Skip to content

vllm.platforms.zen_cpu

ZenCpuPlatform

Bases: CpuPlatform

CPU platform with AMD Zen (ZenDNN/zentorch) optimizations.

Model-load time (dispatch_cpu_unquantized_gemm in layers/utils.py): - Routes linear ops to zentorch_linear_unary. - When VLLM_ZENTORCH_WEIGHT_PREPACK=1 (default), eagerly prepacks weights via zentorch_weight_prepack_for_linear.

Source code in vllm/platforms/zen_cpu.py
class ZenCpuPlatform(CpuPlatform):
    """CPU platform with AMD Zen (ZenDNN/zentorch) optimizations.

    Model-load time (dispatch_cpu_unquantized_gemm in layers/utils.py):
      - Routes linear ops to zentorch_linear_unary.
      - When VLLM_ZENTORCH_WEIGHT_PREPACK=1 (default), eagerly prepacks
        weights via zentorch_weight_prepack_for_linear.
    """

    device_name: str = "cpu"
    device_type: str = "cpu"

    def is_zen_cpu(self) -> bool:
        # is_cpu() also returns True for this platform (inherited from CpuPlatform).
        return True