faiss/faiss/cppcontrib/sa_decode/PQ-avx2-inl.h

823 lines
29 KiB
C++

// (c) Meta Platforms, Inc. and affiliates. Confidential and proprietary.
#pragma once
#include <immintrin.h>
#include <cstddef>
#include <cstdint>
#include <faiss/cppcontrib/detail/UintReader.h>
namespace faiss {
namespace cppcontrib {
////////////////////////////////////////////////////////////////////////////////////
/// IndexPQDecoder
////////////////////////////////////////////////////////////////////////////////////
namespace {
// Despite the following functions are somewhat redundant, I'd like to keep the
// overall basic blocks similar to ones from Index2LevelDecoder.
// A compiler will optimize away the redundant code.
// Processes 4 float values.
// Returns {
// [0..3] = *fine[0..3];
// }
inline __m128 elementaryBlock4x1b(const float* const __restrict fine) {
// load fine
const __m128 fineValue = _mm_loadu_ps(fine);
return fineValue;
}
// Processes 4 float values.
// Returns {
// [0..3] = existingValue[0..3] + weight * (*fine[0..3]);
// }
inline __m128 elementaryBlock4x1bAccum(
const float* const __restrict fine,
const float weight,
const __m128 existingValue) {
const __m128 fineValue = elementaryBlock4x1b(fine);
// this operation is expected to be optimized by a compiler
const __m128 weightAvx = _mm_set1_ps(weight);
// do fma
return _mm_fmadd_ps(fineValue, weightAvx, existingValue);
}
// Processes 8 float values.
// Returns {
// [0..3] = *fine0[0..3];
// [4..7] = *fine1[0..3];
// }
inline __m256 elementaryBlock4x2b(
const float* const __restrict fine0,
const float* const __restrict fine1) {
// load fine
const __m128 fineValue0 = _mm_loadu_ps(fine0);
const __m128 fineValue1 = _mm_loadu_ps(fine1);
// combine two 4b into a single 8b
const __m256 combinedFineValue = _mm256_set_m128(fineValue1, fineValue0);
return combinedFineValue;
}
// Processes 8 float values.
// Returns {
// [0..3] = existingValue[0..3] + weight * (*fine0[0..3]);
// [4..7] = existingValue[4..7] + weight * (*fine1[0..3]);
// }
inline __m256 elementaryBlock4x2bAccum(
const float* const __restrict fine0,
const float* const __restrict fine1,
const float weight,
const __m256 existingValue) {
const __m256 fineValue = elementaryBlock4x2b(fine0, fine1);
// this operation is expected to be optimized by a compiler
const __m256 weightAvx2 = _mm256_set1_ps(weight);
// do fma
return _mm256_fmadd_ps(fineValue, weightAvx2, existingValue);
}
// Processes 8 float values.
// Returns {
// [0..7] = *fine[0..7];
// }
inline __m256 elementaryBlock8x1b(const float* const __restrict fine) {
// load fine
const __m256 fineValue = _mm256_loadu_ps(fine);
return fineValue;
}
// Processes 8 float values.
// Returns {
// [0..7] = existingValue[0..7] + weight * (*fine[0..7]);
// }
inline __m256 elementaryBlock8x1bAccum(
const float* const __restrict fine,
const float weight,
const __m256 existingValue) {
const __m256 fineValue = elementaryBlock8x1b(fine);
// this operation is expected to be optimized by a compiler
const __m256 weightAvx2 = _mm256_set1_ps(weight);
// do fma
return _mm256_fmadd_ps(fineValue, weightAvx2, existingValue);
}
// The following code uses template-based for-loop unrolling,
// because the compiler does not do that on its own as needed.
// The idea is the following:
// template<int I, int MAX>
// struct Foo {
// static void bar() {
// doSomething(I);
// Foo<I + 1, MAX>::bar();
// }
// };
//
// template<int MAX>
// struct Foo<MAX, MAX> {
// static void bar() {}
// };
//
// Initiate the loop:
// Foo<0, MAX>::bar();
template <
intptr_t DIM,
intptr_t FINE_SIZE,
intptr_t FINE_BITS,
intptr_t CPOS,
bool FINE_SIZE_EQ_4 = FINE_SIZE == 4,
bool QPOS_LEFT_GE_8 = (FINE_SIZE - CPOS % FINE_SIZE >= 8),
bool QPOS_LEFT_GE_4 = (FINE_SIZE - CPOS % FINE_SIZE >= 4),
bool DIM_EQ_CPOS = DIM == CPOS>
struct IndexPQDecoderImpl;
template <
intptr_t DIM,
intptr_t FINE_BITS,
intptr_t CPOS,
bool QPOS_LEFT_GE_8,
bool QPOS_LEFT_GE_4>
struct IndexPQDecoderImpl<
DIM,
4,
FINE_BITS,
CPOS,
true,
QPOS_LEFT_GE_8,
QPOS_LEFT_GE_4,
false> {
static constexpr intptr_t FINE_SIZE = 4;
static constexpr intptr_t fineCentroidIdx = CPOS / FINE_SIZE;
static constexpr intptr_t fineCentroidOffset = CPOS % FINE_SIZE;
static constexpr intptr_t QPOS_LEFT = FINE_SIZE - fineCentroidOffset;
static constexpr intptr_t FINE_TABLE_BYTES = (1 << FINE_BITS);
// process 1 sample
static void store(
const float* const __restrict pqFineCentroids0,
const uint8_t* const __restrict code0,
float* const __restrict outputStore) {
// fine quantizer
const uint8_t* const __restrict fine0 = code0;
// clang-format off
// process chunks, 4 float
// but 8 floats per loop
const intptr_t fineCode0a = detail::UintReader<DIM, FINE_SIZE, FINE_BITS, fineCentroidIdx + 0>::get(fine0);
const intptr_t fineCode0b = detail::UintReader<DIM, FINE_SIZE, FINE_BITS, fineCentroidIdx + 1>::get(fine0);
const __m256 storeValue = elementaryBlock4x2b(
pqFineCentroids0 + ((fineCentroidIdx + 0) * FINE_TABLE_BYTES + fineCode0a) * FINE_SIZE + fineCentroidOffset,
pqFineCentroids0 + ((fineCentroidIdx + 1) * FINE_TABLE_BYTES + fineCode0b) * FINE_SIZE + fineCentroidOffset);
_mm256_storeu_ps(outputStore + CPOS, storeValue);
// next
IndexPQDecoderImpl<DIM, FINE_SIZE, FINE_BITS, CPOS + 8>::store(
pqFineCentroids0, code0, outputStore);
// clang-format on
}
// process 1 sample
static void accum(
const float* const __restrict pqFineCentroids0,
const uint8_t* const __restrict code0,
const float weight0,
float* const __restrict outputAccum) {
// fine quantizer
const uint8_t* const __restrict fine0 = code0;
// clang-format off
// process chunks, 4 float
// but 8 floats per loop
const intptr_t fineCode0a = detail::UintReader<DIM, FINE_SIZE, FINE_BITS, fineCentroidIdx + 0>::get(fine0);
const intptr_t fineCode0b = detail::UintReader<DIM, FINE_SIZE, FINE_BITS, fineCentroidIdx + 1>::get(fine0);
__m256 existingValue = _mm256_loadu_ps(outputAccum + CPOS);
existingValue = elementaryBlock4x2bAccum(
pqFineCentroids0 + ((fineCentroidIdx + 0) * FINE_TABLE_BYTES + fineCode0a) * FINE_SIZE + fineCentroidOffset,
pqFineCentroids0 + ((fineCentroidIdx + 1) * FINE_TABLE_BYTES + fineCode0b) * FINE_SIZE + fineCentroidOffset,
weight0,
existingValue);
_mm256_storeu_ps(outputAccum + CPOS, existingValue);
// next
IndexPQDecoderImpl<DIM, FINE_SIZE, FINE_BITS, CPOS + 8>::accum(
pqFineCentroids0, code0, weight0, outputAccum);
// clang-format on
}
// process 2 samples
static void accum(
const float* const __restrict pqFineCentroids0,
const uint8_t* const __restrict code0,
const float weight0,
const float* const __restrict pqFineCentroids1,
const uint8_t* const __restrict code1,
const float weight1,
float* const __restrict outputAccum) {
// fine quantizer
const uint8_t* const __restrict fine0 = code0;
const uint8_t* const __restrict fine1 = code1;
// clang-format off
// process chunks, 4 float
// but 8 floats per loop
const intptr_t fineCode0a = detail::UintReader<DIM, FINE_SIZE, FINE_BITS, fineCentroidIdx + 0>::get(fine0);
const intptr_t fineCode0b = detail::UintReader<DIM, FINE_SIZE, FINE_BITS, fineCentroidIdx + 1>::get(fine0);
const intptr_t fineCode1a = detail::UintReader<DIM, FINE_SIZE, FINE_BITS, fineCentroidIdx + 0>::get(fine1);
const intptr_t fineCode1b = detail::UintReader<DIM, FINE_SIZE, FINE_BITS, fineCentroidIdx + 1>::get(fine1);
__m256 existingValue = _mm256_loadu_ps(outputAccum + CPOS);
existingValue = elementaryBlock4x2bAccum(
pqFineCentroids0 + ((fineCentroidIdx + 0) * FINE_TABLE_BYTES + fineCode0a) * FINE_SIZE + fineCentroidOffset,
pqFineCentroids0 + ((fineCentroidIdx + 1) * FINE_TABLE_BYTES + fineCode0b) * FINE_SIZE + fineCentroidOffset,
weight0,
existingValue);
existingValue = elementaryBlock4x2bAccum(
pqFineCentroids1 + ((fineCentroidIdx + 0) * FINE_TABLE_BYTES + fineCode1a) * FINE_SIZE + fineCentroidOffset,
pqFineCentroids1 + ((fineCentroidIdx + 1) * FINE_TABLE_BYTES + fineCode1b) * FINE_SIZE + fineCentroidOffset,
weight1,
existingValue);
_mm256_storeu_ps(outputAccum + CPOS, existingValue);
// next
IndexPQDecoderImpl<DIM, FINE_SIZE, FINE_BITS, CPOS + 8>::accum(
pqFineCentroids0, code0, weight0,
pqFineCentroids1, code1, weight1,
outputAccum);
// clang-format on
}
// process 3 samples
static void accum(
const float* const __restrict pqFineCentroids0,
const uint8_t* const __restrict code0,
const float weight0,
const float* const __restrict pqFineCentroids1,
const uint8_t* const __restrict code1,
const float weight1,
const float* const __restrict pqFineCentroids2,
const uint8_t* const __restrict code2,
const float weight2,
float* const __restrict outputAccum) {
// fine quantizer
const uint8_t* const __restrict fine0 = code0;
const uint8_t* const __restrict fine1 = code1;
const uint8_t* const __restrict fine2 = code2;
// clang-format off
// process chunks, 4 float
// but 8 floats per loop
const intptr_t fineCode0a = detail::UintReader<DIM, FINE_SIZE, FINE_BITS, fineCentroidIdx + 0>::get(fine0);
const intptr_t fineCode0b = detail::UintReader<DIM, FINE_SIZE, FINE_BITS, fineCentroidIdx + 1>::get(fine0);
const intptr_t fineCode1a = detail::UintReader<DIM, FINE_SIZE, FINE_BITS, fineCentroidIdx + 0>::get(fine1);
const intptr_t fineCode1b = detail::UintReader<DIM, FINE_SIZE, FINE_BITS, fineCentroidIdx + 1>::get(fine1);
const intptr_t fineCode2a = detail::UintReader<DIM, FINE_SIZE, FINE_BITS, fineCentroidIdx + 0>::get(fine2);
const intptr_t fineCode2b = detail::UintReader<DIM, FINE_SIZE, FINE_BITS, fineCentroidIdx + 1>::get(fine2);
__m256 existingValue = _mm256_loadu_ps(outputAccum + CPOS);
existingValue = elementaryBlock4x2bAccum(
pqFineCentroids0 + ((fineCentroidIdx + 0) * FINE_TABLE_BYTES + fineCode0a) * FINE_SIZE + fineCentroidOffset,
pqFineCentroids0 + ((fineCentroidIdx + 1) * FINE_TABLE_BYTES + fineCode0b) * FINE_SIZE + fineCentroidOffset,
weight0,
existingValue);
existingValue = elementaryBlock4x2bAccum(
pqFineCentroids1 + ((fineCentroidIdx + 0) * FINE_TABLE_BYTES + fineCode1a) * FINE_SIZE + fineCentroidOffset,
pqFineCentroids1 + ((fineCentroidIdx + 1) * FINE_TABLE_BYTES + fineCode1b) * FINE_SIZE + fineCentroidOffset,
weight1,
existingValue);
existingValue = elementaryBlock4x2bAccum(
pqFineCentroids2 + ((fineCentroidIdx + 0) * FINE_TABLE_BYTES + fineCode2a) * FINE_SIZE + fineCentroidOffset,
pqFineCentroids2 + ((fineCentroidIdx + 1) * FINE_TABLE_BYTES + fineCode2b) * FINE_SIZE + fineCentroidOffset,
weight2,
existingValue);
_mm256_storeu_ps(outputAccum + CPOS, existingValue);
// next
IndexPQDecoderImpl<DIM, FINE_SIZE, FINE_BITS, CPOS + 8>::accum(
pqFineCentroids0, code0, weight0,
pqFineCentroids1, code1, weight1,
pqFineCentroids2, code2, weight2,
outputAccum);
// clang-format on
}
};
template <intptr_t DIM, intptr_t FINE_SIZE, intptr_t FINE_BITS, intptr_t CPOS>
struct IndexPQDecoderImpl<
DIM,
FINE_SIZE,
FINE_BITS,
CPOS,
false,
true,
true,
false> {
static constexpr intptr_t fineCentroidIdx = CPOS / FINE_SIZE;
static constexpr intptr_t fineCentroidOffset = CPOS % FINE_SIZE;
static constexpr intptr_t QPOS_LEFT = FINE_SIZE - fineCentroidOffset;
static constexpr intptr_t FINE_TABLE_BYTES = (1 << FINE_BITS);
// process 1 sample
static void store(
const float* const __restrict pqFineCentroids0,
const uint8_t* const __restrict code0,
float* const __restrict outputStore) {
// fine quantizer
const uint8_t* const __restrict fine0 = code0;
// clang-format off
// process chunks, 8 float
const intptr_t fineCode0 = detail::UintReader<DIM, FINE_SIZE, FINE_BITS, fineCentroidIdx>::get(fine0);
const __m256 storeValue = elementaryBlock8x1b(
pqFineCentroids0 + (fineCentroidIdx * FINE_TABLE_BYTES + fineCode0) * FINE_SIZE + fineCentroidOffset);
_mm256_storeu_ps(outputStore + CPOS, storeValue);
// next
IndexPQDecoderImpl<DIM, FINE_SIZE, FINE_BITS, CPOS + 8>::store(
pqFineCentroids0, code0, outputStore);
// clang-format on
}
// process 1 sample
static void accum(
const float* const __restrict pqFineCentroids0,
const uint8_t* const __restrict code0,
const float weight0,
float* const __restrict outputAccum) {
// fine quantizer
const uint8_t* const __restrict fine0 = code0;
// clang-format off
// process chunks, 8 float
const intptr_t fineCode0 = detail::UintReader<DIM, FINE_SIZE, FINE_BITS, fineCentroidIdx>::get(fine0);
__m256 existingValue = _mm256_loadu_ps(outputAccum + CPOS);
existingValue = elementaryBlock8x1bAccum(
pqFineCentroids0 + (fineCentroidIdx * FINE_TABLE_BYTES + fineCode0) * FINE_SIZE + fineCentroidOffset,
weight0,
existingValue);
_mm256_storeu_ps(outputAccum + CPOS, existingValue);
// next
IndexPQDecoderImpl<DIM, FINE_SIZE, FINE_BITS, CPOS + 8>::accum(
pqFineCentroids0, code0, weight0, outputAccum);
// clang-format on
}
// process 2 samples
static void accum(
const float* const __restrict pqFineCentroids0,
const uint8_t* const __restrict code0,
const float weight0,
const float* const __restrict pqFineCentroids1,
const uint8_t* const __restrict code1,
const float weight1,
float* const __restrict outputAccum) {
// fine quantizer
const uint8_t* const __restrict fine0 = code0;
const uint8_t* const __restrict fine1 = code1;
// clang-format off
// process chunks, 8 float
const intptr_t fineCode0 = detail::UintReader<DIM, FINE_SIZE, FINE_BITS, fineCentroidIdx>::get(fine0);
const intptr_t fineCode1 = detail::UintReader<DIM, FINE_SIZE, FINE_BITS, fineCentroidIdx>::get(fine1);
__m256 existingValue = _mm256_loadu_ps(outputAccum + CPOS);
existingValue = elementaryBlock8x1bAccum(
pqFineCentroids0 + (fineCentroidIdx * FINE_TABLE_BYTES + fineCode0) * FINE_SIZE + fineCentroidOffset,
weight0,
existingValue);
existingValue = elementaryBlock8x1bAccum(
pqFineCentroids1 + (fineCentroidIdx * FINE_TABLE_BYTES + fineCode1) * FINE_SIZE + fineCentroidOffset,
weight1,
existingValue);
_mm256_storeu_ps(outputAccum + CPOS, existingValue);
// next
IndexPQDecoderImpl<DIM, FINE_SIZE, FINE_BITS, CPOS + 8>::accum(
pqFineCentroids0, code0, weight0,
pqFineCentroids1, code1, weight1,
outputAccum);
// clang-format on
}
// process 3 samples
static void accum(
const float* const __restrict pqFineCentroids0,
const uint8_t* const __restrict code0,
const float weight0,
const float* const __restrict pqFineCentroids1,
const uint8_t* const __restrict code1,
const float weight1,
const float* const __restrict pqFineCentroids2,
const uint8_t* const __restrict code2,
const float weight2,
float* const __restrict outputAccum) {
// fine quantizer
const uint8_t* const __restrict fine0 = code0;
const uint8_t* const __restrict fine1 = code1;
const uint8_t* const __restrict fine2 = code2;
// clang-format off
// process chunks, 8 float
const intptr_t fineCode0 = detail::UintReader<DIM, FINE_SIZE, FINE_BITS, fineCentroidIdx>::get(fine0);
const intptr_t fineCode1 = detail::UintReader<DIM, FINE_SIZE, FINE_BITS, fineCentroidIdx>::get(fine1);
const intptr_t fineCode2 = detail::UintReader<DIM, FINE_SIZE, FINE_BITS, fineCentroidIdx>::get(fine2);
__m256 existingValue = _mm256_loadu_ps(outputAccum + CPOS);
existingValue = elementaryBlock8x1bAccum(
pqFineCentroids0 + (fineCentroidIdx * FINE_TABLE_BYTES + fineCode0) * FINE_SIZE + fineCentroidOffset,
weight0,
existingValue);
existingValue = elementaryBlock8x1bAccum(
pqFineCentroids1 + (fineCentroidIdx * FINE_TABLE_BYTES + fineCode1) * FINE_SIZE + fineCentroidOffset,
weight1,
existingValue);
existingValue = elementaryBlock8x1bAccum(
pqFineCentroids2 + (fineCentroidIdx * FINE_TABLE_BYTES + fineCode2) * FINE_SIZE + fineCentroidOffset,
weight2,
existingValue);
_mm256_storeu_ps(outputAccum + CPOS, existingValue);
// next
IndexPQDecoderImpl<DIM, FINE_SIZE, FINE_BITS, CPOS + 8>::accum(
pqFineCentroids0, code0, weight0,
pqFineCentroids1, code1, weight1,
pqFineCentroids2, code2, weight2,
outputAccum);
// clang-format on
}
};
template <intptr_t DIM, intptr_t FINE_SIZE, intptr_t FINE_BITS, intptr_t CPOS>
struct IndexPQDecoderImpl<
DIM,
FINE_SIZE,
FINE_BITS,
CPOS,
false,
false,
true,
false> {
static constexpr intptr_t fineCentroidIdx = CPOS / FINE_SIZE;
static constexpr intptr_t fineCentroidOffset = CPOS % FINE_SIZE;
static constexpr intptr_t QPOS_LEFT = FINE_SIZE - fineCentroidOffset;
static constexpr intptr_t FINE_TABLE_BYTES = (1 << FINE_BITS);
// process 1 sample
static void store(
const float* const __restrict pqFineCentroids0,
const uint8_t* const __restrict code0,
float* const __restrict outputStore) {
// fine quantizer
const uint8_t* const __restrict fine0 = code0;
// clang-format off
// process chunks, 4 float
const intptr_t fineCode0 = detail::UintReader<DIM, FINE_SIZE, FINE_BITS, fineCentroidIdx>::get(fine0);
const __m128 storeValue = elementaryBlock4x1b(
pqFineCentroids0 + (fineCentroidIdx * FINE_TABLE_BYTES + fineCode0) * FINE_SIZE + fineCentroidOffset);
_mm_storeu_ps(outputStore + CPOS, storeValue);
// next
IndexPQDecoderImpl<DIM, FINE_SIZE, FINE_BITS, CPOS + 4>::store(
pqFineCentroids0, code0, outputStore);
// clang-format on
}
// process 1 sample
static void accum(
const float* const __restrict pqFineCentroids0,
const uint8_t* const __restrict code0,
const float weight0,
float* const __restrict outputAccum) {
// fine quantizer
const uint8_t* const __restrict fine0 = code0;
// clang-format off
// process chunks, 4 float
const intptr_t fineCode0 = detail::UintReader<DIM, FINE_SIZE, FINE_BITS, fineCentroidIdx>::get(fine0);
__m128 existingValue = _mm_loadu_ps(outputAccum + CPOS);
existingValue = elementaryBlock4x1bAccum(
pqFineCentroids0 + (fineCentroidIdx * FINE_TABLE_BYTES + fineCode0) * FINE_SIZE + fineCentroidOffset,
weight0,
existingValue);
_mm_storeu_ps(outputAccum + CPOS, existingValue);
// next
IndexPQDecoderImpl<DIM, FINE_SIZE, FINE_BITS, CPOS + 4>::accum(
pqFineCentroids0, code0, weight0, outputAccum);
// clang-format on
}
// process 2 samples
static void accum(
const float* const __restrict pqFineCentroids0,
const uint8_t* const __restrict code0,
const float weight0,
const float* const __restrict pqFineCentroids1,
const uint8_t* const __restrict code1,
const float weight1,
float* const __restrict outputAccum) {
// fine quantizer
const uint8_t* const __restrict fine0 = code0;
const uint8_t* const __restrict fine1 = code1;
// clang-format off
// process chunks, 4 float
const intptr_t fineCode0 = detail::UintReader<DIM, FINE_SIZE, FINE_BITS, fineCentroidIdx>::get(fine0);
const intptr_t fineCode1 = detail::UintReader<DIM, FINE_SIZE, FINE_BITS, fineCentroidIdx>::get(fine1);
__m128 existingValue = _mm_loadu_ps(outputAccum + CPOS);
existingValue = elementaryBlock4x1bAccum(
pqFineCentroids0 + (fineCentroidIdx * FINE_TABLE_BYTES + fineCode0) * FINE_SIZE + fineCentroidOffset,
weight0,
existingValue);
existingValue = elementaryBlock4x1bAccum(
pqFineCentroids1 + (fineCentroidIdx * FINE_TABLE_BYTES + fineCode1) * FINE_SIZE + fineCentroidOffset,
weight1,
existingValue);
_mm_storeu_ps(outputAccum + CPOS, existingValue);
// next
IndexPQDecoderImpl<DIM, FINE_SIZE, FINE_BITS, CPOS + 4>::accum(
pqFineCentroids0, code0, weight0,
pqFineCentroids1, code1, weight1,
outputAccum);
// clang-format on
}
// process 3 samples
static void accum(
const float* const __restrict pqFineCentroids0,
const uint8_t* const __restrict code0,
const float weight0,
const float* const __restrict pqFineCentroids1,
const uint8_t* const __restrict code1,
const float weight1,
const float* const __restrict pqFineCentroids2,
const uint8_t* const __restrict code2,
const float weight2,
float* const __restrict outputAccum) {
// fine quantizer
const uint8_t* const __restrict fine0 = code0;
const uint8_t* const __restrict fine1 = code1;
const uint8_t* const __restrict fine2 = code2;
// clang-format off
// process chunks, 4 float
const intptr_t fineCode0 = detail::UintReader<DIM, FINE_SIZE, FINE_BITS, fineCentroidIdx>::get(fine0);
const intptr_t fineCode1 = detail::UintReader<DIM, FINE_SIZE, FINE_BITS, fineCentroidIdx>::get(fine1);
const intptr_t fineCode2 = detail::UintReader<DIM, FINE_SIZE, FINE_BITS, fineCentroidIdx>::get(fine2);
__m128 existingValue = _mm_loadu_ps(outputAccum + CPOS);
existingValue = elementaryBlock4x1bAccum(
pqFineCentroids0 + (fineCentroidIdx * FINE_TABLE_BYTES + fineCode0) * FINE_SIZE + fineCentroidOffset,
weight0,
existingValue);
existingValue = elementaryBlock4x1bAccum(
pqFineCentroids1 + (fineCentroidIdx * FINE_TABLE_BYTES + fineCode1) * FINE_SIZE + fineCentroidOffset,
weight1,
existingValue);
existingValue = elementaryBlock4x1bAccum(
pqFineCentroids2 + (fineCentroidIdx * FINE_TABLE_BYTES + fineCode2) * FINE_SIZE + fineCentroidOffset,
weight2,
existingValue);
_mm_storeu_ps(outputAccum + CPOS, existingValue);
// next
IndexPQDecoderImpl<DIM, FINE_SIZE, FINE_BITS, CPOS + 4>::accum(
pqFineCentroids0, code0, weight0,
pqFineCentroids1, code1, weight1,
pqFineCentroids2, code2, weight2,
outputAccum);
// clang-format on
}
};
// This partial specialization is expected to do nothing.
template <
intptr_t DIM,
intptr_t FINE_SIZE,
intptr_t FINE_BITS,
bool FINE_SIZE_EQ_4,
bool QPOS_LEFT_GE_8,
bool QPOS_LEFT_GE_4>
struct IndexPQDecoderImpl<
DIM,
FINE_SIZE,
FINE_BITS,
DIM,
FINE_SIZE_EQ_4,
QPOS_LEFT_GE_8,
QPOS_LEFT_GE_4,
true> {
// clang-format off
// process 1 sample
static void store(
const float* const __restrict pqFineCentroids0,
const uint8_t* const __restrict code0,
float* const __restrict outputStore) {}
// process 1 sample
static void accum(
const float* const __restrict pqFineCentroids0,
const uint8_t* const __restrict code0,
const float weight0,
float* const __restrict outputAccum) {}
// process 2 samples
static void accum(
const float* const __restrict pqFineCentroids0,
const uint8_t* const __restrict code0,
const float weight0,
const float* const __restrict pqFineCentroids1,
const uint8_t* const __restrict code1,
const float weight1,
float* const __restrict outputAccum) {}
// process 3 samples
static void accum(
const float* const __restrict pqFineCentroids0,
const uint8_t* const __restrict code0,
const float weight0,
const float* const __restrict pqFineCentroids1,
const uint8_t* const __restrict code1,
const float weight1,
const float* const __restrict pqFineCentroids2,
const uint8_t* const __restrict code2,
const float weight2,
float* const __restrict outputAccum) {}
// clang-format on
};
} // namespace
// Suitable for PQ[1]x8
// Suitable for PQ[1]x10
// Suitable for PQ[1]x16
template <intptr_t DIM, intptr_t FINE_SIZE, intptr_t FINE_BITS = 8>
struct IndexPQDecoder {
static_assert(
FINE_BITS == 8 || FINE_BITS == 10 || FINE_BITS == 16,
"Only 8, 10 or 16 bits are currently supported for FINE_BITS");
// Process 1 sample.
static void store(
const float* const __restrict pqFineCentroids,
const uint8_t* const __restrict code,
float* const __restrict outputStore) {
IndexPQDecoderImpl<DIM, FINE_SIZE, FINE_BITS, 0>::store(
pqFineCentroids, code, outputStore);
}
// Process 1 sample.
// Performs outputAccum += weight * decoded(code)
static void accum(
const float* const __restrict pqFineCentroids,
const uint8_t* const __restrict code,
const float weight,
float* const __restrict outputAccum) {
IndexPQDecoderImpl<DIM, FINE_SIZE, FINE_BITS, 0>::accum(
pqFineCentroids, code, weight, outputAccum);
}
// process 2 samples
// Performs outputAccum += weight0 * decoded(code0) + weight1 *
// decoded(code1)
static void accum(
const float* const __restrict pqFineCentroids0,
const uint8_t* const __restrict code0,
const float weight0,
const float* const __restrict pqFineCentroids1,
const uint8_t* const __restrict code1,
const float weight1,
float* const __restrict outputAccum) {
IndexPQDecoderImpl<DIM, FINE_SIZE, FINE_BITS, 0>::accum(
pqFineCentroids0,
code0,
weight0,
pqFineCentroids1,
code1,
weight1,
outputAccum);
}
// process 3 samples
// Performs outputAccum += weight0 * decoded(code0) + weight1 *
// decoded(code1) + weight2 * decoded(code2)
static void accum(
const float* const __restrict pqFineCentroids0,
const uint8_t* const __restrict code0,
const float weight0,
const float* const __restrict pqFineCentroids1,
const uint8_t* const __restrict code1,
const float weight1,
const float* const __restrict pqFineCentroids2,
const uint8_t* const __restrict code2,
const float weight2,
float* const __restrict outputAccum) {
IndexPQDecoderImpl<DIM, FINE_SIZE, FINE_BITS, 0>::accum(
pqFineCentroids0,
code0,
weight0,
pqFineCentroids1,
code1,
weight1,
pqFineCentroids2,
code2,
weight2,
outputAccum);
}
};
} // namespace cppcontrib
} // namespace faiss