Move caller-saves saving/restoring to ReadBarrierMarkRegX.
Instead of saving/restoring live caller-save registers
before/after the call to read barrier mark entry points
ReadBarrierMarkRegX, have these entry points save/restore
all the caller-save registers themselves (except register
rX, which contains the return value).
Also refactor the assembly code of these entry points
using macros.
* Boot image code size variation on Nexus 5X
(aosp_bullhead-userdebug build):
- total ARM64 framework Oat files size change:
119196792 bytes -> 115575920 bytes (-3.04%)
- total ARM framework Oat files size change:
100435212 bytes -> 97621188 bytes (-2.80%)
* Benchmarks (ARM64) score variations on Nexus 5X
(aosp_bullhead-userdebug build):
- RitzPerf (lower is better)
- average score difference: -2.71%
- CaffeineMark (higher is better)
- no real difference for most tests
(absolute variation lower than 1%)
- better score on the "Method" benchmark:
score variation 41253 -> 44891 (+8.82%)
Test: ART host and target (ARM, ARM64) tests.
Bug: 29506760
Bug: 12687968
Change-Id: I881bf73139a3f1c2bee9ffc6fc8c00f9a392afa6
diff --git a/compiler/optimizing/code_generator_arm64.cc b/compiler/optimizing/code_generator_arm64.cc
index 07b7823..cec641f 100644
--- a/compiler/optimizing/code_generator_arm64.cc
+++ b/compiler/optimizing/code_generator_arm64.cc
@@ -603,11 +603,9 @@
<< instruction_->DebugName();
__ Bind(GetEntryLabel());
- // Save live registers before the runtime call, and in particular
- // W0 (if it is live), as it is clobbered by functions
- // art_quick_read_barrier_mark_regX.
- SaveLiveRegisters(codegen, locations);
-
+ // No need to save live registers; it's taken care of by the
+ // entrypoint. Also, there is no need to update the stack mask,
+ // as this runtime call will not trigger a garbage collection.
InvokeRuntimeCallingConvention calling_convention;
CodeGeneratorARM64* arm64_codegen = down_cast<CodeGeneratorARM64*>(codegen);
DCHECK_NE(obj_.reg(), LR);
@@ -635,8 +633,6 @@
instruction_,
instruction_->GetDexPc(),
this);
-
- RestoreLiveRegisters(codegen, locations);
__ B(GetExitLabel());
}