fix comments

test=develop

paddle/fluid/inference/api/demo_ci/vis_demo.cc

@@ -82,12 +82,10 @@ void Main(bool use_gpu) {
 
 int main(int argc, char** argv) {
   google::ParseCommandLineFlags(&argc, &argv, true);
-#if CUDNN_VERSION >= 7100
   if (FLAGS_use_gpu) {
     paddle::demo::Main(true /*use_gpu*/);
   } else {
     paddle::demo::Main(false /*use_gpu*/);
   }
-#endif
   return 0;
 }

paddle/fluid/inference/api/paddle_pass_builder.h

@@ -158,9 +158,12 @@ class GpuPassStrategy : public PassStrategy {
           "conv_affine_channel_fuse_pass",             //
           "conv_eltwiseadd_affine_channel_fuse_pass",  //
           "conv_bn_fuse_pass",                         //
+#if CUDNN_VERSION >= 7100  // To run conv_fusion, the version of cudnn must be
+                           // guaranteed at least v7
           "conv_elementwise_add_act_fuse_pass",   //
           "conv_elementwise_add2_act_fuse_pass",  //
           "conv_elementwise_add_fuse_pass",       //
+#endif
     });
 
     for (int i = 6; i >= 3; i--) {

paddle/fluid/inference/tests/api/CMakeLists.txt

@@ -144,8 +144,7 @@ if (WITH_ANAKIN AND WITH_MKL) # only needed in CI
     endif()
 endif()
 
-if (NOT ${CUDNN_VERSION} VERSION_LESS 7100)
-  if(WITH_GPU AND TENSORRT_FOUND)
+if(WITH_GPU AND TENSORRT_FOUND)
     set(TRT_MODEL_INSTALL_DIR "${INFERENCE_DEMO_INSTALL_DIR}/trt")
     if (NOT EXISTS ${TRT_MODEL_INSTALL_DIR})
         inference_download_and_uncompress(${TRT_MODEL_INSTALL_DIR} ${INFERENCE_URL}/tensorrt_test "trt_test_models.tar.gz")
@@ -153,5 +152,4 @@ if (NOT ${CUDNN_VERSION} VERSION_LESS 7100)
     inference_analysis_test(test_trt_models SRCS trt_models_tester.cc
             EXTRA_DEPS ${INFERENCE_EXTRA_DEPS}
             ARGS --infer_model=${TRT_MODEL_INSTALL_DIR}/trt_test_models SERIAL)
-  endif()
 endif()