NVFP4-1.1: add Int32 cast diagnostic test

tests/unit/test_int32_cast.py

@@ -0,0 +1,31 @@
+"""Quick test: Float32 to Int32 conversion in CuTeDSL."""
+import torch
+import cutlass
+import cutlass.cute as cute
+import cutlass.torch as cutlass_torch
+
+
+@cute.kernel
+def test_int32_cast_kernel(
+    input_f32: cute.Tensor,
+    output_i32: cute.Tensor,
+):
+    tidx, _, _ = cute.arch.thread_idx()
+    if tidx == cutlass.Int32(0):
+        f = cute.arch.load(input_f32.iterator, cutlass.Float32)
+        i = cutlass.Int32(f)  # float-to-int conversion
+        cute.arch.store(output_i32.iterator, i, cutlass.Int32)
+
+
+if __name__ == "__main__":
+    x = torch.tensor([3.7], dtype=torch.float32, device='cuda')
+    out = torch.zeros(1, dtype=torch.int32, device='cuda')
+    xc = cutlass_torch.from_dlpack(x).mark_layout_dynamic(leading_dim=0)
+    oc = cutlass_torch.from_dlpack(out).mark_layout_dynamic(leading_dim=0)
+    import cuda.bindings.driver as cuda
+    stream = cuda.CUstream(torch.cuda.current_stream().cuda_stream)
+    print("Compiling...")
+    compiled = cute.compile(test_int32_cast_kernel, xc, oc)
+    print("Running...")
+    compiled(xc, oc)
+    print(f'Result: {out.item()} (3=trunc, 4=RNE)')