Move stack map stream implementation to its own cc file.

It's big enough now to separate the implementation from the header.

It also enables faster compilation time for experiments.

Change-Id: Ica0c72994d5e461c62c32628010f46f9e5c46b57

3 files changed, 410 insertions, 364 deletions

diff --git a/compiler/Android.mk b/compiler/Android.mk
index ac95abd..3458784 100644
--- a/compiler/Android.mk
+++ b/compiler/Android.mk
@@ -124,13 +124,14 @@ LIBART_COMPILER_SRC_FILES := \
 	optimizing/optimizing_compiler.cc \
 	optimizing/parallel_move_resolver.cc \
 	optimizing/prepare_for_register_allocation.cc \
+	optimizing/primitive_type_propagation.cc \
+	optimizing/reference_type_propagation.cc \
 	optimizing/register_allocator.cc \
 	optimizing/side_effects_analysis.cc \
 	optimizing/ssa_builder.cc \
 	optimizing/ssa_liveness_analysis.cc \
 	optimizing/ssa_phi_elimination.cc \
-	optimizing/primitive_type_propagation.cc \
-	optimizing/reference_type_propagation.cc \
+	optimizing/stack_map_stream.cc \
 	trampolines/trampoline_compiler.cc \
 	utils/arena_bit_vector.cc \
 	utils/arm/assembler_arm.cc \
diff --git a/compiler/optimizing/stack_map_stream.cc b/compiler/optimizing/stack_map_stream.cc
new file mode 100644
index 0000000..fcc86d5
--- /dev/null
+++ b/compiler/optimizing/stack_map_stream.cc
@@ -0,0 +1,387 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "stack_map_stream.h"
+
+namespace art {
+
+void StackMapStream::AddStackMapEntry(uint32_t dex_pc,
+                                     uint32_t native_pc_offset,
+                                     uint32_t register_mask,
+                                     BitVector* sp_mask,
+                                     uint32_t num_dex_registers,
+                                     uint8_t inlining_depth) {
+  StackMapEntry entry;
+  entry.dex_pc = dex_pc;
+  entry.native_pc_offset = native_pc_offset;
+  entry.register_mask = register_mask;
+  entry.sp_mask = sp_mask;
+  entry.num_dex_registers = num_dex_registers;
+  entry.inlining_depth = inlining_depth;
+  entry.dex_register_locations_start_index = dex_register_locations_.Size();
+  entry.inline_infos_start_index = inline_infos_.Size();
+  entry.dex_register_map_hash = 0;
+  if (num_dex_registers != 0) {
+    entry.live_dex_registers_mask =
+        new (allocator_) ArenaBitVector(allocator_, num_dex_registers, true);
+  } else {
+    entry.live_dex_registers_mask = nullptr;
+  }
+  stack_maps_.Add(entry);
+
+  if (sp_mask != nullptr) {
+    stack_mask_max_ = std::max(stack_mask_max_, sp_mask->GetHighestBitSet());
+  }
+  if (inlining_depth > 0) {
+    number_of_stack_maps_with_inline_info_++;
+  }
+
+  dex_pc_max_ = std::max(dex_pc_max_, dex_pc);
+  native_pc_offset_max_ = std::max(native_pc_offset_max_, native_pc_offset);
+  register_mask_max_ = std::max(register_mask_max_, register_mask);
+}
+
+void StackMapStream::AddDexRegisterEntry(uint16_t dex_register,
+                                        DexRegisterLocation::Kind kind,
+                                        int32_t value) {
+  StackMapEntry entry = stack_maps_.Get(stack_maps_.Size() - 1);
+  DCHECK_LT(dex_register, entry.num_dex_registers);
+
+  if (kind != DexRegisterLocation::Kind::kNone) {
+    // Ensure we only use non-compressed location kind at this stage.
+    DCHECK(DexRegisterLocation::IsShortLocationKind(kind))
+        << DexRegisterLocation::PrettyDescriptor(kind);
+    DexRegisterLocation location(kind, value);
+
+    // Look for Dex register `location` in the location catalog (using the
+    // companion hash map of locations to indices).  Use its index if it
+    // is already in the location catalog.  If not, insert it (in the
+    // location catalog and the hash map) and use the newly created index.
+    auto it = location_catalog_entries_indices_.Find(location);
+    if (it != location_catalog_entries_indices_.end()) {
+      // Retrieve the index from the hash map.
+      dex_register_locations_.Add(it->second);
+    } else {
+      // Create a new entry in the location catalog and the hash map.
+      size_t index = location_catalog_entries_.Size();
+      location_catalog_entries_.Add(location);
+      dex_register_locations_.Add(index);
+      location_catalog_entries_indices_.Insert(std::make_pair(location, index));
+    }
+
+    entry.live_dex_registers_mask->SetBit(dex_register);
+    entry.dex_register_map_hash +=
+      (1 << (dex_register % (sizeof(entry.dex_register_map_hash) * kBitsPerByte)));
+    entry.dex_register_map_hash += static_cast<uint32_t>(value);
+    entry.dex_register_map_hash += static_cast<uint32_t>(kind);
+    stack_maps_.Put(stack_maps_.Size() - 1, entry);
+  }
+}
+
+void StackMapStream::AddInlineInfoEntry(uint32_t method_index) {
+  InlineInfoEntry entry;
+  entry.method_index = method_index;
+  inline_infos_.Add(entry);
+}
+
+size_t StackMapStream::ComputeNeededSize() {
+  size_t size = CodeInfo::kFixedSize
+      + ComputeDexRegisterLocationCatalogSize()
+      + ComputeStackMapsSize()
+      + ComputeDexRegisterMapsSize()
+      + ComputeInlineInfoSize();
+  // Note: use RoundUp to word-size here if you want CodeInfo objects to be word aligned.
+  return size;
+}
+
+size_t StackMapStream::ComputeStackMaskSize() const {
+  int number_of_bits = stack_mask_max_ + 1;  // Need room for max element too.
+  return RoundUp(number_of_bits, kBitsPerByte) / kBitsPerByte;
+}
+
+size_t StackMapStream::ComputeStackMapsSize() {
+  return stack_maps_.Size() * StackMap::ComputeStackMapSize(
+      ComputeStackMaskSize(),
+      ComputeInlineInfoSize(),
+      ComputeDexRegisterMapsSize(),
+      dex_pc_max_,
+      native_pc_offset_max_,
+      register_mask_max_);
+}
+
+size_t StackMapStream::ComputeDexRegisterLocationCatalogSize() const {
+  size_t size = DexRegisterLocationCatalog::kFixedSize;
+  for (size_t location_catalog_entry_index = 0;
+       location_catalog_entry_index < location_catalog_entries_.Size();
+       ++location_catalog_entry_index) {
+    DexRegisterLocation dex_register_location =
+        location_catalog_entries_.Get(location_catalog_entry_index);
+    size += DexRegisterLocationCatalog::EntrySize(dex_register_location);
+  }
+  return size;
+}
+
+size_t StackMapStream::ComputeDexRegisterMapSize(const StackMapEntry& entry) const {
+  // Size of the map in bytes.
+  size_t size = DexRegisterMap::kFixedSize;
+  // Add the live bit mask for the Dex register liveness.
+  size += DexRegisterMap::GetLiveBitMaskSize(entry.num_dex_registers);
+  // Compute the size of the set of live Dex register entries.
+  size_t number_of_live_dex_registers = 0;
+  for (size_t dex_register_number = 0;
+       dex_register_number < entry.num_dex_registers;
+       ++dex_register_number) {
+    if (entry.live_dex_registers_mask->IsBitSet(dex_register_number)) {
+      ++number_of_live_dex_registers;
+    }
+  }
+  size_t map_entries_size_in_bits =
+      DexRegisterMap::SingleEntrySizeInBits(location_catalog_entries_.Size())
+      * number_of_live_dex_registers;
+  size_t map_entries_size_in_bytes =
+      RoundUp(map_entries_size_in_bits, kBitsPerByte) / kBitsPerByte;
+  size += map_entries_size_in_bytes;
+  return size;
+}
+
+size_t StackMapStream::ComputeDexRegisterMapsSize() {
+  size_t size = 0;
+  for (size_t i = 0; i < stack_maps_.Size(); ++i) {
+    if (FindEntryWithTheSameDexMap(i) == kNoSameDexMapFound) {
+      // Entries with the same dex map will have the same offset.
+      size += ComputeDexRegisterMapSize(stack_maps_.Get(i));
+    }
+  }
+  return size;
+}
+
+size_t StackMapStream::ComputeInlineInfoSize() const {
+  return inline_infos_.Size() * InlineInfo::SingleEntrySize()
+    // For encoding the depth.
+    + (number_of_stack_maps_with_inline_info_ * InlineInfo::kFixedSize);
+}
+
+size_t StackMapStream::ComputeDexRegisterLocationCatalogStart() const {
+  return CodeInfo::kFixedSize;
+}
+
+size_t StackMapStream::ComputeStackMapsStart() const {
+  return ComputeDexRegisterLocationCatalogStart() + ComputeDexRegisterLocationCatalogSize();
+}
+
+size_t StackMapStream::ComputeDexRegisterMapsStart() {
+  return ComputeStackMapsStart() + ComputeStackMapsSize();
+}
+
+size_t StackMapStream::ComputeInlineInfoStart() {
+  return ComputeDexRegisterMapsStart() + ComputeDexRegisterMapsSize();
+}
+
+void StackMapStream::FillIn(MemoryRegion region) {
+  CodeInfo code_info(region);
+  DCHECK_EQ(region.size(), ComputeNeededSize());
+  code_info.SetOverallSize(region.size());
+
+  size_t stack_mask_size = ComputeStackMaskSize();
+
+  size_t dex_register_map_size = ComputeDexRegisterMapsSize();
+  size_t inline_info_size = ComputeInlineInfoSize();
+
+  MemoryRegion dex_register_locations_region = region.Subregion(
+    ComputeDexRegisterMapsStart(),
+    dex_register_map_size);
+
+  MemoryRegion inline_infos_region = region.Subregion(
+    ComputeInlineInfoStart(),
+    inline_info_size);
+
+  code_info.SetEncoding(inline_info_size,
+                        dex_register_map_size,
+                        dex_pc_max_,
+                        native_pc_offset_max_,
+                        register_mask_max_);
+  code_info.SetNumberOfStackMaps(stack_maps_.Size());
+  code_info.SetStackMaskSize(stack_mask_size);
+  DCHECK_EQ(code_info.GetStackMapsSize(), ComputeStackMapsSize());
+
+  // Set the Dex register location catalog.
+  code_info.SetNumberOfDexRegisterLocationCatalogEntries(
+      location_catalog_entries_.Size());
+  MemoryRegion dex_register_location_catalog_region = region.Subregion(
+      ComputeDexRegisterLocationCatalogStart(),
+      ComputeDexRegisterLocationCatalogSize());
+  DexRegisterLocationCatalog dex_register_location_catalog(dex_register_location_catalog_region);
+  // Offset in `dex_register_location_catalog` where to store the next
+  // register location.
+  size_t location_catalog_offset = DexRegisterLocationCatalog::kFixedSize;
+  for (size_t i = 0, e = location_catalog_entries_.Size(); i < e; ++i) {
+    DexRegisterLocation dex_register_location = location_catalog_entries_.Get(i);
+    dex_register_location_catalog.SetRegisterInfo(location_catalog_offset, dex_register_location);
+    location_catalog_offset += DexRegisterLocationCatalog::EntrySize(dex_register_location);
+  }
+  // Ensure we reached the end of the Dex registers location_catalog.
+  DCHECK_EQ(location_catalog_offset, dex_register_location_catalog_region.size());
+
+  uintptr_t next_dex_register_map_offset = 0;
+  uintptr_t next_inline_info_offset = 0;
+  for (size_t i = 0, e = stack_maps_.Size(); i < e; ++i) {
+    StackMap stack_map = code_info.GetStackMapAt(i);
+    StackMapEntry entry = stack_maps_.Get(i);
+
+    stack_map.SetDexPc(code_info, entry.dex_pc);
+    stack_map.SetNativePcOffset(code_info, entry.native_pc_offset);
+    stack_map.SetRegisterMask(code_info, entry.register_mask);
+    if (entry.sp_mask != nullptr) {
+      stack_map.SetStackMask(code_info, *entry.sp_mask);
+    }
+
+    if (entry.num_dex_registers == 0) {
+      // No dex map available.
+      stack_map.SetDexRegisterMapOffset(code_info, StackMap::kNoDexRegisterMap);
+    } else {
+      // Search for an entry with the same dex map.
+      size_t entry_with_same_map = FindEntryWithTheSameDexMap(i);
+      if (entry_with_same_map != kNoSameDexMapFound) {
+        // If we have a hit reuse the offset.
+        stack_map.SetDexRegisterMapOffset(code_info,
+            code_info.GetStackMapAt(entry_with_same_map).GetDexRegisterMapOffset(code_info));
+      } else {
+        // New dex registers maps should be added to the stack map.
+        MemoryRegion register_region =
+            dex_register_locations_region.Subregion(
+                next_dex_register_map_offset,
+                ComputeDexRegisterMapSize(entry));
+        next_dex_register_map_offset += register_region.size();
+        DexRegisterMap dex_register_map(register_region);
+        stack_map.SetDexRegisterMapOffset(
+          code_info, register_region.start() - dex_register_locations_region.start());
+
+        // Set the live bit mask.
+        dex_register_map.SetLiveBitMask(entry.num_dex_registers, *entry.live_dex_registers_mask);
+
+        // Set the dex register location mapping data.
+        for (size_t dex_register_number = 0, index_in_dex_register_locations = 0;
+             dex_register_number < entry.num_dex_registers;
+             ++dex_register_number) {
+          if (entry.live_dex_registers_mask->IsBitSet(dex_register_number)) {
+            size_t location_catalog_entry_index =
+                dex_register_locations_.Get(entry.dex_register_locations_start_index
+                                            + index_in_dex_register_locations);
+            dex_register_map.SetLocationCatalogEntryIndex(
+                index_in_dex_register_locations,
+                location_catalog_entry_index,
+                entry.num_dex_registers,
+                location_catalog_entries_.Size());
+            ++index_in_dex_register_locations;
+          }
+        }
+      }
+    }
+
+    // Set the inlining info.
+    if (entry.inlining_depth != 0) {
+      MemoryRegion inline_region = inline_infos_region.Subregion(
+          next_inline_info_offset,
+          InlineInfo::kFixedSize + entry.inlining_depth * InlineInfo::SingleEntrySize());
+      next_inline_info_offset += inline_region.size();
+      InlineInfo inline_info(inline_region);
+
+      // Currently relative to the dex register map.
+      stack_map.SetInlineDescriptorOffset(
+          code_info, inline_region.start() - dex_register_locations_region.start());
+
+      inline_info.SetDepth(entry.inlining_depth);
+      for (size_t j = 0; j < entry.inlining_depth; ++j) {
+        InlineInfoEntry inline_entry = inline_infos_.Get(j + entry.inline_infos_start_index);
+        inline_info.SetMethodReferenceIndexAtDepth(j, inline_entry.method_index);
+      }
+    } else {
+      if (inline_info_size != 0) {
+        stack_map.SetInlineDescriptorOffset(code_info, StackMap::kNoInlineInfo);
+      }
+    }
+  }
+}
+
+size_t StackMapStream::FindEntryWithTheSameDexMap(size_t entry_index) {
+  StackMapEntry entry = stack_maps_.Get(entry_index);
+  auto entries_it = dex_map_hash_to_stack_map_indices_.find(entry.dex_register_map_hash);
+  if (entries_it == dex_map_hash_to_stack_map_indices_.end()) {
+    // We don't have a perfect hash functions so we need a list to collect all stack maps
+    // which might have the same dex register map.
+    GrowableArray<uint32_t> stack_map_indices(allocator_, 1);
+    stack_map_indices.Add(entry_index);
+    dex_map_hash_to_stack_map_indices_.Put(entry.dex_register_map_hash, stack_map_indices);
+    return kNoSameDexMapFound;
+  }
+
+  // TODO: We don't need to add ourselves to the map if we can guarantee that
+  // FindEntryWithTheSameDexMap is called just once per stack map entry.
+  // A good way to do this is to cache the offset in the stack map entry. This
+  // is easier to do if we add markers when the stack map constructions begins
+  // and when it ends.
+
+  // We might have collisions, so we need to check whether or not we should
+  // add the entry to the map. `needs_to_be_added` keeps track of this.
+  bool needs_to_be_added = true;
+  size_t result = kNoSameDexMapFound;
+  for (size_t i = 0; i < entries_it->second.Size(); i++) {
+    size_t test_entry_index = entries_it->second.Get(i);
+    if (test_entry_index == entry_index) {
+      needs_to_be_added = false;
+    } else if (HaveTheSameDexMaps(stack_maps_.Get(test_entry_index), entry)) {
+      result = test_entry_index;
+      needs_to_be_added = false;
+      break;
+    }
+  }
+  if (needs_to_be_added) {
+    entries_it->second.Add(entry_index);
+  }
+  return result;
+}
+
+bool StackMapStream::HaveTheSameDexMaps(const StackMapEntry& a, const StackMapEntry& b) const {
+  if (a.live_dex_registers_mask == nullptr && b.live_dex_registers_mask == nullptr) {
+    return true;
+  }
+  if (a.live_dex_registers_mask == nullptr || b.live_dex_registers_mask == nullptr) {
+    return false;
+  }
+  if (a.num_dex_registers != b.num_dex_registers) {
+    return false;
+  }
+
+  int index_in_dex_register_locations = 0;
+  for (uint32_t i = 0; i < a.num_dex_registers; i++) {
+    if (a.live_dex_registers_mask->IsBitSet(i) != b.live_dex_registers_mask->IsBitSet(i)) {
+      return false;
+    }
+    if (a.live_dex_registers_mask->IsBitSet(i)) {
+      size_t a_loc = dex_register_locations_.Get(
+          a.dex_register_locations_start_index + index_in_dex_register_locations);
+      size_t b_loc = dex_register_locations_.Get(
+          b.dex_register_locations_start_index + index_in_dex_register_locations);
+      if (a_loc != b_loc) {
+        return false;
+      }
+      ++index_in_dex_register_locations;
+    }
+  }
+  return true;
+}
+
+}  // namespace art
diff --git a/compiler/optimizing/stack_map_stream.h b/compiler/optimizing/stack_map_stream.h
index 9a9e068..990e682 100644
--- a/compiler/optimizing/stack_map_stream.h
+++ b/compiler/optimizing/stack_map_stream.h
@@ -72,12 +72,6 @@ class StackMapStream : public ValueObject {
         number_of_stack_maps_with_inline_info_(0),
         dex_map_hash_to_stack_map_indices_(std::less<uint32_t>(), allocator->Adapter()) {}
 
-  // Compute bytes needed to encode a mask with the given maximum element.
-  static uint32_t StackMaskEncodingSize(int max_element) {
-    int number_of_bits = max_element + 1;  // Need room for max element too.
-    return RoundUp(number_of_bits, kBitsPerByte) / kBitsPerByte;
-  }
-
   // See runtime/stack_map.h to know what these fields contain.
   struct StackMapEntry {
     uint32_t dex_pc;
@@ -101,369 +95,34 @@ class StackMapStream : public ValueObject {
                         uint32_t register_mask,
                         BitVector* sp_mask,
                         uint32_t num_dex_registers,
-                        uint8_t inlining_depth) {
-    StackMapEntry entry;
-    entry.dex_pc = dex_pc;
-    entry.native_pc_offset = native_pc_offset;
-    entry.register_mask = register_mask;
-    entry.sp_mask = sp_mask;
-    entry.num_dex_registers = num_dex_registers;
-    entry.inlining_depth = inlining_depth;
-    entry.dex_register_locations_start_index = dex_register_locations_.Size();
-    entry.inline_infos_start_index = inline_infos_.Size();
-    entry.dex_register_map_hash = 0;
-    if (num_dex_registers != 0) {
-      entry.live_dex_registers_mask =
-          new (allocator_) ArenaBitVector(allocator_, num_dex_registers, true);
-    } else {
-      entry.live_dex_registers_mask = nullptr;
-    }
-    stack_maps_.Add(entry);
-
-    if (sp_mask != nullptr) {
-      stack_mask_max_ = std::max(stack_mask_max_, sp_mask->GetHighestBitSet());
-    }
-    if (inlining_depth > 0) {
-      number_of_stack_maps_with_inline_info_++;
-    }
-
-    dex_pc_max_ = std::max(dex_pc_max_, dex_pc);
-    native_pc_offset_max_ = std::max(native_pc_offset_max_, native_pc_offset);
-    register_mask_max_ = std::max(register_mask_max_, register_mask);
-  }
-
-  void AddInlineInfoEntry(uint32_t method_index) {
-    InlineInfoEntry entry;
-    entry.method_index = method_index;
-    inline_infos_.Add(entry);
-  }
-
-  size_t ComputeNeededSize() {
-    size_t size = CodeInfo::kFixedSize
-        + ComputeDexRegisterLocationCatalogSize()
-        + ComputeStackMapsSize()
-        + ComputeDexRegisterMapsSize()
-        + ComputeInlineInfoSize();
-    // Note: use RoundUp to word-size here if you want CodeInfo objects to be word aligned.
-    return size;
-  }
-
-  size_t ComputeStackMaskSize() const {
-    return StackMaskEncodingSize(stack_mask_max_);
-  }
-
-  size_t ComputeStackMapsSize() {
-    return stack_maps_.Size() * StackMap::ComputeStackMapSize(
-        ComputeStackMaskSize(),
-        ComputeInlineInfoSize(),
-        ComputeDexRegisterMapsSize(),
-        dex_pc_max_,
-        native_pc_offset_max_,
-        register_mask_max_);
-  }
+                        uint8_t inlining_depth);
 
-  // Compute the size of the Dex register location catalog of `entry`.
-  size_t ComputeDexRegisterLocationCatalogSize() const {
-    size_t size = DexRegisterLocationCatalog::kFixedSize;
-    for (size_t location_catalog_entry_index = 0;
-         location_catalog_entry_index < location_catalog_entries_.Size();
-         ++location_catalog_entry_index) {
-      DexRegisterLocation dex_register_location =
-          location_catalog_entries_.Get(location_catalog_entry_index);
-      size += DexRegisterLocationCatalog::EntrySize(dex_register_location);
-    }
-    return size;
-  }
-
-  size_t ComputeDexRegisterMapSize(const StackMapEntry& entry) const {
-    // Size of the map in bytes.
-    size_t size = DexRegisterMap::kFixedSize;
-    // Add the live bit mask for the Dex register liveness.
-    size += DexRegisterMap::GetLiveBitMaskSize(entry.num_dex_registers);
-    // Compute the size of the set of live Dex register entries.
-    size_t number_of_live_dex_registers = 0;
-    for (size_t dex_register_number = 0;
-         dex_register_number < entry.num_dex_registers;
-         ++dex_register_number) {
-      if (entry.live_dex_registers_mask->IsBitSet(dex_register_number)) {
-        ++number_of_live_dex_registers;
-      }
-    }
-    size_t map_entries_size_in_bits =
-        DexRegisterMap::SingleEntrySizeInBits(location_catalog_entries_.Size())
-        * number_of_live_dex_registers;
-    size_t map_entries_size_in_bytes =
-        RoundUp(map_entries_size_in_bits, kBitsPerByte) / kBitsPerByte;
-    size += map_entries_size_in_bytes;
-    return size;
-  }
+  void AddDexRegisterEntry(uint16_t dex_register,
+                           DexRegisterLocation::Kind kind,
+                           int32_t value);
 
-  // Compute the size of all the Dex register maps.
-  size_t ComputeDexRegisterMapsSize() {
-    size_t size = 0;
-    for (size_t i = 0; i < stack_maps_.Size(); ++i) {
-      if (FindEntryWithTheSameDexMap(i) == kNoSameDexMapFound) {
-        // Entries with the same dex map will have the same offset.
-        size += ComputeDexRegisterMapSize(stack_maps_.Get(i));
-      }
-    }
-    return size;
-  }
+  void AddInlineInfoEntry(uint32_t method_index);
 
-  // Compute the size of all the inline information pieces.
-  size_t ComputeInlineInfoSize() const {
-    return inline_infos_.Size() * InlineInfo::SingleEntrySize()
-      // For encoding the depth.
-      + (number_of_stack_maps_with_inline_info_ * InlineInfo::kFixedSize);
-  }
-
-  size_t ComputeDexRegisterLocationCatalogStart() const {
-    return CodeInfo::kFixedSize;
-  }
-
-  size_t ComputeStackMapsStart() const {
-    return ComputeDexRegisterLocationCatalogStart() + ComputeDexRegisterLocationCatalogSize();
-  }
-
-  size_t ComputeDexRegisterMapsStart() {
-    return ComputeStackMapsStart() + ComputeStackMapsSize();
-  }
-
-  size_t ComputeInlineInfoStart() {
-    return ComputeDexRegisterMapsStart() + ComputeDexRegisterMapsSize();
-  }
+  size_t ComputeNeededSize();
+  size_t ComputeStackMaskSize() const;
+  size_t ComputeStackMapsSize();
+  size_t ComputeDexRegisterLocationCatalogSize() const;
+  size_t ComputeDexRegisterMapSize(const StackMapEntry& entry) const;
+  size_t ComputeDexRegisterMapsSize();
+  size_t ComputeInlineInfoSize() const;
 
-  void FillIn(MemoryRegion region) {
-    CodeInfo code_info(region);
-    DCHECK_EQ(region.size(), ComputeNeededSize());
-    code_info.SetOverallSize(region.size());
+  size_t ComputeDexRegisterLocationCatalogStart() const;
+  size_t ComputeStackMapsStart() const;
+  size_t ComputeDexRegisterMapsStart();
+  size_t ComputeInlineInfoStart();
 
-    size_t stack_mask_size = ComputeStackMaskSize();
-
-    size_t dex_register_map_size = ComputeDexRegisterMapsSize();
-    size_t inline_info_size = ComputeInlineInfoSize();
-
-    MemoryRegion dex_register_locations_region = region.Subregion(
-      ComputeDexRegisterMapsStart(),
-      dex_register_map_size);
-
-    MemoryRegion inline_infos_region = region.Subregion(
-      ComputeInlineInfoStart(),
-      inline_info_size);
-
-    code_info.SetEncoding(inline_info_size,
-                          dex_register_map_size,
-                          dex_pc_max_,
-                          native_pc_offset_max_,
-                          register_mask_max_);
-    code_info.SetNumberOfStackMaps(stack_maps_.Size());
-    code_info.SetStackMaskSize(stack_mask_size);
-    DCHECK_EQ(code_info.GetStackMapsSize(), ComputeStackMapsSize());
-
-    // Set the Dex register location catalog.
-    code_info.SetNumberOfDexRegisterLocationCatalogEntries(
-        location_catalog_entries_.Size());
-    MemoryRegion dex_register_location_catalog_region = region.Subregion(
-        ComputeDexRegisterLocationCatalogStart(),
-        ComputeDexRegisterLocationCatalogSize());
-    DexRegisterLocationCatalog dex_register_location_catalog(dex_register_location_catalog_region);
-    // Offset in `dex_register_location_catalog` where to store the next
-    // register location.
-    size_t location_catalog_offset = DexRegisterLocationCatalog::kFixedSize;
-    for (size_t i = 0, e = location_catalog_entries_.Size(); i < e; ++i) {
-      DexRegisterLocation dex_register_location = location_catalog_entries_.Get(i);
-      dex_register_location_catalog.SetRegisterInfo(location_catalog_offset, dex_register_location);
-      location_catalog_offset += DexRegisterLocationCatalog::EntrySize(dex_register_location);
-    }
-    // Ensure we reached the end of the Dex registers location_catalog.
-    DCHECK_EQ(location_catalog_offset, dex_register_location_catalog_region.size());
-
-    uintptr_t next_dex_register_map_offset = 0;
-    uintptr_t next_inline_info_offset = 0;
-    for (size_t i = 0, e = stack_maps_.Size(); i < e; ++i) {
-      StackMap stack_map = code_info.GetStackMapAt(i);
-      StackMapEntry entry = stack_maps_.Get(i);
-
-      stack_map.SetDexPc(code_info, entry.dex_pc);
-      stack_map.SetNativePcOffset(code_info, entry.native_pc_offset);
-      stack_map.SetRegisterMask(code_info, entry.register_mask);
-      if (entry.sp_mask != nullptr) {
-        stack_map.SetStackMask(code_info, *entry.sp_mask);
-      }
-
-      if (entry.num_dex_registers == 0) {
-        // No dex map available.
-        stack_map.SetDexRegisterMapOffset(code_info, StackMap::kNoDexRegisterMap);
-      } else {
-        // Search for an entry with the same dex map.
-        size_t entry_with_same_map = FindEntryWithTheSameDexMap(i);
-        if (entry_with_same_map != kNoSameDexMapFound) {
-          // If we have a hit reuse the offset.
-          stack_map.SetDexRegisterMapOffset(code_info,
-              code_info.GetStackMapAt(entry_with_same_map).GetDexRegisterMapOffset(code_info));
-        } else {
-          // New dex registers maps should be added to the stack map.
-          MemoryRegion register_region =
-              dex_register_locations_region.Subregion(
-                  next_dex_register_map_offset,
-                  ComputeDexRegisterMapSize(entry));
-          next_dex_register_map_offset += register_region.size();
-          DexRegisterMap dex_register_map(register_region);
-          stack_map.SetDexRegisterMapOffset(
-            code_info, register_region.start() - dex_register_locations_region.start());
-
-          // Set the live bit mask.
-          dex_register_map.SetLiveBitMask(entry.num_dex_registers, *entry.live_dex_registers_mask);
-
-          // Set the dex register location mapping data.
-          for (size_t dex_register_number = 0, index_in_dex_register_locations = 0;
-               dex_register_number < entry.num_dex_registers;
-               ++dex_register_number) {
-            if (entry.live_dex_registers_mask->IsBitSet(dex_register_number)) {
-              size_t location_catalog_entry_index =
-                  dex_register_locations_.Get(entry.dex_register_locations_start_index
-                                              + index_in_dex_register_locations);
-              dex_register_map.SetLocationCatalogEntryIndex(
-                  index_in_dex_register_locations,
-                  location_catalog_entry_index,
-                  entry.num_dex_registers,
-                  location_catalog_entries_.Size());
-              ++index_in_dex_register_locations;
-            }
-          }
-        }
-      }
-
-      // Set the inlining info.
-      if (entry.inlining_depth != 0) {
-        MemoryRegion inline_region = inline_infos_region.Subregion(
-            next_inline_info_offset,
-            InlineInfo::kFixedSize + entry.inlining_depth * InlineInfo::SingleEntrySize());
-        next_inline_info_offset += inline_region.size();
-        InlineInfo inline_info(inline_region);
-
-        // Currently relative to the dex register map.
-        stack_map.SetInlineDescriptorOffset(
-            code_info, inline_region.start() - dex_register_locations_region.start());
-
-        inline_info.SetDepth(entry.inlining_depth);
-        for (size_t j = 0; j < entry.inlining_depth; ++j) {
-          InlineInfoEntry inline_entry = inline_infos_.Get(j + entry.inline_infos_start_index);
-          inline_info.SetMethodReferenceIndexAtDepth(j, inline_entry.method_index);
-        }
-      } else {
-        if (inline_info_size != 0) {
-          stack_map.SetInlineDescriptorOffset(code_info, StackMap::kNoInlineInfo);
-        }
-      }
-    }
-  }
-
-  void AddDexRegisterEntry(uint16_t dex_register, DexRegisterLocation::Kind kind, int32_t value) {
-    StackMapEntry entry = stack_maps_.Get(stack_maps_.Size() - 1);
-    DCHECK_LT(dex_register, entry.num_dex_registers);
-
-    if (kind != DexRegisterLocation::Kind::kNone) {
-      // Ensure we only use non-compressed location kind at this stage.
-      DCHECK(DexRegisterLocation::IsShortLocationKind(kind))
-          << DexRegisterLocation::PrettyDescriptor(kind);
-      DexRegisterLocation location(kind, value);
-
-      // Look for Dex register `location` in the location catalog (using the
-      // companion hash map of locations to indices).  Use its index if it
-      // is already in the location catalog.  If not, insert it (in the
-      // location catalog and the hash map) and use the newly created index.
-      auto it = location_catalog_entries_indices_.Find(location);
-      if (it != location_catalog_entries_indices_.end()) {
-        // Retrieve the index from the hash map.
-        dex_register_locations_.Add(it->second);
-      } else {
-        // Create a new entry in the location catalog and the hash map.
-        size_t index = location_catalog_entries_.Size();
-        location_catalog_entries_.Add(location);
-        dex_register_locations_.Add(index);
-        location_catalog_entries_indices_.Insert(std::make_pair(location, index));
-      }
-
-      entry.live_dex_registers_mask->SetBit(dex_register);
-      entry.dex_register_map_hash +=
-        (1 << (dex_register % (sizeof(entry.dex_register_map_hash) * kBitsPerByte)));
-      entry.dex_register_map_hash += static_cast<uint32_t>(value);
-      entry.dex_register_map_hash += static_cast<uint32_t>(kind);
-      stack_maps_.Put(stack_maps_.Size() - 1, entry);
-    }
-  }
+  void FillIn(MemoryRegion region);
 
  private:
   // Returns the index of an entry with the same dex register map
   // or kNoSameDexMapFound if no such entry exists.
-  size_t FindEntryWithTheSameDexMap(size_t entry_index) {
-    StackMapEntry entry = stack_maps_.Get(entry_index);
-    auto entries_it = dex_map_hash_to_stack_map_indices_.find(entry.dex_register_map_hash);
-    if (entries_it == dex_map_hash_to_stack_map_indices_.end()) {
-      // We don't have a perfect hash functions so we need a list to collect all stack maps
-      // which might have the same dex register map.
-      GrowableArray<uint32_t> stack_map_indices(allocator_, 1);
-      stack_map_indices.Add(entry_index);
-      dex_map_hash_to_stack_map_indices_.Put(entry.dex_register_map_hash, stack_map_indices);
-      return kNoSameDexMapFound;
-    }
-
-    // TODO: We don't need to add ourselves to the map if we can guarantee that
-    // FindEntryWithTheSameDexMap is called just once per stack map entry.
-    // A good way to do this is to cache the offset in the stack map entry. This
-    // is easier to do if we add markers when the stack map constructions begins
-    // and when it ends.
-
-    // We might have collisions, so we need to check whether or not we should
-    // add the entry to the map. `needs_to_be_added` keeps track of this.
-    bool needs_to_be_added = true;
-    size_t result = kNoSameDexMapFound;
-    for (size_t i = 0; i < entries_it->second.Size(); i++) {
-      size_t test_entry_index = entries_it->second.Get(i);
-      if (test_entry_index == entry_index) {
-        needs_to_be_added = false;
-      } else if (HaveTheSameDexMaps(stack_maps_.Get(test_entry_index), entry)) {
-        result = test_entry_index;
-        needs_to_be_added = false;
-        break;
-      }
-    }
-    if (needs_to_be_added) {
-      entries_it->second.Add(entry_index);
-    }
-    return result;
-  }
-
-  bool HaveTheSameDexMaps(const StackMapEntry& a, const StackMapEntry& b) const {
-    if (a.live_dex_registers_mask == nullptr && b.live_dex_registers_mask == nullptr) {
-      return true;
-    }
-    if (a.live_dex_registers_mask == nullptr || b.live_dex_registers_mask == nullptr) {
-      return false;
-    }
-    if (a.num_dex_registers != b.num_dex_registers) {
-      return false;
-    }
-
-    int index_in_dex_register_locations = 0;
-    for (uint32_t i = 0; i < a.num_dex_registers; i++) {
-      if (a.live_dex_registers_mask->IsBitSet(i) != b.live_dex_registers_mask->IsBitSet(i)) {
-        return false;
-      }
-      if (a.live_dex_registers_mask->IsBitSet(i)) {
-        size_t a_loc = dex_register_locations_.Get(
-            a.dex_register_locations_start_index + index_in_dex_register_locations);
-        size_t b_loc = dex_register_locations_.Get(
-            b.dex_register_locations_start_index + index_in_dex_register_locations);
-        if (a_loc != b_loc) {
-          return false;
-        }
-        ++index_in_dex_register_locations;
-      }
-    }
-    return true;
-  }
+  size_t FindEntryWithTheSameDexMap(size_t entry_index);
+  bool HaveTheSameDexMaps(const StackMapEntry& a, const StackMapEntry& b) const;
 
   ArenaAllocator* allocator_;
   GrowableArray<StackMapEntry> stack_maps_;
@@ -476,8 +135,7 @@ class StackMapStream : public ValueObject {
                   DexRegisterLocationHashFn> LocationCatalogEntriesIndices;
   LocationCatalogEntriesIndices location_catalog_entries_indices_;
 
-  // A set of concatenated maps of Dex register locations indices to
-  // `location_catalog_entries_`.
+  // A set of concatenated maps of Dex register locations indices to `location_catalog_entries_`.
   GrowableArray<size_t> dex_register_locations_;
   GrowableArray<InlineInfoEntry> inline_infos_;
   int stack_mask_max_;