Re-enable boot image direct string loads for read barriers

Boot.oat code size with CC baker:
ARM32: 70775656 -> 69817028 (-1.35%)
ARM64: 80819424 -> 79417072 (-1.74%)
X86 unmeasured.
X86_64 unmeasured.

Performance unmeasured, should be faster.

Bug: 29516974

Test: test-art-host CC baker, N6P booting CC baker

Change-Id: I219faaca9ed17af81d2815fb5e124120f307af83

4 files changed, 0 insertions, 55 deletions

diff --git a/compiler/optimizing/code_generator_arm.cc b/compiler/optimizing/code_generator_arm.cc
index 3c4a3e8e18..e76190f3da 100644
--- a/compiler/optimizing/code_generator_arm.cc
+++ b/compiler/optimizing/code_generator_arm.cc
@@ -5422,17 +5422,6 @@ void InstructionCodeGeneratorARM::GenerateClassInitializationCheck(
 
 HLoadString::LoadKind CodeGeneratorARM::GetSupportedLoadStringKind(
     HLoadString::LoadKind desired_string_load_kind) {
-  if (kEmitCompilerReadBarrier) {
-    switch (desired_string_load_kind) {
-      case HLoadString::LoadKind::kBootImageLinkTimeAddress:
-      case HLoadString::LoadKind::kBootImageLinkTimePcRelative:
-      case HLoadString::LoadKind::kBootImageAddress:
-        // TODO: Implement for read barrier.
-        return HLoadString::LoadKind::kDexCacheViaMethod;
-      default:
-        break;
-    }
-  }
   switch (desired_string_load_kind) {
     case HLoadString::LoadKind::kBootImageLinkTimeAddress:
       DCHECK(!GetCompilerOptions().GetCompilePic());
@@ -5485,13 +5474,11 @@ void InstructionCodeGeneratorARM::VisitLoadString(HLoadString* load) {
 
   switch (load_kind) {
     case HLoadString::LoadKind::kBootImageLinkTimeAddress: {
-      DCHECK(!kEmitCompilerReadBarrier);
       __ LoadLiteral(out, codegen_->DeduplicateBootImageStringLiteral(load->GetDexFile(),
                                                                       load->GetStringIndex()));
       return;  // No dex cache slow path.
     }
     case HLoadString::LoadKind::kBootImageLinkTimePcRelative: {
-      DCHECK(!kEmitCompilerReadBarrier);
       CodeGeneratorARM::PcRelativePatchInfo* labels =
           codegen_->NewPcRelativeStringPatch(load->GetDexFile(), load->GetStringIndex());
       __ BindTrackedLabel(&labels->movw_label);
@@ -5503,7 +5490,6 @@ void InstructionCodeGeneratorARM::VisitLoadString(HLoadString* load) {
       return;  // No dex cache slow path.
     }
     case HLoadString::LoadKind::kBootImageAddress: {
-      DCHECK(!kEmitCompilerReadBarrier);
       DCHECK_NE(load->GetAddress(), 0u);
       uint32_t address = dchecked_integral_cast<uint32_t>(load->GetAddress());
       __ LoadLiteral(out, codegen_->DeduplicateBootImageAddressLiteral(address));
diff --git a/compiler/optimizing/code_generator_arm64.cc b/compiler/optimizing/code_generator_arm64.cc
index 1d2f33405e..64231ade7e 100644
--- a/compiler/optimizing/code_generator_arm64.cc
+++ b/compiler/optimizing/code_generator_arm64.cc
@@ -4124,17 +4124,6 @@ void InstructionCodeGeneratorARM64::VisitClearException(HClearException* clear A
 
 HLoadString::LoadKind CodeGeneratorARM64::GetSupportedLoadStringKind(
     HLoadString::LoadKind desired_string_load_kind) {
-  if (kEmitCompilerReadBarrier) {
-    switch (desired_string_load_kind) {
-      case HLoadString::LoadKind::kBootImageLinkTimeAddress:
-      case HLoadString::LoadKind::kBootImageLinkTimePcRelative:
-      case HLoadString::LoadKind::kBootImageAddress:
-        // TODO: Implement for read barrier.
-        return HLoadString::LoadKind::kDexCacheViaMethod;
-      default:
-        break;
-    }
-  }
   switch (desired_string_load_kind) {
     case HLoadString::LoadKind::kBootImageLinkTimeAddress:
       DCHECK(!GetCompilerOptions().GetCompilePic());
@@ -4175,12 +4164,10 @@ void InstructionCodeGeneratorARM64::VisitLoadString(HLoadString* load) {
 
   switch (load->GetLoadKind()) {
     case HLoadString::LoadKind::kBootImageLinkTimeAddress:
-      DCHECK(!kEmitCompilerReadBarrier);
       __ Ldr(out, codegen_->DeduplicateBootImageStringLiteral(load->GetDexFile(),
                                                               load->GetStringIndex()));
       return;  // No dex cache slow path.
     case HLoadString::LoadKind::kBootImageLinkTimePcRelative: {
-      DCHECK(!kEmitCompilerReadBarrier);
       // Add ADRP with its PC-relative String patch.
       const DexFile& dex_file = load->GetDexFile();
       uint32_t string_index = load->GetStringIndex();
@@ -4201,7 +4188,6 @@ void InstructionCodeGeneratorARM64::VisitLoadString(HLoadString* load) {
       return;  // No dex cache slow path.
     }
     case HLoadString::LoadKind::kBootImageAddress: {
-      DCHECK(!kEmitCompilerReadBarrier);
       DCHECK(load->GetAddress() != 0u && IsUint<32>(load->GetAddress()));
       __ Ldr(out.W(), codegen_->DeduplicateBootImageAddressLiteral(load->GetAddress()));
       return;  // No dex cache slow path.
diff --git a/compiler/optimizing/code_generator_x86.cc b/compiler/optimizing/code_generator_x86.cc
index 5953badb07..72ab6150f6 100644
--- a/compiler/optimizing/code_generator_x86.cc
+++ b/compiler/optimizing/code_generator_x86.cc
@@ -6065,17 +6065,6 @@ void InstructionCodeGeneratorX86::GenerateClassInitializationCheck(
 
 HLoadString::LoadKind CodeGeneratorX86::GetSupportedLoadStringKind(
     HLoadString::LoadKind desired_string_load_kind) {
-  if (kEmitCompilerReadBarrier) {
-    switch (desired_string_load_kind) {
-      case HLoadString::LoadKind::kBootImageLinkTimeAddress:
-      case HLoadString::LoadKind::kBootImageLinkTimePcRelative:
-      case HLoadString::LoadKind::kBootImageAddress:
-        // TODO: Implement for read barrier.
-        return HLoadString::LoadKind::kDexCacheViaMethod;
-      default:
-        break;
-    }
-  }
   switch (desired_string_load_kind) {
     case HLoadString::LoadKind::kBootImageLinkTimeAddress:
       DCHECK(!GetCompilerOptions().GetCompilePic());
@@ -6129,20 +6118,17 @@ void InstructionCodeGeneratorX86::VisitLoadString(HLoadString* load) {
 
   switch (load->GetLoadKind()) {
     case HLoadString::LoadKind::kBootImageLinkTimeAddress: {
-      DCHECK(!kEmitCompilerReadBarrier);
       __ movl(out, Immediate(/* placeholder */ 0));
       codegen_->RecordStringPatch(load);
       return;  // No dex cache slow path.
     }
     case HLoadString::LoadKind::kBootImageLinkTimePcRelative: {
-      DCHECK(!kEmitCompilerReadBarrier);
       Register method_address = locations->InAt(0).AsRegister<Register>();
       __ leal(out, Address(method_address, CodeGeneratorX86::kDummy32BitOffset));
       codegen_->RecordStringPatch(load);
       return;  // No dex cache slow path.
     }
     case HLoadString::LoadKind::kBootImageAddress: {
-      DCHECK(!kEmitCompilerReadBarrier);
       DCHECK_NE(load->GetAddress(), 0u);
       uint32_t address = dchecked_integral_cast<uint32_t>(load->GetAddress());
       __ movl(out, Immediate(address));
diff --git a/compiler/optimizing/code_generator_x86_64.cc b/compiler/optimizing/code_generator_x86_64.cc
index 46f90603b5..cbb5799d52 100644
--- a/compiler/optimizing/code_generator_x86_64.cc
+++ b/compiler/optimizing/code_generator_x86_64.cc
@@ -5495,17 +5495,6 @@ void InstructionCodeGeneratorX86_64::VisitClinitCheck(HClinitCheck* check) {
 
 HLoadString::LoadKind CodeGeneratorX86_64::GetSupportedLoadStringKind(
     HLoadString::LoadKind desired_string_load_kind) {
-  if (kEmitCompilerReadBarrier) {
-    switch (desired_string_load_kind) {
-      case HLoadString::LoadKind::kBootImageLinkTimeAddress:
-      case HLoadString::LoadKind::kBootImageLinkTimePcRelative:
-      case HLoadString::LoadKind::kBootImageAddress:
-        // TODO: Implement for read barrier.
-        return HLoadString::LoadKind::kDexCacheViaMethod;
-      default:
-        break;
-    }
-  }
   switch (desired_string_load_kind) {
     case HLoadString::LoadKind::kBootImageLinkTimeAddress:
       DCHECK(!GetCompilerOptions().GetCompilePic());
@@ -5548,13 +5537,11 @@ void InstructionCodeGeneratorX86_64::VisitLoadString(HLoadString* load) {
 
   switch (load->GetLoadKind()) {
     case HLoadString::LoadKind::kBootImageLinkTimePcRelative: {
-      DCHECK(!kEmitCompilerReadBarrier);
       __ leal(out, Address::Absolute(CodeGeneratorX86_64::kDummy32BitOffset, /* no_rip */ false));
       codegen_->RecordStringPatch(load);
       return;  // No dex cache slow path.
     }
     case HLoadString::LoadKind::kBootImageAddress: {
-      DCHECK(!kEmitCompilerReadBarrier);
       DCHECK_NE(load->GetAddress(), 0u);
       uint32_t address = dchecked_integral_cast<uint32_t>(load->GetAddress());
       __ movl(out, Immediate(address));  // Zero-extended.