def vectorwise_mm_dequant()

in bitsandbytes/functional.py [0:0]


def vectorwise_mm_dequant(xq, S1, S2, dtype=torch.half, quant_type="vector"):
    if quant_type == "linear":
        norm = S1 * S2 / (C * C)
        # double cast needed to prevent overflows
        return (xq.float() * norm).to(dtype)
    elif quant_type == "zeropoint":
        norm = 1.0 / (S1 * S2)
        return (xq.float() * norm).to(dtype)
    elif quant_type == "row-zeropoint":
        norm = 1.0 / (S1 * S2)
        x = xq.float()
        if len(S1.shape) == 3 and len(x.shape) == 2:
            S1 = S1.squeeze(0)
        if len(S2.shape) == 3 and len(x.shape) == 2:
            S2 = S2.squeeze(0)
        if len(S1.shape) == 2:
            x *= norm
        else:
            x *= norm
        return x.to(dtype)
    elif quant_type == "vector-zeropoint":
        x = xq.float()
        if len(S1.shape) == 3 and len(x.shape) == 2:
            S1 = S1.squeeze(0)
        if len(S2.shape) == 3 and len(x.shape) == 2:
            S2 = S2.squeeze(0)
        if len(S1.shape) == 2:
            x *= 1.0 / S1
        else:
            x *= 1.0 / S1
        x *= 1.0 / S2.t()
        return x.to(dtype)
    elif quant_type == "row":
        x = xq.float()
        if len(S1.shape) == 3 and len(x.shape) == 2:
            S1 = S1.squeeze(0)
        if len(S2.shape) == 3 and len(x.shape) == 2:
            S2 = S2.squeeze(0)
        if len(S1.shape) == 2:
            x *= S1 * S2 / (C * C)
        else:
            x *= S1 * S2 / (C * C)
        return x.to(dtype)
    elif quant_type in ["truncated-vector", "vector"]:
        x = xq.float()
        if len(S1.shape) == 3 and len(x.shape) == 2:
            S1 = S1.squeeze(0)
        if len(S2.shape) == 3 and len(x.shape) == 2:
            S2 = S2.squeeze(0)
        if len(S1.shape) == 2:
            x *= S1 / C
        else:
            x *= S1 / C
        x *= S2 / C
        return x.to(dtype)
    else:
        return None