add some int8 option

paddle/fluid/lite/api/cxx_api.h

@@ -50,6 +50,7 @@ class ExecutorLite {
     optimizer_.KernelPickPreferPlace(prefer_place);
     core::KernelPickFactor factor;
     factor.ConsiderTarget();
+    factor.ConsiderPrecision();
     optimizer_.Run(std::move(program), valid_places, factor);
     program_ = optimizer_.GenRuntimeProgram();
   }

paddle/fluid/lite/core/mir/fusion/quant_dequant_op_fuser.h

@@ -25,7 +25,7 @@ namespace fusion {
 
 /* The model trained by fluid quantization is a simulation of real int8.
  * The quantized Ops(conv2d, mul, depthwise conv2d etc) have fake_quantop
- * in front  and fake_dequantop behind.
+ * in front and fake_dequantop behind.
  *
  * When in int8 mode, the pattern like "fake_quant + quantized_op +
  * fake_dequant"

paddle/fluid/lite/core/mir/pattern_matcher_high_api.cc

@@ -41,7 +41,7 @@ void FuseBase::DeleteInterNodes(SSAGraph *graph) {
     }
   }
 
-  LOG(INFO) << "keys: " << key2nodes_.size();
+  VLOG(4) << "keys: " << key2nodes_.size();
   std::unordered_set<const Node *> nodes2rm;
   for (auto &matched : key2nodes_) {
     for (const auto &key : keys) {

paddle/fluid/lite/core/op_registry.cc

@@ -96,6 +96,7 @@ KernelRegistry::KernelRegistry()
   INIT_FOR(kX86, kAny, kAny);
 
   INIT_FOR(kARM, kFloat, kNCHW);
+  INIT_FOR(kARM, kInt8, kNCHW);
   INIT_FOR(kARM, kAny, kNCHW);
   INIT_FOR(kARM, kAny, kAny);
 #undef INIT_FOR

paddle/fluid/lite/core/op_registry.h

@@ -80,6 +80,8 @@ class KernelRegistry final {
               KernelRegistryForTarget<TARGET(kARM), PRECISION(kAny),
                                       DATALAYOUT(kAny)> *,  //
               KernelRegistryForTarget<TARGET(kARM), PRECISION(kFloat),
+                                      DATALAYOUT(kNCHW)> *,  //
+              KernelRegistryForTarget<TARGET(kARM), PRECISION(kInt8),
                                       DATALAYOUT(kNCHW)> *  //
               >;
 

paddle/fluid/lite/core/optimizer.h

@@ -58,7 +58,6 @@ class Optimizer {
 #ifdef LITE_WITH_LIGHT_WEIGHT_FRAMEWORK
           "lite_elementwise_add_activation_fuse_pass",  //
 #endif
-          "lite_fc_fuse_pass",              //
           "static_kernel_pick_pass",        //
           "variable_place_inference_pass",  //
           "argument_type_display_pass",     //