add marco control and load elementwise sub op

src/framework/load_ops.h

@@ -206,5 +206,8 @@ LOAD_OP2(slice, CPU, MALI_GPU);
 LOAD_OP2(fusion_conv_bn, CPU, FPGA);
 LOAD_FUSION_MATCHER(fusion_conv_bn);
 #endif
+#ifdef ELEMENTWISESUB_OP
+LOAD_OP1(elementwise_sub, CPU)
+#endif
 LOAD_OP1(quantize, CPU);
 LOAD_OP1(dequantize, CPU);

src/operators/op_param.h

@@ -488,6 +488,7 @@ template <typename Dtype>
 using ElementwiseAddReluParam = ElementwiseAddParam<Dtype>;
 #endif
 
+#ifdef ELEMENTWISESUB_OP
 template <typename Dtype>
 class ElementwiseSubParam : OpParam {
   typedef typename DtypeTensorTrait<Dtype>::gtype GType;
@@ -517,6 +518,7 @@ class ElementwiseSubParam : OpParam {
   GType *out_;
   int axis_;
 };
+#endif
 
 #ifdef MUL_OP
 template <typename Dtype>