[BACKEND] Compiler improvements (#557)

This PR adds several optimization capabilities in the compiler backend:
- Now using inline PTX for `tl.store`, making it possible to use things like evict_last
- For A100, mma layout can be directly converted to shared memory
- For A100, an additional "transpose" argument in `dot` allows tensors to be loaded once and used both row- and col- major.
- Fixed liveness analysis; this was broken.
- Now can load/store directly mma layout without converting. Useful for when tl.dot accumulator is initialized with DRAM data inside of an inner loop.
- `tl.dot` can now take LHS inputs in registers when it comes from a previous `tl.dot` instruction. Useful for e.g. fused attention.
This commit is contained in:
Philippe Tillet
2022-06-27 11:49:19 -07:00
committed by GitHub
parent 87413bc925
commit 5b4c8f221e
25 changed files with 882 additions and 284 deletions

View File

@@ -840,10 +840,10 @@ def test_permute(dtype_str, shape, perm, device='cuda'):
@pytest.mark.parametrize("epilogue, allow_tf32, dtype",
[(epilogue, allow_tf32, dtype)
for epilogue in ['none', 'trans', 'add-matrix', 'add-rows', 'add-cols']
for epilogue in ['none', 'trans', 'add-matrix', 'add-rows', 'add-cols', 'softmax', 'chain-dot']
for allow_tf32 in [True, False]
for dtype in ['float32', 'int8']
if not (allow_tf32 and (dtype == 'int8'))])
for dtype in ['float16']
if not (allow_tf32 and (dtype in ['float16']))])
def test_dot(epilogue, allow_tf32, dtype, device='cuda'):
cc = _triton.runtime.cc(_triton.runtime.backend.CUDA, torch.cuda.current_device())
if cc < 80:
@@ -852,21 +852,30 @@ def test_dot(epilogue, allow_tf32, dtype, device='cuda'):
elif dtype == 'float32' and allow_tf32:
pytest.skip("Only test tf32 on devices with sm >= 80")
M, N, K = 128, 128, 64
num_warps = 8
trans_a, trans_b = False, False
# triton kernel
@triton.jit
def kernel(X, stride_xm, stride_xk,
Y, stride_yk, stride_yn,
W, stride_wn, stride_wl,
Z, stride_zm, stride_zn,
BLOCK_M: tl.constexpr, BLOCK_N: tl.constexpr, BLOCK_K: tl.constexpr,
ADD_MATRIX: tl.constexpr, ADD_ROWS: tl.constexpr, ADD_COLS: tl.constexpr,
ALLOW_TF32: tl.constexpr):
ALLOW_TF32: tl.constexpr,
DO_SOFTMAX: tl.constexpr, CHAIN_DOT: tl.constexpr,
TRANS_A: tl.constexpr, TRANS_B: tl.constexpr):
off_m = tl.arange(0, BLOCK_M)
off_n = tl.arange(0, BLOCK_N)
off_l = tl.arange(0, BLOCK_N)
off_k = tl.arange(0, BLOCK_K)
Xs = X + off_m[:, None] * stride_xm + off_k[None, :] * stride_xk
Ys = Y + off_k[:, None] * stride_yk + off_n[None, :] * stride_yn
Ws = W + off_n[:, None] * stride_wn + off_l[None, :] * stride_wl
Zs = Z + off_m[:, None] * stride_zm + off_n[None, :] * stride_zn
z = tl.dot(tl.load(Xs), tl.load(Ys), allow_tf32=ALLOW_TF32)
z = tl.dot(tl.load(Xs), tl.load(Ys), trans_a=TRANS_A, trans_b=TRANS_B, allow_tf32=ALLOW_TF32)
if ADD_MATRIX:
z += tl.load(Zs)
if ADD_ROWS:
@@ -875,39 +884,65 @@ def test_dot(epilogue, allow_tf32, dtype, device='cuda'):
if ADD_COLS:
ZCs = Z + off_n * stride_zn
z += tl.load(ZCs)[None, :]
if DO_SOFTMAX:
max = tl.max(z, 1)
z = z - max[:, None]
num = tl.exp(z)
den = tl.sum(num, 1)
z = num / den[:, None]
if CHAIN_DOT:
# tl.store(Zs, z)
# tl.debug_barrier()
z = tl.dot(z.to(tl.float16), tl.load(Ws), trans_a=TRANS_A)
tl.store(Zs, z)
# input
M, N, K = 64, 64, 32
rs = RandomState(17)
x = numpy_random((M, K), dtype_str=dtype, rs=rs)
y = numpy_random((K, N), dtype_str=dtype, rs=rs)
x = numpy_random((K, M) if trans_a else (M, K), dtype_str=dtype, rs=rs) * .1
y = numpy_random((N, K) if trans_b else (K, N), dtype_str=dtype, rs=rs) * .1
w = numpy_random((N, N), dtype_str=dtype, rs=rs) * .1
if allow_tf32:
x = (x.view('uint32') & np.uint32(0xffffe000)).view('float32')
y = (y.view('uint32') & np.uint32(0xffffe000)).view('float32')
w = (w.view('uint32') & np.uint32(0xffffe000)).view('float32')
x_tri = to_triton(x, device=device)
y_tri = to_triton(y, device=device)
w_tri = to_triton(w, device=device)
# triton result
z = numpy_random((M, N), dtype_str=dtype, rs=rs)
z = 1 + numpy_random((M, N), dtype_str=dtype, rs=rs) * .1
z_tri = to_triton(z, device=device)
if epilogue == 'trans':
z_tri = torch.as_strided(z_tri, (M, N), z_tri.stride()[::-1])
pgm = kernel[(1, 1)](x_tri, x_tri.stride(0), x_tri.stride(1),
y_tri, y_tri.stride(0), y_tri.stride(1),
w_tri, w_tri.stride(0), w_tri.stride(1),
z_tri, z_tri.stride(0), z_tri.stride(1),
TRANS_A=trans_a, TRANS_B=trans_b,
BLOCK_M=M, BLOCK_K=K, BLOCK_N=N,
ADD_MATRIX=epilogue == 'add-matrix',
ADD_ROWS=epilogue == 'add-rows',
ADD_COLS=epilogue == 'add-cols',
ALLOW_TF32=allow_tf32)
DO_SOFTMAX=epilogue == 'softmax',
CHAIN_DOT=epilogue == 'chain-dot',
ALLOW_TF32=allow_tf32,
num_warps=num_warps)
# torch result
z_ref = np.matmul(x, y)
x_ref = x.T if trans_a else x
y_ref = y.T if trans_b else y
z_ref = np.matmul(x_ref, y_ref)
if epilogue == 'add-matrix':
z_ref += z
if epilogue == 'add-rows':
z_ref += z[:, 0][:, None]
if epilogue == 'add-cols':
z_ref += z[0, :][None, :]
if epilogue == 'softmax':
num = np.exp(z_ref - np.max(z_ref, axis=-1, keepdims=True))
denom = np.sum(num, axis=-1, keepdims=True)
z_ref = num / denom
if epilogue == 'chain-dot':
z_ref = np.matmul(z_ref.T if trans_a else z_ref, w)
# compare
# print(z_ref[:,0], z_tri[:,0])
np.testing.assert_allclose(z_ref, to_numpy(z_tri), rtol=0.01)
# make sure ld/st are vectorized
ptx = pgm.asm['ptx']