"""D1: Test hd=64 only with CUDA_LAUNCH_BLOCKING for crash debug."""
import os
os.environ['CUDA_LAUNCH_BLOCKING'] = '1'
import torch, math
import cutlass.cute as cute
import cutlass.torch as ct
import cuda.bindings.driver as cuda
from dsv4.kernels.attention.fmha import FmhaKernel

hd = 64; n = 128; m = 128
torch.manual_seed(42)
q = torch.randn(m, hd, 1, dtype=torch.bfloat16, device='cuda')
k = torch.randn(n, hd, 1, dtype=torch.bfloat16, device='cuda')
v = torch.randn(n, hd, dtype=torch.bfloat16, device='cuda')
c = torch.zeros(m, hd, 1, dtype=torch.bfloat16, device='cuda')
qf = q[:,:,0].float(); kf = k[:,:,0].float()
scale = 1.0 / math.sqrt(hd)
attn = qf @ kf.T * scale; attn = torch.softmax(attn, dim=-1)
ref = attn @ v.float()
v_kernel = v.unsqueeze(-1)
mQ = ct.from_dlpack(q).mark_layout_dynamic(leading_dim=ct.get_leading_dim(q))
mK = ct.from_dlpack(k).mark_layout_dynamic(leading_dim=ct.get_leading_dim(k))
mV = ct.from_dlpack(v_kernel).mark_layout_dynamic(leading_dim=ct.get_leading_dim(v_kernel))
mC = ct.from_dlpack(c).mark_layout_dynamic(leading_dim=ct.get_leading_dim(c))
stream = cuda.CUstream(torch.cuda.current_stream().cuda_stream)
kernel = FmhaKernel(head_dim=hd, s_k=n)
print(f'Compiling hd={hd}...', flush=True)
compiled = cute.compile(kernel, mQ, mK, mV, mC, stream)
print(f'Running hd={hd}...', flush=True)
compiled(mQ, mK, mV, mC, stream)
torch.cuda.synchronize()
out = c[:,:,0].float()
cos = torch.nn.functional.cosine_similarity(out.flatten().unsqueeze(0), ref.flatten().unsqueeze(0)).item()
print(f'hd={hd}: cos {cos:.6f}')