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added SIMD horizontal rotation helper

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Ahmet Inan 2019-09-24 00:05:57 +02:00
commit 8de487af88
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README.md
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@ -87,3 +87,7 @@ Single instruction, multiple data ([SIMD](https://en.wikipedia.org/wiki/SIMD)) w
* [Intel SSE4.1](https://en.wikipedia.org/wiki/SSE4) ([sse4_1.hh](sse4_1.hh))
* [Intel AVX2](https://en.wikipedia.org/wiki/Advanced_Vector_Extensions) ([avx2.hh](avx2.hh))
### [rotate.hh](rotate.hh)
([SIMD](https://en.wikipedia.org/wiki/SIMD)) element wise horizontal rotation

108
rotate.hh Normal file
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@ -0,0 +1,108 @@
/*
SIMD element wise horizontal rotation
Copyright 2019 Ahmet Inan <inan@aicodix.de>
*/
#pragma once
#include "simd.hh"
namespace CODE {
template <typename TYPE, int WIDTH>
class Rotate
{
static const int SIZE = TYPE::SIZE;
static_assert(WIDTH <= SIZE, "width must be smaller or equal to SIMD size");
public:
TYPE operator()(TYPE a, int s)
{
if (s < 0)
s += WIDTH;
int t = WIDTH - s;
TYPE ret;
for (int n = 0; n < s; ++n)
ret.v[n] = a.v[n+t];
for (int n = 0; n < t; ++n)
ret.v[n+s] = a.v[n];
return ret;
}
};
#ifdef __SSE4_1__
template <int WIDTH>
class Rotate<SIMD<int8_t, 16>, WIDTH>
{
static const int SIZE = 16;
static_assert(WIDTH <= SIZE, "width must be smaller or equal to SIMD size");
typedef SIMD<int8_t, SIZE> TYPE;
TYPE rot[WIDTH];
public:
Rotate()
{
for (int i = 0; i < WIDTH; ++i) {
rot[i] = vdup<TYPE>(0x80);
for (int j = 0; j < WIDTH; ++j)
rot[i].v[j] = (j - i + WIDTH) % WIDTH;
}
}
TYPE operator()(TYPE a, int s)
{
if (s < 0)
s += WIDTH;
TYPE ret;
ret.m = _mm_shuffle_epi8(a.m, rot[s].m);
return ret;
}
};
#endif
#ifdef __AVX2__
template <int WIDTH>
class Rotate<SIMD<int8_t, 32>, WIDTH>
{
static const int SIZE = 32;
static_assert(WIDTH <= SIZE, "width must be smaller or equal to SIMD size");
typedef SIMD<int8_t, SIZE> TYPE;
TYPE rot0[WIDTH], rot1[WIDTH];
public:
Rotate()
{
for (int i = 0; i < WIDTH; ++i) {
rot0[i] = vdup<TYPE>(0x80);
rot1[i] = vdup<TYPE>(0x80);
for (int j = 0; j < WIDTH; ++j) {
int pos = (j - i + WIDTH) % WIDTH;
if (j < 16) {
if (pos < 16) {
rot0[i].v[j] = pos;
} else {
rot1[i].v[j+16] = pos-16;
}
} else {
if (pos < 16) {
rot1[i].v[j-16] = pos;
} else {
rot0[i].v[j] = pos-16;
}
}
}
}
}
TYPE operator()(TYPE a, int s)
{
if (s < 0)
s += WIDTH;
__m256i b = _mm256_shuffle_epi8(a.m, rot0[s].m);
__m256i c = _mm256_shuffle_epi8(a.m, rot1[s].m);
__m256i d = _mm256_permute2x128_si256(c, c, 1);
TYPE ret;
ret.m = _mm256_or_si256(b, d);
return ret;
}
};
#endif
}