Fill Class and String .bss slots in runtime.
Shift the responsibility for filling Class and String .bss
slots from compiled code to runtime. This reduces the size
of the compiled code.
Make oatdump list .bss slot mappings (ArtMethod, Class and
String) for each dex file.
aosp_taimen-userdebug boot image size:
- before:
arm boot*.oat: 36534524
arm64 boot*.oat: 42723256
- after:
arm boot*.oat: 36431448 (-101KiB, -0.3%)
arm64 boot*.oat: 42645016 (-76KiB, -0.2%)
Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing
Test: Pixel 2 XL boots.
Test: testrunner.py --target --optimizing
Test: m dump-oat, manually inspect output.
Bug: 65737953
Change-Id: I1330d070307410107e12c309d4c7f8121baba83c
diff --git a/compiler/optimizing/code_generator_arm_vixl.cc b/compiler/optimizing/code_generator_arm_vixl.cc
index 9e7455d..3f8f0c4 100644
--- a/compiler/optimizing/code_generator_arm_vixl.cc
+++ b/compiler/optimizing/code_generator_arm_vixl.cc
@@ -532,29 +532,12 @@
void EmitNativeCode(CodeGenerator* codegen) OVERRIDE {
LocationSummary* locations = instruction_->GetLocations();
Location out = locations->Out();
- constexpr bool call_saves_everything_except_r0 = (!kUseReadBarrier || kUseBakerReadBarrier);
CodeGeneratorARMVIXL* arm_codegen = down_cast<CodeGeneratorARMVIXL*>(codegen);
__ Bind(GetEntryLabel());
SaveLiveRegisters(codegen, locations);
InvokeRuntimeCallingConventionARMVIXL calling_convention;
- // For HLoadClass/kBssEntry/kSaveEverything, make sure we preserve the address of the entry.
- DCHECK_EQ(instruction_->IsLoadClass(), cls_ == instruction_);
- bool is_load_class_bss_entry =
- (cls_ == instruction_) && (cls_->GetLoadKind() == HLoadClass::LoadKind::kBssEntry);
- vixl32::Register entry_address;
- if (is_load_class_bss_entry && call_saves_everything_except_r0) {
- vixl32::Register temp = RegisterFrom(locations->GetTemp(0));
- // In the unlucky case that the `temp` is R0, we preserve the address in `out` across
- // the kSaveEverything call.
- bool temp_is_r0 = temp.Is(calling_convention.GetRegisterAt(0));
- entry_address = temp_is_r0 ? RegisterFrom(out) : temp;
- DCHECK(!entry_address.Is(calling_convention.GetRegisterAt(0)));
- if (temp_is_r0) {
- __ Mov(entry_address, temp);
- }
- }
dex::TypeIndex type_index = cls_->GetTypeIndex();
__ Mov(calling_convention.GetRegisterAt(0), type_index.index_);
QuickEntrypointEnum entrypoint = do_clinit_ ? kQuickInitializeStaticStorage
@@ -566,22 +549,6 @@
CheckEntrypointTypes<kQuickInitializeType, void*, uint32_t>();
}
- // For HLoadClass/kBssEntry, store the resolved Class to the BSS entry.
- if (is_load_class_bss_entry) {
- if (call_saves_everything_except_r0) {
- // The class entry address was preserved in `entry_address` thanks to kSaveEverything.
- __ Str(r0, MemOperand(entry_address));
- } else {
- // For non-Baker read barrier, we need to re-calculate the address of the string entry.
- UseScratchRegisterScope temps(
- down_cast<CodeGeneratorARMVIXL*>(codegen)->GetVIXLAssembler());
- vixl32::Register temp = temps.Acquire();
- CodeGeneratorARMVIXL::PcRelativePatchInfo* labels =
- arm_codegen->NewTypeBssEntryPatch(cls_->GetDexFile(), type_index);
- arm_codegen->EmitMovwMovtPlaceholder(labels, temp);
- __ Str(r0, MemOperand(temp));
- }
- }
// Move the class to the desired location.
if (out.IsValid()) {
DCHECK(out.IsRegister() && !locations->GetLiveRegisters()->ContainsCoreRegister(out.reg()));
@@ -616,48 +583,17 @@
DCHECK_EQ(instruction_->AsLoadString()->GetLoadKind(), HLoadString::LoadKind::kBssEntry);
LocationSummary* locations = instruction_->GetLocations();
DCHECK(!locations->GetLiveRegisters()->ContainsCoreRegister(locations->Out().reg()));
- HLoadString* load = instruction_->AsLoadString();
- const dex::StringIndex string_index = load->GetStringIndex();
- vixl32::Register out = OutputRegister(load);
- constexpr bool call_saves_everything_except_r0 = (!kUseReadBarrier || kUseBakerReadBarrier);
+ const dex::StringIndex string_index = instruction_->AsLoadString()->GetStringIndex();
CodeGeneratorARMVIXL* arm_codegen = down_cast<CodeGeneratorARMVIXL*>(codegen);
__ Bind(GetEntryLabel());
SaveLiveRegisters(codegen, locations);
InvokeRuntimeCallingConventionARMVIXL calling_convention;
- // In the unlucky case that the `temp` is R0, we preserve the address in `out` across
- // the kSaveEverything call.
- vixl32::Register entry_address;
- if (call_saves_everything_except_r0) {
- vixl32::Register temp = RegisterFrom(locations->GetTemp(0));
- bool temp_is_r0 = (temp.Is(calling_convention.GetRegisterAt(0)));
- entry_address = temp_is_r0 ? out : temp;
- DCHECK(!entry_address.Is(calling_convention.GetRegisterAt(0)));
- if (temp_is_r0) {
- __ Mov(entry_address, temp);
- }
- }
-
__ Mov(calling_convention.GetRegisterAt(0), string_index.index_);
arm_codegen->InvokeRuntime(kQuickResolveString, instruction_, instruction_->GetDexPc(), this);
CheckEntrypointTypes<kQuickResolveString, void*, uint32_t>();
- // Store the resolved String to the .bss entry.
- if (call_saves_everything_except_r0) {
- // The string entry address was preserved in `entry_address` thanks to kSaveEverything.
- __ Str(r0, MemOperand(entry_address));
- } else {
- // For non-Baker read barrier, we need to re-calculate the address of the string entry.
- UseScratchRegisterScope temps(
- down_cast<CodeGeneratorARMVIXL*>(codegen)->GetVIXLAssembler());
- vixl32::Register temp = temps.Acquire();
- CodeGeneratorARMVIXL::PcRelativePatchInfo* labels =
- arm_codegen->NewStringBssEntryPatch(load->GetDexFile(), string_index);
- arm_codegen->EmitMovwMovtPlaceholder(labels, temp);
- __ Str(r0, MemOperand(temp));
- }
-
arm_codegen->Move32(locations->Out(), LocationFrom(r0));
RestoreLiveRegisters(codegen, locations);
@@ -7104,9 +7040,6 @@
if (load_kind == HLoadClass::LoadKind::kBssEntry) {
if (!kUseReadBarrier || kUseBakerReadBarrier) {
// Rely on the type resolution or initialization and marking to save everything we need.
- // Note that IP may be clobbered by saving/restoring the live register (only one thanks
- // to the custom calling convention) or by marking, so we request a different temp.
- locations->AddTemp(Location::RequiresRegister());
RegisterSet caller_saves = RegisterSet::Empty();
InvokeRuntimeCallingConventionARMVIXL calling_convention;
caller_saves.Add(LocationFrom(calling_convention.GetRegisterAt(0)));
@@ -7189,13 +7122,10 @@
break;
}
case HLoadClass::LoadKind::kBssEntry: {
- vixl32::Register temp = (!kUseReadBarrier || kUseBakerReadBarrier)
- ? RegisterFrom(locations->GetTemp(0))
- : out;
CodeGeneratorARMVIXL::PcRelativePatchInfo* labels =
codegen_->NewTypeBssEntryPatch(cls->GetDexFile(), cls->GetTypeIndex());
- codegen_->EmitMovwMovtPlaceholder(labels, temp);
- GenerateGcRootFieldLoad(cls, out_loc, temp, /* offset */ 0, read_barrier_option);
+ codegen_->EmitMovwMovtPlaceholder(labels, out);
+ GenerateGcRootFieldLoad(cls, out_loc, out, /* offset */ 0, read_barrier_option);
generate_null_check = true;
break;
}
@@ -7296,9 +7226,6 @@
if (load_kind == HLoadString::LoadKind::kBssEntry) {
if (!kUseReadBarrier || kUseBakerReadBarrier) {
// Rely on the pResolveString and marking to save everything we need, including temps.
- // Note that IP may be clobbered by saving/restoring the live register (only one thanks
- // to the custom calling convention) or by marking, so we request a different temp.
- locations->AddTemp(Location::RequiresRegister());
RegisterSet caller_saves = RegisterSet::Empty();
InvokeRuntimeCallingConventionARMVIXL calling_convention;
caller_saves.Add(LocationFrom(calling_convention.GetRegisterAt(0)));
@@ -7348,13 +7275,10 @@
}
case HLoadString::LoadKind::kBssEntry: {
DCHECK(!codegen_->GetCompilerOptions().IsBootImage());
- vixl32::Register temp = (!kUseReadBarrier || kUseBakerReadBarrier)
- ? RegisterFrom(locations->GetTemp(0))
- : out;
CodeGeneratorARMVIXL::PcRelativePatchInfo* labels =
codegen_->NewStringBssEntryPatch(load->GetDexFile(), load->GetStringIndex());
- codegen_->EmitMovwMovtPlaceholder(labels, temp);
- GenerateGcRootFieldLoad(load, out_loc, temp, /* offset */ 0, kCompilerReadBarrierOption);
+ codegen_->EmitMovwMovtPlaceholder(labels, out);
+ GenerateGcRootFieldLoad(load, out_loc, out, /* offset */ 0, kCompilerReadBarrierOption);
LoadStringSlowPathARMVIXL* slow_path =
new (codegen_->GetScopedAllocator()) LoadStringSlowPathARMVIXL(load);
codegen_->AddSlowPath(slow_path);