ARM: Implement memcpy using NEON.

src/v8utils.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 209 matching lines @@
   case 5:
   case 6:
   case 7:
   case 8: {
     uint32_t part1 = *reinterpret_cast<const uint32_t*>(src);
     uint32_t part2 = *reinterpret_cast<const uint32_t*>(src + num_bytes - 4);
     *reinterpret_cast<uint32_t*>(dst) = part1;
     *reinterpret_cast<uint32_t*>(dst + num_bytes - 4) = part2;
     return;
   }
+#ifdef V8_TARGET_ARCH_ARM
   case 9:
   case 10:
   case 11:
+  case 12: {
+    uint32_t part1 = *reinterpret_cast<const uint32_t*>(src);
+    uint32_t part2 = *reinterpret_cast<const uint32_t*>(src + 4);
+    uint32_t part3 = *reinterpret_cast<const uint32_t*>(src + num_bytes - 4);
+    *reinterpret_cast<uint32_t*>(dst) = part1;
+    *reinterpret_cast<uint32_t*>(dst + 4) = part2;
+    *reinterpret_cast<uint32_t*>(dst + num_bytes - 4) = part3;
+    return;
+  }
+  case 13:
+  case 14:
+  case 15:
+  case 16: {
+    uint32_t part1 = *reinterpret_cast<const uint32_t*>(src);
+    uint32_t part2 = *reinterpret_cast<const uint32_t*>(src + 4);
+    uint32_t part3 = *reinterpret_cast<const uint32_t*>(src + 8);
+    uint32_t part4 = *reinterpret_cast<const uint32_t*>(src + num_bytes - 4);
+    *reinterpret_cast<uint32_t*>(dst) = part1;
+    *reinterpret_cast<uint32_t*>(dst + 4) = part2;
+    *reinterpret_cast<uint32_t*>(dst + 8) = part3;
+    *reinterpret_cast<uint32_t*>(dst + num_bytes - 4) = part4;
+    return;
+  }
+#else
+  case 9:
+  case 10:
+  case 11:
   case 12:
   case 13:
   case 14:
   case 15:
   case 16: {
     double part1 = *reinterpret_cast<const double*>(src);
     double part2 = *reinterpret_cast<const double*>(src + num_bytes - 8);
     *reinterpret_cast<double*>(dst) = part1;
     *reinterpret_cast<double*>(dst + num_bytes - 8) = part2;
     return;
   }
 #endif
+#endif
   default:
     OS::MemMove(dst, src, num_bytes);
     return;
   }
 }
 
 
 template <typename T, typename U>
 inline void MemsetPointer(T** dest, U* value, int counter) {
 #ifdef DEBUG
@@ skipping 55 matching lines @@
                             bool verbose = true);
 Vector<const char> ReadFile(FILE* file,
                             bool* exists,
                             bool verbose = true);
 
 
 template <typename sourcechar, typename sinkchar>
 INLINE(static void CopyCharsUnsigned(sinkchar* dest,
                                      const sourcechar* src,
                                      int chars));
+#if defined(V8_HOST_ARCH_ARM) && defined (V8_HOST_CAN_READ_UNALIGNED)
+INLINE(void CopyCharsUnsigned(uint16_t* dest, const uint8_t* src, int chars));
+#endif
 
 // Copy from ASCII/16bit chars to ASCII/16bit chars.
 template <typename sourcechar, typename sinkchar>
 INLINE(void CopyChars(sinkchar* dest, const sourcechar* src, int chars));
 
 template<typename sourcechar, typename sinkchar>
 void CopyChars(sinkchar* dest, const sourcechar* src, int chars) {
   ASSERT(sizeof(sourcechar) <= 2);
   ASSERT(sizeof(sinkchar) <= 2);
   if (sizeof(sinkchar) == 1) {
@@ skipping 14 matching lines @@
     } else {
       CopyCharsUnsigned(reinterpret_cast<uint16_t*>(dest),
                         reinterpret_cast<const uint16_t*>(src),
                         chars);
     }
   }
 }
 
 template <typename sourcechar, typename sinkchar>
 void CopyCharsUnsigned(sinkchar* dest, const sourcechar* src, int chars) {
-  sinkchar* limit = dest + chars;
 #ifdef V8_HOST_CAN_READ_UNALIGNED
   if (sizeof(*dest) == sizeof(*src)) {
     if (chars >= static_cast<int>(OS::kMinComplexMemCopy / sizeof(*dest))) {
       OS::MemCopy(dest, src, chars * sizeof(*dest));
       return;
     }
+    sinkchar* limit = dest + chars;
     // Number of characters in a uintptr_t.
     static const int kStepSize = sizeof(uintptr_t) / sizeof(*dest);  // NOLINT
-    ASSERT(dest + kStepSize > dest);  // Check for overflow.
-    while (dest + kStepSize <= limit) {
-      *reinterpret_cast<uintptr_t*>(dest) =
-          *reinterpret_cast<const uintptr_t*>(src);
-      dest += kStepSize;
-      src += kStepSize;
+    if (chars >= kStepSize) {
+      sinkchar* limit2 = limit - kStepSize;
+      while (dest <= limit2) {
+        *reinterpret_cast<uintptr_t*>(dest) =
+            *reinterpret_cast<const uintptr_t*>(src);
+        dest += kStepSize;
+        src += kStepSize;
+      }
     }
+    while (dest < limit) {
+      *dest++ = static_cast<sinkchar>(*src++);
+    }
+    return;
   }
 #endif
+  sinkchar* limit = dest + chars;
   while (dest < limit) {
     *dest++ = static_cast<sinkchar>(*src++);
   }
 }
 
 
+#if defined(V8_HOST_ARCH_ARM) && defined (V8_HOST_CAN_READ_UNALIGNED)
+void CopyCharsUnsigned(uint16_t* dest, const uint8_t* src, int chars) {
+  if (chars >= OS::kMinComplexConvertMemCopy) {
+    OS::MemCopyUint16Uint8(dest, src, chars);
+  } else {
+    OS::MemCopyUint16Uint8Wrapper(dest, src, chars);
+  }
+}
+#endif
+
+
 class StringBuilder : public SimpleStringBuilder {
  public:
   explicit StringBuilder(int size) : SimpleStringBuilder(size) { }
   StringBuilder(char* buffer, int size) : SimpleStringBuilder(buffer, size) { }
 
   // Add formatted contents to the builder just like printf().
   void AddFormatted(const char* format, ...);
 
   // Add formatted contents like printf based on a va_list.
   void AddFormattedList(const char* format, va_list list);
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(StringBuilder);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_V8UTILS_H_