Fix assertion error on gemm_splitk_benchmark.py (#2717)

The cause of this error is that we should initialize the results tensor
when using `atomic_add`, otherwise it would read dirty memory from
previous benchmarking cases.

Author: leonling-ll

benchmarks/triton_kernels_benchmark/gemm_splitk_benchmark.py

@@ -128,6 +128,7 @@ def forward(ctx, a, b, c, acc_dtype=None):
             [512, 32768, 8192],
             [1024, 28672, 8192],
             [3072, 4096, 3072],
+            [4096, 4096, 4096],
         ],
         line_arg='provider',
         # argument name whose value corresponds to a different line in the plot
@@ -152,17 +153,17 @@ def benchmark(M, N, K, provider):
         _, min_ms, max_ms, mean_ms, cv = benchmark_suit.do_bench(lambda: torch.matmul(a, b), n_warmup=10, n_repeat=10,
                                                                  quantiles=quantiles)
     elif provider == 'triton':
-        c = torch.empty((M, N), device='xpu', dtype=torch.float32)
+        c = torch.zeros((M, N), device='xpu', dtype=torch.float32)
         triton_fn = lambda: matmul(a, b, c)
         torch_fn = lambda: torch.matmul(a, b).to(torch.float32)
         rtol = 1e-2 if a.dtype == torch.bfloat16 else 1e-3
         benchmark_suit.assert_close(triton_fn(), torch_fn(), atol=1e-4, rtol=rtol, err_msg='triton to torch')
         _, min_ms, max_ms, mean_ms, cv = benchmark_suit.do_bench(triton_fn, n_warmup=10, n_repeat=10,
                                                                  quantiles=quantiles, kernel_name='_kernel')
     elif provider == 'xetla':
-        c = torch.empty((M, N), device='xpu', dtype=torch.float32)
-        acc = torch.empty((M, N), device='xpu', dtype=torch.float32)
-        cnt = torch.empty((M, N), device='xpu', dtype=torch.int32)
+        c = torch.zeros((M, N), device='xpu', dtype=torch.float32)
+        acc = torch.zeros((M, N), device='xpu', dtype=torch.float32)
+        cnt = torch.zeros((M, N), device='xpu', dtype=torch.int32)
 
         name = f'gemm_splitk_shape_{M}_{K}_{N}'
         func = getattr(xetla_kernel, name)

benchmarks/triton_kernels_benchmark/gemm_streamk_benchmark.py

@@ -275,17 +275,17 @@ def benchmark(M, N, K, provider):
         _, min_ms, max_ms, mean_ms, cv = benchmark_suit.do_bench(lambda: torch.matmul(a, b), n_warmup=10, n_repeat=10,
                                                                  quantiles=quantiles)
     elif provider == 'triton':
-        c = torch.empty((M, N), device=a.device, dtype=torch.float32)
+        c = torch.zeros((M, N), device=a.device, dtype=torch.float32)
         triton_fn = lambda: matmul(a, b, c)
         torch_fn = lambda: torch.matmul(a, b).to(torch.float32)
         benchmark_suit.assert_close(triton_fn(), torch_fn(), atol=1e-4, rtol=1e-2, err_msg='triton to torch')
         _, min_ms, max_ms, mean_ms, cv = benchmark_suit.do_bench(triton_fn, n_warmup=10, n_repeat=10,
                                                                  quantiles=quantiles,
                                                                  kernel_name=['first_wave', 'full_tiles'])
     elif provider == 'xetla':
-        c = torch.empty((M, N), device='xpu', dtype=torch.float32)
-        acc = torch.empty((M, N), device='xpu', dtype=torch.float32)
-        cnt = torch.empty((M, N), device='xpu', dtype=torch.int32)
+        c = torch.zeros((M, N), device='xpu', dtype=torch.float32)
+        acc = torch.zeros((M, N), device='xpu', dtype=torch.float32)
+        cnt = torch.zeros((M, N), device='xpu', dtype=torch.int32)
 
         name = f'gemm_streamk_shape_{M}_{K}_{N}'
         func = getattr(xetla_kernel, name)

benchmarks/xetla_kernel/python_main.cpp

@@ -317,6 +317,9 @@ PYBIND11_MODULE(xetla_kernel, m) {
   m.def("gemm_splitk_shape_3072_4096_3072",
         &bf16_split_k_gemm<3072, 4096, 3072, kslicing_impl_t::global>,
         "bf16_gemm_splitk (XeTLA)");
+  m.def("gemm_splitk_shape_4096_4096_4096",
+        &bf16_split_k_gemm<4096, 4096, 4096, kslicing_impl_t::global>,
+        "bf16_gemm_splitk (XeTLA)");
   // flash_attn
   m.def("flash_attn_causal_false", &flash_attn<false, false, false>,
         "flash attn fwd (XeTLA)");