gecko-dev/xpcom/string/nsReadableUtilsImpl.h

55 строки
1.8 KiB
C++

/* -*- 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