[MLIR] Add f8E4M3 IEEE 754 type (#97118)

This PR adds `f8E4M3` type to mlir.

`f8E4M3` type  follows IEEE 754 convention

```c
f8E4M3 (IEEE 754)
- Exponent bias: 7
- Maximum stored exponent value: 14 (binary 1110)
- Maximum unbiased exponent value: 14 - 7 = 7
- Minimum stored exponent value: 1 (binary 0001)
- Minimum unbiased exponent value: 1 − 7 = −6
- Precision specifies the total number of bits used for the significand (mantisa), 
    including implicit leading integer bit = 3 + 1 = 4
- Follows IEEE 754 conventions for representation of special values
- Has Positive and Negative zero
- Has Positive and Negative infinity
- Has NaNs

Additional details:
- Max exp (unbiased): 7
- Min exp (unbiased): -6
- Infinities (+/-): S.1111.000
- Zeros (+/-): S.0000.000
- NaNs: S.1111.{001, 010, 011, 100, 101, 110, 111}
- Max normal number: S.1110.111 = +/-2^(7) x (1 + 0.875) = +/-240
- Min normal number: S.0001.000 = +/-2^(-6)
- Max subnormal number: S.0000.111 = +/-2^(-6) x 0.875 = +/-2^(-9) x 7
- Min subnormal number: S.0000.001 = +/-2^(-6) x 0.125 = +/-2^(-9)
```

Related PRs:
- [PR-97179](llvm/llvm-project#97179) [APFloat]
Add support for f8E4M3 IEEE 754 type

Author: apivovarov

mlir/include/mlir-c/BuiltinTypes.h

@@ -89,6 +89,16 @@ MLIR_CAPI_EXPORTED bool mlirTypeIsAFloat8E5M2(MlirType type);
 /// context.
 MLIR_CAPI_EXPORTED MlirType mlirFloat8E5M2TypeGet(MlirContext ctx);
 
+/// Returns the typeID of an Float8E4M3 type.
+MLIR_CAPI_EXPORTED MlirTypeID mlirFloat8E4M3TypeGetTypeID(void);
+
+/// Checks whether the given type is an f8E4M3 type.
+MLIR_CAPI_EXPORTED bool mlirTypeIsAFloat8E4M3(MlirType type);
+
+/// Creates an f8E4M3 type in the given context. The type is owned by the
+/// context.
+MLIR_CAPI_EXPORTED MlirType mlirFloat8E4M3TypeGet(MlirContext ctx);
+
 /// Returns the typeID of an Float8E4M3FN type.
 MLIR_CAPI_EXPORTED MlirTypeID mlirFloat8E4M3FNTypeGetTypeID(void);
 

mlir/lib/Bindings/Python/IRTypes.cpp

@@ -143,7 +143,7 @@ class PyFloat8E4M3FNType
   }
 };
 
-/// Floating Point Type subclass - Float8M5E2Type.
+/// Floating Point Type subclass - Float8E5M2Type.
 class PyFloat8E5M2Type : public PyConcreteType<PyFloat8E5M2Type, PyFloatType> {
 public:
   static constexpr IsAFunctionTy isaFunction = mlirTypeIsAFloat8E5M2;
@@ -163,6 +163,26 @@ class PyFloat8E5M2Type : public PyConcreteType<PyFloat8E5M2Type, PyFloatType> {
   }
 };
 
+/// Floating Point Type subclass - Float8E4M3Type.
+class PyFloat8E4M3Type : public PyConcreteType<PyFloat8E4M3Type, PyFloatType> {
+public:
+  static constexpr IsAFunctionTy isaFunction = mlirTypeIsAFloat8E4M3;
+  static constexpr GetTypeIDFunctionTy getTypeIdFunction =
+      mlirFloat8E4M3TypeGetTypeID;
+  static constexpr const char *pyClassName = "Float8E4M3Type";
+  using PyConcreteType::PyConcreteType;
+
+  static void bindDerived(ClassTy &c) {
+    c.def_static(
+        "get",
+        [](DefaultingPyMlirContext context) {
+          MlirType t = mlirFloat8E4M3TypeGet(context->get());
+          return PyFloat8E4M3Type(context->getRef(), t);
+        },
+        py::arg("context") = py::none(), "Create a float8_e4m3 type.");
+  }
+};
+
 /// Floating Point Type subclass - Float8E4M3FNUZ.
 class PyFloat8E4M3FNUZType
     : public PyConcreteType<PyFloat8E4M3FNUZType, PyFloatType> {
@@ -840,6 +860,7 @@ void mlir::python::populateIRTypes(py::module &m) {
   PyIndexType::bind(m);
   PyFloat8E4M3FNType::bind(m);
   PyFloat8E5M2Type::bind(m);
+  PyFloat8E4M3Type::bind(m);
   PyFloat8E4M3FNUZType::bind(m);
   PyFloat8E4M3B11FNUZType::bind(m);
   PyFloat8E5M2FNUZType::bind(m);

mlir/lib/CAPI/IR/BuiltinTypes.cpp

@@ -97,6 +97,18 @@ MlirType mlirFloat8E5M2TypeGet(MlirContext ctx) {
   return wrap(FloatType::getFloat8E5M2(unwrap(ctx)));
 }
 
+MlirTypeID mlirFloat8E4M3TypeGetTypeID() {
+  return wrap(Float8E4M3Type::getTypeID());
+}
+
+bool mlirTypeIsAFloat8E4M3(MlirType type) {
+  return unwrap(type).isFloat8E4M3();
+}
+
+MlirType mlirFloat8E4M3TypeGet(MlirContext ctx) {
+  return wrap(FloatType::getFloat8E4M3(unwrap(ctx)));
+}
+
 MlirTypeID mlirFloat8E4M3FNTypeGetTypeID() {
   return wrap(Float8E4M3FNType::getTypeID());
 }

mlir/python/mlir/_mlir_libs/_mlir/ir.pyi

@@ -123,6 +123,7 @@ __all__ = [
     "Float8E4M3B11FNUZType",
     "Float8E4M3FNType",
     "Float8E4M3FNUZType",
+    "Float8E4M3Type",
     "Float8E5M2FNUZType",
     "Float8E5M2Type",
     "FloatAttr",
@@ -1575,6 +1576,19 @@ class Float8E4M3FNUZType(FloatType):
     @property
     def typeid(self) -> TypeID: ...
 
+class Float8E4M3Type(FloatType):
+    static_typeid: ClassVar[TypeID]
+    @staticmethod
+    def get(context: Optional[Context] = None) -> Float8E4M3Type:
+        """
+        Create a float8_e4m3 type.
+        """
+    @staticmethod
+    def isinstance(other: Type) -> bool: ...
+    def __init__(self, cast_from_type: Type) -> None: ...
+    @property
+    def typeid(self) -> TypeID: ...
+
 class Float8E5M2FNUZType(FloatType):
     static_typeid: ClassVar[TypeID]
     @staticmethod

mlir/python/mlir/extras/types.py

@@ -14,6 +14,7 @@
     F64Type,
     Float8E4M3B11FNUZType,
     Float8E4M3FNType,
+    Float8E4M3Type,
     Float8E5M2Type,
     FunctionType,
     IndexType,
@@ -68,6 +69,7 @@ def ui(width):
 bf16 = lambda: BF16Type.get()
 
 f8E5M2 = lambda: Float8E5M2Type.get()
+f8E4M3 = lambda: Float8E4M3Type.get()
 f8E4M3FN = lambda: Float8E4M3FNType.get()
 f8E4M3B11FNUZ = lambda: Float8E4M3B11FNUZType.get()