Reuse arena memory for each block in scheduler.

This reduces the peak memory used for large methods with
multiple blocks to schedule.

Compiling the aosp_taimen-userdebug boot image, the most
memory hungry method BatteryStats.dumpLocked has the
Scheduler memory allocations in ArenaStack hidden by the
register allocator:
  - before:
    MEM: used: 8300224, allocated: 9175040, lost: 197360
    Scheduler       8300224
  - after:
    MEM: used: 5914296, allocated: 7864320, lost: 78200
    SsaLiveness     5532840
    RegAllocator     144968
    RegAllocVldt     236488
The total arena memory used, including the ArenaAllocator
not listed above, goes from 44333648 to 41950324 (-5.4%).
(Measured with kArenaAllocatorCountAllocations=true,
kArenaAllocatorPreciseTracking=false.)

Also remove one unnecessary -Wframe-larger-than= workaround
and add one workaround for large frame with the above arena
alloc tracking flags.

Test: m test-art-host-gtest
Test: testrunner.py --host
Bug: 34053922
Change-Id: I7fd8d90dcc13b184b1e5bd0bcac072388710a129

1 files changed, 8 insertions, 5 deletions

diff --git a/compiler/optimizing/optimizing_compiler.cc b/compiler/optimizing/optimizing_compiler.cc
index d96746fdd7..b2733ee1f2 100644
--- a/compiler/optimizing/optimizing_compiler.cc
+++ b/compiler/optimizing/optimizing_compiler.cc
@@ -1101,15 +1101,18 @@ static void CreateJniStackMap(ArenaStack* arena_stack,
                               const JniCompiledMethod& jni_compiled_method,
                               /* out */ ArenaVector<uint8_t>* stack_map) {
   ScopedArenaAllocator allocator(arena_stack);
-  StackMapStream stack_map_stream(&allocator, jni_compiled_method.GetInstructionSet());
-  stack_map_stream.BeginMethod(
+  // StackMapStream is quite large, so allocate it using the ScopedArenaAllocator
+  // to stay clear of the frame size limit.
+  std::unique_ptr<StackMapStream> stack_map_stream(
+      new (&allocator) StackMapStream(&allocator, jni_compiled_method.GetInstructionSet()));
+  stack_map_stream->BeginMethod(
       jni_compiled_method.GetFrameSize(),
       jni_compiled_method.GetCoreSpillMask(),
       jni_compiled_method.GetFpSpillMask(),
       /* num_dex_registers */ 0);
-  stack_map_stream.EndMethod();
-  stack_map->resize(stack_map_stream.PrepareForFillIn());
-  stack_map_stream.FillInCodeInfo(MemoryRegion(stack_map->data(), stack_map->size()));
+  stack_map_stream->EndMethod();
+  stack_map->resize(stack_map_stream->PrepareForFillIn());
+  stack_map_stream->FillInCodeInfo(MemoryRegion(stack_map->data(), stack_map->size()));
 }
 
 CompiledMethod* OptimizingCompiler::JniCompile(uint32_t access_flags,