From a8fae3869d4f2b0cd44b6ea2985189b414367def Mon Sep 17 00:00:00 2001
From: yinpu <741456392@qq.com>
Date: Tue, 21 Jan 2025 13:38:02 +0800
Subject: [PATCH] fix: avoid redundant normalization in DPO's SFT loss
 calculation (#6722)

Former-commit-id: 971a8ccbdacf130763d40c7ef82a711b2fc1292f
---
 src/llamafactory/train/dpo/trainer.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/llamafactory/train/dpo/trainer.py b/src/llamafactory/train/dpo/trainer.py
index 770b32e5..1a1d5973 100644
--- a/src/llamafactory/train/dpo/trainer.py
+++ b/src/llamafactory/train/dpo/trainer.py
@@ -204,7 +204,11 @@ class CustomDPOTrainer(DPOTrainer):
         chosen_logps, rejected_logps = all_logps.split(batch_size, dim=0)
         chosen_logits, rejected_logits = all_logits.split(batch_size, dim=0)
         chosen_length, _ = valid_length.split(batch_size, dim=0)
-        return chosen_logps, rejected_logps, chosen_logits, rejected_logits, chosen_logps / chosen_length
+
+        if self.loss_type in ["ipo", "orpo", "simpo"]:
+            return chosen_logps, rejected_logps, chosen_logits, rejected_logits, chosen_logps
+        else:
+            return chosen_logps, rejected_logps, chosen_logits, rejected_logits, chosen_logps / chosen_length
 
     @override
     def compute_reference_log_probs(