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bitsandbytes-foundation · Nov 4, 2024 · 875414e · 875414e
1 parent 762daf4
commit 875414e
Showing 1 changed file with 6 additions and 2 deletions.
diff --git a/bitsandbytes/autograd/_functions.py b/bitsandbytes/autograd/_functions.py
@@ -353,9 +353,13 @@ def forward(
 
             # Extract the corresponding weights
             if state.has_fp16_weights:
-                state.subB = B[:, state.idx].t()  # .contiguous()
+                state.subB = B[:, state.idx].t()
             else:
-                outliers = state.CB[:, state.idx]  # .clone()
+                outliers = state.CB[:, state.idx]
+
+                # To dequantize our weights associated with the input outliers,
+                # we want to divide by 127. It's however more performant to multiply
+                # by the reciprocal.
                 state.subB = (7.874016e-3 * outliers * state.SCB.view(-1, 1)).t().to(A.dtype)
         else:
             subA = None