[Mlir-commits] [mlir] Extending UniformQuantizedType with interface-based support for new storage types in Quant dialect (PR #152966)

[Javed Absar]

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@@ -270,6 +332,34 @@ def Builtin_Float4E2M1FN : Builtin_FloatType<"Float4E2M1FN", "f4E2M1FN"> {
     Open Compute Project (OCP) microscaling formats (MX) specification:
     https://www.opencompute.org/documents/ocp-microscaling-formats-mx-v1-0-spec-final-pdf
   }];
+
+  let extraClassDeclaration = [{
+    /// QuantStorageTypeInterface method implementations
+    /// Whether the storage type should default to signed when used in quantization.
+    bool shouldDefaultToSigned() const { return true; }
+    /// Get the bit width of this 4-bit floating point type.
+    unsigned getStorageWidth() const { return 4; }
+    
+    /// Get default maximum value for this 4-bit floating point type.
+    int64_t getDefaultMaximum(bool isSigned) const { return 6; }
+    /// Get default minimum value for this 4-bit floating point type.
+    int64_t getDefaultMinimum(bool isSigned) const { return -getDefaultMaximum(isSigned); }
+    
+    /// Get the storage type as a string.
+    std::string getStorageTypeName(bool isSigned) const { return "f4E2M1FN"; }
+
+    /// Check if this 4-bit floating point type uses packed representation.
+    bool isPacked() const { return true; }
+
+    /// Get the logical bit width per value for this 4-bit floating point type.
+    unsigned getLogicalBitWidth() const { return 4; }
+
+    /// Get the number of logical elements that fit in one byte for this 4-bit floating point type.
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javedabsar1 wrote:

goes beyond 80 cols?

https://github.com/llvm/llvm-project/pull/152966