[Fix] Explicit pad const hasn't been read during pad op construction

The op builder didn't read the value from operand but only set the
pad_const attribute to zero.

Change-Id: Ia6f16490c3fad42200884a9d3a5118fa5c152b53
Signed-off-by: TatWai Chong <tatwai.chong@arm.com>

1 files changed, 25 insertions, 3 deletions

diff --git a/src/TosaSerialize.cpp b/src/TosaSerialize.cpp
index 42ca41e..4bc67ea 100644
--- a/src/TosaSerialize.cpp
+++ b/src/TosaSerialize.cpp
@@ -878,10 +878,11 @@ TosaSerializationOperatorBuilder::build<mlir::tosa::PadOp>(
     mlir::Operation &op) const {
   std::string input_name = GetTensorName(op.getOperand(0));
   std::string output_name = GetTensorName(op.getResult(0));
+  auto pad_op = llvm::cast<mlir::tosa::PadOp>(op);
 
   // Match padding tensor as compile-time constant attribute
   mlir::ElementsAttr paddings_elems;
-  if (!matchPattern(op.getOperand(1), m_Constant(&paddings_elems)))
+  if (!matchPattern(pad_op.getPadding(), m_Constant(&paddings_elems)))
     return nullptr;
 
   std::vector<int> paddings;
@@ -889,8 +890,29 @@ TosaSerializationOperatorBuilder::build<mlir::tosa::PadOp>(
     paddings.push_back(val);
   }
 
-  TosaPadAttribute attribute(paddings, 0 /* pad_const_int */,
-                             0.0f /* pad_const_fp */);
+  auto quant_info = pad_op.getQuantizationInfoAttr();
+  // pad_const includes the zero point if the tensor uses a zero point.
+  int32_t pad_const_int = quant_info ? quant_info.getInputZp() : 0;
+  float pad_const_fp = 0.f;
+
+  if (auto tensor = pad_op.getPadConst()) {
+    // Match pad_const tensor as compile-time constant attribute if present.
+    mlir::DenseElementsAttr attr;
+    if (!matchPattern(tensor, m_Constant(&attr)))
+      return nullptr;
+
+    assert(attr.getNumElements() == 1);
+    auto elementTy = attr.getElementType();
+
+    if (elementTy.isa<mlir::IntegerType>()) {
+      pad_const_int = quant_info ? *attr.value_begin<int8_t>()
+                                 : *attr.value_begin<int32_t>();
+    } else if (elementTy.isa<mlir::FloatType>()) {
+      pad_const_fp = *attr.value_begin<float>();
+    }
+  }
+
+  TosaPadAttribute attribute(paddings, pad_const_int, pad_const_fp);
 
   TosaSerializationOperator *tyop = new TosaSerializationOperator(
       Op_PAD, Attribute_PadAttribute, &attribute,