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"""RMSNorm ops: rmsnorm_fused_parallel (fused parallel RMSNorm for two inputs)."""

import functools
from pathlib import Path

import torch


@functools.cache
def _load_rmsnorm_module():
    import tvm_ffi

    objs_dir = Path(__file__).parent / "objs" / "rmsnorm_fused_parallel"
    so_path = objs_dir / "rmsnorm_fused_parallel.so"
    if not so_path.exists():
        raise RuntimeError(
            f"tokenspeed_kernel rmsnorm library not found at {so_path}. "
            "Run: pip install -e tokenspeed_kernel/python/"
        )
    return tvm_ffi.load_module(str(so_path))


def rmsnorm_fused_parallel(
    input1: torch.Tensor,
    weight1: torch.Tensor,
    output1: torch.Tensor,
    input2: torch.Tensor,
    weight2: torch.Tensor,
    output2: torch.Tensor,
    eps: float = 1e-6,
    enable_pdl: bool = False,
) -> None:
    _load_rmsnorm_module().rmsnorm_fused_parallel(
        input1,
        weight1,
        output1,
        input2,
        weight2,
        output2,
        float(eps),
        bool(enable_pdl),
    )