[BUG] Accuracy Error in CUTLASS GEMM operations.

Describe the bug
The result of accuracy of GEMM operation in CUTLASS (TensorOp, Simt) does not fully match accuracy of cuBLAS GEMM result.

Steps/Code to reproduce bug

using GEMM = cutlass::gemm::device::Gemm<
                            /*ElementA_ = */ float,
                            /*LayoutA_ = */ cutlass::layout::RowMajor,
                            /*ElementB_ = */ float,
                            /*LayoutB_ = */ cutlass::layout::ColumnMajor,
                            /*ElementC_ = */ float,
                            /*LayoutC_ = */ cutlass::layout::RowMajor,
                            /*ElementAccumulator_ = */ float,
                            /*OperatorClass_ = */ cutlass::arch::OpClassSimt,
                            /*ArchTag_ = */ cutlass::arch::Sm50,
                            /*ThreadblockShape_ = */ cutlass::gemm::GemmShape<128, 128, 8>,
                            /*WarpShape_ = */ cutlass::gemm::GemmShape<32, 64, 8>,
                            /*InstructionShape_ = */ cutlass::gemm::GemmShape<1, 1, 1>,
                            /*EpilogueOutputOp_ = */ cutlass::epilogue::thread::LinearCombination<float, 1, float, float, cutlass::epilogue::thread::ScaleType::Nothing, cutlass::FloatRoundStyle::round_to_nearest>,
                            /*ThreadblockSwizzle_ = */ cutlass::gemm::threadblock::GemmIdentityThreadblockSwizzle<4>,
                            /*Stages = */ 2,
                            /*AlignmentA = */ 1,
                            /*AlignmentB = */ 1,
                            /*SplitKSerial = */ false,
                            /* operator = */ cutlass::arch::OpMultiplyAdd
                            >;
    GEMM gemm_operator;
    GEMM::Arguments args({m, n, k},
                        {reinterpret_cast<float *>(A.data_ptr()), k},
                        {reinterpret_cast<float *>(B.data_ptr()), k},
                        {reinterpret_cast<float *>(C.data_ptr()), n},
                        {reinterpret_cast<float *>(C.data_ptr()), n},
                        {float(1.0f), float(0.0f)});
    gemm_operator(args);

Expected behavior

I compare cuBLAS, and CUTLASS GEMM result using both bfloat16 and float32 precision to check CUTLASS get accurate result.
The code shown above is a portion of CUTLASS implementation for float32 data type.
I integrated the implementation into PyTorch via Pybind11 and verified its correctness by comparing the outputs with nn.Linear using absolute tolerance (atol) of 1e-6 and relative tolerance (rtol) of 1e-5.
Typically, the absolute difference is around 1e-3.
How should I improve this?

Environment details (please complete the following information):

• CUDA 12.4
• HW: RTX4070TI

Thank you.

Start with the provided cutlass::gemm::device::Gemm configuration and reproduce its float32 result against cuBLAS on the stated CUDA 12.4 and RTX4070TI environment. Compare the numerical behavior across the shown configuration and inputs; the issue is complete when the accuracy discrepancy is explained and a concrete correction or expected tolerance is established.