCopyLimit &&
-      ((dst < src) || (dst >= (src + num_words * kPointerSize)))) {
-    T* end = dst + num_words;
-    do {
-      num_words--;
-      *dst++ = *src++;
+      *dst_ptr++ = *src_ptr++;
     } while (num_words > 0);
   } else {
-    MemMove(dst, src, num_words * kPointerSize);
+    MemCopy(dst_ptr, src_ptr, num_words * kPointerSize);
   }
 }
 
-
 // Copies data from |src| to |dst|.  The data spans must not overlap.
 template <typename T>
 inline void CopyBytes(T* dst, const T* src, size_t num_bytes) {