updating to latest changes

nostr_dvm/backends/mlx/modules/stable_diffusion/clip.py

@@ -0,0 +1,70 @@
+# Copyright © 2023 Apple Inc.
+
+import mlx.core as mx
+import mlx.nn as nn
+
+from .config import CLIPTextModelConfig
+
+
+class CLIPEncoderLayer(nn.Module):
+    """The transformer encoder layer from CLIP."""
+
+    def __init__(self, model_dims: int, num_heads: int):
+        super().__init__()
+
+        self.layer_norm1 = nn.LayerNorm(model_dims)
+        self.layer_norm2 = nn.LayerNorm(model_dims)
+
+        self.attention = nn.MultiHeadAttention(model_dims, num_heads)
+        # Add biases to the attention projections to match CLIP
+        self.attention.query_proj.bias = mx.zeros(model_dims)
+        self.attention.key_proj.bias = mx.zeros(model_dims)
+        self.attention.value_proj.bias = mx.zeros(model_dims)
+        self.attention.out_proj.bias = mx.zeros(model_dims)
+
+        self.linear1 = nn.Linear(model_dims, 4 * model_dims)
+        self.linear2 = nn.Linear(4 * model_dims, model_dims)
+
+    def __call__(self, x, attn_mask=None):
+        y = self.layer_norm1(x)
+        y = self.attention(y, y, y, attn_mask)
+        x = y + x
+
+        y = self.layer_norm2(x)
+        y = self.linear1(y)
+        y = nn.gelu_approx(y)
+        y = self.linear2(y)
+        x = y + x
+
+        return x
+
+
+class CLIPTextModel(nn.Module):
+    """Implements the text encoder transformer from CLIP."""
+
+    def __init__(self, config: CLIPTextModelConfig):
+        super().__init__()
+
+        self.token_embedding = nn.Embedding(config.vocab_size, config.model_dims)
+        self.position_embedding = nn.Embedding(config.max_length, config.model_dims)
+        self.layers = [
+            CLIPEncoderLayer(config.model_dims, config.num_heads)
+            for i in range(config.num_layers)
+        ]
+        self.final_layer_norm = nn.LayerNorm(config.model_dims)
+
+    def __call__(self, x):
+        # Extract some shapes
+        B, N = x.shape
+
+        # Compute the embeddings
+        x = self.token_embedding(x)
+        x = x + self.position_embedding.weight[:N]
+
+        # Compute the features from the transformer
+        mask = nn.MultiHeadAttention.create_additive_causal_mask(N, x.dtype)
+        for l in self.layers:
+            x = l(x, mask)
+
+        # Apply the final layernorm and return
+        return self.final_layer_norm(x)