IVGCVSW-3836 Add support for Int32 per-axis scales

* Added ScaledInt32PerAxisDecoder implementation
* Added new case for Signed32 in MakeDecoder that returns a
  ScaledInt32PerAxisDecoder if the tensor info has multiple
  quantization scales

Signed-off-by: Aron Virginas-Tar <Aron.Virginas-Tar@arm.com>
Change-Id: I8b3c11091644da993044d2a0fe2aba6b06b5af56

1 files changed, 29 insertions, 0 deletions

diff --git a/src/armnnUtils/TensorUtils.cpp b/src/armnnUtils/TensorUtils.cpp
index 0dbb75c33a..630490ff14 100644
--- a/src/armnnUtils/TensorUtils.cpp
+++ b/src/armnnUtils/TensorUtils.cpp
@@ -138,4 +138,33 @@ unsigned int GetUnsignedAxis(const unsigned int inputDimension, const int axis)
     return uAxis;
 }
 
+unsigned int GetNumElementsAfter(const armnn::TensorShape& shape, unsigned int axis)
+{
+    unsigned int numDim = shape.GetNumDimensions();
+    BOOST_ASSERT(0 >= axis);
+    BOOST_ASSERT(axis < numDim - 1);
+    unsigned int count = 1;
+    for (unsigned int i = axis; i < numDim; i++)
+    {
+        count *= shape[i];
+    }
+    return count;
+}
+
+std::pair<unsigned int, std::vector<float>> GetPerAxisParams(const armnn::TensorInfo& info)
+{
+    const std::vector<float>& scales = info.GetQuantizationScales();
+    armnn::Optional<unsigned int> quantizationDim = info.GetQuantizationDim();
+    if (scales.size() < 1 || !quantizationDim.has_value())
+    {
+        throw armnn::InvalidArgumentException(
+            std::string("Per-axis quantization params not set for tensor of type ") +
+            armnn::GetDataTypeName(info.GetDataType()), CHECK_LOCATION());
+    }
+    unsigned int axisFactor = GetNumElementsAfter(info.GetShape(), quantizationDim.value());
+
+    return { axisFactor, scales };
+}
+
+
 } // namespace armnnUtils