Add GGUF_Q8_0

mz_gguf_loader.py

@@ -19,18 +19,20 @@ class quantize_lazy_load():
 
 
 def quantize_load_state_dict(model, state_dict, device="cpu"):
-    Q4_0_qkey = []
+    quant_keys = []
     for key in state_dict.keys():
         if key.endswith(".Q4_0_qweight"):
-            Q4_0_qkey.append(key.replace(".Q4_0_qweight", ""))
+            quant_keys.append(key.replace(".Q4_0_qweight", ""))
+        elif key.endswith(".Q8_0_qweight"):
+            quant_keys.append(key.replace(".Q8_0_qweight", ""))
 
     for name, module in model.named_modules():
-        if name in Q4_0_qkey:
+        if name in quant_keys:
             #print(name)
             q_linear = WQLinear_GGUF.from_linear(
                 linear=module,
                 device=device,
-                qtype="Q4_0",
+                qtype="Q8_0",
             )
             set_op_by_name(model, name, q_linear)
 
@@ -122,6 +124,9 @@ class WQLinear_GGUF(nn.Module):
         if self.qtype == "Q4_0":
             x = F.linear(x, dequantize_blocks_Q4_0(
                 self.Q4_0_qweight, x.dtype), self.bias.to(x.dtype) if self.bias is not None else None)
+        elif self.qtype == "Q8_0":
+            x = F.linear(x, dequantize_blocks_Q8_0(
+                self.Q8_0_qweight, x.dtype), self.bias.to(x.dtype) if self.bias is not None else None)
         else:
             raise ValueError(f"Unknown qtype: {self.qtype}")
 
@@ -139,7 +144,7 @@ def quant_shape_to_byte_shape(shape, qtype) -> tuple[int, ...]:
     block_size, type_size = GGML_QUANT_SIZES[qtype]
     if shape[-1] % block_size != 0:
         raise ValueError(
-            f"Quantized tensor row size ({shape[-1]}) is not a multiple of Q4_0 block size ({block_size})")
+            f"Quantized tensor row size ({shape[-1]}) is not a multiple of {qtype}  block size ({block_size})")
     return (*shape[:-1], shape[-1] // block_size * type_size)
 
 
@@ -148,17 +153,17 @@ def quant_shape_from_byte_shape(shape, qtype) -> tuple[int, ...]:
     block_size, type_size = GGML_QUANT_SIZES[qtype]
     if shape[-1] % type_size != 0:
         raise ValueError(
-            f"Quantized tensor bytes per row ({shape[-1]}) is not a multiple of Q4_0 type size ({type_size})")
+            f"Quantized tensor bytes per row ({shape[-1]}) is not a multiple of {qtype} type size ({type_size})")
     return (*shape[:-1], shape[-1] // type_size * block_size)
 
 
 GGML_QUANT_SIZES = {
     "Q4_0": (32, 2 + 16),
+    "Q8_0": (32, 2 + 32),
 }
 
-
-def dequantize_blocks_Q4_0(data, dtype=torch.float16):
-    block_size, type_size = GGML_QUANT_SIZES["Q4_0"]
+def dequantize_blocks_Q8_0(data, dtype=torch.float16):
+    block_size, type_size = GGML_QUANT_SIZES["Q8_0"]
 
     data = data.to(torch.uint8)
     shape = data.shape
@@ -173,17 +178,14 @@ def dequantize_blocks_Q4_0(data, dtype=torch.float16):
     n_blocks = blocks.shape[0]
 
     d, qs = split_block_dims(blocks, 2)
-    d = d.view(torch.float16)
+    d = d.view(torch.float16).to(torch.float32)
 
-    qs = qs.reshape((n_blocks, -1, 1, block_size // 2)) >> torch.tensor(
-        [0, 4], device=d.device, dtype=torch.uint8).reshape((1, 1, 2, 1))
-    qs = (qs & 0x0F).reshape((n_blocks, -1)).to(torch.int8) - 8
+    qs = qs.view(torch.int8).to(torch.float32)
 
     out = (d * qs)
 
     out = out.reshape(quant_shape_from_byte_shape(
         shape,
-        qtype="Q4_0",
+        qtype="Q8_0",
     )).to(dtype)
-    return out
-
+    return out

nodes.py

@@ -49,7 +49,8 @@ class DownloadAndLoadMochiModel:
                     [   
                         "mochi_preview_dit_fp8_e4m3fn.safetensors",
                         "mochi_preview_dit_bf16.safetensors",
-                        "mochi_preview_dit_GGUF_Q4_0_v2.safetensors"
+                        "mochi_preview_dit_GGUF_Q4_0_v2.safetensors",
+                        "mochi_preview_dit_GGUF_Q8_0.safetensors",
 
                     ],
                     {"tooltip": "Downloads from 'https://huggingface.co/Kijai/Mochi_preview_comfy' to 'models/diffusion_models/mochi'", },