Only make a text encoder mask if mask_pad_tokens is true (#149)

Author: coryMosaicML

diffusion/models/stable_diffusion.py

@@ -182,11 +182,9 @@ def set_rng_generator(self, rng_generator: torch.Generator):
 
     def forward(self, batch):
         latents, text_embeds, text_pooled_embeds, attention_mask, encoder_attention_mask = None, None, None, None, None
-        if 'attention_mask' in batch:
+        if 'attention_mask' in batch and self.mask_pad_tokens:
             attention_mask = batch['attention_mask']  # mask for text encoders
-            # text mask for U-Net
-            if self.mask_pad_tokens:
-                encoder_attention_mask = _create_unet_attention_mask(attention_mask)
+            encoder_attention_mask = _create_unet_attention_mask(attention_mask)  # text mask for U-Net
 
         # Use latents if specified and available. When specified, they might not exist during eval
         if self.precomputed_latents and self.image_latents_key in batch and self.text_latents_key in batch: