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/* -*- 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/. */
// This file should only be compiled if you're on x86 or x86_64. Additionally,
// you'll need to compile this file with -msse2 if you're using gcc.
#include <emmintrin.h>
#include "nscore.h"
#include "nsAlgorithm.h"
#include "nsTextFragmentImpl.h"
#include <algorithm>
namespace mozilla::SSE2 {
static inline bool is_zero(__m128i x) {
return _mm_movemask_epi8(_mm_cmpeq_epi8(x, _mm_setzero_si128())) == 0xffff;
}
int32_t FirstNon8Bit(const char16_t* str, const char16_t* end) {
const uint32_t numUnicharsPerVector = 8;
typedef Non8BitParameters<sizeof(size_t)> p;
const size_t mask = p::mask();
const uint32_t numUnicharsPerWord = p::numUnicharsPerWord();
const int32_t len = end - str;
int32_t i = 0;
// Align ourselves to a 16-byte boundary, as required by _mm_load_si128
// (i.e. MOVDQA).
int32_t alignLen = std::min(
len, int32_t(((-NS_PTR_TO_INT32(str)) & 0xf) / sizeof(char16_t)));
for (; i < alignLen; i++) {
if (str[i] > 255) return i;
}
// Check one XMM register (16 bytes) at a time.
const int32_t vectWalkEnd =
((len - i) / numUnicharsPerVector) * numUnicharsPerVector;
const uint16_t shortMask = 0xff00;
__m128i vectmask = _mm_set1_epi16(static_cast<int16_t>(shortMask));
for (; i < vectWalkEnd; i += numUnicharsPerVector) {
const __m128i vect = *reinterpret_cast<const __m128i*>(str + i);
if (!is_zero(_mm_and_si128(vect, vectmask))) return i;
}
// Check one word at a time.
const int32_t wordWalkEnd =
((len - i) / numUnicharsPerWord) * numUnicharsPerWord;
for (; i < wordWalkEnd; i += numUnicharsPerWord) {
const size_t word = *reinterpret_cast<const size_t*>(str + i);
if (word & mask) return i;
}
// Take care of the remainder one character at a time.
for (; i < len; i++) {
if (str[i] > 255) {
return i;
}
}
return -1;
}
} // namespace mozilla::SSE2
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