diff --git a/compiler/optimizing/code_generator_arm.cc b/compiler/optimizing/code_generator_arm.cc
index 8a6b94e..1f59816 100644
--- a/compiler/optimizing/code_generator_arm.cc
+++ b/compiler/optimizing/code_generator_arm.cc
@@ -430,7 +430,7 @@
     LocationSummary* locations = instruction_->GetLocations();
     DCHECK(!locations->GetLiveRegisters()->ContainsCoreRegister(locations->Out().reg()));
     HLoadString* load = instruction_->AsLoadString();
-    const uint32_t string_index = load->GetStringIndex();
+    const uint32_t string_index = load->GetStringIndex().index_;
     Register out = locations->Out().AsRegister<Register>();
     Register temp = locations->GetTemp(0).AsRegister<Register>();
     constexpr bool call_saves_everything_except_r0 = (!kUseReadBarrier || kUseBakerReadBarrier);
@@ -5946,7 +5946,7 @@
     case HLoadString::LoadKind::kBootImageLinkTimePcRelative: {
       DCHECK(codegen_->GetCompilerOptions().IsBootImage());
       CodeGeneratorARM::PcRelativePatchInfo* labels =
-          codegen_->NewPcRelativeStringPatch(load->GetDexFile(), load->GetStringIndex());
+          codegen_->NewPcRelativeStringPatch(load->GetDexFile(), load->GetStringIndex().index_);
       __ BindTrackedLabel(&labels->movw_label);
       __ movw(out, /* placeholder */ 0u);
       __ BindTrackedLabel(&labels->movt_label);
@@ -5965,7 +5965,7 @@
       DCHECK(!codegen_->GetCompilerOptions().IsBootImage());
       Register temp = locations->GetTemp(0).AsRegister<Register>();
       CodeGeneratorARM::PcRelativePatchInfo* labels =
-          codegen_->NewPcRelativeStringPatch(load->GetDexFile(), load->GetStringIndex());
+          codegen_->NewPcRelativeStringPatch(load->GetDexFile(), load->GetStringIndex().index_);
       __ BindTrackedLabel(&labels->movw_label);
       __ movw(temp, /* placeholder */ 0u);
       __ BindTrackedLabel(&labels->movt_label);
@@ -5994,7 +5994,7 @@
   DCHECK(load_kind == HLoadString::LoadKind::kDexCacheViaMethod);
   InvokeRuntimeCallingConvention calling_convention;
   DCHECK_EQ(calling_convention.GetRegisterAt(0), out);
-  __ LoadImmediate(calling_convention.GetRegisterAt(0), load->GetStringIndex());
+  __ LoadImmediate(calling_convention.GetRegisterAt(0), load->GetStringIndex().index_);
   codegen_->InvokeRuntime(kQuickResolveString, load, load->GetDexPc());
   CheckEntrypointTypes<kQuickResolveString, void*, uint32_t>();
 }
@@ -7340,7 +7340,7 @@
 }
 
 Literal* CodeGeneratorARM::DeduplicateBootImageStringLiteral(const DexFile& dex_file,
-                                                             uint32_t string_index) {
+                                                             dex::StringIndex string_index) {
   return boot_image_string_patches_.GetOrCreate(
       StringReference(&dex_file, string_index),
       [this]() { return __ NewLiteral<uint32_t>(/* placeholder */ 0u); });
@@ -7364,7 +7364,7 @@
 }
 
 Literal* CodeGeneratorARM::DeduplicateJitStringLiteral(const DexFile& dex_file,
-                                                       uint32_t string_index) {
+                                                       dex::StringIndex string_index) {
   jit_string_roots_.Overwrite(StringReference(&dex_file, string_index), /* placeholder */ 0u);
   return jit_string_patches_.GetOrCreate(
       StringReference(&dex_file, string_index),
@@ -7436,7 +7436,7 @@
     uint32_t literal_offset = literal->GetLabel()->Position();
     linker_patches->push_back(LinkerPatch::StringPatch(literal_offset,
                                                        target_string.dex_file,
-                                                       target_string.string_index));
+                                                       target_string.string_index.index_));
   }
   if (!GetCompilerOptions().IsBootImage()) {
     EmitPcRelativeLinkerPatches<LinkerPatch::StringBssEntryPatch>(pc_relative_string_patches_,
diff --git a/compiler/optimizing/code_generator_arm.h b/compiler/optimizing/code_generator_arm.h
index a4ccb57..8230512 100644
--- a/compiler/optimizing/code_generator_arm.h
+++ b/compiler/optimizing/code_generator_arm.h
@@ -485,11 +485,12 @@
   PcRelativePatchInfo* NewPcRelativeTypePatch(const DexFile& dex_file, dex::TypeIndex type_index);
   PcRelativePatchInfo* NewPcRelativeDexCacheArrayPatch(const DexFile& dex_file,
                                                        uint32_t element_offset);
-  Literal* DeduplicateBootImageStringLiteral(const DexFile& dex_file, uint32_t string_index);
+  Literal* DeduplicateBootImageStringLiteral(const DexFile& dex_file,
+                                             dex::StringIndex string_index);
   Literal* DeduplicateBootImageTypeLiteral(const DexFile& dex_file, dex::TypeIndex type_index);
   Literal* DeduplicateBootImageAddressLiteral(uint32_t address);
   Literal* DeduplicateDexCacheAddressLiteral(uint32_t address);
-  Literal* DeduplicateJitStringLiteral(const DexFile& dex_file, uint32_t string_index);
+  Literal* DeduplicateJitStringLiteral(const DexFile& dex_file, dex::StringIndex string_index);
 
   void EmitLinkerPatches(ArenaVector<LinkerPatch>* linker_patches) OVERRIDE;
 
diff --git a/compiler/optimizing/code_generator_arm64.cc b/compiler/optimizing/code_generator_arm64.cc
index a78b3da..ab6a33f 100644
--- a/compiler/optimizing/code_generator_arm64.cc
+++ b/compiler/optimizing/code_generator_arm64.cc
@@ -349,7 +349,7 @@
     SaveLiveRegisters(codegen, locations);
 
     InvokeRuntimeCallingConvention calling_convention;
-    const uint32_t string_index = instruction_->AsLoadString()->GetStringIndex();
+    const uint32_t string_index = instruction_->AsLoadString()->GetStringIndex().index_;
     __ Mov(calling_convention.GetRegisterAt(0).W(), string_index);
     arm64_codegen->InvokeRuntime(kQuickResolveString, instruction_, instruction_->GetDexPc(), this);
     CheckEntrypointTypes<kQuickResolveString, void*, uint32_t>();
@@ -4132,7 +4132,7 @@
 }
 
 vixl::aarch64::Literal<uint32_t>* CodeGeneratorARM64::DeduplicateBootImageStringLiteral(
-    const DexFile& dex_file, uint32_t string_index) {
+    const DexFile& dex_file, dex::StringIndex string_index) {
   return boot_image_string_patches_.GetOrCreate(
       StringReference(&dex_file, string_index),
       [this]() { return __ CreateLiteralDestroyedWithPool<uint32_t>(/* placeholder */ 0u); });
@@ -4158,7 +4158,7 @@
 }
 
 vixl::aarch64::Literal<uint32_t>* CodeGeneratorARM64::DeduplicateJitStringLiteral(
-    const DexFile& dex_file, uint32_t string_index) {
+    const DexFile& dex_file, dex::StringIndex string_index) {
   jit_string_roots_.Overwrite(StringReference(&dex_file, string_index), /* placeholder */ 0u);
   return jit_string_patches_.GetOrCreate(
       StringReference(&dex_file, string_index),
@@ -4246,7 +4246,7 @@
     vixl::aarch64::Literal<uint32_t>* literal = entry.second;
     linker_patches->push_back(LinkerPatch::StringPatch(literal->GetOffset(),
                                                        target_string.dex_file,
-                                                       target_string.string_index));
+                                                       target_string.string_index.index_));
   }
   if (!GetCompilerOptions().IsBootImage()) {
     EmitPcRelativeLinkerPatches<LinkerPatch::StringBssEntryPatch>(pc_relative_string_patches_,
@@ -4594,7 +4594,7 @@
     case HLoadString::LoadKind::kBootImageLinkTimePcRelative: {
       // Add ADRP with its PC-relative String patch.
       const DexFile& dex_file = load->GetDexFile();
-      uint32_t string_index = load->GetStringIndex();
+      uint32_t string_index = load->GetStringIndex().index_;
       DCHECK(codegen_->GetCompilerOptions().IsBootImage());
       vixl::aarch64::Label* adrp_label = codegen_->NewPcRelativeStringPatch(dex_file, string_index);
       codegen_->EmitAdrpPlaceholder(adrp_label, out.X());
@@ -4612,7 +4612,7 @@
     case HLoadString::LoadKind::kBssEntry: {
       // Add ADRP with its PC-relative String .bss entry patch.
       const DexFile& dex_file = load->GetDexFile();
-      uint32_t string_index = load->GetStringIndex();
+      uint32_t string_index = load->GetStringIndex().index_;
       DCHECK(!codegen_->GetCompilerOptions().IsBootImage());
       UseScratchRegisterScope temps(codegen_->GetVIXLAssembler());
       Register temp = temps.AcquireX();
@@ -4653,7 +4653,7 @@
   // TODO: Re-add the compiler code to do string dex cache lookup again.
   InvokeRuntimeCallingConvention calling_convention;
   DCHECK_EQ(calling_convention.GetRegisterAt(0).GetCode(), out.GetCode());
-  __ Mov(calling_convention.GetRegisterAt(0).W(), load->GetStringIndex());
+  __ Mov(calling_convention.GetRegisterAt(0).W(), load->GetStringIndex().index_);
   codegen_->InvokeRuntime(kQuickResolveString, load, load->GetDexPc());
   CheckEntrypointTypes<kQuickResolveString, void*, uint32_t>();
 }
diff --git a/compiler/optimizing/code_generator_arm64.h b/compiler/optimizing/code_generator_arm64.h
index 1545fd3..868c8b0 100644
--- a/compiler/optimizing/code_generator_arm64.h
+++ b/compiler/optimizing/code_generator_arm64.h
@@ -560,14 +560,15 @@
       uint32_t element_offset,
       vixl::aarch64::Label* adrp_label = nullptr);
 
-  vixl::aarch64::Literal<uint32_t>* DeduplicateBootImageStringLiteral(const DexFile& dex_file,
-                                                                      uint32_t string_index);
+  vixl::aarch64::Literal<uint32_t>* DeduplicateBootImageStringLiteral(
+      const DexFile& dex_file,
+      dex::StringIndex string_index);
   vixl::aarch64::Literal<uint32_t>* DeduplicateBootImageTypeLiteral(const DexFile& dex_file,
                                                                     dex::TypeIndex type_index);
   vixl::aarch64::Literal<uint32_t>* DeduplicateBootImageAddressLiteral(uint64_t address);
   vixl::aarch64::Literal<uint64_t>* DeduplicateDexCacheAddressLiteral(uint64_t address);
   vixl::aarch64::Literal<uint32_t>* DeduplicateJitStringLiteral(const DexFile& dex_file,
-                                                                uint32_t string_index);
+                                                                dex::StringIndex string_index);
 
   void EmitAdrpPlaceholder(vixl::aarch64::Label* fixup_label, vixl::aarch64::Register reg);
   void EmitAddPlaceholder(vixl::aarch64::Label* fixup_label,
diff --git a/compiler/optimizing/code_generator_arm_vixl.cc b/compiler/optimizing/code_generator_arm_vixl.cc
index e399f32..9cc8000 100644
--- a/compiler/optimizing/code_generator_arm_vixl.cc
+++ b/compiler/optimizing/code_generator_arm_vixl.cc
@@ -5116,7 +5116,7 @@
   // TODO: Re-add the compiler code to do string dex cache lookup again.
   DCHECK_EQ(load->GetLoadKind(), HLoadString::LoadKind::kDexCacheViaMethod);
   InvokeRuntimeCallingConventionARMVIXL calling_convention;
-  __ Mov(calling_convention.GetRegisterAt(0), load->GetStringIndex());
+  __ Mov(calling_convention.GetRegisterAt(0), load->GetStringIndex().index_);
   codegen_->InvokeRuntime(kQuickResolveString, load, load->GetDexPc());
   CheckEntrypointTypes<kQuickResolveString, void*, uint32_t>();
 }
diff --git a/compiler/optimizing/code_generator_mips.cc b/compiler/optimizing/code_generator_mips.cc
index 8f94834..572d900 100644
--- a/compiler/optimizing/code_generator_mips.cc
+++ b/compiler/optimizing/code_generator_mips.cc
@@ -280,7 +280,7 @@
 
     InvokeRuntimeCallingConvention calling_convention;
     HLoadString* load = instruction_->AsLoadString();
-    const uint32_t string_index = load->GetStringIndex();
+    const uint32_t string_index = load->GetStringIndex().index_;
     __ LoadConst32(calling_convention.GetRegisterAt(0), string_index);
     mips_codegen->InvokeRuntime(kQuickResolveString, instruction_, instruction_->GetDexPc(), this);
     CheckEntrypointTypes<kQuickResolveString, void*, uint32_t>();
@@ -1047,7 +1047,7 @@
     uint32_t literal_offset = __ GetLabelLocation(literal->GetLabel());
     linker_patches->push_back(LinkerPatch::StringPatch(literal_offset,
                                                        target_string.dex_file,
-                                                       target_string.string_index));
+                                                       target_string.string_index.index_));
   }
   for (const auto& entry : boot_image_type_patches_) {
     const TypeReference& target_type = entry.first;
@@ -1110,7 +1110,7 @@
 }
 
 Literal* CodeGeneratorMIPS::DeduplicateBootImageStringLiteral(const DexFile& dex_file,
-                                                              uint32_t string_index) {
+                                                              dex::StringIndex string_index) {
   return boot_image_string_patches_.GetOrCreate(
       StringReference(&dex_file, string_index),
       [this]() { return __ NewLiteral<uint32_t>(/* placeholder */ 0u); });
@@ -5743,7 +5743,7 @@
       DCHECK(!kEmitCompilerReadBarrier);
       DCHECK(codegen_->GetCompilerOptions().IsBootImage());
       CodeGeneratorMIPS::PcRelativePatchInfo* info =
-          codegen_->NewPcRelativeStringPatch(load->GetDexFile(), load->GetStringIndex());
+          codegen_->NewPcRelativeStringPatch(load->GetDexFile(), load->GetStringIndex().index_);
       codegen_->EmitPcRelativeAddressPlaceholder(info, out, base_or_current_method_reg);
       return;  // No dex cache slow path.
     }
@@ -5759,7 +5759,7 @@
     case HLoadString::LoadKind::kBssEntry: {
       DCHECK(!codegen_->GetCompilerOptions().IsBootImage());
       CodeGeneratorMIPS::PcRelativePatchInfo* info =
-          codegen_->NewPcRelativeStringPatch(load->GetDexFile(), load->GetStringIndex());
+          codegen_->NewPcRelativeStringPatch(load->GetDexFile(), load->GetStringIndex().index_);
       codegen_->EmitPcRelativeAddressPlaceholder(info, out, base_or_current_method_reg);
       __ LoadFromOffset(kLoadWord, out, out, 0);
       SlowPathCodeMIPS* slow_path = new (GetGraph()->GetArena()) LoadStringSlowPathMIPS(load);
@@ -5775,7 +5775,7 @@
   // TODO: Re-add the compiler code to do string dex cache lookup again.
   DCHECK(load_kind == HLoadString::LoadKind::kDexCacheViaMethod);
   InvokeRuntimeCallingConvention calling_convention;
-  __ LoadConst32(calling_convention.GetRegisterAt(0), load->GetStringIndex());
+  __ LoadConst32(calling_convention.GetRegisterAt(0), load->GetStringIndex().index_);
   codegen_->InvokeRuntime(kQuickResolveString, load, load->GetDexPc());
   CheckEntrypointTypes<kQuickResolveString, void*, uint32_t>();
 }
diff --git a/compiler/optimizing/code_generator_mips.h b/compiler/optimizing/code_generator_mips.h
index e225d20..2273e52 100644
--- a/compiler/optimizing/code_generator_mips.h
+++ b/compiler/optimizing/code_generator_mips.h
@@ -18,6 +18,7 @@
 #define ART_COMPILER_OPTIMIZING_CODE_GENERATOR_MIPS_H_
 
 #include "code_generator.h"
+#include "dex_file_types.h"
 #include "driver/compiler_options.h"
 #include "nodes.h"
 #include "parallel_move_resolver.h"
@@ -452,7 +453,8 @@
   PcRelativePatchInfo* NewPcRelativeTypePatch(const DexFile& dex_file, dex::TypeIndex type_index);
   PcRelativePatchInfo* NewPcRelativeDexCacheArrayPatch(const DexFile& dex_file,
                                                        uint32_t element_offset);
-  Literal* DeduplicateBootImageStringLiteral(const DexFile& dex_file, uint32_t string_index);
+  Literal* DeduplicateBootImageStringLiteral(const DexFile& dex_file,
+                                             dex::StringIndex string_index);
   Literal* DeduplicateBootImageTypeLiteral(const DexFile& dex_file, dex::TypeIndex type_index);
   Literal* DeduplicateBootImageAddressLiteral(uint32_t address);
 
diff --git a/compiler/optimizing/code_generator_mips64.cc b/compiler/optimizing/code_generator_mips64.cc
index 02b01c8..b5e9871 100644
--- a/compiler/optimizing/code_generator_mips64.cc
+++ b/compiler/optimizing/code_generator_mips64.cc
@@ -234,7 +234,7 @@
     SaveLiveRegisters(codegen, locations);
 
     InvokeRuntimeCallingConvention calling_convention;
-    const uint32_t string_index = instruction_->AsLoadString()->GetStringIndex();
+    const uint32_t string_index = instruction_->AsLoadString()->GetStringIndex().index_;
     __ LoadConst32(calling_convention.GetRegisterAt(0), string_index);
     mips64_codegen->InvokeRuntime(kQuickResolveString,
                                   instruction_,
diff --git a/compiler/optimizing/code_generator_x86.cc b/compiler/optimizing/code_generator_x86.cc
index 51e902a..12aa03c 100644
--- a/compiler/optimizing/code_generator_x86.cc
+++ b/compiler/optimizing/code_generator_x86.cc
@@ -225,7 +225,7 @@
     SaveLiveRegisters(codegen, locations);
 
     InvokeRuntimeCallingConvention calling_convention;
-    const uint32_t string_index = instruction_->AsLoadString()->GetStringIndex();
+    const uint32_t string_index = instruction_->AsLoadString()->GetStringIndex().index_;
     __ movl(calling_convention.GetRegisterAt(0), Immediate(string_index));
     x86_codegen->InvokeRuntime(kQuickResolveString, instruction_, instruction_->GetDexPc(), this);
     CheckEntrypointTypes<kQuickResolveString, void*, uint32_t>();
@@ -4607,7 +4607,7 @@
 
 void CodeGeneratorX86::RecordBootStringPatch(HLoadString* load_string) {
   DCHECK(GetCompilerOptions().IsBootImage());
-  string_patches_.emplace_back(load_string->GetDexFile(), load_string->GetStringIndex());
+  string_patches_.emplace_back(load_string->GetDexFile(), load_string->GetStringIndex().index_);
   __ Bind(&string_patches_.back().label);
 }
 
@@ -4618,7 +4618,7 @@
 
 Label* CodeGeneratorX86::NewStringBssEntryPatch(HLoadString* load_string) {
   DCHECK(!GetCompilerOptions().IsBootImage());
-  string_patches_.emplace_back(load_string->GetDexFile(), load_string->GetStringIndex());
+  string_patches_.emplace_back(load_string->GetDexFile(), load_string->GetStringIndex().index_);
   return &string_patches_.back().label;
 }
 
@@ -6253,10 +6253,11 @@
   }
 }
 
-Label* CodeGeneratorX86::NewJitRootStringPatch(const DexFile& dex_file, uint32_t dex_index) {
+Label* CodeGeneratorX86::NewJitRootStringPatch(const DexFile& dex_file,
+                                               dex::StringIndex dex_index) {
   jit_string_roots_.Overwrite(StringReference(&dex_file, dex_index), /* placeholder */ 0u);
   // Add a patch entry and return the label.
-  jit_string_patches_.emplace_back(dex_file, dex_index);
+  jit_string_patches_.emplace_back(dex_file, dex_index.index_);
   PatchInfo<Label>* info = &jit_string_patches_.back();
   return &info->label;
 }
@@ -6313,7 +6314,7 @@
   // TODO: Re-add the compiler code to do string dex cache lookup again.
   InvokeRuntimeCallingConvention calling_convention;
   DCHECK_EQ(calling_convention.GetRegisterAt(0), out);
-  __ movl(calling_convention.GetRegisterAt(0), Immediate(load->GetStringIndex()));
+  __ movl(calling_convention.GetRegisterAt(0), Immediate(load->GetStringIndex().index_));
   codegen_->InvokeRuntime(kQuickResolveString, load, load->GetDexPc());
   CheckEntrypointTypes<kQuickResolveString, void*, uint32_t>();
 }
@@ -7755,7 +7756,8 @@
 
 void CodeGeneratorX86::EmitJitRootPatches(uint8_t* code, const uint8_t* roots_data) {
   for (const PatchInfo<Label>& info : jit_string_patches_) {
-    const auto& it = jit_string_roots_.find(StringReference(&info.dex_file, info.index));
+    const auto& it = jit_string_roots_.find(StringReference(&info.dex_file,
+                                                            dex::StringIndex(info.index)));
     DCHECK(it != jit_string_roots_.end());
     size_t index_in_table = it->second;
     uint32_t code_offset = info.label.Position() - kLabelPositionToLiteralOffsetAdjustment;
diff --git a/compiler/optimizing/code_generator_x86.h b/compiler/optimizing/code_generator_x86.h
index 16ea6b5..2ae3670 100644
--- a/compiler/optimizing/code_generator_x86.h
+++ b/compiler/optimizing/code_generator_x86.h
@@ -20,6 +20,7 @@
 #include "arch/x86/instruction_set_features_x86.h"
 #include "base/enums.h"
 #include "code_generator.h"
+#include "dex_file_types.h"
 #include "driver/compiler_options.h"
 #include "nodes.h"
 #include "parallel_move_resolver.h"
@@ -414,7 +415,7 @@
   void RecordTypePatch(HLoadClass* load_class);
   Label* NewStringBssEntryPatch(HLoadString* load_string);
   Label* NewPcRelativeDexCacheArrayPatch(const DexFile& dex_file, uint32_t element_offset);
-  Label* NewJitRootStringPatch(const DexFile& dex_file, uint32_t dex_index);
+  Label* NewJitRootStringPatch(const DexFile& dex_file, dex::StringIndex dex_index);
 
   void MoveFromReturnRegister(Location trg, Primitive::Type type) OVERRIDE;
 
diff --git a/compiler/optimizing/code_generator_x86_64.cc b/compiler/optimizing/code_generator_x86_64.cc
index 3467313..22f7f6b 100644
--- a/compiler/optimizing/code_generator_x86_64.cc
+++ b/compiler/optimizing/code_generator_x86_64.cc
@@ -300,7 +300,7 @@
     __ Bind(GetEntryLabel());
     SaveLiveRegisters(codegen, locations);
 
-    const uint32_t string_index = instruction_->AsLoadString()->GetStringIndex();
+    const uint32_t string_index = instruction_->AsLoadString()->GetStringIndex().index_;
     // Custom calling convention: RAX serves as both input and output.
     __ movl(CpuRegister(RAX), Immediate(string_index));
     x86_64_codegen->InvokeRuntime(kQuickResolveString,
@@ -1106,7 +1106,7 @@
 
 void CodeGeneratorX86_64::RecordBootStringPatch(HLoadString* load_string) {
   DCHECK(GetCompilerOptions().IsBootImage());
-  string_patches_.emplace_back(load_string->GetDexFile(), load_string->GetStringIndex());
+  string_patches_.emplace_back(load_string->GetDexFile(), load_string->GetStringIndex().index_);
   __ Bind(&string_patches_.back().label);
 }
 
@@ -1117,7 +1117,7 @@
 
 Label* CodeGeneratorX86_64::NewStringBssEntryPatch(HLoadString* load_string) {
   DCHECK(!GetCompilerOptions().IsBootImage());
-  string_patches_.emplace_back(load_string->GetDexFile(), load_string->GetStringIndex());
+  string_patches_.emplace_back(load_string->GetDexFile(), load_string->GetStringIndex().index_);
   return &string_patches_.back().label;
 }
 
@@ -5660,10 +5660,11 @@
   }
 }
 
-Label* CodeGeneratorX86_64::NewJitRootStringPatch(const DexFile& dex_file, uint32_t dex_index) {
+Label* CodeGeneratorX86_64::NewJitRootStringPatch(const DexFile& dex_file,
+                                                  dex::StringIndex dex_index) {
   jit_string_roots_.Overwrite(StringReference(&dex_file, dex_index), /* placeholder */ 0u);
   // Add a patch entry and return the label.
-  jit_string_patches_.emplace_back(dex_file, dex_index);
+  jit_string_patches_.emplace_back(dex_file, dex_index.index_);
   PatchInfo<Label>* info = &jit_string_patches_.back();
   return &info->label;
 }
@@ -5714,7 +5715,7 @@
 
   // TODO: Re-add the compiler code to do string dex cache lookup again.
   // Custom calling convention: RAX serves as both input and output.
-  __ movl(CpuRegister(RAX), Immediate(load->GetStringIndex()));
+  __ movl(CpuRegister(RAX), Immediate(load->GetStringIndex().index_));
   codegen_->InvokeRuntime(kQuickResolveString,
                           load,
                           load->GetDexPc());
@@ -7111,7 +7112,8 @@
 
 void CodeGeneratorX86_64::EmitJitRootPatches(uint8_t* code, const uint8_t* roots_data) {
   for (const PatchInfo<Label>& info : jit_string_patches_) {
-    const auto& it = jit_string_roots_.find(StringReference(&info.dex_file, info.index));
+    const auto& it = jit_string_roots_.find(StringReference(&info.dex_file,
+                                                            dex::StringIndex(info.index)));
     DCHECK(it != jit_string_roots_.end());
     size_t index_in_table = it->second;
     uint32_t code_offset = info.label.Position() - kLabelPositionToLiteralOffsetAdjustment;
diff --git a/compiler/optimizing/code_generator_x86_64.h b/compiler/optimizing/code_generator_x86_64.h
index 0f70b15..2f41f73 100644
--- a/compiler/optimizing/code_generator_x86_64.h
+++ b/compiler/optimizing/code_generator_x86_64.h
@@ -412,7 +412,7 @@
   void RecordTypePatch(HLoadClass* load_class);
   Label* NewStringBssEntryPatch(HLoadString* load_string);
   Label* NewPcRelativeDexCacheArrayPatch(const DexFile& dex_file, uint32_t element_offset);
-  Label* NewJitRootStringPatch(const DexFile& dex_file, uint32_t dex_index);
+  Label* NewJitRootStringPatch(const DexFile& dex_file, dex::StringIndex dex_index);
 
   void MoveFromReturnRegister(Location trg, Primitive::Type type) OVERRIDE;
 
diff --git a/compiler/optimizing/instruction_builder.cc b/compiler/optimizing/instruction_builder.cc
index 40de5ce..b97581b 100644
--- a/compiler/optimizing/instruction_builder.cc
+++ b/compiler/optimizing/instruction_builder.cc
@@ -2625,7 +2625,7 @@
     }
 
     case Instruction::CONST_STRING: {
-      uint32_t string_index = instruction.VRegB_21c();
+      dex::StringIndex string_index(instruction.VRegB_21c());
       AppendInstruction(
           new (arena_) HLoadString(graph_->GetCurrentMethod(), string_index, *dex_file_, dex_pc));
       UpdateLocal(instruction.VRegA_21c(), current_block_->GetLastInstruction());
@@ -2633,7 +2633,7 @@
     }
 
     case Instruction::CONST_STRING_JUMBO: {
-      uint32_t string_index = instruction.VRegB_31c();
+      dex::StringIndex string_index(instruction.VRegB_31c());
       AppendInstruction(
           new (arena_) HLoadString(graph_->GetCurrentMethod(), string_index, *dex_file_, dex_pc));
       UpdateLocal(instruction.VRegA_31c(), current_block_->GetLastInstruction());
diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index eebc49c..165dce3 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -5698,7 +5698,7 @@
   };
 
   HLoadString(HCurrentMethod* current_method,
-              uint32_t string_index,
+              dex::StringIndex string_index,
               const DexFile& dex_file,
               uint32_t dex_pc)
       : HInstruction(SideEffectsForArchRuntimeCalls(), dex_pc),
@@ -5717,7 +5717,7 @@
 
   void SetLoadKindWithStringReference(LoadKind load_kind,
                                       const DexFile& dex_file,
-                                      uint32_t string_index) {
+                                      dex::StringIndex string_index) {
     DCHECK(HasStringReference(load_kind));
     load_data_.dex_file_ = &dex_file;
     string_index_ = string_index;
@@ -5730,7 +5730,7 @@
 
   const DexFile& GetDexFile() const;
 
-  uint32_t GetStringIndex() const {
+  dex::StringIndex GetStringIndex() const {
     DCHECK(HasStringReference(GetLoadKind()) || /* For slow paths. */ !IsInDexCache());
     return string_index_;
   }
@@ -5744,7 +5744,7 @@
 
   bool InstructionDataEquals(const HInstruction* other) const OVERRIDE;
 
-  size_t ComputeHashCode() const OVERRIDE { return string_index_; }
+  size_t ComputeHashCode() const OVERRIDE { return string_index_.index_; }
 
   // Will call the runtime if we need to load the string through
   // the dex cache and the string is not guaranteed to be there yet.
@@ -5823,7 +5823,7 @@
 
   // String index serves also as the hash code and it's also needed for slow-paths,
   // so it must not be overwritten with other load data.
-  uint32_t string_index_;
+  dex::StringIndex string_index_;
 
   union {
     const DexFile* dex_file_;            // For string reference.
diff --git a/compiler/optimizing/sharpening.cc b/compiler/optimizing/sharpening.cc
index a127708..daf160a 100644
--- a/compiler/optimizing/sharpening.cc
+++ b/compiler/optimizing/sharpening.cc
@@ -267,7 +267,7 @@
   DCHECK(!load_string->IsInDexCache());
 
   const DexFile& dex_file = load_string->GetDexFile();
-  uint32_t string_index = load_string->GetStringIndex();
+  dex::StringIndex string_index = load_string->GetStringIndex();
 
   HLoadString::LoadKind desired_load_kind = HLoadString::LoadKind::kDexCacheViaMethod;
   uint64_t address = 0u;  // String or dex cache element address.