Use look up table for fp16 activation

- Enables FP16 lut for logistic activation
- Adds LUTManager to re-use lut where appropriate.

Signed-off-by: Mohammed Suhail Munshi <MohammedSuhail.Munshi@arm.com>
Change-Id: I94667b63b452a8e58a1eb59cb0b5866178954523
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/10864
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Gunes Bayir <gunes.bayir@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Benchmark: Arm Jenkins <bsgcomp@arm.com>

1 files changed, 28 insertions, 1 deletions

diff --git a/src/cpu/kernels/activation/generic/sve/fp16.cpp b/src/cpu/kernels/activation/generic/sve/fp16.cpp
index 97399e01e0..19d9126556 100644
--- a/src/cpu/kernels/activation/generic/sve/fp16.cpp
+++ b/src/cpu/kernels/activation/generic/sve/fp16.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020-2023 Arm Limited.
+ * Copyright (c) 2020-2024 Arm Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -30,6 +30,7 @@
 #include "arm_compute/function_info/ActivationLayerInfo.h"
 
 #include "src/core/NEON/SVEMath.h"
+#include "src/cpu/kernels/lut/list.h"
 
 #include <arm_sve.h>
 #include <cmath>
@@ -141,6 +142,32 @@ void sve_fp16_activation(const ITensor *src, ITensor *dst, const ActivationLayer
         },
         input, output);
 }
+
+void sve_fp16_activation_lut(const ITensor             *src,
+                             ITensor                   *dst,
+                             const ActivationLayerInfo &act_info,
+                             const Window              &window)
+{
+    ARM_COMPUTE_ERROR_ON(src->info()->data_type() != DataType::F16);
+    const auto window_start_x = window.x().start();
+    const auto window_end_x   = window.x().end();
+    const auto size           = window_end_x - window_start_x;
+    Window     win_collapsed  = window.collapse_if_possible(window, Window::DimZ);
+    win_collapsed.set(Window::DimX, Window::Dimension(0, 1, 1));
+
+    Iterator input(src, win_collapsed);
+    Iterator output(dst, win_collapsed);
+    execute_window_loop(
+        win_collapsed,
+        [&](const Coordinates &)
+        {
+            const auto input_ptr  = reinterpret_cast<const uint16_t *>(input.ptr());
+            auto       output_ptr = reinterpret_cast<uint16_t *>(output.ptr());
+            lut_u16_sve(reinterpret_cast<const uint16_t *>(act_info.lut_fp16().data()), 1U /* num_strings (UNUSED) */,
+                        size, input_ptr + window_start_x, output_ptr + window_start_x);
+        },
+        input, output);
+}
 } // namespace cpu
 } // namespace arm_compute
 #endif /* defined(__ARM_FEATURE_FP16_VECTOR_ARITHMETIC) && defined(ENABLE_FP16_KERNELS) */