Skip to content

[BUGFIX] Move scores to float32 in case of running xgrammar on cpu #12152

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Jan 19, 2025
Merged

[BUGFIX] Move scores to float32 in case of running xgrammar on cpu #12152

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
7 changes: 5 additions & 2 deletions vllm/model_executor/guided_decoding/xgrammar_decoding.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -298,16 +298,19 @@ def __call__(self, input_ids: list[int],
# token_bitmask is a CPU tensor for use with accept_token and
# fill_next_token_bitmask so we move it to the device of scores
device_type = scores.device.type
dtype = scores.dtype
if device_type != "cuda":
scores = scores.to("cpu").unsqueeze(0)
# xgrammar on cpu only supports float32 scores
# see: https://github.com/mlc-ai/xgrammar/blob/c1b64920cad24f44f235778c1c00bb52d57da01a/python/xgrammar/kernels/apply_token_bitmask_inplace_cpu.py#L22
scores = scores.to("cpu").float().unsqueeze(0)

# Note: In this method, if the tensors have different dimensions
# on CPU device fails, but on GPU it runs without error. Hence the
# unsqueeze above for scores, to match the token bitmask shape
xgr.apply_token_bitmask_inplace(scores,
self.token_bitmask.to(scores.device))
if device_type != "cuda":
scores = scores.to(device_type).squeeze()
scores = scores.to(dtype).to(device_type).squeeze()

return scores

Expand Down
Loading