Switch text encoder to manual cast.

Use fp16 text encoder weights for CPU inference to lower memory usage.

comfy/model_management.py

@@ -503,6 +503,9 @@ def text_encoder_dtype(device=None):
     elif args.fp32_text_enc:
         return torch.float32
 
+    if is_device_cpu(device):
+        return torch.float16
+
     if should_use_fp16(device, prioritize_performance=False):
         return torch.float16
     else:

comfy/ops.py

@@ -29,6 +29,39 @@ def conv_nd(dims, *args, **kwargs):
     else:
         raise ValueError(f"unsupported dimensions: {dims}")
 
+def cast_bias_weight(s, input):
+    bias = None
+    if s.bias is not None:
+        bias = s.bias.to(device=input.device, dtype=input.dtype)
+    weight = s.weight.to(device=input.device, dtype=input.dtype)
+    return weight, bias
+
+class manual_cast:
+    class Linear(Linear):
+        def forward(self, input):
+            weight, bias = cast_bias_weight(self, input)
+            return torch.nn.functional.linear(input, weight, bias)
+
+    class Conv2d(Conv2d):
+        def forward(self, input):
+            weight, bias = cast_bias_weight(self, input)
+            return self._conv_forward(input, weight, bias)
+
+    class Conv3d(Conv3d):
+        def forward(self, input):
+            weight, bias = cast_bias_weight(self, input)
+            return self._conv_forward(input, weight, bias)
+
+    class GroupNorm(GroupNorm):
+        def forward(self, input):
+            weight, bias = cast_bias_weight(self, input)
+            return torch.nn.functional.group_norm(input, self.num_groups, weight, bias, self.eps)
+
+    class LayerNorm(LayerNorm):
+        def forward(self, input):
+            weight, bias = cast_bias_weight(self, input)
+            return torch.nn.functional.layer_norm(input, self.normalized_shape, weight, bias, self.eps)
+
 @contextmanager
 def use_comfy_ops(device=None, dtype=None): # Kind of an ugly hack but I can't think of a better way
     old_torch_nn_linear = torch.nn.Linear

comfy/sd1_clip.py

@@ -78,7 +78,7 @@ class SDClipModel(torch.nn.Module, ClipTokenWeightEncoder):
         with open(textmodel_json_config) as f:
             config = json.load(f)
 
-        self.transformer = model_class(config, dtype, device, comfy.ops)
+        self.transformer = model_class(config, dtype, device, comfy.ops.manual_cast)
         self.num_layers = self.transformer.num_layers
 
         self.max_length = max_length
@@ -160,37 +160,31 @@ class SDClipModel(torch.nn.Module, ClipTokenWeightEncoder):
         tokens = self.set_up_textual_embeddings(tokens, backup_embeds)
         tokens = torch.LongTensor(tokens).to(device)
 
-        if self.transformer.dtype != torch.float32:
-            precision_scope = torch.autocast
+        attention_mask = None
+        if self.enable_attention_masks:
+            attention_mask = torch.zeros_like(tokens)
+            max_token = self.transformer.get_input_embeddings().weight.shape[0] - 1
+            for x in range(attention_mask.shape[0]):
+                for y in range(attention_mask.shape[1]):
+                    attention_mask[x, y] = 1
+                    if tokens[x, y] == max_token:
+                        break
+
+        outputs = self.transformer(tokens, attention_mask, intermediate_output=self.layer_idx, final_layer_norm_intermediate=self.layer_norm_hidden_state)
+        self.transformer.set_input_embeddings(backup_embeds)
+
+        if self.layer == "last":
+            z = outputs[0]
         else:
-            precision_scope = lambda a, dtype: contextlib.nullcontext(a)
-
-        with precision_scope(model_management.get_autocast_device(device), dtype=torch.float32):
-            attention_mask = None
-            if self.enable_attention_masks:
-                attention_mask = torch.zeros_like(tokens)
-                max_token = self.transformer.get_input_embeddings().weight.shape[0] - 1
-                for x in range(attention_mask.shape[0]):
-                    for y in range(attention_mask.shape[1]):
-                        attention_mask[x, y] = 1
-                        if tokens[x, y] == max_token:
-                            break
-
-            outputs = self.transformer(tokens, attention_mask, intermediate_output=self.layer_idx, final_layer_norm_intermediate=self.layer_norm_hidden_state)
-            self.transformer.set_input_embeddings(backup_embeds)
-
-            if self.layer == "last":
-                z = outputs[0]
-            else:
-                z = outputs[1]
+            z = outputs[1]
 
-            if outputs[2] is not None:
-                pooled_output = outputs[2].float()
-            else:
-                pooled_output = None
+        if outputs[2] is not None:
+            pooled_output = outputs[2].float()
+        else:
+            pooled_output = None
 
-            if self.text_projection is not None and pooled_output is not None:
-                pooled_output = pooled_output.float().to(self.text_projection.device) @ self.text_projection.float()
+        if self.text_projection is not None and pooled_output is not None:
+            pooled_output = pooled_output.float().to(self.text_projection.device) @ self.text_projection.float()
         return z.float(), pooled_output
 
     def encode(self, tokens):