1 files changed, 54 insertions, 0 deletions
diff --git a/xpcom/string/nsReadableUtilsImpl.h b/xpcom/string/nsReadableUtilsImpl.h
new file mode 100644
index 0000000000..ff1497b514
--- /dev/null
+++ b/xpcom/string/nsReadableUtilsImpl.h
@@ -0,0 +1,54 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <stdint.h>
+
+namespace mozilla {
+
+inline bool IsASCII(char16_t aChar) {
+  return (aChar & 0xFF80) == 0;
+}
+
+/**
+ * Provides a pointer before or equal to |aPtr| that is is suitably aligned.
+ */
+inline const char16_t* aligned(const char16_t* aPtr, const uintptr_t aMask)
+{
+  return reinterpret_cast<const char16_t*>(
+      reinterpret_cast<const uintptr_t>(aPtr) & ~aMask);
+}
+
+/**
+ * Structures for word-sized vectorization of ASCII checking for UTF-16
+ * strings.
+ */
+template<size_t size> struct NonASCIIParameters;
+template<> struct NonASCIIParameters<4> {
+  static inline size_t mask() { return 0xff80ff80; }
+  static inline uintptr_t alignMask() { return 0x3; }
+  static inline size_t numUnicharsPerWord() { return 2; }
+};
+
+template<> struct NonASCIIParameters<8> {
+  static inline size_t mask() {
+    static const uint64_t maskAsUint64 = UINT64_C(0xff80ff80ff80ff80);
+    // We have to explicitly cast this 64-bit value to a size_t, or else
+    // compilers for 32-bit platforms will warn about it being too large to fit
+    // in the size_t return type. (Fortunately, this code isn't actually
+    // invoked on 32-bit platforms -- they'll use the <4> specialization above.
+    // So it is, in fact, OK that this value is too large for a 32-bit size_t.)
+    return (size_t)maskAsUint64;
+  }
+  static inline uintptr_t alignMask() { return 0x7; }
+  static inline size_t numUnicharsPerWord() { return 4; }
+};
+
+namespace SSE2 {
+
+int32_t FirstNonASCII(const char16_t* aBegin, const char16_t* aEnd);
+
+} // namespace SSE2
+} // namespace mozilla