[Inference]Add Nopadding Llama Modeling (#5327)

* add nopadding llama modeling

* add nopadding_llama.py

* rm unused codes

* fix bugs in test_xine_copy.py

* fix code style

colossalai/inference/core/engine.py

@@ -57,7 +57,11 @@ class InferenceEngine:
         model.to(self.dtype)
 
         if model_policy is None:
-            model_policy = model_policy_map[self.model_config.model_type]()
+            if self.inference_config.pad_input:
+                model_type = "padding_" + self.model_config.model_type
+            else:
+                model_type = "nopadding_" + self.model_config.model_type
+            model_policy = model_policy_map[model_type]()
 
         pg_mesh = ProcessGroupMesh(inference_config.pp_size, inference_config.tp_size)
 
@@ -168,7 +172,9 @@ class InferenceEngine:
 
         if prompts_token_ids is None:
             assert prompts, "When the prompts_token_ids is none, the input prompt list must be provided."
-            prompts_token_ids = self.tokenizer.batch_encode_plus(prompts, padding=True)["input_ids"]
+            prompts_token_ids = self.tokenizer.batch_encode_plus(prompts, padding=self.inference_config.pad_input)[
+                "input_ids"
+            ]
 
         if isinstance(prompts_token_ids, list):
             pass
@@ -237,7 +243,9 @@ class InferenceEngine:
             self.v_cache,
         )
 
-        logits = logits[:, -1, :]
+        if self.inference_config.pad_input:
+            logits = logits[:, -1, :]
+
         self.request_handler.search_tokens(self.generation_config, logits)
         finished_sequences = self.request_handler.update()