1 files changed, 95 insertions, 77 deletions

diff --git a/compiler/optimizing/builder.cc b/compiler/optimizing/builder.cc
index 732630d76b..fe52c44306 100644
--- a/compiler/optimizing/builder.cc
+++ b/compiler/optimizing/builder.cc
@@ -259,14 +259,20 @@ bool HGraphBuilder::SkipCompilation(const DexFile::CodeItem& code_item,
   return false;
 }
 
-bool HGraphBuilder::IsBlockInPcRange(HBasicBlock* block,
-                                     uint32_t dex_pc_start,
-                                     uint32_t dex_pc_end) {
-  uint32_t dex_pc = block->GetDexPc();
-  return block != entry_block_
-      && block != exit_block_
-      && dex_pc >= dex_pc_start
-      && dex_pc < dex_pc_end;
+static const DexFile::TryItem* GetTryItem(HBasicBlock* block,
+                                          const DexFile::CodeItem& code_item,
+                                          const ArenaBitVector& can_block_throw) {
+  DCHECK(!block->IsSingleTryBoundary());
+
+  // Block does not contain throwing instructions. Even if it is covered by
+  // a TryItem, we will consider it not in a try block.
+  if (!can_block_throw.IsBitSet(block->GetBlockId())) {
+    return nullptr;
+  }
+
+  // Instructions in the block may throw. Find a TryItem covering this block.
+  int32_t try_item_idx = DexFile::FindTryItem(code_item, block->GetDexPc());
+  return (try_item_idx == -1) ? nullptr : DexFile::GetTryItems(code_item, try_item_idx);
 }
 
 void HGraphBuilder::CreateBlocksForTryCatch(const DexFile::CodeItem& code_item) {
@@ -327,80 +333,90 @@ void HGraphBuilder::InsertTryBoundaryBlocks(const DexFile::CodeItem& code_item)
     return;
   }
 
+  // Bit vector stores information on which blocks contain throwing instructions.
+  // Must be expandable because catch blocks may be split into two.
+  ArenaBitVector can_block_throw(arena_, graph_->GetBlocks().Size(), /* expandable */ true);
+
+  // Scan blocks and mark those which contain throwing instructions.
+  for (size_t block_id = 0, e = graph_->GetBlocks().Size(); block_id < e; ++block_id) {
+    HBasicBlock* block = graph_->GetBlocks().Get(block_id);
+    bool can_throw = false;
+    for (HInstructionIterator insn(block->GetInstructions()); !insn.Done(); insn.Advance()) {
+      if (insn.Current()->CanThrow()) {
+        can_throw = true;
+        break;
+      }
+    }
+
+    if (can_throw) {
+      if (block->IsCatchBlock()) {
+        // Catch blocks are always considered an entry point into the TryItem in
+        // order to avoid splitting exceptional edges. We split the block after
+        // the move-exception (if present) and mark the first part non-throwing.
+        // Later on, a TryBoundary will be inserted between the two blocks.
+        HInstruction* first_insn = block->GetFirstInstruction();
+        if (first_insn->IsLoadException()) {
+          // Catch block starts with a LoadException. Split the block after the
+          // StoreLocal that must come after the load.
+          DCHECK(first_insn->GetNext()->IsStoreLocal());
+          block = block->SplitBefore(first_insn->GetNext()->GetNext());
+        } else {
+          // Catch block does not load the exception. Split at the beginning to
+          // create an empty catch block.
+          block = block->SplitBefore(first_insn);
+        }
+      }
+      can_block_throw.SetBit(block->GetBlockId());
+    }
+  }
+
   // Iterate over all blocks, find those covered by some TryItem and:
   //   (a) split edges which enter/exit the try range,
   //   (b) create TryBoundary instructions in the new blocks,
   //   (c) link the new blocks to corresponding exception handlers.
   // We cannot iterate only over blocks in `branch_targets_` because switch-case
   // blocks share the same dex_pc.
-  for (size_t block_id = 1, e = graph_->GetBlocks().Size(); block_id < e; ++block_id) {
+  for (size_t block_id = 0, e = graph_->GetBlocks().Size(); block_id < e; ++block_id) {
     HBasicBlock* try_block = graph_->GetBlocks().Get(block_id);
 
-    // Iteration starts from 1 to skip the entry block.
-    DCHECK_NE(try_block, entry_block_);
-    // Exit block has not yet been added to the graph at this point.
-    DCHECK_NE(try_block, exit_block_);
     // TryBoundary blocks are added at the end of the list and not iterated over.
     DCHECK(!try_block->IsSingleTryBoundary());
 
     // Find the TryItem for this block.
-    int32_t try_item_idx = DexFile::FindTryItem(code_item, try_block->GetDexPc());
-    if (try_item_idx == -1) {
+    const DexFile::TryItem* try_item = GetTryItem(try_block, code_item, can_block_throw);
+    if (try_item == nullptr) {
       continue;
     }
-    const DexFile::TryItem& try_item = *DexFile::GetTryItems(code_item, try_item_idx);
-    uint32_t try_start = try_item.start_addr_;
-    uint32_t try_end = try_start + try_item.insn_count_;
-
-    if (try_block->IsCatchBlock()) {
-      // Catch blocks are always considered an entry point into the TryItem in
-      // order to avoid splitting exceptional edges (they might not have been
-      // created yet). We separate the move-exception (if present) from the
-      // rest of the block and insert a TryBoundary after it, creating a
-      // landing pad for the exceptional edges.
-      HInstruction* first_insn = try_block->GetFirstInstruction();
-      HInstruction* split_position = nullptr;
-      if (first_insn->IsLoadException()) {
-        // Catch block starts with a LoadException. Split the block after the
-        // StoreLocal that must come after the load.
-        DCHECK(first_insn->GetNext()->IsStoreLocal());
-        split_position = first_insn->GetNext()->GetNext();
-      } else {
-        // Catch block does not obtain the exception. Split at the beginning
-        // to create an empty catch block.
-        split_position = first_insn;
-      }
-      DCHECK(split_position != nullptr);
-      HBasicBlock* catch_block = try_block;
-      try_block = catch_block->SplitBefore(split_position);
-      SplitTryBoundaryEdge(catch_block, try_block, HTryBoundary::kEntry, code_item, try_item);
-    } else {
-      // For non-catch blocks, find predecessors which are not covered by the
-      // same TryItem range. Such edges enter the try block and will have
-      // a TryBoundary inserted.
-      for (size_t i = 0; i < try_block->GetPredecessors().Size(); ++i) {
-        HBasicBlock* predecessor = try_block->GetPredecessors().Get(i);
-        if (predecessor->IsSingleTryBoundary()) {
-          // The edge was already split because of an exit from a neighbouring
-          // TryItem. We split it again and insert an entry point.
-          if (kIsDebugBuild) {
-            HTryBoundary* last_insn = predecessor->GetLastInstruction()->AsTryBoundary();
-            DCHECK(!last_insn->IsEntry());
-            DCHECK_EQ(last_insn->GetNormalFlowSuccessor(), try_block);
-            DCHECK(try_block->IsFirstIndexOfPredecessor(predecessor, i));
-            DCHECK(!IsBlockInPcRange(predecessor->GetSinglePredecessor(), try_start, try_end));
-          }
-        } else if (!IsBlockInPcRange(predecessor, try_start, try_end)) {
-          // This is an entry point into the TryItem and the edge has not been
-          // split yet. That means that `predecessor` is not in a TryItem, or
-          // it is in a different TryItem and we happened to iterate over this
-          // block first. We split the edge and insert an entry point.
-        } else {
-          // Not an edge on the boundary of the try block.
-          continue;
+
+    // Catch blocks were split earlier and cannot throw.
+    DCHECK(!try_block->IsCatchBlock());
+
+    // Find predecessors which are not covered by the same TryItem range. Such
+    // edges enter the try block and will have a TryBoundary inserted.
+    for (size_t i = 0; i < try_block->GetPredecessors().Size(); ++i) {
+      HBasicBlock* predecessor = try_block->GetPredecessors().Get(i);
+      if (predecessor->IsSingleTryBoundary()) {
+        // The edge was already split because of an exit from a neighbouring
+        // TryItem. We split it again and insert an entry point.
+        if (kIsDebugBuild) {
+          HTryBoundary* last_insn = predecessor->GetLastInstruction()->AsTryBoundary();
+          const DexFile::TryItem* predecessor_try_item =
+              GetTryItem(predecessor->GetSinglePredecessor(), code_item, can_block_throw);
+          DCHECK(!last_insn->IsEntry());
+          DCHECK_EQ(last_insn->GetNormalFlowSuccessor(), try_block);
+          DCHECK(try_block->IsFirstIndexOfPredecessor(predecessor, i));
+          DCHECK_NE(try_item, predecessor_try_item);
         }
-        SplitTryBoundaryEdge(predecessor, try_block, HTryBoundary::kEntry, code_item, try_item);
+      } else if (GetTryItem(predecessor, code_item, can_block_throw) != try_item) {
+        // This is an entry point into the TryItem and the edge has not been
+        // split yet. That means that `predecessor` is not in a TryItem, or
+        // it is in a different TryItem and we happened to iterate over this
+        // block first. We split the edge and insert an entry point.
+      } else {
+        // Not an edge on the boundary of the try block.
+        continue;
       }
+      SplitTryBoundaryEdge(predecessor, try_block, HTryBoundary::kEntry, code_item, *try_item);
     }
 
     // Find successors which are not covered by the same TryItem range. Such
@@ -416,11 +432,13 @@ void HGraphBuilder::InsertTryBoundaryBlocks(const DexFile::CodeItem& code_item)
         // TryItem. We split it again and insert an exit.
         if (kIsDebugBuild) {
           HTryBoundary* last_insn = successor->GetLastInstruction()->AsTryBoundary();
+          const DexFile::TryItem* successor_try_item =
+              GetTryItem(last_insn->GetNormalFlowSuccessor(), code_item, can_block_throw);
           DCHECK_EQ(try_block, successor->GetSinglePredecessor());
           DCHECK(last_insn->IsEntry());
-          DCHECK(!IsBlockInPcRange(last_insn->GetNormalFlowSuccessor(), try_start, try_end));
+          DCHECK_NE(try_item, successor_try_item);
         }
-      } else if (!IsBlockInPcRange(successor, try_start, try_end)) {
+      } else if (GetTryItem(successor, code_item, can_block_throw) != try_item) {
         // This is an exit out of the TryItem and the edge has not been split
         // yet. That means that either `successor` is not in a TryItem, or it
         // is in a different TryItem and we happened to iterate over this
@@ -437,7 +455,7 @@ void HGraphBuilder::InsertTryBoundaryBlocks(const DexFile::CodeItem& code_item)
         // Not an edge on the boundary of the try block.
         continue;
       }
-      SplitTryBoundaryEdge(try_block, successor, HTryBoundary::kExit, code_item, try_item);
+      SplitTryBoundaryEdge(try_block, successor, HTryBoundary::kExit, code_item, *try_item);
     }
   }
 }
@@ -496,14 +514,14 @@ bool HGraphBuilder::BuildGraph(const DexFile::CodeItem& code_item) {
   // Add the suspend check to the entry block.
   entry_block_->AddInstruction(new (arena_) HSuspendCheck(0));
   entry_block_->AddInstruction(new (arena_) HGoto());
+  // Add the exit block at the end.
+  graph_->AddBlock(exit_block_);
 
   // Iterate over blocks covered by TryItems and insert TryBoundaries at entry
   // and exit points. This requires all control-flow instructions and
   // non-exceptional edges to have been created.
   InsertTryBoundaryBlocks(code_item);
 
-  // Add the exit block at the end to give it the highest id.
-  graph_->AddBlock(exit_block_);
   return true;
 }
 
@@ -657,7 +675,7 @@ void HGraphBuilder::Binop_23x_shift(const Instruction& instruction,
 
 void HGraphBuilder::Binop_23x_cmp(const Instruction& instruction,
                                   Primitive::Type type,
-                                  HCompare::Bias bias,
+                                  ComparisonBias bias,
                                   uint32_t dex_pc) {
   HInstruction* first = LoadLocal(instruction.VRegB(), type);
   HInstruction* second = LoadLocal(instruction.VRegC(), type);
@@ -2311,27 +2329,27 @@ bool HGraphBuilder::AnalyzeDexInstruction(const Instruction& instruction, uint32
     }
 
     case Instruction::CMP_LONG: {
-      Binop_23x_cmp(instruction, Primitive::kPrimLong, HCompare::kNoBias, dex_pc);
+      Binop_23x_cmp(instruction, Primitive::kPrimLong, kNoBias, dex_pc);
       break;
     }
 
     case Instruction::CMPG_FLOAT: {
-      Binop_23x_cmp(instruction, Primitive::kPrimFloat, HCompare::kGtBias, dex_pc);
+      Binop_23x_cmp(instruction, Primitive::kPrimFloat, kGtBias, dex_pc);
       break;
     }
 
     case Instruction::CMPG_DOUBLE: {
-      Binop_23x_cmp(instruction, Primitive::kPrimDouble, HCompare::kGtBias, dex_pc);
+      Binop_23x_cmp(instruction, Primitive::kPrimDouble, kGtBias, dex_pc);
       break;
     }
 
     case Instruction::CMPL_FLOAT: {
-      Binop_23x_cmp(instruction, Primitive::kPrimFloat, HCompare::kLtBias, dex_pc);
+      Binop_23x_cmp(instruction, Primitive::kPrimFloat, kLtBias, dex_pc);
       break;
     }
 
     case Instruction::CMPL_DOUBLE: {
-      Binop_23x_cmp(instruction, Primitive::kPrimDouble, HCompare::kLtBias, dex_pc);
+      Binop_23x_cmp(instruction, Primitive::kPrimDouble, kLtBias, dex_pc);
       break;
     }