Optimize register mask and stack mask in stack maps.

Use BitTable to store the masks as well and move the
deduplication responsibility to the BitTable builders.

Don't generate entries for masks which are all zeros.
This saves 0.2% of .oat file size on both Arm64 and Arm.

Encode registers as (value+shift) due to tailing zeros.
This saves 1.0% of .oat file size on Arm64 and 0.2% on Arm.

Test: test-art-host-gtest
Change-Id: I636b7edd49e10e8afc9f2aa385b5980f7ee0e1f1

1 files changed, 0 insertions, 12 deletions

diff --git a/compiler/optimizing/stack_map_stream.h b/compiler/optimizing/stack_map_stream.h
index ea97cf6530..19863d882a 100644
--- a/compiler/optimizing/stack_map_stream.h
+++ b/compiler/optimizing/stack_map_stream.h
@@ -68,11 +68,8 @@ class StackMapStream : public ValueObject {
         location_catalog_entries_indices_(allocator->Adapter(kArenaAllocStackMapStream)),
         dex_register_locations_(allocator->Adapter(kArenaAllocStackMapStream)),
         inline_infos_(allocator->Adapter(kArenaAllocStackMapStream)),
-        stack_masks_(allocator->Adapter(kArenaAllocStackMapStream)),
-        register_masks_(allocator->Adapter(kArenaAllocStackMapStream)),
         method_indices_(allocator->Adapter(kArenaAllocStackMapStream)),
         dex_register_entries_(allocator->Adapter(kArenaAllocStackMapStream)),
-        stack_mask_max_(-1),
         out_(allocator->Adapter(kArenaAllocStackMapStream)),
         dex_map_hash_to_stack_map_indices_(std::less<uint32_t>(),
                                            allocator->Adapter(kArenaAllocStackMapStream)),
@@ -171,12 +168,6 @@ class StackMapStream : public ValueObject {
  private:
   size_t ComputeDexRegisterLocationCatalogSize() const;
 
-  // Returns the number of unique stack masks.
-  size_t PrepareStackMasks(size_t entry_size_in_bits);
-
-  // Returns the number of unique register masks.
-  size_t PrepareRegisterMasks();
-
   // Prepare and deduplicate method indices.
   void PrepareMethodIndices();
 
@@ -217,11 +208,8 @@ class StackMapStream : public ValueObject {
   // A set of concatenated maps of Dex register locations indices to `location_catalog_entries_`.
   ScopedArenaVector<size_t> dex_register_locations_;
   ScopedArenaVector<InlineInfoEntry> inline_infos_;
-  ScopedArenaVector<uint8_t> stack_masks_;
-  ScopedArenaVector<uint32_t> register_masks_;
   ScopedArenaVector<uint32_t> method_indices_;
   ScopedArenaVector<DexRegisterMapEntry> dex_register_entries_;
-  int stack_mask_max_;
 
   ScopedArenaVector<uint8_t> out_;