Fix loras not working on mixed fp8. (#10899)

comfy/quant_ops.py

@@ -1,6 +1,7 @@
 import torch
 import logging
 from typing import Tuple, Dict
+import comfy.float
 
 _LAYOUT_REGISTRY = {}
 _GENERIC_UTILS = {}
@@ -393,7 +394,7 @@ class TensorCoreFP8Layout(QuantizedLayout):
     - orig_dtype: Original dtype before quantization (for casting back)
     """
     @classmethod
-    def quantize(cls, tensor, scale=None, dtype=torch.float8_e4m3fn):
+    def quantize(cls, tensor, scale=None, dtype=torch.float8_e4m3fn, stochastic_rounding=0, inplace_ops=False):
         orig_dtype = tensor.dtype
 
         if scale is None:
@@ -403,17 +404,23 @@ class TensorCoreFP8Layout(QuantizedLayout):
             scale = torch.tensor(scale)
         scale = scale.to(device=tensor.device, dtype=torch.float32)
 
-        tensor_scaled = tensor * (1.0 / scale).to(tensor.dtype)
-        # TODO: uncomment this if it's actually needed because the clamp has a small performance penality'
-        lp_amax = torch.finfo(dtype).max
-        torch.clamp(tensor_scaled, min=-lp_amax, max=lp_amax, out=tensor_scaled)
-        qdata = tensor_scaled.to(dtype, memory_format=torch.contiguous_format)
+        if inplace_ops:
+            tensor *= (1.0 / scale).to(tensor.dtype)
+        else:
+            tensor = tensor * (1.0 / scale).to(tensor.dtype)
+
+        if stochastic_rounding > 0:
+            tensor = comfy.float.stochastic_rounding(tensor, dtype=dtype, seed=stochastic_rounding)
+        else:
+            lp_amax = torch.finfo(dtype).max
+            torch.clamp(tensor, min=-lp_amax, max=lp_amax, out=tensor)
+            tensor = tensor.to(dtype, memory_format=torch.contiguous_format)
 
         layout_params = {
             'scale': scale,
             'orig_dtype': orig_dtype
         }
-        return qdata, layout_params
+        return tensor, layout_params
 
     @staticmethod
     def dequantize(qdata, scale, orig_dtype, **kwargs):