Add meta-data to express dynamic shapes in ITensorInfo

Add `get_tensor_shape_state` and `set_tensor_shape_state` to inject
shape dynamism.
The state is represented by an array of integers which index maps to the
respective shape dimension index.
If -1 is passed as a dimension state then the corresponding dimension
is dynamic.

Signed-off-by: Georgios Pinitas <georgios.pinitas@arm.com>
Change-Id: I3a8a5ad109b90d4df8545b460a9f8dfcc13dfa0f
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/4784
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>

3 files changed, 41 insertions, 28 deletions

diff --git a/arm_compute/core/ITensorInfo.h b/arm_compute/core/ITensorInfo.h
index 3eb7239460..9ddafce7c0 100644
--- a/arm_compute/core/ITensorInfo.h
+++ b/arm_compute/core/ITensorInfo.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016-2020 Arm Limited.
+ * Copyright (c) 2016-2021 Arm Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -40,6 +40,9 @@ namespace arm_compute
 class ITensorInfo : public misc::ICloneable<ITensorInfo>
 {
 public:
+    using TensorDimsState = Coordinates;
+
+public:
     /** Default virtual destructor */
     virtual ~ITensorInfo() = default;
     /** Set the data type to the specified value.
@@ -81,6 +84,17 @@ public:
      * @return Reference to this ITensorInfo object
      */
     virtual ITensorInfo &set_tensor_shape(const TensorShape &shape) = 0;
+    /** Set the state for each dimension of the tensor
+     *
+     * This sets the state of each dimension of the shape in terms of dynamic behavior using -1 where appropriate.
+     * The index in the state is a 1 to 1 mapping with the shape dimension index.
+     * For example if you want to express [?, 3, 3] as a dynamic input then [-1, 3, 3] has to be set as a state
+     *
+     * @param[in] state Tensor dimensions state
+     *
+     * @return Reference to this ITensorInfo object
+     */
+    virtual ITensorInfo &set_tensor_dims_state(const TensorDimsState &state) = 0;
     /** Set the quantization settings (scale and offset) of the tensor.
      *
      * @param[in] quantization_info QuantizationInfo containing the scale and offset
@@ -170,6 +184,11 @@ public:
      * @return A vector with the size for each dimension of the tensor
      */
     virtual const TensorShape &tensor_shape() const = 0;
+    /** State of each dimension of the tensor shape
+     *
+     * @return A vector with the state for each dimension of the tensor, where -1 specifies dynamic dimension
+     */
+    virtual const TensorDimsState &tensor_dims_state() const = 0;
     /** Data type used for each element of the tensor
      *
      * @return Tensor data type
@@ -212,13 +231,6 @@ public:
      * @return Reference to this ITensorInfo object
      */
     virtual ITensorInfo &set_is_resizable(bool is_resizable) = 0;
-    /** Set the flag whether the tensor size is dynamic.
-     *
-     * @param[in] is_dynamic Flag that marks the tensor if it's dynamic.
-     *
-     * @return Reference to this ITensorInfo object
-     */
-    virtual ITensorInfo &set_is_dynamic(bool is_dynamic) = 0;
     /** Valid region of the tensor. All elements in the valid region have defined values, i.e. are not undefined.
      *
      * @return The valid region.
diff --git a/arm_compute/core/SubTensorInfo.h b/arm_compute/core/SubTensorInfo.h
index 6654ccf00a..1b2278d99b 100644
--- a/arm_compute/core/SubTensorInfo.h
+++ b/arm_compute/core/SubTensorInfo.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017-2020 Arm Limited.
+ * Copyright (c) 2017-2021 Arm Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -98,6 +98,7 @@ public:
         return *this;
     };
     ITensorInfo &set_tensor_shape(const TensorShape &shape) override;
+    ITensorInfo &set_tensor_dims_state(const TensorDimsState &state) override;
     ITensorInfo &set_quantization_info(const QuantizationInfo &quantization_info) override
     {
         ARM_COMPUTE_ERROR_ON(_parent == nullptr);
@@ -155,6 +156,11 @@ public:
         ARM_COMPUTE_ERROR_ON(_parent == nullptr);
         return _tensor_shape;
     }
+    const TensorDimsState &tensor_dims_state() const override
+    {
+        ARM_COMPUTE_ERROR_ON(_parent == nullptr);
+        return _dims_state;
+    }
     DataType data_type() const override
     {
         ARM_COMPUTE_ERROR_ON(_parent == nullptr);
@@ -196,12 +202,6 @@ public:
         _parent->set_is_resizable(is_resizable);
         return *this;
     }
-    ITensorInfo &set_is_dynamic(bool is_dynamic) override
-    {
-        ARM_COMPUTE_ERROR_ON(_parent == nullptr);
-        _parent->set_is_dynamic(is_dynamic);
-        return *this;
-    }
     ValidRegion valid_region() const override
     {
         return _valid_region;
@@ -228,11 +228,12 @@ public:
     }
 
 private:
-    ITensorInfo *_parent;
-    TensorShape  _tensor_shape;
-    Coordinates  _coords;
-    ValidRegion  _valid_region;
-    bool         _extend_parent;
+    ITensorInfo    *_parent;
+    TensorShape     _tensor_shape;
+    TensorDimsState _dims_state;
+    Coordinates     _coords;
+    ValidRegion     _valid_region;
+    bool            _extend_parent;
 };
 } // namespace arm_compute
 #endif /*ARM_COMPUTE_SUBTENSORINFO_H */
diff --git a/arm_compute/core/TensorInfo.h b/arm_compute/core/TensorInfo.h
index 31f27328dd..42a969e01b 100644
--- a/arm_compute/core/TensorInfo.h
+++ b/arm_compute/core/TensorInfo.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016-2019 Arm Limited.
+ * Copyright (c) 2016-2021 Arm Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -224,6 +224,7 @@ public:
     ITensorInfo &set_num_channels(int num_channels) override;
     ITensorInfo &set_format(Format format) override;
     ITensorInfo &set_tensor_shape(const TensorShape &shape) override;
+    ITensorInfo &set_tensor_dims_state(const TensorDimsState &state) override;
     ITensorInfo &set_quantization_info(const QuantizationInfo &quantization_info) override;
     ITensorInfo &set_data_layout(const DataLayout &data_layout) override;
     ITensorInfo &reset_padding() override;
@@ -262,6 +263,10 @@ public:
     {
         return _tensor_shape;
     }
+    const TensorDimsState &tensor_dims_state() const override
+    {
+        return _dims_state;
+    }
     DataType data_type() const override
     {
         return _data_type;
@@ -288,18 +293,13 @@ public:
     }
     bool is_dynamic() const override
     {
-        return _is_dynamic;
+        return std::find(std::cbegin(_dims_state), std::cend(_dims_state), -1) != std::cend(_dims_state);
     }
     ITensorInfo &set_is_resizable(bool is_resizable) override
     {
         _is_resizable = is_resizable;
         return *this;
     }
-    ITensorInfo &set_is_dynamic(bool is_dynamic) override
-    {
-        _is_dynamic = is_dynamic;
-        return *this;
-    }
     ValidRegion valid_region() const override
     {
         return _valid_region;
@@ -329,10 +329,10 @@ private:
     Strides          _strides_in_bytes;
     size_t           _num_channels;
     TensorShape      _tensor_shape;
+    TensorDimsState  _dims_state;
     DataType         _data_type;
     Format           _format;
     bool             _is_resizable;
-    bool             _is_dynamic;
     ValidRegion      _valid_region;
     PaddingSize      _padding;
     QuantizationInfo _quantization_info;