I want to pad my matrix but tvm wipe the paddings when lowering

I just write a matrix multiplication computation, and here is my code, it is easy

A = te.placeholder((49, 576))
B = te.placeholder((64, 576))
D = topi.nn.pad(A, (0, 0), (15, 0))
k = te.reduce_axis((0, 576))
C = te.compute(
    (64, 64),
    lambda i, j: te.sum(
        D(i, k) * B(j, k),
        axis=[k]
    )
)
E = topi.nn.pad(C, (0, 0), (-15, 0))

s = te.create_schedule(E.op)
code = tvm.lower(s, [A, B, E], simple_mode=True)
print(code)

I want to pad D to (64, 576) then I can do tensorize of (16, 16) in the matrix multiplication. But I got the tir like this:

primfn(placeholder_2: handle, placeholder_3: handle, PadInput_1: handle) -> ()
  attr = {"global_symbol": "main", "tir.noalias": True}
  buffers = {PadInput: Buffer(PadInput_2: Pointer(float32), float32, [49, 64], []),
             placeholder: Buffer(placeholder_4: Pointer(float32), float32, [49, 576], []),
             placeholder_1: Buffer(placeholder_5: Pointer(float32), float32, [64, 576], [])}
  buffer_map = {placeholder_2: placeholder, placeholder_3: placeholder_1, PadInput_1: PadInput} {
  attr [PadInput_3: Pointer(float32)] "storage_scope" = "global";
  allocate(PadInput_3, float32, [28224]);
  attr [compute: Pointer(float32)] "storage_scope" = "global";
  allocate(compute, float32, [3136]) {
    for (i0: int32, 0, 49) {
      for (i1: int32, 0, 576) {
        PadInput_3[((i0*576) + i1)] = (float32*)placeholder_4[((i0*576) + i1)]
      }
    }
    for (i: int32, 0, 49) {
      for (j: int32, 0, 64) {
        compute[((i*64) + j)] = 0f32
        for (rv: int32, 0, 576) {
          compute[((i*64) + j)] = ((float32*)compute[((i*64) + j)] + ((float32*)PadInput_3[((i*576) + rv)]*(float32*)placeholder_5[((j*576) + rv)]))
        }
      }
    }
    for (i0_1: int32, 0, 49) {
      for (i1_1: int32, 0, 64) {
        PadInput_2[((i0_1*64) + i1_1)] = (float32*)compute[((i0_1*64) + i1_1)]
      }
    }
  }
}

It seems like the padding I did was eliminated because tvm might think it is useless. But it is important in my scheduling. So is there anybody can tell me, is there an option to shut down the elimination? Thanks a lot!