Do not save/restore regs in ClinitCheck slow path.
The entrypoint is kSaveEverything, so the only register that
needs to be saved is the argument/return value register.
The size of the aosp_taimen-userdebug prebuilts:
- before:
arm/boot*.oat: 16811692
arm64/boot*.oat: 19801032
oat/arm64/services.odex: 20232208
- after:
arm/boot*.oat: 16798804 (-12.6KiB, -0.08%)
arm64/boot*.oat: 19804392 (+3.3KiB, +0.02%)
oat/arm64/services.odex: 20227784 (-4.3KiB, -0.02%)
Note that though there is less code, the metadata for the
arm64/boot*.oat outweighs the code size reduction because of
the register map encoding as value+shift introduced in
https://android-review.googlesource.com/695682
which it's ill-suited for kSaveEverything entrypoints. We
should reconsider that encoding.
Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing
Test: Pixel 2 XL boots.
Test: testrunner.py --target --optimizing
Change-Id: I5cd1deb90332a3b88a0a59d87925c557d9bff1ab
diff --git a/compiler/optimizing/code_generator_arm64.cc b/compiler/optimizing/code_generator_arm64.cc
index 00bf2f1..3446dd6 100644
--- a/compiler/optimizing/code_generator_arm64.cc
+++ b/compiler/optimizing/code_generator_arm64.cc
@@ -164,6 +164,16 @@
return ARM64ReturnLocation(return_type);
}
+static RegisterSet OneRegInReferenceOutSaveEverythingCallerSaves() {
+ InvokeRuntimeCallingConvention calling_convention;
+ RegisterSet caller_saves = RegisterSet::Empty();
+ caller_saves.Add(Location::RegisterLocation(calling_convention.GetRegisterAt(0).GetCode()));
+ DCHECK_EQ(calling_convention.GetRegisterAt(0).GetCode(),
+ RegisterFrom(calling_convention.GetReturnLocation(DataType::Type::kReference),
+ DataType::Type::kReference).GetCode());
+ return caller_saves;
+}
+
// NOLINT on __ macro to suppress wrong warning/fix (misc-macro-parentheses) from clang-tidy.
#define __ down_cast<CodeGeneratorARM64*>(codegen)->GetVIXLAssembler()-> // NOLINT
#define QUICK_ENTRY_POINT(x) QUICK_ENTRYPOINT_OFFSET(kArm64PointerSize, x).Int32Value()
@@ -3178,6 +3188,8 @@
if (check->HasUses()) {
locations->SetOut(Location::SameAsFirstInput());
}
+ // Rely on the type initialization to save everything we need.
+ locations->SetCustomSlowPathCallerSaves(OneRegInReferenceOutSaveEverythingCallerSaves());
}
void InstructionCodeGeneratorARM64::VisitClinitCheck(HClinitCheck* check) {
@@ -5053,13 +5065,7 @@
if (cls->GetLoadKind() == HLoadClass::LoadKind::kBssEntry) {
if (!kUseReadBarrier || kUseBakerReadBarrier) {
// Rely on the type resolution or initialization and marking to save everything we need.
- RegisterSet caller_saves = RegisterSet::Empty();
- InvokeRuntimeCallingConvention calling_convention;
- caller_saves.Add(Location::RegisterLocation(calling_convention.GetRegisterAt(0).GetCode()));
- DCHECK_EQ(calling_convention.GetRegisterAt(0).GetCode(),
- RegisterFrom(calling_convention.GetReturnLocation(DataType::Type::kReference),
- DataType::Type::kReference).GetCode());
- locations->SetCustomSlowPathCallerSaves(caller_saves);
+ locations->SetCustomSlowPathCallerSaves(OneRegInReferenceOutSaveEverythingCallerSaves());
} else {
// For non-Baker read barrier we have a temp-clobbering call.
}
@@ -5257,13 +5263,7 @@
if (load->GetLoadKind() == HLoadString::LoadKind::kBssEntry) {
if (!kUseReadBarrier || kUseBakerReadBarrier) {
// Rely on the pResolveString and marking to save everything we need.
- RegisterSet caller_saves = RegisterSet::Empty();
- InvokeRuntimeCallingConvention calling_convention;
- caller_saves.Add(Location::RegisterLocation(calling_convention.GetRegisterAt(0).GetCode()));
- DCHECK_EQ(calling_convention.GetRegisterAt(0).GetCode(),
- RegisterFrom(calling_convention.GetReturnLocation(DataType::Type::kReference),
- DataType::Type::kReference).GetCode());
- locations->SetCustomSlowPathCallerSaves(caller_saves);
+ locations->SetCustomSlowPathCallerSaves(OneRegInReferenceOutSaveEverythingCallerSaves());
} else {
// For non-Baker read barrier we have a temp-clobbering call.
}