compile random sampling

nanovllm/layers/sampler.py

@@ -7,10 +7,9 @@ class Sampler(nn.Module):
     def __init__(self):
         super().__init__()
 
+    @torch.compile
     def forward(self, logits: torch.Tensor, temperatures: torch.Tensor):
-        logits = logits.float()
-        greedy_tokens = logits.argmax(dim=-1)
-        logits.div_(temperatures.unsqueeze(dim=1))
-        probs = torch.softmax(logits, dim=-1, dtype=torch.float)
-        sample_tokens = probs.div_(torch.empty_like(probs).exponential_(1) + 1e-10).argmax(dim=-1)  
-        return torch.where(temperatures == 0, greedy_tokens, sample_tokens)
+        logits = logits.float().div_(temperatures.unsqueeze(dim=1))
+        probs = torch.softmax(logits, dim=-1)
+        sample_tokens = probs.div_(torch.empty_like(probs).exponential_(1).clamp_min_(1e-10)).argmax(dim=-1)
+        return sample_tokens

nanovllm/sampling_params.py

@@ -6,3 +6,6 @@ class SamplingParams:
     temperature: float = 1.0
     max_tokens: int = 64
     ignore_eos: bool = False
+
+    def __post_init__(self):
+        assert self.temperature > 1e-10, "greedy sampling is not permitted"