mamba_custom.py

# Copyright (c) 2023, Tri Dao, Albert Gu.

import math
from typing import Optional

import torch
import torch.nn as nn
import torch.nn.functional as F
from torch import Tensor

from torch.cuda.amp import custom_bwd, custom_fwd
from causal_conv1d import causal_conv1d_fn
import causal_conv1d_cuda
import selective_scan_cuda

from einops import rearrange, repeat

try:
    from causal_conv1d import causal_conv1d_fn, causal_conv1d_update
except ImportError:
    causal_conv1d_fn, causal_conv1d_update = None

# try:
from mamba_ssm.ops.selective_scan_interface import selective_scan_fn, mamba_inner_fn
# except ImportError:
#     selective_scan_fn, mamba_inner_fn, mamba_inner_fn_no_out_proj = None, None, None, None

try:
    from mamba_ssm.ops.triton.selective_state_update import selective_state_update
except ImportError:
    selective_state_update = None

try:
    from mamba_ssm.ops.triton.layernorm import RMSNorm, layer_norm_fn, rms_norm_fn
except ImportError:
    RMSNorm, layer_norm_fn, rms_norm_fn = None, None, None


class Mamba(nn.Module):
    def __init__(
        self,
        d_model,
        d_state=16,
        d_conv=4,
        expand=2,
        dt_rank="auto",
        dt_min=0.001,
        dt_max=0.1,
        dt_init="random",
        dt_scale=1.0,
        dt_init_floor=1e-4,
        conv_bias=True,
        bias=False,
        use_fast_path=True,  # Fused kernel options
        layer_idx=None,
        device=None,
        dtype=None,
        biscan=False,
    ):
        factory_kwargs = {"device": device, "dtype": dtype}
        super().__init__()
        self.d_model = d_model
        self.d_state = d_state
        self.d_conv = d_conv
        self.expand = expand
        self.d_inner = int(self.expand * self.d_model)
        self.dt_rank = math.ceil(self.d_model / 16) if dt_rank == "auto" else dt_rank
        self.use_fast_path = use_fast_path
        self.layer_idx = layer_idx
        self.biscan = biscan

        self.in_proj = nn.Linear(self.d_model, self.d_inner * 2, bias=bias, **factory_kwargs)

        self.conv1d = nn.Conv1d(
            in_channels=self.d_inner,
            out_channels=self.d_inner,
            bias=conv_bias,
            kernel_size=d_conv,
            groups=self.d_inner,
            padding=d_conv - 1,
            **factory_kwargs,
        )

        self.activation = "silu"
        self.act = nn.SiLU()

        self.x_proj = nn.Linear(
            self.d_inner, self.dt_rank + self.d_state * 2, bias=False, **factory_kwargs
        )
        self.dt_proj = nn.Linear(self.dt_rank, self.d_inner, bias=True, **factory_kwargs)

        # Initialize special dt projection to preserve variance at initialization
        dt_init_std = self.dt_rank**-0.5 * dt_scale
        if dt_init == "constant":
            nn.init.constant_(self.dt_proj.weight, dt_init_std)
        elif dt_init == "random":
            nn.init.uniform_(self.dt_proj.weight, -dt_init_std, dt_init_std)
        else:
            raise NotImplementedError

        # Initialize dt bias so that F.softplus(dt_bias) is between dt_min and dt_max
        dt = torch.exp(
            torch.rand(self.d_inner, **factory_kwargs) * (math.log(dt_max) - math.log(dt_min))
            + math.log(dt_min)
        ).clamp(min=dt_init_floor)
        # Inverse of softplus: https://github.com/pytorch/pytorch/issues/72759
        inv_dt = dt + torch.log(-torch.expm1(-dt))
        with torch.no_grad():
            self.dt_proj.bias.copy_(inv_dt)
        # Our initialization would set all Linear.bias to zero, need to mark this one as _no_reinit
        self.dt_proj.bias._no_reinit = True

        # S4D real initialization
        A = repeat(
            torch.arange(1, self.d_state + 1, dtype=torch.float32, device=device),
            "n -> d n",
            d=self.d_inner,
        ).contiguous()
        A_log = torch.log(A)  # Keep A_log in fp32
        self.A_log = nn.Parameter(A_log)
        self.A_log._no_weight_decay = True

        # D "skip" parameter
        self.D = nn.Parameter(torch.ones(self.d_inner, device=device))  # Keep in fp32
        self.D._no_weight_decay = True

        # bidirectional
        if biscan:
            A_b = repeat(
                torch.arange(1, self.d_state + 1, dtype=torch.float32, device=device),
                "n -> d n",
                d=self.d_inner,
            ).contiguous()
            A_b_log = torch.log(A_b)  # Keep A_b_log in fp32
            self.A_b_log = nn.Parameter(A_b_log)
            self.A_b_log._no_weight_decay = True 

            self.conv1d_b = nn.Conv1d(
                in_channels=self.d_inner,
                out_channels=self.d_inner,
                bias=conv_bias,
                kernel_size=d_conv,
                groups=self.d_inner,
                padding=d_conv - 1,
                **factory_kwargs,
            )

            self.x_proj_b = nn.Linear(
                self.d_inner, self.dt_rank + self.d_state * 2, bias=False, **factory_kwargs
            )
            self.dt_proj_b = nn.Linear(self.dt_rank, self.d_inner, bias=True, **factory_kwargs)

            self.D_b = nn.Parameter(torch.ones(self.d_inner, device=device))  # Keep in fp32
            self.D_b._no_weight_decay = True

        self.out_proj = nn.Linear(self.d_inner, self.d_model, bias=bias, **factory_kwargs)

    def forward(self, hidden_states, inference_params=None):
        """
        hidden_states: (B, L, D)
        Returns: same shape as hidden_states
        """
        batch, seqlen, dim = hidden_states.shape

        conv_state, ssm_state = None, None
        if inference_params is not None:
            conv_state, ssm_state = self._get_states_from_cache(inference_params, batch)
            if inference_params.seqlen_offset > 0:
                # The states are updated inplace
                out, _, _ = self.step(hidden_states, conv_state, ssm_state)
                return out

        # We do matmul and transpose BLH -> HBL at the same time
        xz = rearrange(
            self.in_proj.weight @ rearrange(hidden_states, "b l d -> d (b l)"),
            "d (b l) -> b d l",
            l=seqlen,
        )
        if self.in_proj.bias is not None:
            xz = xz + rearrange(self.in_proj.bias.to(dtype=xz.dtype), "d -> d 1")

        A = -torch.exp(self.A_log.float())  # (d_inner, d_state)
        # In the backward pass we write dx and dz next to each other to avoid torch.cat
        if self.use_fast_path and inference_params is None:  # Doesn't support outputting the states
            if self.biscan:
                A_b = -torch.exp(self.A_b_log.float())
                out = mamba_inner_fn_no_out_proj(
                    xz,
                    self.conv1d.weight,
                    self.conv1d.bias,
                    self.x_proj.weight,
                    self.dt_proj.weight,
                    A,
                    None,  # input-dependent B
                    None,  # input-dependent C
                    self.D.float(),
                    delta_bias=self.dt_proj.bias.float(),
                    delta_softplus=True,
                )
                out_b = mamba_inner_fn_no_out_proj(
                    xz.flip([-1]),
                    self.conv1d_b.weight,
                    self.conv1d_b.bias,
                    self.x_proj_b.weight,
                    self.dt_proj_b.weight,
                    A_b,
                    None,
                    None,
                    self.D_b.float(),
                    delta_bias=self.dt_proj_b.bias.float(),
                    delta_softplus=True,
                )
                out = F.linear(rearrange(out + out_b.flip([-1]), "b d l -> b l d") / 2, self.out_proj.weight, self.out_proj.bias)

            else:
                out = mamba_inner_fn(
                    xz,
                    self.conv1d.weight,
                    self.conv1d.bias,
                    self.x_proj.weight,
                    self.dt_proj.weight,
                    self.out_proj.weight,
                    self.out_proj.bias,
                    A,
                    None,  # input-dependent B
                    None,  # input-dependent C
                    self.D.float(),
                    delta_bias=self.dt_proj.bias.float(),
                    delta_softplus=True,
                )
        else:
            x, z = xz.chunk(2, dim=1)
            # Compute short convolution
            if conv_state is not None:
                # If we just take x[:, :, -self.d_conv :], it will error if seqlen < self.d_conv
                # Instead F.pad will pad with zeros if seqlen < self.d_conv, and truncate otherwise.
                conv_state.copy_(F.pad(x, (self.d_conv - x.shape[-1], 0)))  # Update state (B D W)
            if causal_conv1d_fn is None:
                x = self.act(self.conv1d(x)[..., :seqlen])
            else:
                assert self.activation in ["silu", "swish"]
                x = causal_conv1d_fn(
                    x=x,
                    weight=rearrange(self.conv1d.weight, "d 1 w -> d w"),
                    bias=self.conv1d.bias,
                    activation=self.activation,
                )

            # We're careful here about the layout, to avoid extra transposes.
            # We want dt to have d as the slowest moving dimension
            # and L as the fastest moving dimension, since those are what the ssm_scan kernel expects.
            x_dbl = self.x_proj(rearrange(x, "b d l -> (b l) d"))  # (bl d)
            dt, B, C = torch.split(x_dbl, [self.dt_rank, self.d_state, self.d_state], dim=-1)
            dt = self.dt_proj.weight @ dt.t()
            dt = rearrange(dt, "d (b l) -> b d l", l=seqlen)
            B = rearrange(B, "(b l) dstate -> b dstate l", l=seqlen).contiguous()
            C = rearrange(C, "(b l) dstate -> b dstate l", l=seqlen).contiguous()
            assert self.activation in ["silu", "swish"]
            y = selective_scan_fn(
                x,
                dt,
                A,
                B,
                C,
                self.D.float(),
                z=z,
                delta_bias=self.dt_proj.bias.float(),
                delta_softplus=True,
                return_last_state=ssm_state is not None,
            )
            if ssm_state is not None:
                y, last_state = y
                ssm_state.copy_(last_state)
            y = rearrange(y, "b d l -> b l d")
            out = self.out_proj(y)  
        return out
    
    def step(self, hidden_states, conv_state, ssm_state):
        dtype = hidden_states.dtype
        assert hidden_states.shape[1] == 1, "Only support decoding with 1 token at a time for now"
        xz = self.in_proj(hidden_states.squeeze(1))  # (B 2D)
        x, z = xz.chunk(2, dim=-1)  # (B D)

        # Conv step
        if causal_conv1d_update is None:
            conv_state.copy_(torch.roll(conv_state, shifts=-1, dims=-1))  # Update state (B D W)
            conv_state[:, :, -1] = x
            x = torch.sum(conv_state * rearrange(self.conv1d.weight, "d 1 w -> d w"), dim=-1)  # (B D)
            if self.conv1d.bias is not None:
                x = x + self.conv1d.bias
            x = self.act(x).to(dtype=dtype)
        else:
            x = causal_conv1d_update(
                x,
                conv_state,
                rearrange(self.conv1d.weight, "d 1 w -> d w"),
                self.conv1d.bias,
                self.activation,
            )

        x_db = self.x_proj(x)  # (B dt_rank+2*d_state)
        dt, B, C = torch.split(x_db, [self.dt_rank, self.d_state, self.d_state], dim=-1)
        # Don't add dt_bias here
        dt = F.linear(dt, self.dt_proj.weight)  # (B d_inner)
        A = -torch.exp(self.A_log.float())  # (d_inner, d_state)

        # SSM step
        if selective_state_update is None:
            # Discretize A and B
            dt = F.softplus(dt + self.dt_proj.bias.to(dtype=dt.dtype))
            dA = torch.exp(torch.einsum("bd,dn->bdn", dt, A))
            dB = torch.einsum("bd,bn->bdn", dt, B)
            ssm_state.copy_(ssm_state * dA + rearrange(x, "b d -> b d 1") * dB)
            y = torch.einsum("bdn,bn->bd", ssm_state.to(dtype), C)
            y = y + self.D.to(dtype) * x
            y = y * self.act(z)  # (B D)
        else:
            y = selective_state_update(
                ssm_state, x, dt, A, B, C, self.D, z=z, dt_bias=self.dt_proj.bias, dt_softplus=True
            )

        out = self.out_proj(y)
        return out.unsqueeze(1), conv_state, ssm_state

    def allocate_inference_cache(self, batch_size, max_seqlen, dtype=None, **kwargs):
        device = self.out_proj.weight.device
        conv_dtype = self.conv1d.weight.dtype if dtype is None else dtype
        conv_state = torch.zeros(
            batch_size, self.d_model * self.expand, self.d_conv, device=device, dtype=conv_dtype
        )
        ssm_dtype = self.dt_proj.weight.dtype if dtype is None else dtype
        # ssm_dtype = torch.float32
        ssm_state = torch.zeros(
            batch_size, self.d_model * self.expand, self.d_state, device=device, dtype=ssm_dtype
        )
        return conv_state, ssm_state

    def _get_states_from_cache(self, inference_params, batch_size, initialize_states=False):
        assert self.layer_idx is not None
        if self.layer_idx not in inference_params.key_value_memory_dict:
            batch_shape = (batch_size,)
            conv_state = torch.zeros(
                batch_size,
                self.d_model * self.expand,
                self.d_conv,
                device=self.conv1d.weight.device,
                dtype=self.conv1d.weight.dtype,
            )
            ssm_state = torch.zeros(
                batch_size,
                self.d_model * self.expand,
                self.d_state,
                device=self.dt_proj.weight.device,
                dtype=self.dt_proj.weight.dtype,
                # dtype=torch.float32,
            )
            inference_params.key_value_memory_dict[self.layer_idx] = (conv_state, ssm_state)
        else:
            conv_state, ssm_state = inference_params.key_value_memory_dict[self.layer_idx]
            # TODO: What if batch size changes between generation, and we reuse the same states?
            if initialize_states:
                conv_state.zero_()
                ssm_state.zero_()
        return conv_state, ssm_state


class Block(nn.Module):
    def __init__(
        self, dim, mixer_cls, norm_cls=nn.LayerNorm, fused_add_norm=False, residual_in_fp32=False
    ):
        """
        Simple block wrapping a mixer class with LayerNorm/RMSNorm and residual connection"

        This Block has a slightly different structure compared to a regular
        prenorm Transformer block.
        The standard block is: LN -> MHA/MLP -> Add.
        [Ref: https://arxiv.org/abs/2002.04745]
        Here we have: Add -> LN -> Mixer, returning both
        the hidden_states (output of the mixer) and the residual.
        This is purely for performance reasons, as we can fuse add and LayerNorm.
        The residual needs to be provided (except for the very first block).
        """
        super().__init__()
        self.residual_in_fp32 = residual_in_fp32
        self.fused_add_norm = fused_add_norm
        self.mixer = mixer_cls(dim)
        self.norm = norm_cls(dim)
        if self.fused_add_norm:
            assert RMSNorm is not None, "RMSNorm import fails"
            assert isinstance(
                self.norm, (nn.LayerNorm, RMSNorm)
            ), "Only LayerNorm and RMSNorm are supported for fused_add_norm"

    def forward(
        self, hidden_states: Tensor, residual: Optional[Tensor] = None, inference_params=None
    ):
        r"""Pass the input through the encoder layer.

        Args:
            hidden_states: the sequence to the encoder layer (required).
            residual: hidden_states = Mixer(LN(residual))
        """
        if not self.fused_add_norm:
            residual = (hidden_states + residual) if residual is not None else hidden_states
            hidden_states = self.norm(residual.to(dtype=self.norm.weight.dtype))
            if self.residual_in_fp32:
                residual = residual.to(torch.float32)
        else:
            fused_add_norm_fn = rms_norm_fn if isinstance(self.norm, RMSNorm) else layer_norm_fn
            hidden_states, residual = fused_add_norm_fn(
                hidden_states,
                self.norm.weight,
                self.norm.bias,
                residual=residual,
                prenorm=True,
                residual_in_fp32=self.residual_in_fp32,
                eps=self.norm.eps,
            )
        hidden_states = self.mixer(hidden_states, inference_params=inference_params)
        return hidden_states, residual

    def allocate_inference_cache(self, batch_size, max_seqlen, dtype=None, **kwargs):
        return self.mixer.allocate_inference_cache(batch_size, max_seqlen, dtype=dtype, **kwargs)

class MambaInnerFnCustom(torch.autograd.Function):
    """
        Customized mamba inner fn with output_proj discarded.
        Taken from https://github.com/hustvl/Vim.
    """

    @staticmethod
    @custom_fwd
    def forward(ctx, xz, conv1d_weight, conv1d_bias, x_proj_weight, delta_proj_weight,
                A, B=None, C=None, D=None, delta_bias=None, B_proj_bias=None,
                C_proj_bias=None, delta_softplus=True, checkpoint_lvl=1):
        """
             xz: (batch, dim, seqlen)
        """
        assert checkpoint_lvl in [0, 1]
        L = xz.shape[-1]
        delta_rank = delta_proj_weight.shape[1]
        d_state = A.shape[-1] * (1 if not A.is_complex() else 2)
        if torch.is_autocast_enabled():
            x_proj_weight = x_proj_weight.to(dtype=torch.get_autocast_gpu_dtype())
            delta_proj_weight = delta_proj_weight.to(dtype=torch.get_autocast_gpu_dtype())
        if xz.stride(-1) != 1:
            xz = xz.contiguous()
        conv1d_weight = rearrange(conv1d_weight, "d 1 w -> d w")
        x, z = xz.chunk(2, dim=1)
        conv1d_bias = conv1d_bias.contiguous() if conv1d_bias is not None else None
        conv1d_out = causal_conv1d_cuda.causal_conv1d_fwd(x, conv1d_weight, conv1d_bias,None, True)
        # We're being very careful here about the layout, to avoid extra transposes.
        # We want delta to have d as the slowest moving dimension
        # and L as the fastest moving dimension, since those are what the ssm_scan kernel expects.
        x_dbl = F.linear(rearrange(conv1d_out, 'b d l -> (b l) d'), x_proj_weight)  # (bl d)
        delta = rearrange(delta_proj_weight @ x_dbl[:, :delta_rank].t(), "d (b l) -> b d l", l = L)
        ctx.is_variable_B = B is None
        ctx.is_variable_C = C is None
        ctx.B_proj_bias_is_None = B_proj_bias is None
        ctx.C_proj_bias_is_None = C_proj_bias is None
        if B is None:  # variable B
            B = x_dbl[:, delta_rank:delta_rank + d_state]  # (bl dstate)
            if B_proj_bias is not None:
                B = B + B_proj_bias.to(dtype=B.dtype)
            if not A.is_complex():
                # B = rearrange(B, "(b l) dstate -> b dstate l", l=L).contiguous()
                B = rearrange(B, "(b l) dstate -> b 1 dstate l", l=L).contiguous()
            else:
                B = rearrange(B, "(b l) (dstate two) -> b 1 dstate (l two)", l=L, two=2).contiguous()
        else:
            if B.stride(-1) != 1:
                B = B.contiguous()
        if C is None:  # variable C
            C = x_dbl[:, -d_state:]  # (bl dstate)
            if C_proj_bias is not None:
                C = C + C_proj_bias.to(dtype=C.dtype)
            if not A.is_complex():
                # C = rearrange(C, "(b l) dstate -> b dstate l", l=L).contiguous()
                C = rearrange(C, "(b l) dstate -> b 1 dstate l", l=L).contiguous()
            else:
                C = rearrange(C, "(b l) (dstate two) -> b 1 dstate (l two)", l=L, two=2).contiguous()
        else:
            if C.stride(-1) != 1:
                C = C.contiguous()
        if D is not None:
            D = D.contiguous()
        out, scan_intermediates, out_z = selective_scan_cuda.fwd(
            conv1d_out, delta, A, B, C, D, z, delta_bias, delta_softplus
        )
        ctx.delta_softplus = delta_softplus
        ctx.checkpoint_lvl = checkpoint_lvl
        if checkpoint_lvl >= 1:  # Will recompute conv1d_out and delta in the backward pass
            conv1d_out, delta = None, None
        ctx.save_for_backward(xz, conv1d_weight, conv1d_bias, x_dbl, x_proj_weight,
                              delta_proj_weight, conv1d_out, delta,
                              A, B, C, D, delta_bias, scan_intermediates, out)
        # return rearrange(out_z, "b d l -> b l d")
        return out_z

    @staticmethod
    @custom_bwd
    def backward(ctx, dout):
        # dout: (batch, seqlen, dim)
        (xz, conv1d_weight, conv1d_bias, x_dbl, x_proj_weight, delta_proj_weight, 
         conv1d_out, delta, A, B, C, D, delta_bias, scan_intermediates, out) = ctx.saved_tensors
        L = xz.shape[-1]
        delta_rank = delta_proj_weight.shape[1]
        d_state = A.shape[-1] * (1 if not A.is_complex() else 2)
        x, z = xz.chunk(2, dim=1)
        if dout.stride(-1) != 1:
            dout = dout.contiguous()
        if ctx.checkpoint_lvl == 1:
            conv1d_out = causal_conv1d_cuda.causal_conv1d_fwd(x, conv1d_weight, conv1d_bias,None, True)
            delta = rearrange(delta_proj_weight @ x_dbl[:, :delta_rank].t(),
                              "d (b l) -> b d l", l = L)
        # The kernel supports passing in a pre-allocated dz (e.g., in case we want to fuse the
        # backward of selective_scan_cuda with the backward of chunk).
        dxz = torch.empty_like(xz)  # (batch, dim, seqlen)
        dx, dz = dxz.chunk(2, dim=1)
        # dout_y = rearrange(dout, "b l d -> b d l") # because no arrange at end of forward, so dout shape is b d l
        dconv1d_out, ddelta, dA, dB, dC, dD, ddelta_bias, dz, out_z = selective_scan_cuda.bwd(
            conv1d_out, delta, A, B, C, D, z, delta_bias, dout, scan_intermediates, out, dz,
            ctx.delta_softplus,
            True  # option to recompute out_z
        )
        dD = dD if D is not None else None
        dx_dbl = torch.empty_like(x_dbl)
        dB_proj_bias = None
        if ctx.is_variable_B:
            if not A.is_complex():
                dB = rearrange(dB, "b 1 dstate l -> (b l) dstate").contiguous()
            else:
                dB = rearrange(dB, "b 1 dstate (l two) -> (b l) (dstate two)", two=2).contiguous()
            dB_proj_bias = dB.sum(0) if not ctx.B_proj_bias_is_None else None
            dx_dbl[:, delta_rank:delta_rank + d_state] = dB  # (bl d)
            dB = None
        dC_proj_bias = None
        if ctx.is_variable_C:
            if not A.is_complex():
                dC = rearrange(dC, "b 1 dstate l -> (b l) dstate").contiguous()
            else:
                dC = rearrange(dC, "b 1 dstate (l two) -> (b l) (dstate two)", two=2).contiguous()
            dC_proj_bias = dC.sum(0) if not ctx.C_proj_bias_is_None else None
            dx_dbl[:, -d_state:] = dC  # (bl d)
            dC = None
        ddelta = rearrange(ddelta, "b d l -> d (b l)")
        ddelta_proj_weight = torch.einsum("dB,Br->dr", ddelta, x_dbl[:, :delta_rank])
        dx_dbl[:, :delta_rank] = torch.einsum("dB,dr->Br", ddelta, delta_proj_weight)
        dconv1d_out = rearrange(dconv1d_out, "b d l -> d (b l)")
        dx_proj_weight = torch.einsum("Br,Bd->rd", dx_dbl, rearrange(conv1d_out, "b d l -> (b l) d"))
        dconv1d_out = torch.addmm(dconv1d_out, x_proj_weight.t(), dx_dbl.t(), out=dconv1d_out)
        dconv1d_out = rearrange(dconv1d_out, "d (b l) -> b d l", b=x.shape[0], l=x.shape[-1])
        # The kernel supports passing in a pre-allocated dx (e.g., in case we want to fuse the
        # backward of conv1d with the backward of chunk).
        dx, dconv1d_weight, dconv1d_bias = causal_conv1d_cuda.causal_conv1d_bwd(
            x, conv1d_weight, conv1d_bias, dconv1d_out, None, dx, True
        )
        dconv1d_bias = dconv1d_bias if conv1d_bias is not None else None
        dconv1d_weight = rearrange(dconv1d_weight, "d w -> d 1 w")
        return (dxz, dconv1d_weight, dconv1d_bias, dx_proj_weight, ddelta_proj_weight,
                dA, dB, dC, dD,
                ddelta_bias if delta_bias is not None else None,
                dB_proj_bias, dC_proj_bias, None)

def mamba_inner_fn_no_out_proj(
    xz, conv1d_weight, conv1d_bias, x_proj_weight, delta_proj_weight,
    A, B=None, C=None, D=None, delta_bias=None, B_proj_bias=None,
    C_proj_bias=None, delta_softplus=True
):
    return MambaInnerFnCustom.apply(xz, conv1d_weight, conv1d_bias, x_proj_weight, delta_proj_weight,
                              A, B, C, D, delta_bias, B_proj_bias, C_proj_bias, delta_softplus)