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@ita9naiwa
Created August 25, 2025 20:15
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sm_120.py
import torch
import triton
import triton.language as tl
@triton.jit
def mxfp_matmul(
a_ptr, b_ptr, output_ptr,
a_scale, b_scale,
M, N, K,
stride_scale: tl.constexpr,
stride_am, stride_ak,
stride_bk, stride_bn,
stride_cm, stride_cn,
BLOCK_M: tl.constexpr, BLOCK_N: tl.constexpr, BLOCK_K: tl.constexpr,
NUM_STAGES: tl.constexpr):
pid = tl.program_id(axis=0)
num_pid_m = tl.cdiv(M, BLOCK_M)
pid_m = pid % num_pid_m
pid_n = pid // num_pid_m
offs_am = (pid_m * BLOCK_M + tl.arange(0, BLOCK_M)) % M
offs_bn = (pid_n * BLOCK_N + tl.arange(0, BLOCK_N)) % N
offs_k = tl.arange(0, BLOCK_K)
offs_scale_k = tl.arange(0, BLOCK_K // 32)
a_scale_ptr = a_scale + offs_am[:, None] * stride_scale + offs_scale_k[None, :]
b_scale_ptr = b_scale + offs_bn[:, None] * stride_scale + offs_scale_k[None, :]
a_ptrs = a_ptr + (offs_am[:, None] * stride_am + offs_k[None, :] * stride_ak)
b_ptrs = b_ptr + (offs_k[:, None] * stride_bk + offs_bn[None, :] * stride_bn)
accumulator = tl.zeros((BLOCK_M, BLOCK_N), dtype=output_ptr.dtype.element_ty)
for k in tl.range(0, tl.cdiv(K, BLOCK_K), num_stages=NUM_STAGES):
a = tl.load(a_ptrs)
b = tl.load(b_ptrs)
scale_a = tl.load(a_scale_ptr)
scale_b = tl.load(b_scale_ptr)
accumulator = tl.dot_scaled(a, scale_a, 'e5m2', b, scale_b, 'e5m2', accumulator)
a_ptrs += BLOCK_K * stride_ak
b_ptrs += BLOCK_K * stride_bk
a_scale_ptr += BLOCK_K // 32
b_scale_ptr += BLOCK_K // 32
c_ptrs = output_ptr + stride_cm * offs_am[:, None] + stride_cn * offs_bn[None, :]
tl.store(c_ptrs, accumulator)
# Test with NUM_CTAS=2
device = 'cuda'
M, N, K = 128, 128, 128
BLOCK_M, BLOCK_N, BLOCK_K = 128, 128, 128
NUM_STAGES = 1
torch.manual_seed(42)
a = torch.randint(20, 40, (M, K), dtype=torch.uint8, device=device).view(torch.float8_e5m2)
b = torch.randint(20, 40, (K, N), dtype=torch.uint8, device=device).view(torch.float8_e5m2)
a_scale = torch.randint(64, 130, (M, K // 32), dtype=torch.uint8, device=device)
b_scale = torch.randint(64, 130, (N, K // 32), dtype=torch.uint8, device=device)
output = torch.empty((M, N), dtype=torch.float32, device=device)
grid = (triton.cdiv(M, BLOCK_M) * triton.cdiv(N, BLOCK_N), 1)
print("Testing with NUM_CTAS=2...")
try:
out = mxfp_matmul[grid](
a, b, output, a_scale, b_scale, M, N, K,
a_scale.stride(0), a.stride(0), a.stride(1),
b.stride(0), b.stride(1), output.stride(0), output.stride(1),
BLOCK_M, BLOCK_N, BLOCK_K,
NUM_STAGES=NUM_STAGES, num_warps=4, num_ctas=2
)
print('Success with NUM_CTAS=2')
except RuntimeError as e:
print(f'Failed with NUM_CTAS=2:\n{str(e)[:2000]}')
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