Optimize stack maps: add fast path for no inline info.

Consumers of CodeInfo can skip significant chunks of work
if they can quickly determine that method has no inlining.

Store this fact as a flag bit at the start of code info.
This changes binary format and adds <0.1% to oat size.

I added the extra flag field as the simplest solution for now,
although I would like to use it for more things in the future.
(e.g. store the special cases of empty/deduped tables in it)

This improves app startup by 0.4% (maps,speed).
PMD on golem seems to gets around 15% faster.

Bug: 133257467
Test: ./art/test.py -b --host --64
Change-Id: Ia498a31bafc74b51cc95b8c70cf1da4b0e3d894e

1 files changed, 2 insertions, 0 deletions

diff --git a/compiler/optimizing/stack_map_stream.cc b/compiler/optimizing/stack_map_stream.cc
index 8c3664312d..e21e21cdf3 100644
--- a/compiler/optimizing/stack_map_stream.cc
+++ b/compiler/optimizing/stack_map_stream.cc
@@ -184,6 +184,7 @@ void StackMapStream::BeginInlineInfoEntry(ArtMethod* method,
   in_inline_info_ = true;
   DCHECK_EQ(expected_num_dex_registers_, current_dex_registers_.size());
 
+  flags_ |= CodeInfo::kHasInlineInfo;
   expected_num_dex_registers_ += num_dex_registers;
 
   BitTableBuilder<InlineInfo>::Entry entry;
@@ -305,6 +306,7 @@ ScopedArenaVector<uint8_t> StackMapStream::Encode() {
 
   ScopedArenaVector<uint8_t> buffer(allocator_->Adapter(kArenaAllocStackMapStream));
   BitMemoryWriter<ScopedArenaVector<uint8_t>> out(&buffer);
+  out.WriteVarint(flags_);
   out.WriteVarint(packed_frame_size_);
   out.WriteVarint(core_spill_mask_);
   out.WriteVarint(fp_spill_mask_);