COMPMID-3079: Implement Hard-Swish in NEON.

Change-Id: I019e36f65b4d821009bada9c6cdebc096d893b54
Signed-off-by: morgolock <pablo.tello@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/2802
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Michele Di Giorgio <michele.digiorgio@arm.com>

1 files changed, 22 insertions, 9 deletions

diff --git a/src/core/NEON/kernels/NEActivationLayerKernel.cpp b/src/core/NEON/kernels/NEActivationLayerKernel.cpp
index 44f76f6e22..a0bf9e8010 100644
--- a/src/core/NEON/kernels/NEActivationLayerKernel.cpp
+++ b/src/core/NEON/kernels/NEActivationLayerKernel.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017-2019 ARM Limited.
+ * Copyright (c) 2017-2020 ARM Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -156,6 +156,8 @@ void NEActivationLayerKernel::configure(ITensor *input, ITensor *output, Activat
         { ActivationFunction::SQUARE, &NEActivationLayerKernel::activation<ActivationFunction::SQUARE, float> },
         { ActivationFunction::TANH, &NEActivationLayerKernel::activation<ActivationFunction::TANH, float> },
         { ActivationFunction::IDENTITY, &NEActivationLayerKernel::activation<ActivationFunction::IDENTITY, float> },
+        { ActivationFunction::HARD_SWISH, &NEActivationLayerKernel::activation<ActivationFunction::HARD_SWISH, float> },
+
     };
 
 #ifdef __ARM_FEATURE_FP16_VECTOR_ARITHMETIC
@@ -175,6 +177,8 @@ void NEActivationLayerKernel::configure(ITensor *input, ITensor *output, Activat
         { ActivationFunction::SQUARE, &NEActivationLayerKernel::activation<ActivationFunction::SQUARE, float16_t> },
         { ActivationFunction::TANH, &NEActivationLayerKernel::activation<ActivationFunction::TANH, float16_t> },
         { ActivationFunction::IDENTITY, &NEActivationLayerKernel::activation<ActivationFunction::IDENTITY, float16_t> },
+        { ActivationFunction::HARD_SWISH, &NEActivationLayerKernel::activation<ActivationFunction::HARD_SWISH, float16_t> },
+
     };
 #endif /* __ARM_FEATURE_FP16_VECTOR_ARITHMETIC*/
 
@@ -254,14 +258,17 @@ NEActivationLayerKernel::activation(const Window &window)
     Iterator input(_input, win_collapsed);
     Iterator output(_output, win_collapsed);
 
-    const auto epsilon = wrapper::vdup_n(static_cast<T>(1e-24), ExactTagType{});
-    const auto const_1 = wrapper::vdup_n(static_cast<T>(1.f), ExactTagType{});
-    const auto const_0 = wrapper::vdup_n(static_cast<T>(0.f), ExactTagType{});
-    const auto va      = wrapper::vdup_n(static_cast<T>(_act_info.a()), ExactTagType{});
-    const auto vb      = wrapper::vdup_n(static_cast<T>(_act_info.b()), ExactTagType{});
-    const auto a       = static_cast<T>(_act_info.a());
-    const auto b       = static_cast<T>(_act_info.b());
-
+    const auto epsilon     = wrapper::vdup_n(static_cast<T>(1e-24), ExactTagType{});
+    const auto const_1     = wrapper::vdup_n(static_cast<T>(1.f), ExactTagType{});
+    const auto const_0     = wrapper::vdup_n(static_cast<T>(0.f), ExactTagType{});
+    const auto const_6     = wrapper::vdup_n(static_cast<T>(6.f), ExactTagType{});
+    const auto const_3     = wrapper::vdup_n(static_cast<T>(3.f), ExactTagType{});
+    const auto const_inv_6 = wrapper::vdup_n(static_cast<T>(0.166666667f), ExactTagType{});
+
+    const auto va = wrapper::vdup_n(static_cast<T>(_act_info.a()), ExactTagType{});
+    const auto vb = wrapper::vdup_n(static_cast<T>(_act_info.b()), ExactTagType{});
+    const auto a  = static_cast<T>(_act_info.a());
+    const auto b  = static_cast<T>(_act_info.b());
     execute_window_loop(win_collapsed, [&](const Coordinates &)
     {
         const auto input_ptr  = reinterpret_cast<const T *>(input.ptr());
@@ -315,6 +322,9 @@ NEActivationLayerKernel::activation(const Window &window)
                 case ActivationFunction::IDENTITY:
                     tmp = vin;
                     break;
+                case ActivationFunction::HARD_SWISH:
+                    tmp = wrapper::vmul(vin, wrapper::vmul(const_inv_6, wrapper::vmin(const_6, wrapper::vmax(const_0, wrapper::vadd(vin, const_3)))));
+                    break;
                 default:
                     ARM_COMPUTE_ERROR("Unsupported activation function");
             }
@@ -367,6 +377,9 @@ NEActivationLayerKernel::activation(const Window &window)
                 case ActivationFunction::IDENTITY:
                     tmp = in;
                     break;
+                case ActivationFunction::HARD_SWISH:
+                    tmp = in * ((std::min(std::max((in + 3), 0.0f), 6.0f)) * 0.166666667f);
+                    break;
                 default:
                     ARM_COMPUTE_ERROR("Unsupported activation function");
             }