Add float8_e4m3 and float8_e3m4 types support

jax/_src/dtypes.py

@@ -90,12 +90,17 @@ def type(self) -> type: ...
 
 
 # fp8 support
+# TODO: remove Optional when minimum ml_dtypes version >= 0.5.0
+float8_e3m4: type[np.generic] | None = None
+float8_e4m3: type[np.generic] | None = None
 float8_e4m3b11fnuz: type[np.generic] = ml_dtypes.float8_e4m3b11fnuz
 float8_e4m3fn: type[np.generic] = ml_dtypes.float8_e4m3fn
 float8_e4m3fnuz: type[np.generic] = ml_dtypes.float8_e4m3fnuz
 float8_e5m2: type[np.generic] = ml_dtypes.float8_e5m2
 float8_e5m2fnuz: type[np.generic] = ml_dtypes.float8_e5m2fnuz
 
+_float8_e3m4_dtype: np.dtype | None = None
+_float8_e4m3_dtype: np.dtype | None = None
 _float8_e4m3b11fnuz_dtype: np.dtype = np.dtype(float8_e4m3b11fnuz)
 _float8_e4m3fn_dtype: np.dtype = np.dtype(float8_e4m3fn)
 _float8_e4m3fnuz_dtype: np.dtype = np.dtype(float8_e4m3fnuz)
@@ -137,6 +142,20 @@ def supports_inf(dtype: DTypeLike) -> bool:
     _float8_e5m2fnuz_dtype,
 ]
 
+# TODO: remove the if statements below when minimum ml_dtypes version >= 0.5.0
+if hasattr(ml_dtypes, "float8_e4m3"):
+  float8_e4m3 = ml_dtypes.float8_e4m3
+  _float8_e4m3_dtype = np.dtype(float8_e4m3)
+  _custom_float_scalar_types.insert(0, float8_e4m3)  # type: ignore[arg-type]
+  _custom_float_dtypes.insert(0, _float8_e4m3_dtype)
+  _float8_dtypes.insert(0, _float8_e4m3_dtype)
+if hasattr(ml_dtypes, "float8_e3m4"):
+  float8_e3m4 = ml_dtypes.float8_e3m4
+  _float8_e3m4_dtype = np.dtype(float8_e3m4)
+  _custom_float_scalar_types.insert(0, float8_e3m4)  # type: ignore[arg-type]
+  _custom_float_dtypes.insert(0, _float8_e3m4_dtype)
+  _float8_dtypes.insert(0, _float8_e3m4_dtype)
+
 # 2-bit integer support
 int2: type[np.generic] | None = None
 uint2: type[np.generic] | None = None

jax/_src/export/serialization.fbs

@@ -64,6 +64,8 @@ enum DType: byte {
   i4 = 15,
   ui4 = 16,
 
+  f8_e3m4 = 24,
+  f8_e4m3 = 23,
   f8_e4m3b11fnuz = 17,
   f8_e4m3fn = 18,
   f8_e4m3fnuz = 19,

jax/_src/export/serialization.py

@@ -324,6 +324,10 @@ def _deserialize_pytreedef_to_pytree(p: ser_flatbuf.PyTreeDef):
     dtypes._float8_e5m2fnuz_dtype: ser_flatbuf.DType.f8_e5m2fnuz,
 }
 
+if dtypes._float8_e3m4_dtype is not None:
+  _dtype_to_dtype_kind[dtypes._float8_e3m4_dtype] = ser_flatbuf.DType.f8_e3m4
+if dtypes._float8_e4m3_dtype is not None:
+  _dtype_to_dtype_kind[dtypes._float8_e4m3_dtype] = ser_flatbuf.DType.f8_e4m3
 
 _dtype_kind_to_dtype = {
     kind: dtype for dtype, kind in _dtype_to_dtype_kind.items()

jax/_src/export/serialization_generated.py

@@ -52,6 +52,8 @@ class DType:
     bf16 = 14
     i4 = 15
     ui4 = 16
+    f8_e3m4 = 24
+    f8_e4m3 = 23
     f8_e4m3b11fnuz = 17
     f8_e4m3fn = 18
     f8_e4m3fnuz = 19

jax/_src/interpreters/mlir.py

@@ -186,13 +186,13 @@ def _is_ir_values(x: IrValues) -> bool:
 
 if dtypes.int2 is not None:
   assert dtypes.uint2 is not None
-  _dtype_to_ir_type[np.dtype(dtypes.int2)] = partial(
-      ir.IntegerType.get_signless, 2
-  )
-  _dtype_to_ir_type[np.dtype(dtypes.uint2)] = partial(
-      ir.IntegerType.get_unsigned, 2
-  )
+  _dtype_to_ir_type[np.dtype(dtypes.int2)] = partial(ir.IntegerType.get_signless, 2)
+  _dtype_to_ir_type[np.dtype(dtypes.uint2)] = partial(ir.IntegerType.get_unsigned, 2)
 
+if dtypes.float8_e3m4 is not None:
+  _dtype_to_ir_type[np.dtype(dtypes.float8_e3m4)] = ir.Float8E3M4Type.get
+if dtypes.float8_e4m3 is not None:
+  _dtype_to_ir_type[np.dtype(dtypes.float8_e4m3)] = ir.Float8E4M3Type.get
 
 def dtype_to_ir_type(dtype: core.bint | np.dtype | np.generic) -> ir.Type:
   if isinstance(dtype, core.bint):

jax/_src/lax/lax.py

@@ -942,11 +942,15 @@ def _convert_to_hlo_attr(self, lhs_dtype: DTypeLike,
           DotAlgorithmPreset.ANY_F8_ANY_F8_ANY |
           DotAlgorithmPreset.ANY_F8_ANY_F8_ANY_FAST_ACCUM
       ):
-        fp8_dtypes = (np.dtype(dtypes.float8_e4m3b11fnuz),
+        fp8_dtypes = [np.dtype(dtypes.float8_e4m3b11fnuz),
                       np.dtype(dtypes.float8_e4m3fn),
                       np.dtype(dtypes.float8_e4m3fnuz),
                       np.dtype(dtypes.float8_e5m2),
-                      np.dtype(dtypes.float8_e5m2fnuz))
+                      np.dtype(dtypes.float8_e5m2fnuz)]
+        if dtypes.float8_e3m4 is not None:
+          fp8_dtypes += [np.dtype(dtypes.float8_e3m4)]
+        if dtypes.float8_e4m3 is not None:
+          fp8_dtypes += [np.dtype(dtypes.float8_e4m3)]
         if lhs_dtype not in fp8_dtypes or rhs_dtype not in fp8_dtypes:
           raise ValueError(
               f"The dot algorithm '{self}' requires both inputs to have float8 "
@@ -3485,6 +3489,10 @@ def _dot_general_lower(ctx, lhs, rhs, *, dimension_numbers,
   def _is_fp8_mixed_precision_matmul(_lhs_dtypes, _rhs_dtypes):
     fp8_dtypes = (dtypes.float8_e4m3fn, dtypes.float8_e5m2,
                   dtypes.float8_e5m2fnuz, dtypes.float8_e4m3fnuz)
+    if dtypes.float8_e3m4 is not None:
+      fp8_dtypes += (dtypes.float8_e3m4,)
+    if dtypes.float8_e4m3 is not None:
+      fp8_dtypes += (dtypes.float8_e4m3,)
     return _lhs_dtypes in fp8_dtypes and _rhs_dtypes in fp8_dtypes
   del preferred_element_type  # Implied by the output aval
   lhs_aval, rhs_aval = ctx.avals_in

jax/_src/numpy/lax_numpy.py

@@ -210,6 +210,10 @@ def _make_scalar_type(np_scalar_type: type) -> _ScalarMeta:
 int16 = _make_scalar_type(np.int16)
 int32 = _make_scalar_type(np.int32)
 int64 = _make_scalar_type(np.int64)
+if dtypes.float8_e3m4 is not None:
+  float8_e3m4 = _make_scalar_type(dtypes.float8_e3m4)
+if dtypes.float8_e4m3 is not None:
+  float8_e4m3 = _make_scalar_type(dtypes.float8_e4m3)
 float8_e4m3fn = _make_scalar_type(dtypes.float8_e4m3fn)
 float8_e4m3fnuz = _make_scalar_type(dtypes.float8_e4m3fnuz)
 float8_e5m2 = _make_scalar_type(dtypes.float8_e5m2)

jax/_src/public_test_util.py

@@ -90,6 +90,14 @@ def default_tolerance():
   np.dtype(np.complex128): 1e-5,
 }
 
+# TODO: make this unconditional when ml_dtypes>=0.5.0 is required
+if _dtypes.float8_e3m4 is not None:
+  _default_tolerance[np.dtype(_dtypes.float8_e3m4)] = 1e-1
+  default_gradient_tolerance[np.dtype(_dtypes.float8_e3m4)] = 1e-1
+if _dtypes.float8_e4m3 is not None:
+  _default_tolerance[np.dtype(_dtypes.float8_e4m3)] = 1e-1
+  default_gradient_tolerance[np.dtype(_dtypes.float8_e4m3)] = 1e-1
+
 def is_python_scalar(val):
   return not isinstance(val, np.generic) and isinstance(val, (bool, int, float, complex))
 
@@ -106,6 +114,12 @@ def _assert_numpy_allclose(a, b, atol=None, rtol=None, err_msg=''):
     _dtypes.float8_e5m2fnuz,
     _dtypes.bfloat16,
   ]
+
+  if _dtypes.float8_e4m3 is not None:
+    custom_float_dtypes.insert(0, _dtypes.float8_e4m3)
+  if _dtypes.float8_e3m4 is not None:
+    custom_float_dtypes.insert(0, _dtypes.float8_e3m4)
+
   def maybe_upcast(x):
     if x.dtype in custom_float_dtypes:
       return x.astype(np.float32)

jax/_src/test_util.py

@@ -1433,10 +1433,22 @@ def supported(self, dtypes):
 
   @_cached_property
   def custom_floats(self):
-    return [np.dtype(t) for t in [
-      _dtypes.bfloat16, _dtypes.float8_e4m3b11fnuz,
-      _dtypes.float8_e4m3fn, _dtypes.float8_e4m3fnuz,
-      _dtypes.float8_e5m2, _dtypes.float8_e5m2fnuz]]
+    float_dtypes = [
+      _dtypes.bfloat16,
+      _dtypes.float8_e4m3b11fnuz,
+      _dtypes.float8_e4m3fn,
+      _dtypes.float8_e4m3fnuz,
+      _dtypes.float8_e5m2,
+      _dtypes.float8_e5m2fnuz,
+    ]
+    # TODO: Remove lib.version check once minimum_jaxlib_version is 0.4.35+
+    # TODO: Remove "cpu" check once xla::GetDefaultStablehloVersion() is 1.7.0+
+    if device_under_test() == "cpu" and jax._src.lib.version >= (0, 4, 35):
+      if _dtypes.float8_e3m4 is not None:
+        float_dtypes += [_dtypes.float8_e3m4]
+      if _dtypes.float8_e4m3 is not None:
+        float_dtypes += [_dtypes.float8_e4m3]
+    return [np.dtype(t) for t in float_dtypes]
 
   @_cached_property
   def floating(self):

jax/numpy/__init__.py

@@ -273,6 +273,15 @@
 except ImportError:
   pass
 
+# TODO: Remove the try-except once we upgrade to ml_dtypes 0.5.0
+try:
+  from jax._src.numpy.lax_numpy import (
+    float8_e3m4 as float8_e3m4,
+    float8_e4m3 as float8_e4m3,
+  )
+except ImportError:
+  pass
+
 from jax._src.numpy.array_api_metadata import (
   __array_api_version__ as __array_api_version__,
   __array_namespace_info__ as __array_namespace_info__,

tests/dtypes_test.py

@@ -64,6 +64,13 @@
 fp8_dtypes = [np.dtype(dtypes.float8_e4m3b11fnuz), np.dtype(dtypes.float8_e4m3fn),
               np.dtype(dtypes.float8_e4m3fnuz), np.dtype(dtypes.float8_e5m2),
               np.dtype(dtypes.float8_e5m2fnuz)]
+# TODO: Remove lib.version check once minimum_jaxlib_version is 0.4.35+
+# TODO: Remove "cpu" check once xla::GetDefaultStablehloVersion() is 1.7.0+
+if jtu.device_under_test() == "cpu" and jax._src.lib.version >= (0, 4, 35):
+  if dtypes.float8_e3m4 is not None:
+    fp8_dtypes += [np.dtype(dtypes.float8_e3m4)]
+  if dtypes.float8_e4m3 is not None:
+    fp8_dtypes += [np.dtype(dtypes.float8_e4m3)]
 float_dtypes += fp8_dtypes
 custom_float_dtypes += fp8_dtypes
 

tests/export_test.py

@@ -905,13 +905,21 @@ def f_jax(x):  # x: bool[b]
       for dtype in dtypes._jax_types if dtype != np.dtype("bool")
   ])
   def test_poly_numeric_dtypes(self, dtype=np.int32):
-    if str(dtype) in {"float8_e4m3b11fnuz",
-                      "float8_e4m3fnuz",
-                      "float8_e5m2fnuz",
-                      "int2",
-                      "int4",
-                      "uint2",
-                      "uint4"}:
+    unsupported_dtypes = {
+      "float8_e4m3b11fnuz",
+      "float8_e4m3fnuz",
+      "float8_e5m2fnuz",
+      "int2",
+      "int4",
+      "uint2",
+      "uint4",
+    }
+    # TODO: Remove once minimum_jaxlib_version is 0.4.35+
+    # TODO: Remove "cpu" check once xla::GetDefaultStablehloVersion() is 1.7.0+
+    if not (jtu.device_under_test() == "cpu" and jax._src.lib.version >= (0, 4, 35)):
+      unsupported_dtypes.add("float8_e3m4")
+      unsupported_dtypes.add("float8_e4m3")
+    if str(dtype) in unsupported_dtypes:
       self.skipTest(f"TODO: serialization not supported for {str(dtype)}")
     @jax.jit
     def f_jax(x):