Encode frame info using varints.

This saves 0.3% of oat file size.

Test: test-art-host-gtest-stack_map_test
Change-Id: I85003946a9579f03cb1ed2b5e9b2c62b3efe6734

2 files changed, 9 insertions, 8 deletions

diff --git a/compiler/optimizing/stack_map_stream.cc b/compiler/optimizing/stack_map_stream.cc
index 429054cec7..b26b53fc9f 100644
--- a/compiler/optimizing/stack_map_stream.cc
+++ b/compiler/optimizing/stack_map_stream.cc
@@ -45,9 +45,10 @@ void StackMapStream::BeginMethod(size_t frame_size_in_bytes,
                                  uint32_t num_dex_registers) {
   DCHECK(!in_method_) << "Mismatched Begin/End calls";
   in_method_ = true;
-  DCHECK_EQ(frame_size_in_bytes_, 0u) << "BeginMethod was already called";
+  DCHECK_EQ(packed_frame_size_, 0u) << "BeginMethod was already called";
 
-  frame_size_in_bytes_ = frame_size_in_bytes;
+  DCHECK_ALIGNED(frame_size_in_bytes, kStackAlignment);
+  packed_frame_size_ = frame_size_in_bytes / kStackAlignment;
   core_spill_mask_ = core_spill_mask;
   fp_spill_mask_ = fp_spill_mask;
   num_dex_registers_ = num_dex_registers;
@@ -292,11 +293,11 @@ size_t StackMapStream::PrepareForFillIn() {
     }
   }
 
-  EncodeUnsignedLeb128(&out_, frame_size_in_bytes_);
-  EncodeUnsignedLeb128(&out_, core_spill_mask_);
-  EncodeUnsignedLeb128(&out_, fp_spill_mask_);
-  EncodeUnsignedLeb128(&out_, num_dex_registers_);
-  BitMemoryWriter<ScopedArenaVector<uint8_t>> out(&out_, out_.size() * kBitsPerByte);
+  BitMemoryWriter<ScopedArenaVector<uint8_t>> out(&out_);
+  EncodeVarintBits(out, packed_frame_size_);
+  EncodeVarintBits(out, core_spill_mask_);
+  EncodeVarintBits(out, fp_spill_mask_);
+  EncodeVarintBits(out, num_dex_registers_);
   EncodeTable(out, stack_maps_);
   EncodeTable(out, inline_infos_);
   EncodeTable(out, method_infos_);
diff --git a/compiler/optimizing/stack_map_stream.h b/compiler/optimizing/stack_map_stream.h
index de79f4921e..a5f7ff3a49 100644
--- a/compiler/optimizing/stack_map_stream.h
+++ b/compiler/optimizing/stack_map_stream.h
@@ -98,7 +98,7 @@ class StackMapStream : public ValueObject {
   void CreateDexRegisterMap();
 
   const InstructionSet instruction_set_;
-  uint32_t frame_size_in_bytes_ = 0;
+  uint32_t packed_frame_size_ = 0;
   uint32_t core_spill_mask_ = 0;
   uint32_t fp_spill_mask_ = 0;
   uint32_t num_dex_registers_ = 0;