Support diffusion models with scaled fp8 weights.

comfy/model_base.py

@@ -96,7 +96,8 @@ class BaseModel(torch.nn.Module):
 
         if not unet_config.get("disable_unet_model_creation", False):
             if model_config.custom_operations is None:
-                operations = comfy.ops.pick_operations(unet_config.get("dtype", None), self.manual_cast_dtype, fp8_optimizations=model_config.optimizations.get("fp8", False))
+                fp8 = model_config.optimizations.get("fp8", model_config.scaled_fp8)
+                operations = comfy.ops.pick_operations(unet_config.get("dtype", None), self.manual_cast_dtype, fp8_optimizations=fp8, scaled_fp8=model_config.scaled_fp8)
             else:
                 operations = model_config.custom_operations
             self.diffusion_model = unet_model(**unet_config, device=device, operations=operations)
@@ -244,6 +245,10 @@ class BaseModel(torch.nn.Module):
             extra_sds.append(self.model_config.process_clip_vision_state_dict_for_saving(clip_vision_state_dict))
 
         unet_state_dict = self.diffusion_model.state_dict()
+
+        if self.model_config.scaled_fp8:
+            unet_state_dict["scaled_fp8"] = torch.tensor([])
+
         unet_state_dict = self.model_config.process_unet_state_dict_for_saving(unet_state_dict)
 
         if self.model_type == ModelType.V_PREDICTION:

comfy/model_detection.py

@@ -286,9 +286,12 @@ def model_config_from_unet(state_dict, unet_key_prefix, use_base_if_no_match=Fal
         return None
     model_config = model_config_from_unet_config(unet_config, state_dict)
     if model_config is None and use_base_if_no_match:
-        return comfy.supported_models_base.BASE(unet_config)
-    else:
-        return model_config
+        model_config = comfy.supported_models_base.BASE(unet_config)
+
+    if "{}scaled_fp8".format(unet_key_prefix) in state_dict:
+        model_config.scaled_fp8 = True
+
+    return model_config
 
 def unet_prefix_from_state_dict(state_dict):
     candidates = ["model.diffusion_model.", #ldm/sgm models

comfy/model_patcher.py

@@ -317,7 +317,26 @@ class ModelPatcher:
         if key not in self.patches:
             return
 
-        weight = comfy.utils.get_attr(self.model, key)
+        set_func = None
+        convert_func = None
+        op_keys = key.rsplit('.', 1)
+        if len(op_keys) < 2:
+            weight = comfy.utils.get_attr(self.model, key)
+        else:
+            op = comfy.utils.get_attr(self.model, op_keys[0])
+            try:
+                set_func = getattr(op, "set_{}".format(op_keys[1]))
+            except AttributeError:
+                pass
+
+            try:
+                convert_func = getattr(op, "convert_{}".format(op_keys[1]))
+            except AttributeError:
+                pass
+
+            weight = getattr(op, op_keys[1])
+            if convert_func is not None:
+                weight = comfy.utils.get_attr(self.model, key)
 
         inplace_update = self.weight_inplace_update or inplace_update
 
@@ -328,12 +347,18 @@ class ModelPatcher:
             temp_weight = comfy.model_management.cast_to_device(weight, device_to, torch.float32, copy=True)
         else:
             temp_weight = weight.to(torch.float32, copy=True)
+        if convert_func is not None:
+            temp_weight = convert_func(temp_weight)
+
         out_weight = comfy.lora.calculate_weight(self.patches[key], temp_weight, key)
-        out_weight = comfy.float.stochastic_rounding(out_weight, weight.dtype, seed=string_to_seed(key))
-        if inplace_update:
-            comfy.utils.copy_to_param(self.model, key, out_weight)
+        if set_func is None:
+            out_weight = comfy.float.stochastic_rounding(out_weight, weight.dtype, seed=string_to_seed(key))
+            if inplace_update:
+                comfy.utils.copy_to_param(self.model, key, out_weight)
+            else:
+                comfy.utils.set_attr_param(self.model, key, out_weight)
         else:
-            comfy.utils.set_attr_param(self.model, key, out_weight)
+            set_func(out_weight, inplace_update=inplace_update, seed=string_to_seed(key))
 
     def load(self, device_to=None, lowvram_model_memory=0, force_patch_weights=False, full_load=False):
         mem_counter = 0

comfy/ops.py

@@ -19,6 +19,7 @@
 import torch
 import comfy.model_management
 from comfy.cli_args import args
+import comfy.float
 
 cast_to = comfy.model_management.cast_to #TODO: remove once no more references
 
@@ -250,18 +251,18 @@ def fp8_linear(self, input):
         return None
 
     if len(input.shape) == 3:
-        inn = input.reshape(-1, input.shape[2]).to(dtype)
         w, bias = cast_bias_weight(self, input, dtype=dtype, bias_dtype=input.dtype)
         w = w.t()
 
         scale_weight = self.scale_weight
         scale_input = self.scale_input
         if scale_weight is None:
-            scale_weight = torch.ones((1), device=input.device, dtype=torch.float32)
-            if scale_input is None:
-                scale_input = scale_weight
+            scale_weight = torch.ones((), device=input.device, dtype=torch.float32)
         if scale_input is None:
-            scale_input = torch.ones((1), device=input.device, dtype=torch.float32)
+            scale_input = torch.ones((), device=input.device, dtype=torch.float32)
+            inn = input.reshape(-1, input.shape[2]).to(dtype)
+        else:
+            inn = (input * (1.0 / scale_input).to(input.dtype)).reshape(-1, input.shape[2]).to(dtype)
 
         if bias is not None:
             o = torch._scaled_mm(inn, w, out_dtype=input.dtype, bias=bias, scale_a=scale_input, scale_b=scale_weight)
@@ -289,15 +290,46 @@ class fp8_ops(manual_cast):
             weight, bias = cast_bias_weight(self, input)
             return torch.nn.functional.linear(input, weight, bias)
 
+def scaled_fp8_ops(fp8_matrix_mult=False):
+    class scaled_fp8_op(manual_cast):
+        class Linear(manual_cast.Linear):
+            def reset_parameters(self):
+                if not hasattr(self, 'scale_weight'):
+                    self.scale_weight = torch.nn.parameter.Parameter(data=torch.ones((), device=self.weight.device, dtype=torch.float32), requires_grad=False)
+                if not hasattr(self, 'scale_input'):
+                    self.scale_input = torch.nn.parameter.Parameter(data=torch.ones((), device=self.weight.device, dtype=torch.float32), requires_grad=False)
+                return None
 
-def pick_operations(weight_dtype, compute_dtype, load_device=None, disable_fast_fp8=False, fp8_optimizations=False):
-    if comfy.model_management.supports_fp8_compute(load_device):
-        if (fp8_optimizations or args.fast) and not disable_fast_fp8:
-            return fp8_ops
+            def forward_comfy_cast_weights(self, input):
+                if fp8_matrix_mult:
+                    out = fp8_linear(self, input)
+                    if out is not None:
+                        return out
+
+                weight, bias = cast_bias_weight(self, input)
+                return torch.nn.functional.linear(input, weight * self.scale_weight.to(device=weight.device, dtype=weight.dtype), bias)
+
+            def convert_weight(self, weight):
+                return weight * self.scale_weight.to(device=weight.device, dtype=weight.dtype)
+
+            def set_weight(self, weight, inplace_update=False, seed=None, **kwargs):
+                weight = comfy.float.stochastic_rounding(weight / self.scale_weight.to(device=weight.device, dtype=weight.dtype), self.weight.dtype, seed=seed)
+                if inplace_update:
+                    self.weight.data.copy_(weight)
+                else:
+                    self.weight = torch.nn.Parameter(weight, requires_grad=False)
+
+    return scaled_fp8_op
+
+def pick_operations(weight_dtype, compute_dtype, load_device=None, disable_fast_fp8=False, fp8_optimizations=False, scaled_fp8=False):
+    fp8_compute = comfy.model_management.supports_fp8_compute(load_device)
+    if scaled_fp8:
+        return scaled_fp8_ops(fp8_matrix_mult=fp8_compute)
+
+    if fp8_compute and (fp8_optimizations or args.fast) and not disable_fast_fp8:
+        return fp8_ops
 
     if compute_dtype is None or weight_dtype == compute_dtype:
         return disable_weight_init
-    if args.fast and not disable_fast_fp8:
-        if comfy.model_management.supports_fp8_compute(load_device):
-            return fp8_ops
+
     return manual_cast

comfy/sd.py

@@ -649,6 +649,8 @@ def load_diffusion_model_state_dict(sd, model_options={}): #load unet in diffuse
         sd = temp_sd
 
     parameters = comfy.utils.calculate_parameters(sd)
+    weight_dtype = comfy.utils.weight_dtype(sd)
+
     load_device = model_management.get_torch_device()
     model_config = model_detection.model_config_from_unet(sd, "")
 
@@ -675,8 +677,12 @@ def load_diffusion_model_state_dict(sd, model_options={}): #load unet in diffuse
                     logging.warning("{} {}".format(diffusers_keys[k], k))
 
     offload_device = model_management.unet_offload_device()
+    unet_weight_dtype = list(model_config.supported_inference_dtypes)
+    if weight_dtype is not None:
+        unet_weight_dtype.append(weight_dtype)
+
     if dtype is None:
-        unet_dtype = model_management.unet_dtype(model_params=parameters, supported_dtypes=model_config.supported_inference_dtypes)
+        unet_dtype = model_management.unet_dtype(model_params=parameters, supported_dtypes=unet_weight_dtype)
     else:
         unet_dtype = dtype
 

comfy/supported_models_base.py

@@ -49,6 +49,7 @@ class BASE:
 
     manual_cast_dtype = None
     custom_operations = None
+    scaled_fp8 = False
     optimizations = {"fp8": False}
 
     @classmethod

comfy/utils.py

@@ -68,7 +68,7 @@ def weight_dtype(sd, prefix=""):
     for k in sd.keys():
         if k.startswith(prefix):
             w = sd[k]
-            dtypes[w.dtype] = dtypes.get(w.dtype, 0) + 1
+            dtypes[w.dtype] = dtypes.get(w.dtype, 0) + w.numel()
 
     if len(dtypes) == 0:
         return None