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.
       }
diff --git a/compiler/optimizing/code_generator_arm_vixl.cc b/compiler/optimizing/code_generator_arm_vixl.cc
index d1b5bcb..4e70d8b 100644
--- a/compiler/optimizing/code_generator_arm_vixl.cc
+++ b/compiler/optimizing/code_generator_arm_vixl.cc
@@ -150,6 +150,15 @@
   int32_t adr_location_;
 };
 
+static RegisterSet OneRegInReferenceOutSaveEverythingCallerSaves() {
+  InvokeRuntimeCallingConventionARMVIXL calling_convention;
+  RegisterSet caller_saves = RegisterSet::Empty();
+  caller_saves.Add(LocationFrom(calling_convention.GetRegisterAt(0)));
+  // TODO: Add GetReturnLocation() to the calling convention so that we can DCHECK()
+  // that the the kPrimNot result register is the same as the first argument register.
+  return caller_saves;
+}
+
 // SaveLiveRegisters and RestoreLiveRegisters from SlowPathCodeARM operate on sets of S registers,
 // for each live D registers they treat two corresponding S registers as live ones.
 //
@@ -7416,12 +7425,7 @@
   if (load_kind == 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();
-      InvokeRuntimeCallingConventionARMVIXL calling_convention;
-      caller_saves.Add(LocationFrom(calling_convention.GetRegisterAt(0)));
-      // TODO: Add GetReturnLocation() to the calling convention so that we can DCHECK()
-      // that the the kPrimNot result register is the same as the first argument register.
-      locations->SetCustomSlowPathCallerSaves(caller_saves);
+      locations->SetCustomSlowPathCallerSaves(OneRegInReferenceOutSaveEverythingCallerSaves());
     } else {
       // For non-Baker read barrier we have a temp-clobbering call.
     }
@@ -7549,6 +7553,8 @@
   if (check->HasUses()) {
     locations->SetOut(Location::SameAsFirstInput());
   }
+  // Rely on the type initialization to save everything we need.
+  locations->SetCustomSlowPathCallerSaves(OneRegInReferenceOutSaveEverythingCallerSaves());
 }
 
 void InstructionCodeGeneratorARMVIXL::VisitClinitCheck(HClinitCheck* check) {
@@ -7668,12 +7674,7 @@
     if (load_kind == HLoadString::LoadKind::kBssEntry) {
       if (!kUseReadBarrier || kUseBakerReadBarrier) {
         // Rely on the pResolveString and marking to save everything we need, including temps.
-        RegisterSet caller_saves = RegisterSet::Empty();
-        InvokeRuntimeCallingConventionARMVIXL calling_convention;
-        caller_saves.Add(LocationFrom(calling_convention.GetRegisterAt(0)));
-        // TODO: Add GetReturnLocation() to the calling convention so that we can DCHECK()
-        // that the the kPrimNot result register is the same as the first argument register.
-        locations->SetCustomSlowPathCallerSaves(caller_saves);
+        locations->SetCustomSlowPathCallerSaves(OneRegInReferenceOutSaveEverythingCallerSaves());
       } else {
         // For non-Baker read barrier we have a temp-clobbering call.
       }
diff --git a/compiler/optimizing/code_generator_mips.cc b/compiler/optimizing/code_generator_mips.cc
index 60bbf4c..8b7479a 100644
--- a/compiler/optimizing/code_generator_mips.cc
+++ b/compiler/optimizing/code_generator_mips.cc
@@ -160,6 +160,14 @@
   return MipsReturnLocation(type);
 }
 
+static RegisterSet OneRegInReferenceOutSaveEverythingCallerSaves() {
+  InvokeRuntimeCallingConvention calling_convention;
+  RegisterSet caller_saves = RegisterSet::Empty();
+  caller_saves.Add(Location::RegisterLocation(calling_convention.GetRegisterAt(0)));
+  // The reference is returned in the same register. This differs from the standard return location.
+  return caller_saves;
+}
+
 // NOLINT on __ macro to suppress wrong warning/fix (misc-macro-parentheses) from clang-tidy.
 #define __ down_cast<CodeGeneratorMIPS*>(codegen)->GetAssembler()->  // NOLINT
 #define QUICK_ENTRY_POINT(x) QUICK_ENTRYPOINT_OFFSET(kMipsPointerSize, x).Int32Value()
@@ -3594,6 +3602,8 @@
   if (check->HasUses()) {
     locations->SetOut(Location::SameAsFirstInput());
   }
+  // Rely on the type initialization to save everything we need.
+  locations->SetCustomSlowPathCallerSaves(OneRegInReferenceOutSaveEverythingCallerSaves());
 }
 
 void InstructionCodeGeneratorMIPS::VisitClinitCheck(HClinitCheck* check) {
@@ -8134,10 +8144,7 @@
   if (load_kind == 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)));
-      locations->SetCustomSlowPathCallerSaves(caller_saves);
+      locations->SetCustomSlowPathCallerSaves(OneRegInReferenceOutSaveEverythingCallerSaves());
     } else {
       // For non-Baker read barriers we have a temp-clobbering call.
     }
@@ -8368,10 +8375,7 @@
     if (load_kind == 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)));
-        locations->SetCustomSlowPathCallerSaves(caller_saves);
+        locations->SetCustomSlowPathCallerSaves(OneRegInReferenceOutSaveEverythingCallerSaves());
       } else {
         // For non-Baker read barriers we have a temp-clobbering call.
       }
diff --git a/compiler/optimizing/code_generator_mips64.cc b/compiler/optimizing/code_generator_mips64.cc
index 81d86a9..1d93fc8 100644
--- a/compiler/optimizing/code_generator_mips64.cc
+++ b/compiler/optimizing/code_generator_mips64.cc
@@ -112,6 +112,14 @@
   return Mips64ReturnLocation(type);
 }
 
+static RegisterSet OneRegInReferenceOutSaveEverythingCallerSaves() {
+  InvokeRuntimeCallingConvention calling_convention;
+  RegisterSet caller_saves = RegisterSet::Empty();
+  caller_saves.Add(Location::RegisterLocation(calling_convention.GetRegisterAt(0)));
+  // The reference is returned in the same register. This differs from the standard return location.
+  return caller_saves;
+}
+
 // NOLINT on __ macro to suppress wrong warning/fix (misc-macro-parentheses) from clang-tidy.
 #define __ down_cast<CodeGeneratorMIPS64*>(codegen)->GetAssembler()->  // NOLINT
 #define QUICK_ENTRY_POINT(x) QUICK_ENTRYPOINT_OFFSET(kMips64PointerSize, x).Int32Value()
@@ -3149,6 +3157,8 @@
   if (check->HasUses()) {
     locations->SetOut(Location::SameAsFirstInput());
   }
+  // Rely on the type initialization to save everything we need.
+  locations->SetCustomSlowPathCallerSaves(OneRegInReferenceOutSaveEverythingCallerSaves());
 }
 
 void InstructionCodeGeneratorMIPS64::VisitClinitCheck(HClinitCheck* check) {
@@ -6206,10 +6216,7 @@
   if (load_kind == 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)));
-      locations->SetCustomSlowPathCallerSaves(caller_saves);
+      locations->SetCustomSlowPathCallerSaves(OneRegInReferenceOutSaveEverythingCallerSaves());
     } else {
       // For non-Baker read barriers we have a temp-clobbering call.
     }
@@ -6381,10 +6388,7 @@
     if (load_kind == 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)));
-        locations->SetCustomSlowPathCallerSaves(caller_saves);
+        locations->SetCustomSlowPathCallerSaves(OneRegInReferenceOutSaveEverythingCallerSaves());
       } else {
         // For non-Baker read barriers we have a temp-clobbering call.
       }
diff --git a/compiler/optimizing/code_generator_x86.cc b/compiler/optimizing/code_generator_x86.cc
index 83ce734..46bd479 100644
--- a/compiler/optimizing/code_generator_x86.cc
+++ b/compiler/optimizing/code_generator_x86.cc
@@ -55,6 +55,15 @@
 static constexpr int64_t kDoubleNaN = INT64_C(0x7FF8000000000000);
 static constexpr int32_t kFloatNaN = INT32_C(0x7FC00000);
 
+static RegisterSet OneRegInReferenceOutSaveEverythingCallerSaves() {
+  InvokeRuntimeCallingConvention calling_convention;
+  RegisterSet caller_saves = RegisterSet::Empty();
+  caller_saves.Add(Location::RegisterLocation(calling_convention.GetRegisterAt(0)));
+  // TODO: Add GetReturnLocation() to the calling convention so that we can DCHECK()
+  // that the the kPrimNot result register is the same as the first argument register.
+  return caller_saves;
+}
+
 // NOLINT on __ macro to suppress wrong warning/fix (misc-macro-parentheses) from clang-tidy.
 #define __ down_cast<X86Assembler*>(codegen->GetAssembler())->  // NOLINT
 #define QUICK_ENTRY_POINT(x) QUICK_ENTRYPOINT_OFFSET(kX86PointerSize, x).Int32Value()
@@ -6489,10 +6498,7 @@
   if (load_kind == HLoadClass::LoadKind::kBssEntry) {
     if (!kUseReadBarrier || kUseBakerReadBarrier) {
       // Rely on the type resolution and/or initialization to save everything.
-      RegisterSet caller_saves = RegisterSet::Empty();
-      InvokeRuntimeCallingConvention calling_convention;
-      caller_saves.Add(Location::RegisterLocation(calling_convention.GetRegisterAt(0)));
-      locations->SetCustomSlowPathCallerSaves(caller_saves);
+      locations->SetCustomSlowPathCallerSaves(OneRegInReferenceOutSaveEverythingCallerSaves());
     } else {
       // For non-Baker read barrier we have a temp-clobbering call.
     }
@@ -6631,6 +6637,8 @@
   if (check->HasUses()) {
     locations->SetOut(Location::SameAsFirstInput());
   }
+  // Rely on the type initialization to save everything we need.
+  locations->SetCustomSlowPathCallerSaves(OneRegInReferenceOutSaveEverythingCallerSaves());
 }
 
 void InstructionCodeGeneratorX86::VisitClinitCheck(HClinitCheck* check) {
@@ -6710,10 +6718,7 @@
     if (load_kind == HLoadString::LoadKind::kBssEntry) {
       if (!kUseReadBarrier || kUseBakerReadBarrier) {
         // Rely on the pResolveString to save everything.
-        RegisterSet caller_saves = RegisterSet::Empty();
-        InvokeRuntimeCallingConvention calling_convention;
-        caller_saves.Add(Location::RegisterLocation(calling_convention.GetRegisterAt(0)));
-        locations->SetCustomSlowPathCallerSaves(caller_saves);
+        locations->SetCustomSlowPathCallerSaves(OneRegInReferenceOutSaveEverythingCallerSaves());
       } else {
         // For non-Baker read barrier we have a temp-clobbering call.
       }
diff --git a/compiler/optimizing/code_generator_x86_64.cc b/compiler/optimizing/code_generator_x86_64.cc
index aabf2e0..7e3fded 100644
--- a/compiler/optimizing/code_generator_x86_64.cc
+++ b/compiler/optimizing/code_generator_x86_64.cc
@@ -56,6 +56,13 @@
 
 static constexpr int kC2ConditionMask = 0x400;
 
+static RegisterSet OneRegInReferenceOutSaveEverythingCallerSaves() {
+  // Custom calling convention: RAX serves as both input and output.
+  RegisterSet caller_saves = RegisterSet::Empty();
+  caller_saves.Add(Location::RegisterLocation(RAX));
+  return caller_saves;
+}
+
 // NOLINT on __ macro to suppress wrong warning/fix (misc-macro-parentheses) from clang-tidy.
 #define __ down_cast<X86_64Assembler*>(codegen->GetAssembler())->  // NOLINT
 #define QUICK_ENTRY_POINT(x) QUICK_ENTRYPOINT_OFFSET(kX86_64PointerSize, x).Int32Value()
@@ -5832,10 +5839,7 @@
   if (load_kind == HLoadClass::LoadKind::kBssEntry) {
     if (!kUseReadBarrier || kUseBakerReadBarrier) {
       // Rely on the type resolution and/or initialization to save everything.
-      // Custom calling convention: RAX serves as both input and output.
-      RegisterSet caller_saves = RegisterSet::Empty();
-      caller_saves.Add(Location::RegisterLocation(RAX));
-      locations->SetCustomSlowPathCallerSaves(caller_saves);
+      locations->SetCustomSlowPathCallerSaves(OneRegInReferenceOutSaveEverythingCallerSaves());
     } else {
       // For non-Baker read barrier we have a temp-clobbering call.
     }
@@ -5950,6 +5954,8 @@
   if (check->HasUses()) {
     locations->SetOut(Location::SameAsFirstInput());
   }
+  // Rely on the type initialization to save everything we need.
+  locations->SetCustomSlowPathCallerSaves(OneRegInReferenceOutSaveEverythingCallerSaves());
 }
 
 void LocationsBuilderX86_64::VisitLoadMethodHandle(HLoadMethodHandle* load) {
@@ -6009,10 +6015,7 @@
     if (load->GetLoadKind() == HLoadString::LoadKind::kBssEntry) {
       if (!kUseReadBarrier || kUseBakerReadBarrier) {
         // Rely on the pResolveString to save everything.
-        // Custom calling convention: RAX serves as both input and output.
-        RegisterSet caller_saves = RegisterSet::Empty();
-        caller_saves.Add(Location::RegisterLocation(RAX));
-        locations->SetCustomSlowPathCallerSaves(caller_saves);
+        locations->SetCustomSlowPathCallerSaves(OneRegInReferenceOutSaveEverythingCallerSaves());
       } else {
         // For non-Baker read barrier we have a temp-clobbering call.
       }