[LITE][PASS] Fix static kernel pick pass, if op is not int8, but kernel is...

[LITE][PASS] Fix static kernel pick pass, if op is not int8, but kernel is int8. test=develop (#2526)

lite/core/mir/static_kernel_pick_pass.cc

@@ -49,7 +49,7 @@ void StaticKernelPickPass::Apply(const std::unique_ptr<SSAGraph>& graph) {
                                        << instruct.op_type();
     VLOG(4) << "instruct.kernels().size():" << instruct.kernels().size();
     for (auto&& kernel : instruct.kernels()) {
-      float score = KernelGrade(*kernel, graph->valid_places());
+      float score = KernelGrade(instruct, *kernel, graph->valid_places());
       VLOG(4) << "kernel->summary():" << kernel->summary()
               << " score:" << score;
       scored.emplace_back(score, std::move(kernel));
@@ -99,7 +99,7 @@ void StaticKernelPickPass::Apply(const std::unique_ptr<SSAGraph>& graph) {
         instruct.ResetOp(update_desc, graph->valid_places());
         scored.clear();
         for (auto&& kernel : instruct.kernels()) {
-          float score = KernelGrade(*kernel, graph->valid_places());
+          float score = KernelGrade(instruct, *kernel, graph->valid_places());
           scored.emplace_back(score, std::move(kernel));
         }
         std::sort(scored.begin(), scored.end(), KernelScoreCmp);

lite/core/mir/static_kernel_pick_pass.h

@@ -48,7 +48,8 @@ class StaticKernelPickPass : public mir::StmtPass {
 
  private:
   // Score the kernel.
-  size_t KernelGrade(const lite::KernelBase& kernel,
+  size_t KernelGrade(const lite::mir::Node::Stmt& instruct,
+                     const lite::KernelBase& kernel,
                      const std::vector<Place>& places) {
     CHECK_GT(places.size(), 0) << "valid_places is empty.";
     float final_score{-1.};
@@ -66,7 +67,7 @@ class StaticKernelPickPass : public mir::StmtPass {
     // valid_places.size() as default.
     //         where i is the place's index in valid_places array.
     // score:  score is the weighted sum of target、percision and layout
-    for (int i = 0; i < place_size; ++i) {
+    for (size_t i = 0; i < place_size; ++i) {
       const auto& place = places[i];
       float weight = static_cast<float>(place_size - i) / place_size;
       size_t score{};
@@ -83,9 +84,13 @@ class StaticKernelPickPass : public mir::StmtPass {
           (place.precision == kernel.precision() ||
            kernel.precision() == PRECISION(kAny) ||
            place.precision == PRECISION(kAny))) {
+        // score skipped, if kernel is int8, but op is not int8
+        if (!(kernel.precision() == PRECISION(kInt8) &&
+              !instruct.op_info()->HasAttr("enable_int8"))) {
           score += kMax / static_cast<int>(
                               core::KernelPickFactor::Factor::PrecisionFirst);
         }
+      }
       VLOG(4) << "[score s2]:" << score;
       if (kernel_pick_factors_.IsDataLayoutConsidered() &&
           (place.layout == kernel.layout() ||