[Mlir-commits] [mlir] [mlir][tosa] Add constant block scaled support (PR #205506)

[Sayan Saha]

================
@@ -771,6 +825,43 @@ LogicalResult OpTrait::tosa::verifyBlockScaledTensorType(Operation &op,
   return success();
 }
 
+LogicalResult OpTrait::tosa::verifyBlockScaledTensorType(Operation &op,
+                                                         mlir::Type type) {
+  return ::verifyBlockScaledTensorType(op, type, /*allowScaleValues=*/false);
+}
+
+size_t mlir::tosa::BlockScaledType::getDenseElementBitSize() const {
+  const Type valueType = getValueType();
+  if (isa<tosa::mxint8Type>(valueType))
+    return 8;
+  return valueType.getIntOrFloatBitWidth();
+}
+
+Attribute
+mlir::tosa::BlockScaledType::convertToAttribute(ArrayRef<char> rawData) const {
+  assert(rawData.size() == 1 && "expected 1 byte for block_scaled element");
+  const Type valueType = getValueType();
+  if (const auto mxint8Value = dyn_cast<tosa::mxint8Type>(valueType))
+    return mxint8Value.convertToAttribute(rawData);
+  if (!isa<FloatType>(valueType))
+    return {};
+  return mlir::detail::convertFloatTypeToAttribute(valueType, rawData);
+}
+
+LogicalResult mlir::tosa::BlockScaledType::convertFromAttribute(
+    Attribute attr, SmallVectorImpl<char> &result) const {
+  const Type valueType = getValueType();
+  if (const auto mxint8Value = dyn_cast<tosa::mxint8Type>(valueType))
+    return mxint8Value.convertFromAttribute(attr, result);
+
+  const auto floatAttr = dyn_cast<FloatAttr>(attr);
+  if (!floatAttr || floatAttr.getType() != valueType)
+    return failure();
+  const APFloat value = floatAttr.getValue();
+  return mlir::detail::convertFloatTypeFromAttribute(
+      valueType, FloatAttr::get(valueType, value), result);
----------------
sahas3 wrote:

```suggestion
      valueType, floatAttr, result);
```

https://github.com/llvm/llvm-project/pull/205506