Remove HNativeDebugInfo from start of basic blocks.

We do not require full environment at the start of basic block.
The dex pc contained in basic block is sufficient for line mapping.

Change-Id: I5ba9e5f5acbc4a783ad544769f9a73bb33e2bafa

1 files changed, 4 insertions, 13 deletions

diff --git a/compiler/optimizing/builder.cc b/compiler/optimizing/builder.cc
index 05e1356ed8..35ec7d41ff 100644
--- a/compiler/optimizing/builder.cc
+++ b/compiler/optimizing/builder.cc
@@ -368,7 +368,6 @@ GraphAnalysisResult HGraphBuilder::BuildGraph(const DexFile::CodeItem& code_item
   if (native_debuggable) {
     const uint32_t num_instructions = code_item.insns_size_in_code_units_;
     native_debug_info_locations = new (arena_) ArenaBitVector (arena_, num_instructions, false);
-    native_debug_info_locations->ClearAllBits();
     FindNativeDebugInfoLocations(code_item, native_debug_info_locations);
   }
 
@@ -443,23 +442,15 @@ void HGraphBuilder::FindNativeDebugInfoLocations(const DexFile::CodeItem& code_i
     }
   };
   dex_file_->DecodeDebugPositionInfo(&code_item, Callback::Position, locations);
-  // Add native debug info at the start of every basic block.
-  for (uint32_t pc = 0; pc < code_item.insns_size_in_code_units_; pc++) {
-    if (FindBlockStartingAt(pc) != nullptr) {
-      locations->SetBit(pc);
-    }
-  }
   // Instruction-specific tweaks.
   const Instruction* const begin = Instruction::At(code_item.insns_);
   const Instruction* const end = begin->RelativeAt(code_item.insns_size_in_code_units_);
   for (const Instruction* inst = begin; inst < end; inst = inst->Next()) {
     switch (inst->Opcode()) {
-      case Instruction::MOVE_EXCEPTION:
-      case Instruction::MOVE_RESULT:
-      case Instruction::MOVE_RESULT_WIDE:
-      case Instruction::MOVE_RESULT_OBJECT: {
-        // The compiler checks that there are no instructions before those.
-        // So generate HNativeDebugInfo after them instead.
+      case Instruction::MOVE_EXCEPTION: {
+        // Stop in native debugger after the exception has been moved.
+        // The compiler also expects the move at the start of basic block so
+        // we do not want to interfere by inserting native-debug-info before it.
         locations->ClearBit(inst->GetDexPc(code_item.insns_));
         const Instruction* next = inst->Next();
         if (next < end) {