Add k_activation.py

Author: tridao

mamba_ssm/__init__.py

@@ -1,4 +1,4 @@
-__version__ = "2.0.1"
+__version__ = "2.0.2"
 
 from mamba_ssm.ops.selective_scan_interface import selective_scan_fn, mamba_inner_fn
 from mamba_ssm.modules.mamba_simple import Mamba

mamba_ssm/ops/triton/k_activation.py

@@ -0,0 +1,153 @@
+# Copyright (c) 2024, Tri Dao, Albert Gu.
+
+import torch
+
+import triton
+import triton.language as tl
+
+
+@triton.autotune(
+    configs=[
+        triton.Config({'BLOCK_N': 32}),
+        triton.Config({'BLOCK_N': 64}),
+        triton.Config({'BLOCK_N': 128}),
+        triton.Config({'BLOCK_N': 256}),
+        triton.Config({'BLOCK_N': 512}),
+        triton.Config({'BLOCK_N': 1024}),
+    ],
+    key=['ncols'],
+)
+@triton.jit
+def _swiglu_fwd_kernel(
+    X,
+    Y,
+    OUT,
+    stride_x_row,  # how much to increase the pointer when moving by 1 row
+    stride_y_row,
+    stride_out_row,
+    ncols,
+    BLOCK_N: tl.constexpr,
+):
+    # Map the program id to the row of X and Y it should compute.
+    row = tl.program_id(0)
+    start_col = tl.program_id(1) * BLOCK_N
+    X += row * stride_x_row
+    Y += row * stride_y_row
+    OUT += row * stride_out_row
+    cols = start_col + tl.arange(0, BLOCK_N)
+    x = tl.load(X + cols, mask=cols < ncols, other=0.).to(tl.float32)
+    y = tl.load(Y + cols, mask=cols < ncols, other=0.).to(tl.float32)
+    out = x * tl.sigmoid(x) * y
+    tl.store(OUT + cols, out, mask=cols < ncols)
+
+
+def _swiglu_fwd(xy, out=None):
+    if xy.stride(-1) != 1:
+        xy = xy.contiguous()
+    batch_shape = xy.shape[:-1]
+    xy = xy.reshape(-1, xy.shape[-1])
+    x, y = xy.chunk(2, dim=-1)
+    if out is None:
+        out = torch.empty_like(x)
+    else:
+        out = out.reshape(-1, out.shape[-1])
+        assert out.shape == x.shape
+    assert out.stride(-1) == 1
+    M, N = x.shape
+    grid = lambda META: (M, triton.cdiv(N, META['BLOCK_N']))
+    with torch.cuda.device(x.device.index):
+        _swiglu_fwd_kernel[grid](x, y, out, x.stride(0), y.stride(0), out.stride(0), N)
+    return out.reshape(*batch_shape, out.shape[-1])
+
+
+@triton.autotune(
+    configs=[
+        triton.Config({'BLOCK_N': 32}),
+        triton.Config({'BLOCK_N': 64}),
+        triton.Config({'BLOCK_N': 128}),
+        triton.Config({'BLOCK_N': 256}),
+        triton.Config({'BLOCK_N': 512}),
+        triton.Config({'BLOCK_N': 1024}),
+    ],
+    key=['ncols'],
+)
+@triton.heuristics({"RECOMPUTE_OUTPUT": lambda args: args["OUT"] is not None})
+@triton.jit
+def _swiglu_bwd_kernel(
+    X,
+    Y,
+    DOUT,
+    OUT,
+    DX,
+    DY,
+    stride_x_row,  # how much to increase the pointer when moving by 1 row
+    stride_y_row,
+    stride_dout_row,
+    stride_out_row,
+    stride_dx_row,
+    stride_dy_row,
+    ncols,
+    BLOCK_N: tl.constexpr,
+    RECOMPUTE_OUTPUT: tl.constexpr,
+):
+    # Map the program id to the row of X and Y it should compute.
+    row = tl.program_id(0)
+    start_col = tl.program_id(1) * BLOCK_N
+    X += row * stride_x_row
+    Y += row * stride_y_row
+    DOUT += row * stride_dout_row
+    if RECOMPUTE_OUTPUT:
+        OUT += row * stride_out_row
+    DX += row * stride_dx_row
+    DY += row * stride_dy_row
+    cols = start_col + tl.arange(0, BLOCK_N)
+    x = tl.load(X + cols, mask=cols < ncols, other=0.).to(tl.float32)
+    y = tl.load(Y + cols, mask=cols < ncols, other=0.).to(tl.float32)
+    dout = tl.load(DOUT + cols, mask=cols < ncols, other=0.).to(tl.float32)
+    x_sigmoid = tl.sigmoid(x)
+    dx = x_sigmoid * (1 + x * (1 - x_sigmoid)) * y * dout
+    dy = x * x_sigmoid * dout
+    tl.store(DX + cols, dx, mask=cols < ncols)
+    tl.store(DY + cols, dy, mask=cols < ncols)
+    if RECOMPUTE_OUTPUT:
+        out = x * x_sigmoid * y
+        tl.store(OUT + cols, out, mask=cols < ncols)
+
+
+def _swiglu_bwd(xy, dout, dxy=None, recompute_output=False, out=None):
+    if xy.stride(-1) != 1:
+        xy = xy.contiguous()
+    if dout.stride(-1) != 1:
+        dout = dout.contiguous()
+    batch_shape = xy.shape[:-1]
+    xy = xy.reshape(-1, xy.shape[-1])
+    x, y = xy.chunk(2, dim=-1)
+    dout = dout.reshape(-1, dout.shape[-1])
+    assert dout.shape == x.shape
+    if dxy is None:
+        dxy = torch.empty_like(xy)
+    else:
+        dxy = dxy.reshape(-1, dxy.shape[-1])
+        assert dxy.shape == xy.shape
+    dx, dy = dxy.chunk(2, dim=-1)
+    assert dx.stride(-1) == 1
+    assert dy.stride(-1) == 1
+    if recompute_output:
+        if out is None:
+            out = torch.empty_like(x)
+        else:
+            out = out.reshape(-1, out.shape[-1])
+            assert out.shape == x.shape
+        assert out.stride(-1) == 1
+    M, N = x.shape
+    grid = lambda META: (M, triton.cdiv(N, META['BLOCK_N']))
+    with torch.cuda.device(x.device.index):
+        _swiglu_bwd_kernel[grid](x, y, dout, out if recompute_output else None, dx, dy,
+                                 x.stride(0), y.stride(0), dout.stride(0),
+                                 out.stride(0) if recompute_output else 0,
+                                 dx.stride(0), dy.stride(0),
+                                 N)
+    if not recompute_output:
+        return dxy.reshape(*batch_shape, dxy.shape[-1])
+    else:
+        return dxy.reshape(*batch_shape, dxy.shape[-1]), out.reshape(*batch_shape, out.shape[-1])