Optimize CL softmax

* The new softmax implementation consists of only a single kernel.
  - There are 2 versions of softmax, one for the x dimension
    and one for any other dimensions.
  - Softmax kernel handles both native and quantized data type.

Resolves: COMPMID-6447
Signed-off-by: Viet-Hoa Do <viet-hoa.do@arm.com>
Change-Id: I4a9ae5bc63f78aebeaa85ee48a0d102c9c245eda
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/10489
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: SiCong Li <sicong.li@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Benchmark: Arm Jenkins <bsgcomp@arm.com>
diff --git a/src/gpu/cl/operators/ClSoftmax.cpp b/src/gpu/cl/operators/ClSoftmax.cpp
index 2bec400..427f6b4 100644
--- a/src/gpu/cl/operators/ClSoftmax.cpp
+++ b/src/gpu/cl/operators/ClSoftmax.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021 Arm Limited.
+ * Copyright (c) 2021, 2023 Arm Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -23,15 +23,14 @@
  */
 #include "src/gpu/cl/operators/ClSoftmax.h"
 
-#include "arm_compute/core/utils/misc/ShapeCalculator.h"
+#include "arm_compute/core/experimental/Types.h"
+#include "arm_compute/core/ITensorPack.h"
+#include "arm_compute/runtime/CL/CLScheduler.h"
 
 #include "src/common/utils/Log.h"
 #include "src/core/helpers/MemoryHelpers.h"
-#include "src/core/helpers/SoftmaxHelpers.h"
 #include "src/gpu/cl/kernels/ClSoftmaxKernel.h"
-#include "src/gpu/cl/operators/ClPermute.h"
 #include "src/gpu/cl/utils/ClAuxTensorHandler.h"
-#include "support/Cast.h"
 
 using namespace arm_compute::experimental;
 
@@ -39,17 +38,8 @@
 {
 namespace opencl
 {
-ClSoftmax::ClSoftmax()
-    : _permute_input(std::make_unique<ClPermute>()),
-      _permute_output(std::make_unique<ClPermute>()),
-      _max_shift_exp_sum_kernel(std::make_unique<kernels::ClLogits1DMaxShiftExpSumKernel>()),
-      _norm_kernel(std::make_unique<kernels::ClLogits1DNormKernel>()),
-      _max_info(),
-      _sum_info(),
-      _tmp_info(),
-      _permuted_src_info(),
-      _permuted_dst_info(),
-      _aux_mem(InternalTensorIdx::COUNT)
+
+ClSoftmax::ClSoftmax() : _aux_mem(InternalTensorIdx::COUNT)
 {
 }
 
@@ -58,152 +48,37 @@
                           ITensorInfo             &dst,
                           const SoftmaxKernelInfo &info)
 {
-    ARM_COMPUTE_ERROR_THROW_ON(validate(src, dst, info));
     ARM_COMPUTE_LOG_PARAMS(src, dst, info);
 
-    const size_t actual_axis = static_cast<size_t>(wrap_around(info.axis, static_cast<int32_t>(src.num_dimensions())));
+    auto k = std::make_unique<kernels::ClSoftmaxKernel>();
+    k->configure(compile_context, src, dst, info);
 
-    _needs_permute = actual_axis != 0;
+    _tmp_info = k->tmp_tensor_info();
 
-    const ITensorInfo &tmp_input_info  = _needs_permute ? _permuted_src_info : src;
-    ITensorInfo       &tmp_output_info = _needs_permute ? _permuted_dst_info : dst;
+    _kernel = std::move(k);
 
-    if (_needs_permute)
-    {
-        const auto perm_info = softmax_helpers::get_permutation_vector_from_softmax_axis(actual_axis);
-        _permute_input->configure(compile_context, &src, &_permuted_src_info, perm_info);
-    }
-
-    DataType tmp_data_type =
-        is_data_type_quantized_asymmetric(tmp_input_info.data_type()) ? DataType::S32 : tmp_input_info.data_type();
-    _tmp_info = tmp_input_info.clone()->set_data_type(tmp_data_type);
-
-    TensorShape max_sum_shape = tmp_input_info.tensor_shape();
-    _max_info                 = tmp_input_info.clone()->set_tensor_shape(max_sum_shape);
-    _sum_info                 = tmp_input_info.clone()->set_tensor_shape(max_sum_shape).set_data_type(tmp_data_type);
-
-    // Set GPU target to kernels
-    _max_shift_exp_sum_kernel->set_target(CLScheduler::get().target());
-
-    _max_shift_exp_sum_kernel->configure(compile_context, tmp_input_info, _max_info, _tmp_info, _sum_info, info);
-    _norm_kernel->configure(compile_context, _tmp_info, _sum_info, tmp_output_info, info);
-
-    if (_needs_permute)
-    {
-        const auto perm_info = softmax_helpers::get_permutation_vector_from_softmax_axis(actual_axis);
-        _permute_output->configure(compile_context, &_permuted_dst_info, &dst, perm_info);
-    }
-
-    _aux_mem[InternalTensorIdx::SUM] =
-        MemoryInfo(offset_int_vec(InternalTensorIdx::SUM), MemoryLifetime::Temporary, _sum_info.total_size());
     _aux_mem[InternalTensorIdx::TMP] =
         MemoryInfo(offset_int_vec(InternalTensorIdx::TMP), MemoryLifetime::Temporary, _tmp_info.total_size());
-    _aux_mem[InternalTensorIdx::MAX] =
-        MemoryInfo(offset_int_vec(InternalTensorIdx::MAX), MemoryLifetime::Temporary, _max_info.total_size());
-
-    _aux_mem[InternalTensorIdx::PERMUTED_SRC] = MemoryInfo(offset_int_vec(InternalTensorIdx::PERMUTED_SRC),
-                                                           MemoryLifetime::Temporary, _permuted_src_info.total_size());
-    _aux_mem[InternalTensorIdx::PERMUTED_DST] = MemoryInfo(offset_int_vec(InternalTensorIdx::PERMUTED_DST),
-                                                           MemoryLifetime::Temporary, _permuted_dst_info.total_size());
 }
 
 Status ClSoftmax::validate(const ITensorInfo &src, const ITensorInfo &dst, const SoftmaxKernelInfo &info)
 {
-    ARM_COMPUTE_RETURN_ERROR_ON_MSG(src.num_dimensions() > 4, "Only up to 4 dimensions are supported");
-    ARM_COMPUTE_UNUSED(info.beta);
-    ARM_COMPUTE_RETURN_ERROR_ON(info.axis < static_cast<int32_t>(-src.num_dimensions()) ||
-                                static_cast<int32_t>(src.num_dimensions()) <= info.axis);
-
-    const size_t actual_axis = static_cast<size_t>(wrap_around(info.axis, static_cast<int32_t>(src.num_dimensions())));
-    const bool   needs_permute = actual_axis != 0;
-    if (needs_permute)
-    {
-        const PermutationVector permutation_vector =
-            softmax_helpers::get_permutation_vector_from_softmax_axis(actual_axis);
-        const TensorShape permuted_shape =
-            misc::shape_calculator::compute_permutation_output_shape(src, permutation_vector);
-        TensorInfo input_permuted(src.clone()->set_tensor_shape(permuted_shape));
-        ARM_COMPUTE_RETURN_ON_ERROR(ClPermute::validate(&src, &input_permuted, permutation_vector));
-        TensorInfo output_permuted(dst.clone()->set_tensor_shape(permuted_shape));
-        ARM_COMPUTE_RETURN_ON_ERROR(ClPermute::validate(&output_permuted, &dst, permutation_vector));
-    }
-
-    // Create intermediate tensor info
-    DataType   tmp_data_type = is_data_type_quantized_asymmetric(src.data_type()) ? DataType::S32 : src.data_type();
-    TensorInfo tensor_info_tmp(src.clone()->set_data_type(tmp_data_type).set_is_resizable(true));
-
-    TensorShape max_sum_shape = src.tensor_shape();
-    max_sum_shape.set(0, 1);
-    TensorInfo tensor_info_max(src.clone()->set_tensor_shape(max_sum_shape).set_is_resizable(true));
-    TensorInfo tensor_info_sum(src.clone()
-                                   ->set_tensor_shape(max_sum_shape)
-                                   .set_data_type(tmp_data_type)
-                                   .set_quantization_info(QuantizationInfo())
-                                   .set_is_resizable(true));
-
-    ARM_COMPUTE_RETURN_ON_ERROR(
-        kernels::ClLogits1DMaxShiftExpSumKernel::validate(src, tensor_info_max, tensor_info_tmp, tensor_info_sum));
-    ARM_COMPUTE_RETURN_ON_ERROR(kernels::ClLogits1DNormKernel::validate(tensor_info_tmp, tensor_info_sum, dst, info));
-
-    return Status{};
+    return kernels::ClSoftmaxKernel::validate(src, dst, info);
 }
 
 void ClSoftmax::run(ITensorPack &tensors)
 {
-    auto src = tensors.get_const_tensor(TensorType::ACL_SRC);
-    auto dst = tensors.get_tensor(TensorType::ACL_DST);
+    CLAuxTensorHandler tmp(offset_int_vec(InternalTensorIdx::TMP), _tmp_info, tensors);
 
-    CLAuxTensorHandler sum(offset_int_vec(InternalTensorIdx::SUM), _sum_info, tensors, false);
-    CLAuxTensorHandler tmp(offset_int_vec(InternalTensorIdx::TMP), _tmp_info, tensors, false);
-    CLAuxTensorHandler max(offset_int_vec(InternalTensorIdx::MAX), _max_info, tensors, false);
+    tensors.add_tensor(TensorType::ACL_INT_0, tmp.get());
 
-    CLAuxTensorHandler permuted_src(offset_int_vec(InternalTensorIdx::PERMUTED_SRC), _permuted_src_info, tensors,
-                                    false);
-    CLAuxTensorHandler permuted_dst(offset_int_vec(InternalTensorIdx::PERMUTED_DST), _permuted_dst_info, tensors,
-                                    false);
-
-    if (_needs_permute)
-    {
-        ITensorPack pack;
-        pack.add_const_tensor(TensorType::ACL_SRC, src);
-        pack.add_tensor(TensorType::ACL_DST, permuted_src.get());
-        _permute_input.get()->run(pack);
-    }
-
-    ITensorPack sum_pack;
-    ITensorPack norm_pack;
-    if (_needs_permute)
-    {
-        sum_pack.add_const_tensor(TensorType::ACL_SRC, permuted_src.get());
-        norm_pack.add_tensor(TensorType::ACL_DST, permuted_dst.get());
-    }
-    else
-    {
-        sum_pack.add_const_tensor(TensorType::ACL_SRC, src);
-        norm_pack.add_tensor(TensorType::ACL_DST, dst);
-    }
-    sum_pack.add_tensor(TensorType::ACL_DST, tmp.get());
-    sum_pack.add_tensor(TensorType::ACL_INT_0, max.get());
-    sum_pack.add_tensor(TensorType::ACL_INT_1, sum.get());
-
-    norm_pack.add_const_tensor(TensorType::ACL_SRC, tmp.get());
-    norm_pack.add_tensor(TensorType::ACL_INT_0, sum.get());
-
-    CLScheduler::get().enqueue_op(*_max_shift_exp_sum_kernel.get(), sum_pack, false);
-    CLScheduler::get().enqueue_op(*_norm_kernel.get(), norm_pack, false);
-
-    if (_needs_permute)
-    {
-        ITensorPack pack;
-        pack.add_const_tensor(TensorType::ACL_SRC, permuted_dst.get());
-        pack.add_tensor(TensorType::ACL_DST, dst);
-        _permute_output.get()->run(pack);
-    }
+    CLScheduler::get().enqueue_op(*_kernel, tensors, false);
 }
 
 experimental::MemoryRequirements ClSoftmax::workspace() const
 {
     return _aux_mem;
 }
+
 } // namespace opencl
 } // namespace arm_compute