Make Softmax kernels and operator stateless
COMPMID-3997
Change-Id: I3a3cc76d8247dd769d9a5e6e171d718ea909312c
Signed-off-by: Michalis Spyrou <michalis.spyrou@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/4986
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
diff --git a/src/runtime/cpu/operators/CpuSoftmax.h b/src/runtime/cpu/operators/CpuSoftmax.h
new file mode 100644
index 0000000..9f18e0e
--- /dev/null
+++ b/src/runtime/cpu/operators/CpuSoftmax.h
@@ -0,0 +1,105 @@
+/*
+ * Copyright (c) 2021 Arm Limited.
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#ifndef ARM_COMPUTE_CPU_SOFTMAX_H
+#define ARM_COMPUTE_CPU_SOFTMAX_H
+
+#include "arm_compute/core/ITensorInfo.h"
+#include "arm_compute/core/experimental/Types.h"
+#include "src/core/cpu/ICpuKernel.h"
+#include "src/runtime/cpu/ICpuOperator.h"
+#include "src/runtime/cpu/operators/CpuPermute.h"
+#include <memory>
+
+namespace arm_compute
+{
+namespace cpu
+{
+class CpuLogits1DMaxKernel;
+template <bool IS_LOG>
+class CpuLogits1DSoftmaxKernel;
+
+/** Basic function to compute a SoftmaxLayer and a Log SoftmaxLayer.
+ *
+ * Softmax is calculated by :
+ * @f[ out = exp((x - max(x)) * beta) / sum(exp((x - max(x)) * beta)) @f]
+ *
+ * Log Softmax is calculated by :
+ * @f[ out = (x - max(x) * beta) - log(\sum{e^{x - max(x) * beta}}) @f]
+ *
+ * This function runs the following function/kernels:
+ * -# If axis is not 0:
+ * -# @ref CpuPermute
+ * -# @ref kernels::CpuLogits1DMaxKernel
+ * -# @ref kernels::CpuLogits1DSoftmaxKernel
+ */
+template <bool IS_LOG = false>
+class CpuSoftmaxGeneric : public ICpuOperator
+{
+public:
+ /** Constructor */
+ CpuSoftmaxGeneric();
+ /** Set the input and output tensors.
+ *
+ * @param[in,out] src Source tensor info. Data types supported: QASYMM8/QASYMM8_SIGNED/F16/F32.
+ * last value of each row to the nearest multiple.
+ * @param[out] dst Destination tensor ifo. Data types supported: same as @p input.
+ * @param[in] beta (Optional) A scaling factor for the exponent.
+ * @param[in] axis (Optional) The dimension in which to apply the function. E.g. for input of shape 4x5x6 and
+ * axis=1, softmax will be applied to 4x6=24 vectors of size 5. Defaults to 0
+ */
+ void configure(const ITensorInfo *src, ITensorInfo *dst, float beta = 1.0f, int32_t axis = 0);
+
+ /** Static function to check if given info will lead to a valid configuration of @ref CpuSoftmax
+ *
+ * @param[in] src Source tensor info. Data types supported: QASYMM8/QASYMM8_SIGNED/F16/F32.
+ * @param[in] dst Destination tensor info. Data types supported: same as @p input
+ * @param[in] beta (Optional) A scaling factor for the exponent.
+ * @param[in] axis (Optional) The dimension in which to apply the function. E.g. for input of shape 4x5x6 and
+ * axis=1, softmax will be applied to 4x6=24 vectors of size 5. Defaults to 0
+ *
+ * @return a status
+ */
+ static Status validate(const ITensorInfo *src, const ITensorInfo *dst, float beta = 1.0f, int32_t axis = 0);
+
+ // Inherited methods overridden:
+ void run(ITensorPack &tensors) override;
+ experimental::MemoryRequirements workspace() const override;
+
+private:
+ CpuPermute _permute_input;
+ CpuPermute _permute_output;
+ std::unique_ptr<ICpuKernel> _max_kernel;
+ std::unique_ptr<ICpuKernel> _softmax_kernel;
+ std::unique_ptr<ITensorInfo> _max;
+ std::unique_ptr<ITensorInfo> _tmp;
+ std::unique_ptr<ITensorInfo> _input_permuted;
+ std::unique_ptr<ITensorInfo> _output_permuted;
+ bool _needs_permute;
+};
+using CpuSoftmax = CpuSoftmaxGeneric<false>;
+using CpuLogSoftmax = CpuSoftmaxGeneric<true>;
+
+} // namespace cpu
+} // namespace arm_compute
+#endif /* ARM_COMPUTE_CPU_SOFTMAX_H */