Add Fused-Attention Layer for AVX2 Platforms (#137)

* add prefer_fp32

* add avx2 mha

* TARGET_512

* follow clang-tidy

* fix ut on linux

* move intrin utils to btla

* move btla templates to mha_dense_wrapper.h

* add f16c target for avx2 intrin

* move tests to mha_dense_tests.cpp

* fix format

bestla/bestla/kernel_avx2.h

@@ -24,7 +24,7 @@ namespace avx2 {
 #if CompileAVX2()
 #ifdef __GNUC__
 #pragma GCC push_options
-#pragma GCC target("avx2", "fma")
+#pragma GCC target("avx2", "fma", "f16c")
 #else
 #endif
 
@@ -1118,6 +1118,95 @@ static inline BTLA_CODE layernorm(const float* srcptr, const float* scaleptr, co
   return BTLA_CODE::Success;
 }
 
+inline __m256 poly_scale_2nd_ps(const __m256i z, const __m256 f, const __m256 c0, const __m256 c1, const __m256 c2) {
+  const auto y = _mm256_fmadd_ps(_mm256_fmadd_ps(f, c0, c1), f, c2);  // auto y = (f * c0 + c1) * f + c2;
+  static const auto mask_exp = _mm256_set1_epi32(0x7f800000);
+  static const auto mask_not_exp = _mm256_set1_epi32(~0x7f800000);
+
+  const auto y_exp = _mm256_and_si256(_mm256_castps_si256(y), mask_exp);
+  const auto y_not_exp = _mm256_and_si256(_mm256_castps_si256(y), mask_not_exp);
+
+  const auto y_exp_scaled = _mm256_add_epi32(y_exp, _mm256_slli_epi32(z, 23));
+  return _mm256_castsi256_ps(_mm256_or_si256(y_not_exp, _mm256_and_si256(y_exp_scaled, mask_exp)));
+}
+
+inline __m256 exp_ps_0_1(const __m256 x) {
+  static const auto c0 = _mm256_set1_ps(0.240226507f);
+  static const auto c1 = _mm256_set1_ps(0.452920674f);
+  static const auto c2 = _mm256_set1_ps(0.713483036f);
+  static const float v_log2e = std::log2(std::exp(1.f));
+  static const auto log2e = _mm256_set1_ps(v_log2e);
+  static const auto half = _mm256_set1_ps(.5f);
+
+  const auto x1 = _mm256_fmadd_ps(x, log2e, half);  // auto x1 = x * log2e + _mm256_set1_ps(.5f);
+  const auto z = _mm256_floor_ps(x1);
+  const auto f = _mm256_sub_ps(x1, z);  // auto f = x1 - z;
+
+  return poly_scale_2nd_ps(_mm256_cvtps_epi32(z), f, c0, c1, c2);
+}
+
+#ifdef __GNUC__
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wignored-attributes"  // https://stackoverflow.com/a/49216021
+#endif
+// Interleave 8 xmm vectors of words inplace
+static inline std::array<__m128i, 8> tr_x8_word(std::array<__m128i, 8>& src) {  // NOLINT [runtime/references]
+  std::array<__m128i, 8> dst;
+
+  for (int i = 0; i < 8; i += 2) {
+    dst[i + 0] = _mm_unpacklo_epi16(src[i + 0], src[i + 1]);
+    dst[i + 1] = _mm_unpackhi_epi16(src[i + 0], src[i + 1]);
+  }
+  for (int i = 0; i < 8; i += 4) {
+    src[i + 0] = _mm_unpacklo_epi32(dst[i + 0], dst[i + 2]);
+    src[i + 1] = _mm_unpackhi_epi32(dst[i + 0], dst[i + 2]);
+    src[i + 2] = _mm_unpacklo_epi32(dst[i + 1], dst[i + 3]);
+    src[i + 3] = _mm_unpackhi_epi32(dst[i + 1], dst[i + 3]);
+  }
+  dst[0] = _mm_unpacklo_epi64(src[0], src[4]);
+  dst[1] = _mm_unpackhi_epi64(src[0], src[4]);
+  dst[2] = _mm_unpacklo_epi64(src[1], src[5]);
+  dst[3] = _mm_unpackhi_epi64(src[1], src[5]);
+  dst[4] = _mm_unpacklo_epi64(src[2], src[6]);
+  dst[5] = _mm_unpackhi_epi64(src[2], src[6]);
+  dst[6] = _mm_unpacklo_epi64(src[3], src[7]);
+  dst[7] = _mm_unpackhi_epi64(src[3], src[7]);
+  return dst;
+}
+
+template <int tail>
+inline std::array<__m128i, 8> load_fp32_fp16_tr_x8_word(const float* a, size_t lda) {
+  static_assert(tail > 0 && tail <= 8, "Unexpected tail value.");
+  std::array<__m128i, 8> dst;
+  for (int i = 0; i < tail; ++i) {
+    dst[i] = _mm256_cvtps_ph(_mm256_loadu_ps(a + i * lda), _MM_FROUND_TO_NEAREST_INT);
+  }
+  for (int i = tail; i < 8; ++i) dst[i] = _mm_setzero_si128();
+  return tr_x8_word(dst);
+}
+constexpr decltype(load_fp32_fp16_tr_x8_word<1>)* load_fp32_fp16_tr_x8_word_tbl[9]{
+    load_fp32_fp16_tr_x8_word<1>, load_fp32_fp16_tr_x8_word<1>, load_fp32_fp16_tr_x8_word<2>,
+    load_fp32_fp16_tr_x8_word<3>, load_fp32_fp16_tr_x8_word<4>, load_fp32_fp16_tr_x8_word<5>,
+    load_fp32_fp16_tr_x8_word<6>, load_fp32_fp16_tr_x8_word<7>, load_fp32_fp16_tr_x8_word<8>};
+
+template <int tail>
+inline std::array<__m128i, 8> load_maskz_fp32_fp16_tr_x8_word(const float* a, size_t lda, __m256i mask) {
+  static_assert(tail > 0 && tail <= 8, "Unexpected tail value.");
+  std::array<__m128i, 8> dst;
+  for (int i = 0; i < tail; ++i) {
+    dst[i] = _mm256_cvtps_ph(_mm256_maskload_ps(a + i * lda, mask), _MM_FROUND_TO_NEAREST_INT);
+  }
+  for (int i = tail; i < 8; ++i) dst[i] = _mm_setzero_si128();
+  return tr_x8_word(dst);
+}
+constexpr decltype(load_maskz_fp32_fp16_tr_x8_word<1>)* load_maskz_fp32_fp16_tr_x8_word_tbl[9]{
+    load_maskz_fp32_fp16_tr_x8_word<1>, load_maskz_fp32_fp16_tr_x8_word<1>, load_maskz_fp32_fp16_tr_x8_word<2>,
+    load_maskz_fp32_fp16_tr_x8_word<3>, load_maskz_fp32_fp16_tr_x8_word<4>, load_maskz_fp32_fp16_tr_x8_word<5>,
+    load_maskz_fp32_fp16_tr_x8_word<6>, load_maskz_fp32_fp16_tr_x8_word<7>, load_maskz_fp32_fp16_tr_x8_word<8>};
+#ifdef __GNUC__
+#pragma GCC diagnostic pop
+#endif
+
 #ifdef __GNUC__
 #pragma GCC pop_options
 #else

bestla/bestla/kernel_avx512f.h

@@ -2383,6 +2383,28 @@ static inline BTLA_CODE layernorm(const float* srcptr, const float* scaleptr, co
   }
   return BTLA_CODE::Success;
 }
+
+inline __m512 poly_scale_2nd_ps(const __m512 z, const __m512 f, const __m512 c0, const __m512 c1, const __m512 c2) {
+  const auto y = _mm512_fmadd_ps(_mm512_fmadd_ps(f, c0, c1), f, c2);  // auto y = (f * c0 + c1) * f + c2;
+  const auto exp = _mm512_scalef_ps(y, z);
+  return exp;
+}
+
+inline __m512 exp_ps_0_1(const __m512 x) {
+  static const auto c0 = _mm512_set1_ps(0.240226507f);
+  static const auto c1 = _mm512_set1_ps(0.452920674f);
+  static const auto c2 = _mm512_set1_ps(0.713483036f);
+  static const float v_log2e = std::log2(std::exp(1.f));
+  static const auto log2e = _mm512_set1_ps(v_log2e);
+  static const auto half = _mm512_set1_ps(.5f);
+
+  const auto x1 = _mm512_fmadd_ps(x, log2e, half);  // auto x1 = x * log2e + _mm512_set1_ps(.5f);
+  const auto z = _mm512_floor_ps(x1);
+  const auto f = _mm512_sub_ps(x1, z);  // auto f = x1 - z;
+
+  return poly_scale_2nd_ps(z, f, c0, c1, c2);
+}
+
 #ifdef __GNUC__
 #pragma GCC pop_options
 #else

bestla/bestla/kernel_ref.h

@@ -1522,6 +1522,17 @@ static inline BTLA_CODE layernorm(const T* srcptr, const T* scaleptr, const T* b
   }
   return BTLA_CODE::Success;
 }
+
+inline float exp_ps_0_1(float x) {
+  static const float log2e = std::log2(std::exp(1.f));
+  static const float ln2 = std::log(2.f);
+  const float x1 = x * log2e + .5f;
+  const float z = std::floor(x1);
+  const float f = x1 - z;
+  constexpr std::array<float, 3> coeff{0.240226507f, 0.452920674f, 0.713483036f};
+  // same as a * std::pow(2, z) but more precise
+  return ldexpf(coeff[0] * f * f + coeff[1] * f + coeff[2], static_cast<int>(z));
+}
 }  // namespace ref
 }  // namespace kernel
 }  // namespace bestla

neural_speed/core/CMakeLists.txt

@@ -14,6 +14,8 @@
 
 find_package(Threads REQUIRED)
 file(GLOB layers_srcs "layers/*.cpp")
+file(GLOB test_srcs "layers/*test*.cpp")
+list(REMOVE_ITEM layers_srcs ${test_srcs})
 set(sources ne_layers.c ${layers_srcs})
 
 add_shareable_library_w_warning(ne_layers "${sources}")
@@ -37,27 +39,27 @@ endif()
 
 if (NS_BUILD_TESTS)
 
-function(add_test_target src)
+function(add_test_target src)  # ARGN: additional source
   get_filename_component(test_target ${src} NAME_WE)
   get_filename_component(src_dir ${src} DIRECTORY)
   string(REGEX REPLACE [/\\] "_" src_dir ${src_dir})
   if(src_dir)
     set (test_target "${src_dir}_${test_target}")
   endif()
   set (test_target "test_${test_target}")
-  add_executable_w_warning(${test_target} ${src})
+  add_executable_w_warning(${test_target} ${src} ${ARGN})
   target_compile_definitions(${test_target} PRIVATE NS_TESTS)
   target_compile_options(${test_target} PRIVATE -fsanitize=address)
   target_link_options(${test_target} PRIVATE -fsanitize=address)
   target_include_directories(${test_target} PUBLIC .)
-  target_link_libraries(${test_target} PUBLIC Threads::Threads bestla::bestla ne_vec)
+  target_link_libraries(${test_target} PUBLIC Threads::Threads bestla ne_vec)
   if(NOT WIN32)
     target_link_libraries(${test_target} PUBLIC rt)
   endif()
   add_test(NAME ${test_target} COMMAND ${test_target})
   set_tests_properties(${test_target} PROPERTIES LABELS "${src_dir}_test")
 endfunction()
 
-add_test_target(layers/mha_dense.cpp)
+add_test_target(layers/mha_dense.cpp layers/mha_dense_tests.cpp)
 
 endif()