add support for Apple hardware using MPS acceleration

scripts/orig_scripts/img2img.py

@@ -18,6 +18,7 @@ from pytorch_lightning import seed_everything
 from ldm.util import instantiate_from_config
 from ldm.models.diffusion.ddim import DDIMSampler
 from ldm.models.diffusion.plms import PLMSSampler
+from ldm.dream.devices         import choose_torch_device
 
 
 def chunk(it, size):
@@ -40,7 +41,7 @@ def load_model_from_config(config, ckpt, verbose=False):
         print("unexpected keys:")
         print(u)
 
-    model.cuda()
+    model.to(choose_torch_device())
     model.eval()
     return model
 
@@ -199,7 +200,7 @@ def main():
     config = OmegaConf.load(f"{opt.config}")
     model = load_model_from_config(config, f"{opt.ckpt}")
 
-    device = torch.device("cuda") if torch.cuda.is_available() else torch.device("cpu")
+    device = choose_torch_device()
     model = model.to(device)
 
     if opt.plms:
@@ -241,8 +242,10 @@ def main():
     print(f"target t_enc is {t_enc} steps")
 
     precision_scope = autocast if opt.precision == "autocast" else nullcontext
+    if device.type in ['mps', 'cpu']:
+        precision_scope = nullcontext # have to use f32 on mps
     with torch.no_grad():
-        with precision_scope("cuda"):
+        with precision_scope(device.type):
             with model.ema_scope():
                 tic = time.time()
                 all_samples = list()