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nvfp4-megamoe-kernel/tests/unit/test_fmha_pv16.py
2026-05-28 19:12:23 +00:00

53 lines
1.4 KiB
Python

"""Test FMHA with pv_n_tile=16 (N=16 sub-tiles for PV GEMM)."""
import torch
import math
import sys
import os
sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..', '..'))
from dsv4.kernels.attention.production import dsv4_attention_per_head
def test_fmha_pv16(hd):
sk = 128
scale = 1.0 / math.sqrt(hd)
torch.manual_seed(42)
q = torch.randn(1, 1, hd, dtype=torch.bfloat16, device='cuda')
k = torch.randn(sk, hd, dtype=torch.bfloat16, device='cuda')
v = torch.randn(hd, sk, dtype=torch.bfloat16, device='cuda')
o = dsv4_attention_per_head(q, k, v, scale=scale, swa_len=sk)
# Reference
q_ref = q[0, 0].float()
k_ref = k.float()
v_ref = v.float()
s = (q_ref @ k_ref.T) * scale
p = torch.softmax(s, dim=-1)
o_ref = (p @ v_ref.T).to(torch.bfloat16)
o_f = o[0, 0].float()
o_ref_f = o_ref.float()
cs = torch.nn.functional.cosine_similarity(o_f.unsqueeze(0), o_ref_f.unsqueeze(0)).item()
print(f"HD={hd} pv_n_tile=16: cosine={cs:.8f}")
if cs < 0.999:
print(f" FAILED")
print(f" o[0:4] = {o_f[0:4].tolist()}")
print(f" o_ref[0:4] = {o_ref_f[0:4].tolist()}")
return False
print(f" PASSED")
return True
if __name__ == '__main__':
all_pass = True
for hd in [16, 64, 128]:
if not test_fmha_pv16(hd):
all_pass = False
sys.exit(0 if all_pass else 1)