Use SSE intrinsics for uint32_t byte swapping
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@ -44,10 +44,12 @@ void copy_and_swap_16_aligned(uint16_t* dest, const uint16_t* src,
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void copy_and_swap_16_unaligned(uint16_t* dest, const uint16_t* src,
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size_t count) {
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size_t i;
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__m128i input, output;
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for (i = 0; i + 8 <= count; i += 8) {
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__m128i s = _mm_loadu_si128((__m128i*)&src[i]);
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__m128i d = _mm_or_si128(_mm_slli_epi16(s, 8), _mm_srli_epi16(s, 8));
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_mm_storeu_si128((__m128i*)&dest[i], d);
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input = _mm_loadu_si128((__m128i*)&src[i]);
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output = _mm_or_si128(_mm_slli_epi16(input, 8), _mm_srli_epi16(input, 8));
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_mm_storeu_si128((__m128i*)&dest[i], output);
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}
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for (; i < count; ++i) { // handle residual elements
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@ -62,7 +64,31 @@ void copy_and_swap_32_aligned(uint32_t* dest, const uint32_t* src,
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void copy_and_swap_32_unaligned(uint32_t* dest, const uint32_t* src,
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size_t count) {
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for (size_t i = 0; i < count; ++i) {
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size_t i;
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__m128i input, byte1, byte2, byte3, byte4, output;
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__m128i byte2mask = _mm_set1_epi32(0x00FF0000);
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__m128i byte3mask = _mm_set1_epi32(0x0000FF00);
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for (i = 0; i + 4 <= count; i += 4) {
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input = _mm_loadu_si128((__m128i*)&src[i]);
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// Do the four shifts
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byte1 = _mm_slli_epi32(input, 24);
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byte2 = _mm_slli_epi32(input, 8);
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byte3 = _mm_srli_epi32(input, 8);
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byte4 = _mm_srli_epi32(input, 24);
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// Or bytes together
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output = _mm_or_si128(byte1, byte4);
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byte2 = _mm_and_si128(byte2, byte2mask);
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output = _mm_or_si128(output, byte2);
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byte3 = _mm_and_si128(byte3, byte3mask);
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output = _mm_or_si128(output, byte3);
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_mm_storeu_si128((__m128i*)&dest[i], output);
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}
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for (; i < count; ++i) { // handle residual elements
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dest[i] = byte_swap(src[i]);
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}
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}
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