[Bugfix] support `tie_word_embeddings` for all models (#5724)

vllm/model_executor/models/mixtral_quant.py

@@ -347,6 +347,8 @@ class MixtralForCausalLM(nn.Module):
         self.lm_head = ParallelLMHead(config.vocab_size,
                                       config.hidden_size,
                                       quant_config=quant_config)
+        if self.config.tie_word_embeddings:
+            self.lm_head.weight = self.model.embed_tokens.weight
         self.logits_processor = LogitsProcessor(config.vocab_size)
         self.sampler = Sampler()
 

vllm/model_executor/models/opt.py

@@ -36,7 +36,7 @@ from vllm.model_executor.layers.quantization.base_config import (
     QuantizationConfig)
 from vllm.model_executor.layers.sampler import Sampler
 from vllm.model_executor.layers.vocab_parallel_embedding import (
-    VocabParallelEmbedding)
+    ParallelLMHead, VocabParallelEmbedding)
 from vllm.model_executor.model_loader.weight_utils import default_weight_loader
 from vllm.model_executor.sampling_metadata import SamplingMetadata
 from vllm.sequence import IntermediateTensors, SamplerOutput
@@ -307,7 +307,11 @@ class OPTForCausalLM(nn.Module):
         self.config = config
         self.quant_config = quant_config
         self.model = OPTModel(config, cache_config, quant_config)
-        self.lm_head = self.model.decoder.embed_tokens
+        if self.config.tie_word_embeddings:
+            self.lm_head = self.model.decoder.embed_tokens
+        else:
+            self.lm_head = ParallelLMHead(config.vocab_size,
+                                          config.word_embed_proj_dim)
         self.logits_processor = LogitsProcessor(config.vocab_size)
         self.sampler = Sampler()
 

vllm/model_executor/models/orion.py

@@ -262,6 +262,8 @@ class OrionForCausalLM(nn.Module):
         self.lm_head = ParallelLMHead(config.vocab_size,
                                       config.hidden_size,
                                       quant_config=quant_config)
+        if self.config.tie_word_embeddings:
+            self.lm_head.weight = self.model.embed_tokens.weight
         self.logits_processor = LogitsProcessor(config.vocab_size)
         self.sampler = Sampler()
 

vllm/model_executor/models/phi.py

@@ -260,6 +260,8 @@ class PhiForCausalLM(nn.Module, SupportsLoRA):
         super().__init__()
 
         self.config = config
+        # lm_head use bias, cannot share word embeddings
+        assert not config.tie_word_embeddings
         self.lora_config = lora_config
 
         self.quant_config = quant_config

vllm/model_executor/models/phi3_small.py

@@ -368,6 +368,8 @@ class Phi3SmallForCausalLM(nn.Module):
             padding_size=DEFAULT_VOCAB_PADDING_SIZE,
             quant_config=quant_config,
         )
+        if self.config.tie_word_embeddings:
+            self.lm_head.weight = self.model.embed_tokens.weight
         self.logits_processor = LogitsProcessor(config.vocab_size)
         self.sampler = Sampler()
 
@@ -449,4 +451,3 @@ class Phi3SmallForCausalLM(nn.Module):
             weight_loader = getattr(param, "weight_loader",
                                     default_weight_loader)
             weight_loader(param, loaded_weight)
-        self.lm_head.weight.data.copy_(self.model.embed_tokens.weight.data)

vllm/model_executor/models/phi3v.py

@@ -477,6 +477,8 @@ class Phi3VForCausalLM(nn.Module, SupportsMultiModal):
         self.lm_head = ParallelLMHead(config.vocab_size,
                                       config.hidden_size,
                                       quant_config=quant_config)
+        if self.config.tie_word_embeddings:
+            self.lm_head.weight = self.model.embed_tokens.weight
         self.logits_processor = LogitsProcessor(config.vocab_size)
         self.sampler = Sampler()
 

vllm/model_executor/models/qwen.py

@@ -252,6 +252,8 @@ class QWenLMHeadModel(nn.Module):
         self.lm_head = ParallelLMHead(config.vocab_size,
                                       config.hidden_size,
                                       quant_config=quant_config)
+        if self.config.tie_word_embeddings:
+            self.lm_head.weight = self.transformer.wte.weight
         self.logits_processor = LogitsProcessor(config.vocab_size)
         self.sampler = Sampler()
 

vllm/model_executor/models/qwen2_moe.py

@@ -385,6 +385,8 @@ class Qwen2MoeForCausalLM(nn.Module):
         self.lm_head = ParallelLMHead(config.vocab_size,
                                       config.hidden_size,
                                       quant_config=quant_config)
+        if self.config.tie_word_embeddings:
+            self.lm_head.weight = self.model.embed_tokens.weight
         self.logits_processor = LogitsProcessor(config.vocab_size)
         self.sampler = Sampler()
 

vllm/model_executor/models/stablelm.py

@@ -243,6 +243,8 @@ class StablelmForCausalLM(nn.Module):
         self.lm_head = ParallelLMHead(config.vocab_size,
                                       config.hidden_size,
                                       quant_config=quant_config)
+        if self.config.tie_word_embeddings:
+            self.lm_head.weight = self.model.embed_tokens.weight
         self.logits_processor = LogitsProcessor(config.vocab_size)
         self.sampler = Sampler()
 

vllm/model_executor/models/xverse.py

@@ -313,6 +313,8 @@ class XverseForCausalLM(nn.Module, SupportsLoRA):
         self.lm_head = ParallelLMHead(config.vocab_size,
                                       config.hidden_size,
                                       quant_config=quant_config)
+        if self.config.tie_word_embeddings:
+            self.lm_head.weight = self.model.embed_tokens.weight
         self.logits_processor = LogitsProcessor(config.vocab_size)
         self.sampler = Sampler()