ART: Arm intrinsics for Optimizing compiler

Add arm32 intrinsics to the optimizing compiler.

Change-Id: If4aeedbf560862074d8ee08ca4484b666d6b9bf0

8 files changed, 1074 insertions, 49 deletions

diff --git a/compiler/Android.mk b/compiler/Android.mk
index b87201ad8d..61379fbf18 100644
--- a/compiler/Android.mk
+++ b/compiler/Android.mk
@@ -100,6 +100,7 @@ LIBART_COMPILER_SRC_FILES := \
 	optimizing/inliner.cc \
 	optimizing/instruction_simplifier.cc \
 	optimizing/intrinsics.cc \
+	optimizing/intrinsics_arm.cc \
 	optimizing/intrinsics_arm64.cc \
 	optimizing/intrinsics_x86_64.cc \
 	optimizing/licm.cc \
diff --git a/compiler/optimizing/code_generator_arm.cc b/compiler/optimizing/code_generator_arm.cc
index 78fd181dcf..c77755d2e1 100644
--- a/compiler/optimizing/code_generator_arm.cc
+++ b/compiler/optimizing/code_generator_arm.cc
@@ -19,6 +19,8 @@
 #include "arch/arm/instruction_set_features_arm.h"
 #include "entrypoints/quick/quick_entrypoints.h"
 #include "gc/accounting/card_table.h"
+#include "intrinsics.h"
+#include "intrinsics_arm.h"
 #include "mirror/array-inl.h"
 #include "mirror/art_method.h"
 #include "mirror/class.h"
@@ -32,11 +34,6 @@ namespace art {
 
 namespace arm {
 
-static DRegister FromLowSToD(SRegister reg) {
-  DCHECK_EQ(reg % 2, 0);
-  return static_cast<DRegister>(reg / 2);
-}
-
 static bool ExpectedPairLayout(Location location) {
   // We expected this for both core and fpu register pairs.
   return ((location.low() & 1) == 0) && (location.low() + 1 == location.high());
@@ -73,20 +70,6 @@ class InvokeRuntimeCallingConvention : public CallingConvention<Register, SRegis
 #define __ reinterpret_cast<ArmAssembler*>(codegen->GetAssembler())->
 #define QUICK_ENTRY_POINT(x) QUICK_ENTRYPOINT_OFFSET(kArmWordSize, x).Int32Value()
 
-class SlowPathCodeARM : public SlowPathCode {
- public:
-  SlowPathCodeARM() : entry_label_(), exit_label_() {}
-
-  Label* GetEntryLabel() { return &entry_label_; }
-  Label* GetExitLabel() { return &exit_label_; }
-
- private:
-  Label entry_label_;
-  Label exit_label_;
-
-  DISALLOW_COPY_AND_ASSIGN(SlowPathCodeARM);
-};
-
 class NullCheckSlowPathARM : public SlowPathCodeARM {
  public:
   explicit NullCheckSlowPathARM(HNullCheck* instruction) : instruction_(instruction) {}
@@ -1168,6 +1151,12 @@ void InstructionCodeGeneratorARM::VisitReturn(HReturn* ret) {
 }
 
 void LocationsBuilderARM::VisitInvokeStaticOrDirect(HInvokeStaticOrDirect* invoke) {
+  IntrinsicLocationsBuilderARM intrinsic(GetGraph()->GetArena(),
+                                         codegen_->GetInstructionSetFeatures());
+  if (intrinsic.TryDispatch(invoke)) {
+    return;
+  }
+
   HandleInvoke(invoke);
 }
 
@@ -1175,37 +1164,23 @@ void CodeGeneratorARM::LoadCurrentMethod(Register reg) {
   __ LoadFromOffset(kLoadWord, reg, SP, kCurrentMethodStackOffset);
 }
 
-void InstructionCodeGeneratorARM::VisitInvokeStaticOrDirect(HInvokeStaticOrDirect* invoke) {
-  Register temp = invoke->GetLocations()->GetTemp(0).AsRegister<Register>();
-
-  // TODO: Implement all kinds of calls:
-  // 1) boot -> boot
-  // 2) app -> boot
-  // 3) app -> app
-  //
-  // Currently we implement the app -> app logic, which looks up in the resolve cache.
+static bool TryGenerateIntrinsicCode(HInvoke* invoke, CodeGeneratorARM* codegen) {
+  if (invoke->GetLocations()->Intrinsified()) {
+    IntrinsicCodeGeneratorARM intrinsic(codegen);
+    intrinsic.Dispatch(invoke);
+    return true;
+  }
+  return false;
+}
 
-  // temp = method;
-  codegen_->LoadCurrentMethod(temp);
-  if (!invoke->IsRecursive()) {
-    // temp = temp->dex_cache_resolved_methods_;
-    __ LoadFromOffset(
-        kLoadWord, temp, temp, mirror::ArtMethod::DexCacheResolvedMethodsOffset().Int32Value());
-    // temp = temp[index_in_cache]
-    __ LoadFromOffset(
-        kLoadWord, temp, temp, CodeGenerator::GetCacheOffset(invoke->GetDexMethodIndex()));
-    // LR = temp[offset_of_quick_compiled_code]
-    __ LoadFromOffset(kLoadWord, LR, temp,
-                      mirror::ArtMethod::EntryPointFromQuickCompiledCodeOffset(
-                             kArmWordSize).Int32Value());
-    // LR()
-    __ blx(LR);
-  } else {
-    __ bl(codegen_->GetFrameEntryLabel());
+void InstructionCodeGeneratorARM::VisitInvokeStaticOrDirect(HInvokeStaticOrDirect* invoke) {
+  if (TryGenerateIntrinsicCode(invoke, codegen_)) {
+    return;
   }
 
-  codegen_->RecordPcInfo(invoke, invoke->GetDexPc());
-  DCHECK(!codegen_->IsLeafMethod());
+  Register temp = invoke->GetLocations()->GetTemp(0).AsRegister<Register>();
+
+  codegen_->GenerateStaticOrDirectCall(invoke, temp);
 }
 
 void LocationsBuilderARM::HandleInvoke(HInvoke* invoke) {
@@ -1223,10 +1198,20 @@ void LocationsBuilderARM::HandleInvoke(HInvoke* invoke) {
 }
 
 void LocationsBuilderARM::VisitInvokeVirtual(HInvokeVirtual* invoke) {
+  IntrinsicLocationsBuilderARM intrinsic(GetGraph()->GetArena(),
+                                         codegen_->GetInstructionSetFeatures());
+  if (intrinsic.TryDispatch(invoke)) {
+    return;
+  }
+
   HandleInvoke(invoke);
 }
 
 void InstructionCodeGeneratorARM::VisitInvokeVirtual(HInvokeVirtual* invoke) {
+  if (TryGenerateIntrinsicCode(invoke, codegen_)) {
+    return;
+  }
+
   Register temp = invoke->GetLocations()->GetTemp(0).AsRegister<Register>();
   uint32_t method_offset = mirror::Class::EmbeddedVTableOffset().Uint32Value() +
           invoke->GetVTableIndex() * sizeof(mirror::Class::VTableEntry);
@@ -3776,5 +3761,38 @@ void InstructionCodeGeneratorARM::HandleBitwiseOperation(HBinaryOperation* instr
   }
 }
 
+void CodeGeneratorARM::GenerateStaticOrDirectCall(HInvokeStaticOrDirect* invoke, Register temp) {
+  DCHECK_EQ(temp, kArtMethodRegister);
+
+  // TODO: Implement all kinds of calls:
+  // 1) boot -> boot
+  // 2) app -> boot
+  // 3) app -> app
+  //
+  // Currently we implement the app -> app logic, which looks up in the resolve cache.
+
+  // temp = method;
+  LoadCurrentMethod(temp);
+  if (!invoke->IsRecursive()) {
+    // temp = temp->dex_cache_resolved_methods_;
+    __ LoadFromOffset(
+        kLoadWord, temp, temp, mirror::ArtMethod::DexCacheResolvedMethodsOffset().Int32Value());
+    // temp = temp[index_in_cache]
+    __ LoadFromOffset(
+        kLoadWord, temp, temp, CodeGenerator::GetCacheOffset(invoke->GetDexMethodIndex()));
+    // LR = temp[offset_of_quick_compiled_code]
+    __ LoadFromOffset(kLoadWord, LR, temp,
+                      mirror::ArtMethod::EntryPointFromQuickCompiledCodeOffset(
+                          kArmWordSize).Int32Value());
+    // LR()
+    __ blx(LR);
+  } else {
+    __ bl(GetFrameEntryLabel());
+  }
+
+  RecordPcInfo(invoke, invoke->GetDexPc());
+  DCHECK(!IsLeafMethod());
+}
+
 }  // namespace arm
 }  // namespace art
diff --git a/compiler/optimizing/code_generator_arm.h b/compiler/optimizing/code_generator_arm.h
index 4b03dffd38..47d81ff984 100644
--- a/compiler/optimizing/code_generator_arm.h
+++ b/compiler/optimizing/code_generator_arm.h
@@ -39,6 +39,14 @@ static constexpr SRegister kParameterFpuRegisters[] =
     { S0, S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, S14, S15 };
 static constexpr size_t kParameterFpuRegistersLength = arraysize(kParameterFpuRegisters);
 
+static constexpr Register kArtMethodRegister = R0;
+
+static constexpr DRegister FromLowSToD(SRegister reg) {
+  return DCHECK_CONSTEXPR(reg % 2 == 0, , D0)
+      static_cast<DRegister>(reg / 2);
+}
+
+
 class InvokeDexCallingConvention : public CallingConvention<Register, SRegister> {
  public:
   InvokeDexCallingConvention()
@@ -90,6 +98,20 @@ class ParallelMoveResolverARM : public ParallelMoveResolver {
   DISALLOW_COPY_AND_ASSIGN(ParallelMoveResolverARM);
 };
 
+class SlowPathCodeARM : public SlowPathCode {
+ public:
+  SlowPathCodeARM() : entry_label_(), exit_label_() {}
+
+  Label* GetEntryLabel() { return &entry_label_; }
+  Label* GetExitLabel() { return &exit_label_; }
+
+ private:
+  Label entry_label_;
+  Label exit_label_;
+
+  DISALLOW_COPY_AND_ASSIGN(SlowPathCodeARM);
+};
+
 class LocationsBuilderARM : public HGraphVisitor {
  public:
   LocationsBuilderARM(HGraph* graph, CodeGeneratorARM* codegen)
@@ -249,6 +271,8 @@ class CodeGeneratorARM : public CodeGenerator {
 
   Label* GetFrameEntryLabel() { return &frame_entry_label_; }
 
+  void GenerateStaticOrDirectCall(HInvokeStaticOrDirect* invoke, Register temp);
+
  private:
   // Labels for each block that will be compiled.
   GrowableArray<Label> block_labels_;
diff --git a/compiler/optimizing/intrinsics_arm.cc b/compiler/optimizing/intrinsics_arm.cc
new file mode 100644
index 0000000000..a82d80af13
--- /dev/null
+++ b/compiler/optimizing/intrinsics_arm.cc
@@ -0,0 +1,883 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "intrinsics_arm.h"
+
+#include "arch/arm/instruction_set_features_arm.h"
+#include "code_generator_arm.h"
+#include "entrypoints/quick/quick_entrypoints.h"
+#include "intrinsics.h"
+#include "mirror/array-inl.h"
+#include "mirror/art_method.h"
+#include "mirror/string.h"
+#include "thread.h"
+#include "utils/arm/assembler_arm.h"
+
+namespace art {
+
+namespace arm {
+
+ArmAssembler* IntrinsicCodeGeneratorARM::GetAssembler() {
+  return codegen_->GetAssembler();
+}
+
+ArenaAllocator* IntrinsicCodeGeneratorARM::GetAllocator() {
+  return codegen_->GetGraph()->GetArena();
+}
+
+#define __ codegen->GetAssembler()->
+
+static void MoveFromReturnRegister(Location trg, Primitive::Type type, CodeGeneratorARM* codegen) {
+  if (!trg.IsValid()) {
+    DCHECK(type == Primitive::kPrimVoid);
+    return;
+  }
+
+  DCHECK_NE(type, Primitive::kPrimVoid);
+
+  if (Primitive::IsIntegralType(type)) {
+    if (type == Primitive::kPrimLong) {
+      Register trg_reg_lo = trg.AsRegisterPairLow<Register>();
+      Register trg_reg_hi = trg.AsRegisterPairHigh<Register>();
+      Register res_reg_lo = R0;
+      Register res_reg_hi = R1;
+      if (trg_reg_lo != res_reg_hi) {
+        if (trg_reg_lo != res_reg_lo) {
+          __ mov(trg_reg_lo, ShifterOperand(res_reg_lo));
+          __ mov(trg_reg_hi, ShifterOperand(res_reg_hi));
+        } else {
+          DCHECK_EQ(trg_reg_lo + 1, trg_reg_hi);
+        }
+      } else {
+        __ mov(trg_reg_hi, ShifterOperand(res_reg_hi));
+        __ mov(trg_reg_lo, ShifterOperand(res_reg_lo));
+      }
+    } else {
+      Register trg_reg = trg.AsRegister<Register>();
+      Register res_reg = R0;
+      if (trg_reg != res_reg) {
+        __ mov(trg_reg, ShifterOperand(res_reg));
+      }
+    }
+  } else {
+    UNIMPLEMENTED(FATAL) << "Floating-point return.";
+  }
+}
+
+static void MoveArguments(HInvoke* invoke, ArenaAllocator* arena, CodeGeneratorARM* codegen) {
+  if (invoke->InputCount() == 0) {
+    return;
+  }
+
+  LocationSummary* locations = invoke->GetLocations();
+  InvokeDexCallingConventionVisitor calling_convention_visitor;
+
+  // We're moving potentially two or more locations to locations that could overlap, so we need
+  // a parallel move resolver.
+  HParallelMove parallel_move(arena);
+
+  for (size_t i = 0; i < invoke->InputCount(); i++) {
+    HInstruction* input = invoke->InputAt(i);
+    Location cc_loc = calling_convention_visitor.GetNextLocation(input->GetType());
+    Location actual_loc = locations->InAt(i);
+
+    parallel_move.AddMove(actual_loc, cc_loc, nullptr);
+  }
+
+  codegen->GetMoveResolver()->EmitNativeCode(&parallel_move);
+}
+
+// Slow-path for fallback (calling the managed code to handle the intrinsic) in an intrinsified
+// call. This will copy the arguments into the positions for a regular call.
+//
+// Note: The actual parameters are required to be in the locations given by the invoke's location
+//       summary. If an intrinsic modifies those locations before a slowpath call, they must be
+//       restored!
+class IntrinsicSlowPathARM : public SlowPathCodeARM {
+ public:
+  explicit IntrinsicSlowPathARM(HInvoke* invoke) : invoke_(invoke) { }
+
+  void EmitNativeCode(CodeGenerator* codegen_in) OVERRIDE {
+    CodeGeneratorARM* codegen = down_cast<CodeGeneratorARM*>(codegen_in);
+    __ Bind(GetEntryLabel());
+
+    codegen->SaveLiveRegisters(invoke_->GetLocations());
+
+    MoveArguments(invoke_, codegen->GetGraph()->GetArena(), codegen);
+
+    if (invoke_->IsInvokeStaticOrDirect()) {
+      codegen->GenerateStaticOrDirectCall(invoke_->AsInvokeStaticOrDirect(), kArtMethodRegister);
+    } else {
+      UNIMPLEMENTED(FATAL) << "Non-direct intrinsic slow-path not yet implemented";
+      UNREACHABLE();
+    }
+
+    // Copy the result back to the expected output.
+    Location out = invoke_->GetLocations()->Out();
+    if (out.IsValid()) {
+      DCHECK(out.IsRegister());  // TODO: Replace this when we support output in memory.
+      DCHECK(!invoke_->GetLocations()->GetLiveRegisters()->ContainsCoreRegister(out.reg()));
+      MoveFromReturnRegister(out, invoke_->GetType(), codegen);
+    }
+
+    codegen->RestoreLiveRegisters(invoke_->GetLocations());
+    __ b(GetExitLabel());
+  }
+
+ private:
+  // The instruction where this slow path is happening.
+  HInvoke* const invoke_;
+
+  DISALLOW_COPY_AND_ASSIGN(IntrinsicSlowPathARM);
+};
+
+#undef __
+
+bool IntrinsicLocationsBuilderARM::TryDispatch(HInvoke* invoke) {
+  Dispatch(invoke);
+  LocationSummary* res = invoke->GetLocations();
+  return res != nullptr && res->Intrinsified();
+}
+
+#define __ assembler->
+
+static void CreateFPToIntLocations(ArenaAllocator* arena, HInvoke* invoke) {
+  LocationSummary* locations = new (arena) LocationSummary(invoke,
+                                                           LocationSummary::kNoCall,
+                                                           kIntrinsified);
+  locations->SetInAt(0, Location::RequiresFpuRegister());
+  locations->SetOut(Location::RequiresRegister());
+}
+
+static void CreateIntToFPLocations(ArenaAllocator* arena, HInvoke* invoke) {
+  LocationSummary* locations = new (arena) LocationSummary(invoke,
+                                                           LocationSummary::kNoCall,
+                                                           kIntrinsified);
+  locations->SetInAt(0, Location::RequiresRegister());
+  locations->SetOut(Location::RequiresFpuRegister());
+}
+
+static void MoveFPToInt(LocationSummary* locations, bool is64bit, ArmAssembler* assembler) {
+  Location input = locations->InAt(0);
+  Location output = locations->Out();
+  if (is64bit) {
+    __ vmovrrd(output.AsRegisterPairLow<Register>(),
+               output.AsRegisterPairHigh<Register>(),
+               FromLowSToD(input.AsFpuRegisterPairLow<SRegister>()));
+  } else {
+    __ vmovrs(output.AsRegister<Register>(), input.AsFpuRegister<SRegister>());
+  }
+}
+
+static void MoveIntToFP(LocationSummary* locations, bool is64bit, ArmAssembler* assembler) {
+  Location input = locations->InAt(0);
+  Location output = locations->Out();
+  if (is64bit) {
+    __ vmovdrr(FromLowSToD(output.AsFpuRegisterPairLow<SRegister>()),
+               input.AsRegisterPairLow<Register>(),
+               input.AsRegisterPairHigh<Register>());
+  } else {
+    __ vmovsr(output.AsFpuRegister<SRegister>(), input.AsRegister<Register>());
+  }
+}
+
+void IntrinsicLocationsBuilderARM::VisitDoubleDoubleToRawLongBits(HInvoke* invoke) {
+  CreateFPToIntLocations(arena_, invoke);
+}
+void IntrinsicLocationsBuilderARM::VisitDoubleLongBitsToDouble(HInvoke* invoke) {
+  CreateIntToFPLocations(arena_, invoke);
+}
+
+void IntrinsicCodeGeneratorARM::VisitDoubleDoubleToRawLongBits(HInvoke* invoke) {
+  MoveFPToInt(invoke->GetLocations(), true, GetAssembler());
+}
+void IntrinsicCodeGeneratorARM::VisitDoubleLongBitsToDouble(HInvoke* invoke) {
+  MoveIntToFP(invoke->GetLocations(), true, GetAssembler());
+}
+
+void IntrinsicLocationsBuilderARM::VisitFloatFloatToRawIntBits(HInvoke* invoke) {
+  CreateFPToIntLocations(arena_, invoke);
+}
+void IntrinsicLocationsBuilderARM::VisitFloatIntBitsToFloat(HInvoke* invoke) {
+  CreateIntToFPLocations(arena_, invoke);
+}
+
+void IntrinsicCodeGeneratorARM::VisitFloatFloatToRawIntBits(HInvoke* invoke) {
+  MoveFPToInt(invoke->GetLocations(), false, GetAssembler());
+}
+void IntrinsicCodeGeneratorARM::VisitFloatIntBitsToFloat(HInvoke* invoke) {
+  MoveIntToFP(invoke->GetLocations(), false, GetAssembler());
+}
+
+static void CreateIntToIntLocations(ArenaAllocator* arena, HInvoke* invoke) {
+  LocationSummary* locations = new (arena) LocationSummary(invoke,
+                                                           LocationSummary::kNoCall,
+                                                           kIntrinsified);
+  locations->SetInAt(0, Location::RequiresRegister());
+  locations->SetOut(Location::RequiresRegister(), Location::kNoOutputOverlap);
+}
+
+static void CreateFPToFPLocations(ArenaAllocator* arena, HInvoke* invoke) {
+  LocationSummary* locations = new (arena) LocationSummary(invoke,
+                                                           LocationSummary::kNoCall,
+                                                           kIntrinsified);
+  locations->SetInAt(0, Location::RequiresFpuRegister());
+  locations->SetOut(Location::RequiresFpuRegister(), Location::kNoOutputOverlap);
+}
+
+static void MathAbsFP(LocationSummary* locations, bool is64bit, ArmAssembler* assembler) {
+  Location in = locations->InAt(0);
+  Location out = locations->Out();
+
+  if (is64bit) {
+    __ vabsd(FromLowSToD(out.AsFpuRegisterPairLow<SRegister>()),
+             FromLowSToD(in.AsFpuRegisterPairLow<SRegister>()));
+  } else {
+    __ vabss(out.AsFpuRegister<SRegister>(), in.AsFpuRegister<SRegister>());
+  }
+}
+
+void IntrinsicLocationsBuilderARM::VisitMathAbsDouble(HInvoke* invoke) {
+  CreateFPToFPLocations(arena_, invoke);
+}
+
+void IntrinsicCodeGeneratorARM::VisitMathAbsDouble(HInvoke* invoke) {
+  MathAbsFP(invoke->GetLocations(), true, GetAssembler());
+}
+
+void IntrinsicLocationsBuilderARM::VisitMathAbsFloat(HInvoke* invoke) {
+  CreateFPToFPLocations(arena_, invoke);
+}
+
+void IntrinsicCodeGeneratorARM::VisitMathAbsFloat(HInvoke* invoke) {
+  MathAbsFP(invoke->GetLocations(), false, GetAssembler());
+}
+
+static void CreateIntToIntPlusTemp(ArenaAllocator* arena, HInvoke* invoke) {
+  LocationSummary* locations = new (arena) LocationSummary(invoke,
+                                                           LocationSummary::kNoCall,
+                                                           kIntrinsified);
+  locations->SetInAt(0, Location::RequiresRegister());
+  locations->SetOut(Location::RequiresRegister(), Location::kNoOutputOverlap);
+
+  locations->AddTemp(Location::RequiresRegister());
+}
+
+static void GenAbsInteger(LocationSummary* locations,
+                          bool is64bit,
+                          ArmAssembler* assembler) {
+  Location in = locations->InAt(0);
+  Location output = locations->Out();
+
+  Register mask = locations->GetTemp(0).AsRegister<Register>();
+
+  if (is64bit) {
+    Register in_reg_lo = in.AsRegisterPairLow<Register>();
+    Register in_reg_hi = in.AsRegisterPairHigh<Register>();
+    Register out_reg_lo = output.AsRegisterPairLow<Register>();
+    Register out_reg_hi = output.AsRegisterPairHigh<Register>();
+
+    DCHECK_NE(out_reg_lo, in_reg_hi) << "Diagonal overlap unexpected.";
+
+    __ Asr(mask, in_reg_hi, 31);
+    __ adds(out_reg_lo, in_reg_lo, ShifterOperand(mask));
+    __ adc(out_reg_hi, in_reg_hi, ShifterOperand(mask));
+    __ eor(out_reg_lo, mask, ShifterOperand(out_reg_lo));
+    __ eor(out_reg_hi, mask, ShifterOperand(out_reg_hi));
+  } else {
+    Register in_reg = in.AsRegister<Register>();
+    Register out_reg = output.AsRegister<Register>();
+
+    __ Asr(mask, in_reg, 31);
+    __ add(out_reg, in_reg, ShifterOperand(mask));
+    __ eor(out_reg, mask, ShifterOperand(out_reg));
+  }
+}
+
+void IntrinsicLocationsBuilderARM::VisitMathAbsInt(HInvoke* invoke) {
+  CreateIntToIntPlusTemp(arena_, invoke);
+}
+
+void IntrinsicCodeGeneratorARM::VisitMathAbsInt(HInvoke* invoke) {
+  GenAbsInteger(invoke->GetLocations(), false, GetAssembler());
+}
+
+
+void IntrinsicLocationsBuilderARM::VisitMathAbsLong(HInvoke* invoke) {
+  CreateIntToIntPlusTemp(arena_, invoke);
+}
+
+void IntrinsicCodeGeneratorARM::VisitMathAbsLong(HInvoke* invoke) {
+  GenAbsInteger(invoke->GetLocations(), true, GetAssembler());
+}
+
+static void GenMinMax(LocationSummary* locations,
+                      bool is_min,
+                      ArmAssembler* assembler) {
+  Register op1 = locations->InAt(0).AsRegister<Register>();
+  Register op2 = locations->InAt(1).AsRegister<Register>();
+  Register out = locations->Out().AsRegister<Register>();
+
+  __ cmp(op1, ShifterOperand(op2));
+
+  __ it((is_min) ? Condition::LT : Condition::GT, kItElse);
+  __ mov(out, ShifterOperand(op1), is_min ? Condition::LT : Condition::GT);
+  __ mov(out, ShifterOperand(op2), is_min ? Condition::GE : Condition::LE);
+}
+
+static void CreateIntIntToIntLocations(ArenaAllocator* arena, HInvoke* invoke) {
+  LocationSummary* locations = new (arena) LocationSummary(invoke,
+                                                           LocationSummary::kNoCall,
+                                                           kIntrinsified);
+  locations->SetInAt(0, Location::RequiresRegister());
+  locations->SetInAt(1, Location::RequiresRegister());
+  locations->SetOut(Location::RequiresRegister(), Location::kNoOutputOverlap);
+}
+
+void IntrinsicLocationsBuilderARM::VisitMathMinIntInt(HInvoke* invoke) {
+  CreateIntIntToIntLocations(arena_, invoke);
+}
+
+void IntrinsicCodeGeneratorARM::VisitMathMinIntInt(HInvoke* invoke) {
+  GenMinMax(invoke->GetLocations(), true, GetAssembler());
+}
+
+void IntrinsicLocationsBuilderARM::VisitMathMaxIntInt(HInvoke* invoke) {
+  CreateIntIntToIntLocations(arena_, invoke);
+}
+
+void IntrinsicCodeGeneratorARM::VisitMathMaxIntInt(HInvoke* invoke) {
+  GenMinMax(invoke->GetLocations(), false, GetAssembler());
+}
+
+void IntrinsicLocationsBuilderARM::VisitMathSqrt(HInvoke* invoke) {
+  CreateFPToFPLocations(arena_, invoke);
+}
+
+void IntrinsicCodeGeneratorARM::VisitMathSqrt(HInvoke* invoke) {
+  LocationSummary* locations = invoke->GetLocations();
+  ArmAssembler* assembler = GetAssembler();
+  __ vsqrtd(FromLowSToD(locations->Out().AsFpuRegisterPairLow<SRegister>()),
+            FromLowSToD(locations->InAt(0).AsFpuRegisterPairLow<SRegister>()));
+}
+
+void IntrinsicLocationsBuilderARM::VisitMemoryPeekByte(HInvoke* invoke) {
+  CreateIntToIntLocations(arena_, invoke);
+}
+
+void IntrinsicCodeGeneratorARM::VisitMemoryPeekByte(HInvoke* invoke) {
+  ArmAssembler* assembler = GetAssembler();
+  // Ignore upper 4B of long address.
+  __ ldrsb(invoke->GetLocations()->Out().AsRegister<Register>(),
+           Address(invoke->GetLocations()->InAt(0).AsRegisterPairLow<Register>()));
+}
+
+void IntrinsicLocationsBuilderARM::VisitMemoryPeekIntNative(HInvoke* invoke) {
+  CreateIntToIntLocations(arena_, invoke);
+}
+
+void IntrinsicCodeGeneratorARM::VisitMemoryPeekIntNative(HInvoke* invoke) {
+  ArmAssembler* assembler = GetAssembler();
+  // Ignore upper 4B of long address.
+  __ ldr(invoke->GetLocations()->Out().AsRegister<Register>(),
+         Address(invoke->GetLocations()->InAt(0).AsRegisterPairLow<Register>()));
+}
+
+void IntrinsicLocationsBuilderARM::VisitMemoryPeekLongNative(HInvoke* invoke) {
+  CreateIntToIntLocations(arena_, invoke);
+}
+
+void IntrinsicCodeGeneratorARM::VisitMemoryPeekLongNative(HInvoke* invoke) {
+  ArmAssembler* assembler = GetAssembler();
+  // Ignore upper 4B of long address.
+  Register addr = invoke->GetLocations()->InAt(0).AsRegisterPairLow<Register>();
+  // Worst case: Control register bit SCTLR.A = 0. Then unaligned accesses throw a processor
+  // exception. So we can't use ldrd as addr may be unaligned.
+  Register lo = invoke->GetLocations()->Out().AsRegisterPairLow<Register>();
+  Register hi = invoke->GetLocations()->Out().AsRegisterPairHigh<Register>();
+  if (addr == lo) {
+    __ ldr(hi, Address(addr, 4));
+    __ ldr(lo, Address(addr, 0));
+  } else {
+    __ ldr(lo, Address(addr, 0));
+    __ ldr(hi, Address(addr, 4));
+  }
+}
+
+void IntrinsicLocationsBuilderARM::VisitMemoryPeekShortNative(HInvoke* invoke) {
+  CreateIntToIntLocations(arena_, invoke);
+}
+
+void IntrinsicCodeGeneratorARM::VisitMemoryPeekShortNative(HInvoke* invoke) {
+  ArmAssembler* assembler = GetAssembler();
+  // Ignore upper 4B of long address.
+  __ ldrsh(invoke->GetLocations()->Out().AsRegister<Register>(),
+           Address(invoke->GetLocations()->InAt(0).AsRegisterPairLow<Register>()));
+}
+
+static void CreateIntIntToVoidLocations(ArenaAllocator* arena, HInvoke* invoke) {
+  LocationSummary* locations = new (arena) LocationSummary(invoke,
+                                                           LocationSummary::kNoCall,
+                                                           kIntrinsified);
+  locations->SetInAt(0, Location::RequiresRegister());
+  locations->SetInAt(1, Location::RequiresRegister());
+}
+
+void IntrinsicLocationsBuilderARM::VisitMemoryPokeByte(HInvoke* invoke) {
+  CreateIntIntToVoidLocations(arena_, invoke);
+}
+
+void IntrinsicCodeGeneratorARM::VisitMemoryPokeByte(HInvoke* invoke) {
+  ArmAssembler* assembler = GetAssembler();
+  __ strb(invoke->GetLocations()->InAt(1).AsRegister<Register>(),
+          Address(invoke->GetLocations()->InAt(0).AsRegisterPairLow<Register>()));
+}
+
+void IntrinsicLocationsBuilderARM::VisitMemoryPokeIntNative(HInvoke* invoke) {
+  CreateIntIntToVoidLocations(arena_, invoke);
+}
+
+void IntrinsicCodeGeneratorARM::VisitMemoryPokeIntNative(HInvoke* invoke) {
+  ArmAssembler* assembler = GetAssembler();
+  __ str(invoke->GetLocations()->InAt(1).AsRegister<Register>(),
+         Address(invoke->GetLocations()->InAt(0).AsRegisterPairLow<Register>()));
+}
+
+void IntrinsicLocationsBuilderARM::VisitMemoryPokeLongNative(HInvoke* invoke) {
+  CreateIntIntToVoidLocations(arena_, invoke);
+}
+
+void IntrinsicCodeGeneratorARM::VisitMemoryPokeLongNative(HInvoke* invoke) {
+  ArmAssembler* assembler = GetAssembler();
+  // Ignore upper 4B of long address.
+  Register addr = invoke->GetLocations()->InAt(0).AsRegisterPairLow<Register>();
+  // Worst case: Control register bit SCTLR.A = 0. Then unaligned accesses throw a processor
+  // exception. So we can't use ldrd as addr may be unaligned.
+  __ str(invoke->GetLocations()->InAt(1).AsRegisterPairLow<Register>(), Address(addr, 0));
+  __ str(invoke->GetLocations()->InAt(1).AsRegisterPairHigh<Register>(), Address(addr, 4));
+}
+
+void IntrinsicLocationsBuilderARM::VisitMemoryPokeShortNative(HInvoke* invoke) {
+  CreateIntIntToVoidLocations(arena_, invoke);
+}
+
+void IntrinsicCodeGeneratorARM::VisitMemoryPokeShortNative(HInvoke* invoke) {
+  ArmAssembler* assembler = GetAssembler();
+  __ strh(invoke->GetLocations()->InAt(1).AsRegister<Register>(),
+          Address(invoke->GetLocations()->InAt(0).AsRegisterPairLow<Register>()));
+}
+
+void IntrinsicLocationsBuilderARM::VisitThreadCurrentThread(HInvoke* invoke) {
+  LocationSummary* locations = new (arena_) LocationSummary(invoke,
+                                                            LocationSummary::kNoCall,
+                                                            kIntrinsified);
+  locations->SetOut(Location::RequiresRegister());
+}
+
+void IntrinsicCodeGeneratorARM::VisitThreadCurrentThread(HInvoke* invoke) {
+  ArmAssembler* assembler = GetAssembler();
+  __ LoadFromOffset(kLoadWord,
+                    invoke->GetLocations()->Out().AsRegister<Register>(),
+                    TR,
+                    Thread::PeerOffset<kArmPointerSize>().Int32Value());
+}
+
+static void GenUnsafeGet(HInvoke* invoke,
+                         Primitive::Type type,
+                         bool is_volatile,
+                         CodeGeneratorARM* codegen) {
+  LocationSummary* locations = invoke->GetLocations();
+  DCHECK((type == Primitive::kPrimInt) ||
+         (type == Primitive::kPrimLong) ||
+         (type == Primitive::kPrimNot));
+  ArmAssembler* assembler = codegen->GetAssembler();
+  Register base = locations->InAt(1).AsRegister<Register>();           // Object pointer.
+  Register offset = locations->InAt(2).AsRegisterPairLow<Register>();  // Long offset, lo part only.
+
+  if (type == Primitive::kPrimLong) {
+    Register trg_lo = locations->Out().AsRegisterPairLow<Register>();
+    __ add(IP, base, ShifterOperand(offset));
+    if (is_volatile && !codegen->GetInstructionSetFeatures().HasAtomicLdrdAndStrd()) {
+      Register trg_hi = locations->Out().AsRegisterPairHigh<Register>();
+      __ ldrexd(trg_lo, trg_hi, IP);
+    } else {
+      __ ldrd(trg_lo, Address(IP));
+    }
+  } else {
+    Register trg = locations->Out().AsRegister<Register>();
+    __ ldr(trg, Address(base, offset));
+  }
+
+  if (is_volatile) {
+    __ dmb(ISH);
+  }
+}
+
+static void CreateIntIntIntToIntLocations(ArenaAllocator* arena, HInvoke* invoke) {
+  LocationSummary* locations = new (arena) LocationSummary(invoke,
+                                                           LocationSummary::kNoCall,
+                                                           kIntrinsified);
+  locations->SetInAt(0, Location::NoLocation());        // Unused receiver.
+  locations->SetInAt(1, Location::RequiresRegister());
+  locations->SetInAt(2, Location::RequiresRegister());
+  locations->SetOut(Location::RequiresRegister(), Location::kNoOutputOverlap);
+}
+
+void IntrinsicLocationsBuilderARM::VisitUnsafeGet(HInvoke* invoke) {
+  CreateIntIntIntToIntLocations(arena_, invoke);
+}
+void IntrinsicLocationsBuilderARM::VisitUnsafeGetVolatile(HInvoke* invoke) {
+  CreateIntIntIntToIntLocations(arena_, invoke);
+}
+void IntrinsicLocationsBuilderARM::VisitUnsafeGetLong(HInvoke* invoke) {
+  CreateIntIntIntToIntLocations(arena_, invoke);
+}
+void IntrinsicLocationsBuilderARM::VisitUnsafeGetLongVolatile(HInvoke* invoke) {
+  CreateIntIntIntToIntLocations(arena_, invoke);
+}
+void IntrinsicLocationsBuilderARM::VisitUnsafeGetObject(HInvoke* invoke) {
+  CreateIntIntIntToIntLocations(arena_, invoke);
+}
+void IntrinsicLocationsBuilderARM::VisitUnsafeGetObjectVolatile(HInvoke* invoke) {
+  CreateIntIntIntToIntLocations(arena_, invoke);
+}
+
+void IntrinsicCodeGeneratorARM::VisitUnsafeGet(HInvoke* invoke) {
+  GenUnsafeGet(invoke, Primitive::kPrimInt, false, codegen_);
+}
+void IntrinsicCodeGeneratorARM::VisitUnsafeGetVolatile(HInvoke* invoke) {
+  GenUnsafeGet(invoke, Primitive::kPrimInt, true, codegen_);
+}
+void IntrinsicCodeGeneratorARM::VisitUnsafeGetLong(HInvoke* invoke) {
+  GenUnsafeGet(invoke, Primitive::kPrimLong, false, codegen_);
+}
+void IntrinsicCodeGeneratorARM::VisitUnsafeGetLongVolatile(HInvoke* invoke) {
+  GenUnsafeGet(invoke, Primitive::kPrimLong, true, codegen_);
+}
+void IntrinsicCodeGeneratorARM::VisitUnsafeGetObject(HInvoke* invoke) {
+  GenUnsafeGet(invoke, Primitive::kPrimNot, false, codegen_);
+}
+void IntrinsicCodeGeneratorARM::VisitUnsafeGetObjectVolatile(HInvoke* invoke) {
+  GenUnsafeGet(invoke, Primitive::kPrimNot, true, codegen_);
+}
+
+static void CreateIntIntIntIntToVoid(ArenaAllocator* arena,
+                                     const ArmInstructionSetFeatures& features,
+                                     Primitive::Type type,
+                                     bool is_volatile,
+                                     HInvoke* invoke) {
+  LocationSummary* locations = new (arena) LocationSummary(invoke,
+                                                           LocationSummary::kNoCall,
+                                                           kIntrinsified);
+  locations->SetInAt(0, Location::NoLocation());        // Unused receiver.
+  locations->SetInAt(1, Location::RequiresRegister());
+  locations->SetInAt(2, Location::RequiresRegister());
+  locations->SetInAt(3, Location::RequiresRegister());
+
+  if (type == Primitive::kPrimLong) {
+    // Potentially need temps for ldrexd-strexd loop.
+    if (is_volatile && !features.HasAtomicLdrdAndStrd()) {
+      locations->AddTemp(Location::RequiresRegister());  // Temp_lo.
+      locations->AddTemp(Location::RequiresRegister());  // Temp_hi.
+    }
+  } else if (type == Primitive::kPrimNot) {
+    // Temps for card-marking.
+    locations->AddTemp(Location::RequiresRegister());  // Temp.
+    locations->AddTemp(Location::RequiresRegister());  // Card.
+  }
+}
+
+void IntrinsicLocationsBuilderARM::VisitUnsafePut(HInvoke* invoke) {
+  CreateIntIntIntIntToVoid(arena_, features_, Primitive::kPrimInt, false, invoke);
+}
+void IntrinsicLocationsBuilderARM::VisitUnsafePutOrdered(HInvoke* invoke) {
+  CreateIntIntIntIntToVoid(arena_, features_, Primitive::kPrimInt, false, invoke);
+}
+void IntrinsicLocationsBuilderARM::VisitUnsafePutVolatile(HInvoke* invoke) {
+  CreateIntIntIntIntToVoid(arena_, features_, Primitive::kPrimInt, true, invoke);
+}
+void IntrinsicLocationsBuilderARM::VisitUnsafePutObject(HInvoke* invoke) {
+  CreateIntIntIntIntToVoid(arena_, features_, Primitive::kPrimNot, false, invoke);
+}
+void IntrinsicLocationsBuilderARM::VisitUnsafePutObjectOrdered(HInvoke* invoke) {
+  CreateIntIntIntIntToVoid(arena_, features_, Primitive::kPrimNot, false, invoke);
+}
+void IntrinsicLocationsBuilderARM::VisitUnsafePutObjectVolatile(HInvoke* invoke) {
+  CreateIntIntIntIntToVoid(arena_, features_, Primitive::kPrimNot, true, invoke);
+}
+void IntrinsicLocationsBuilderARM::VisitUnsafePutLong(HInvoke* invoke) {
+  CreateIntIntIntIntToVoid(arena_, features_, Primitive::kPrimLong, false, invoke);
+}
+void IntrinsicLocationsBuilderARM::VisitUnsafePutLongOrdered(HInvoke* invoke) {
+  CreateIntIntIntIntToVoid(arena_, features_, Primitive::kPrimLong, false, invoke);
+}
+void IntrinsicLocationsBuilderARM::VisitUnsafePutLongVolatile(HInvoke* invoke) {
+  CreateIntIntIntIntToVoid(arena_, features_, Primitive::kPrimLong, true, invoke);
+}
+
+static void GenUnsafePut(LocationSummary* locations,
+                         Primitive::Type type,
+                         bool is_volatile,
+                         bool is_ordered,
+                         CodeGeneratorARM* codegen) {
+  ArmAssembler* assembler = codegen->GetAssembler();
+
+  Register base = locations->InAt(1).AsRegister<Register>();           // Object pointer.
+  Register offset = locations->InAt(2).AsRegisterPairLow<Register>();  // Long offset, lo part only.
+  Register value;
+
+  if (is_volatile || is_ordered) {
+    __ dmb(ISH);
+  }
+
+  if (type == Primitive::kPrimLong) {
+    Register value_lo = locations->InAt(3).AsRegisterPairLow<Register>();
+    value = value_lo;
+    if (is_volatile && !codegen->GetInstructionSetFeatures().HasAtomicLdrdAndStrd()) {
+      Register temp_lo = locations->GetTemp(0).AsRegister<Register>();
+      Register temp_hi = locations->GetTemp(1).AsRegister<Register>();
+      Register value_hi = locations->InAt(3).AsRegisterPairHigh<Register>();
+
+      __ add(IP, base, ShifterOperand(offset));
+      Label loop_head;
+      __ Bind(&loop_head);
+      __ ldrexd(temp_lo, temp_hi, IP);
+      __ strexd(temp_lo, value_lo, value_hi, IP);
+      __ cmp(temp_lo, ShifterOperand(0));
+      __ b(&loop_head, NE);
+    } else {
+      __ add(IP, base, ShifterOperand(offset));
+      __ strd(value_lo, Address(IP));
+    }
+  } else {
+    value =  locations->InAt(3).AsRegister<Register>();
+    __ str(value, Address(base, offset));
+  }
+
+  if (is_volatile) {
+    __ dmb(ISH);
+  }
+
+  if (type == Primitive::kPrimNot) {
+    Register temp = locations->GetTemp(0).AsRegister<Register>();
+    Register card = locations->GetTemp(1).AsRegister<Register>();
+    codegen->MarkGCCard(temp, card, base, value);
+  }
+}
+
+void IntrinsicCodeGeneratorARM::VisitUnsafePut(HInvoke* invoke) {
+  GenUnsafePut(invoke->GetLocations(), Primitive::kPrimInt, false, false, codegen_);
+}
+void IntrinsicCodeGeneratorARM::VisitUnsafePutOrdered(HInvoke* invoke) {
+  GenUnsafePut(invoke->GetLocations(), Primitive::kPrimInt, false, true, codegen_);
+}
+void IntrinsicCodeGeneratorARM::VisitUnsafePutVolatile(HInvoke* invoke) {
+  GenUnsafePut(invoke->GetLocations(), Primitive::kPrimInt, true, false, codegen_);
+}
+void IntrinsicCodeGeneratorARM::VisitUnsafePutObject(HInvoke* invoke) {
+  GenUnsafePut(invoke->GetLocations(), Primitive::kPrimNot, false, false, codegen_);
+}
+void IntrinsicCodeGeneratorARM::VisitUnsafePutObjectOrdered(HInvoke* invoke) {
+  GenUnsafePut(invoke->GetLocations(), Primitive::kPrimNot, false, true, codegen_);
+}
+void IntrinsicCodeGeneratorARM::VisitUnsafePutObjectVolatile(HInvoke* invoke) {
+  GenUnsafePut(invoke->GetLocations(), Primitive::kPrimNot, true, false, codegen_);
+}
+void IntrinsicCodeGeneratorARM::VisitUnsafePutLong(HInvoke* invoke) {
+  GenUnsafePut(invoke->GetLocations(), Primitive::kPrimLong, false, false, codegen_);
+}
+void IntrinsicCodeGeneratorARM::VisitUnsafePutLongOrdered(HInvoke* invoke) {
+  GenUnsafePut(invoke->GetLocations(), Primitive::kPrimLong, false, true, codegen_);
+}
+void IntrinsicCodeGeneratorARM::VisitUnsafePutLongVolatile(HInvoke* invoke) {
+  GenUnsafePut(invoke->GetLocations(), Primitive::kPrimLong, true, false, codegen_);
+}
+
+static void CreateIntIntIntIntIntToIntPlusTemps(ArenaAllocator* arena,
+                                                HInvoke* invoke) {
+  LocationSummary* locations = new (arena) LocationSummary(invoke,
+                                                           LocationSummary::kNoCall,
+                                                           kIntrinsified);
+  locations->SetInAt(0, Location::NoLocation());        // Unused receiver.
+  locations->SetInAt(1, Location::RequiresRegister());
+  locations->SetInAt(2, Location::RequiresRegister());
+  locations->SetInAt(3, Location::RequiresRegister());
+  locations->SetInAt(4, Location::RequiresRegister());
+
+  locations->SetOut(Location::RequiresRegister(), Location::kNoOutputOverlap);
+
+  locations->AddTemp(Location::RequiresRegister());  // Pointer.
+  locations->AddTemp(Location::RequiresRegister());  // Temp 1.
+  locations->AddTemp(Location::RequiresRegister());  // Temp 2.
+}
+
+static void GenCas(LocationSummary* locations, Primitive::Type type, CodeGeneratorARM* codegen) {
+  DCHECK_NE(type, Primitive::kPrimLong);
+
+  ArmAssembler* assembler = codegen->GetAssembler();
+
+  Register out = locations->Out().AsRegister<Register>();              // Boolean result.
+
+  Register base = locations->InAt(1).AsRegister<Register>();           // Object pointer.
+  Register offset = locations->InAt(2).AsRegisterPairLow<Register>();  // Offset (discard high 4B).
+  Register expected_lo = locations->InAt(3).AsRegister<Register>();    // Expected.
+  Register value_lo = locations->InAt(4).AsRegister<Register>();       // Value.
+
+  Register tmp_ptr = locations->GetTemp(0).AsRegister<Register>();     // Pointer to actual memory.
+  Register tmp_lo = locations->GetTemp(1).AsRegister<Register>();      // Value in memory.
+
+  if (type == Primitive::kPrimNot) {
+    // Mark card for object assuming new value is stored. Worst case we will mark an unchanged
+    // object and scan the receiver at the next GC for nothing.
+    codegen->MarkGCCard(tmp_ptr, tmp_lo, base, value_lo);
+  }
+
+  // Prevent reordering with prior memory operations.
+  __ dmb(ISH);
+
+  __ add(tmp_ptr, base, ShifterOperand(offset));
+
+  // do {
+  //   tmp = [r_ptr] - expected;
+  // } while (tmp == 0 && failure([r_ptr] <- r_new_value));
+  // result = tmp != 0;
+
+  Label loop_head;
+  __ Bind(&loop_head);
+
+  __ ldrex(tmp_lo, tmp_ptr);
+
+  __ subs(tmp_lo, tmp_lo, ShifterOperand(expected_lo));
+
+  __ it(EQ, ItState::kItT);
+  __ strex(tmp_lo, value_lo, tmp_ptr, EQ);
+  __ cmp(tmp_lo, ShifterOperand(1), EQ);
+
+  __ b(&loop_head, EQ);
+
+  __ dmb(ISH);
+
+  __ rsbs(out, tmp_lo, ShifterOperand(1));
+  __ it(CC);
+  __ mov(out, ShifterOperand(0), CC);
+}
+
+void IntrinsicLocationsBuilderARM::VisitUnsafeCASInt(HInvoke* invoke ATTRIBUTE_UNUSED) {
+  CreateIntIntIntIntIntToIntPlusTemps(arena_, invoke);
+}
+void IntrinsicLocationsBuilderARM::VisitUnsafeCASObject(HInvoke* invoke ATTRIBUTE_UNUSED) {
+  CreateIntIntIntIntIntToIntPlusTemps(arena_, invoke);
+}
+void IntrinsicCodeGeneratorARM::VisitUnsafeCASInt(HInvoke* invoke) {
+  GenCas(invoke->GetLocations(), Primitive::kPrimInt, codegen_);
+}
+void IntrinsicCodeGeneratorARM::VisitUnsafeCASObject(HInvoke* invoke) {
+  GenCas(invoke->GetLocations(), Primitive::kPrimNot, codegen_);
+}
+
+void IntrinsicLocationsBuilderARM::VisitStringCharAt(HInvoke* invoke) {
+  LocationSummary* locations = new (arena_) LocationSummary(invoke,
+                                                            LocationSummary::kCallOnSlowPath,
+                                                            kIntrinsified);
+  locations->SetInAt(0, Location::RequiresRegister());
+  locations->SetInAt(1, Location::RequiresRegister());
+  locations->SetOut(Location::RequiresRegister(), Location::kOutputOverlap);
+
+  locations->AddTemp(Location::RequiresRegister());
+  locations->AddTemp(Location::RequiresRegister());
+}
+
+void IntrinsicCodeGeneratorARM::VisitStringCharAt(HInvoke* invoke) {
+  ArmAssembler* assembler = GetAssembler();
+  LocationSummary* locations = invoke->GetLocations();
+
+  // Location of reference to data array
+  const MemberOffset value_offset = mirror::String::ValueOffset();
+  // Location of count
+  const MemberOffset count_offset = mirror::String::CountOffset();
+  // Starting offset within data array
+  const MemberOffset offset_offset = mirror::String::OffsetOffset();
+  // Start of char data with array_
+  const MemberOffset data_offset = mirror::Array::DataOffset(sizeof(uint16_t));
+
+  Register obj = locations->InAt(0).AsRegister<Register>();  // String object pointer.
+  Register idx = locations->InAt(1).AsRegister<Register>();  // Index of character.
+  Register out = locations->Out().AsRegister<Register>();    // Result character.
+
+  Register temp = locations->GetTemp(0).AsRegister<Register>();
+  Register array_temp = locations->GetTemp(1).AsRegister<Register>();
+
+  // TODO: Maybe we can support range check elimination. Overall, though, I think it's not worth
+  //       the cost.
+  // TODO: For simplicity, the index parameter is requested in a register, so different from Quick
+  //       we will not optimize the code for constants (which would save a register).
+
+  SlowPathCodeARM* slow_path = new (GetAllocator()) IntrinsicSlowPathARM(invoke);
+  codegen_->AddSlowPath(slow_path);
+
+  __ ldr(temp, Address(obj, count_offset.Int32Value()));          // temp = str.length.
+  codegen_->MaybeRecordImplicitNullCheck(invoke);
+  __ cmp(idx, ShifterOperand(temp));
+  __ b(slow_path->GetEntryLabel(), CS);
+
+  // Index computation.
+  __ ldr(temp, Address(obj, offset_offset.Int32Value()));         // temp := str.offset.
+  __ ldr(array_temp, Address(obj, value_offset.Int32Value()));    // array_temp := str.offset.
+  __ add(temp, temp, ShifterOperand(idx));
+  DCHECK_EQ(data_offset.Int32Value() % 2, 0);                     // We'll compensate by shifting.
+  __ add(temp, temp, ShifterOperand(data_offset.Int32Value() / 2));
+
+  // Load the value.
+  __ ldrh(out, Address(array_temp, temp, LSL, 1));                // out := array_temp[temp].
+
+  __ Bind(slow_path->GetExitLabel());
+}
+
+// Unimplemented intrinsics.
+
+#define UNIMPLEMENTED_INTRINSIC(Name)                                                  \
+void IntrinsicLocationsBuilderARM::Visit ## Name(HInvoke* invoke ATTRIBUTE_UNUSED) { \
+}                                                                                      \
+void IntrinsicCodeGeneratorARM::Visit ## Name(HInvoke* invoke ATTRIBUTE_UNUSED) {    \
+}
+
+UNIMPLEMENTED_INTRINSIC(IntegerReverse)
+UNIMPLEMENTED_INTRINSIC(IntegerReverseBytes)
+UNIMPLEMENTED_INTRINSIC(LongReverse)
+UNIMPLEMENTED_INTRINSIC(LongReverseBytes)
+UNIMPLEMENTED_INTRINSIC(ShortReverseBytes)
+UNIMPLEMENTED_INTRINSIC(MathMinDoubleDouble)
+UNIMPLEMENTED_INTRINSIC(MathMinFloatFloat)
+UNIMPLEMENTED_INTRINSIC(MathMaxDoubleDouble)
+UNIMPLEMENTED_INTRINSIC(MathMaxFloatFloat)
+UNIMPLEMENTED_INTRINSIC(MathMinLongLong)
+UNIMPLEMENTED_INTRINSIC(MathMaxLongLong)
+UNIMPLEMENTED_INTRINSIC(MathCeil)          // Could be done by changing rounding mode, maybe?
+UNIMPLEMENTED_INTRINSIC(MathFloor)         // Could be done by changing rounding mode, maybe?
+UNIMPLEMENTED_INTRINSIC(MathRint)
+UNIMPLEMENTED_INTRINSIC(MathRoundDouble)   // Could be done by changing rounding mode, maybe?
+UNIMPLEMENTED_INTRINSIC(MathRoundFloat)    // Could be done by changing rounding mode, maybe?
+UNIMPLEMENTED_INTRINSIC(UnsafeCASLong)     // High register pressure.
+UNIMPLEMENTED_INTRINSIC(SystemArrayCopyChar)
+UNIMPLEMENTED_INTRINSIC(StringCompareTo)
+UNIMPLEMENTED_INTRINSIC(StringIsEmpty)  // Might not want to do these two anyways, inlining should
+UNIMPLEMENTED_INTRINSIC(StringLength)   // be good enough here.
+UNIMPLEMENTED_INTRINSIC(StringIndexOf)
+UNIMPLEMENTED_INTRINSIC(StringIndexOfAfter)
+UNIMPLEMENTED_INTRINSIC(ReferenceGetReferent)
+
+}  // namespace arm
+}  // namespace art
diff --git a/compiler/optimizing/intrinsics_arm.h b/compiler/optimizing/intrinsics_arm.h
new file mode 100644
index 0000000000..8bfb7d4686
--- /dev/null
+++ b/compiler/optimizing/intrinsics_arm.h
@@ -0,0 +1,88 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ART_COMPILER_OPTIMIZING_INTRINSICS_ARM_H_
+#define ART_COMPILER_OPTIMIZING_INTRINSICS_ARM_H_
+
+#include "intrinsics.h"
+
+namespace art {
+
+class ArenaAllocator;
+class ArmInstructionSetFeatures;
+class HInvokeStaticOrDirect;
+class HInvokeVirtual;
+
+namespace arm {
+
+class ArmAssembler;
+class CodeGeneratorARM;
+
+class IntrinsicLocationsBuilderARM FINAL : public IntrinsicVisitor {
+ public:
+  explicit IntrinsicLocationsBuilderARM(ArenaAllocator* arena,
+                                        const ArmInstructionSetFeatures& features)
+      : arena_(arena), features_(features) {}
+
+  // Define visitor methods.
+
+#define OPTIMIZING_INTRINSICS(Name, IsStatic)   \
+  void Visit ## Name(HInvoke* invoke) OVERRIDE;
+#include "intrinsics_list.h"
+INTRINSICS_LIST(OPTIMIZING_INTRINSICS)
+#undef INTRINSICS_LIST
+#undef OPTIMIZING_INTRINSICS
+
+  // Check whether an invoke is an intrinsic, and if so, create a location summary. Returns whether
+  // a corresponding LocationSummary with the intrinsified_ flag set was generated and attached to
+  // the invoke.
+  bool TryDispatch(HInvoke* invoke);
+
+ private:
+  ArenaAllocator* arena_;
+
+  const ArmInstructionSetFeatures& features_;
+
+  DISALLOW_COPY_AND_ASSIGN(IntrinsicLocationsBuilderARM);
+};
+
+class IntrinsicCodeGeneratorARM FINAL : public IntrinsicVisitor {
+ public:
+  explicit IntrinsicCodeGeneratorARM(CodeGeneratorARM* codegen) : codegen_(codegen) {}
+
+  // Define visitor methods.
+
+#define OPTIMIZING_INTRINSICS(Name, IsStatic)   \
+  void Visit ## Name(HInvoke* invoke) OVERRIDE;
+#include "intrinsics_list.h"
+INTRINSICS_LIST(OPTIMIZING_INTRINSICS)
+#undef INTRINSICS_LIST
+#undef OPTIMIZING_INTRINSICS
+
+ private:
+  ArmAssembler* GetAssembler();
+
+  ArenaAllocator* GetAllocator();
+
+  CodeGeneratorARM* codegen_;
+
+  DISALLOW_COPY_AND_ASSIGN(IntrinsicCodeGeneratorARM);
+};
+
+}  // namespace arm
+}  // namespace art
+
+#endif  // ART_COMPILER_OPTIMIZING_INTRINSICS_ARM_H_
diff --git a/compiler/optimizing/intrinsics_arm64.cc b/compiler/optimizing/intrinsics_arm64.cc
index 7a3d7d8389..8874edc341 100644
--- a/compiler/optimizing/intrinsics_arm64.cc
+++ b/compiler/optimizing/intrinsics_arm64.cc
@@ -300,7 +300,6 @@ void IntrinsicCodeGeneratorARM64::VisitLongReverse(HInvoke* invoke) {
 }
 
 static void CreateFPToFPLocations(ArenaAllocator* arena, HInvoke* invoke) {
-  // We only support FP registers here.
   LocationSummary* locations = new (arena) LocationSummary(invoke,
                                                            LocationSummary::kNoCall,
                                                            kIntrinsified);
@@ -924,7 +923,6 @@ void IntrinsicCodeGeneratorARM64::VisitUnsafeCASObject(HInvoke* invoke) {
 }
 
 void IntrinsicLocationsBuilderARM64::VisitStringCharAt(HInvoke* invoke) {
-  // The inputs plus one temp.
   LocationSummary* locations = new (arena_) LocationSummary(invoke,
                                                             LocationSummary::kCallOnSlowPath,
                                                             kIntrinsified);
diff --git a/compiler/utils/arm/assembler_arm.cc b/compiler/utils/arm/assembler_arm.cc
index 05287732c5..1f44f19b23 100644
--- a/compiler/utils/arm/assembler_arm.cc
+++ b/compiler/utils/arm/assembler_arm.cc
@@ -245,6 +245,7 @@ uint32_t Address::encodingThumb(bool is_32bit) const {
 
 // This is very like the ARM encoding except the offset is 10 bits.
 uint32_t Address::encodingThumbLdrdStrd() const {
+  DCHECK(IsImmediate());
   uint32_t encoding;
   uint32_t am = am_;
   // If P is 0 then W must be 1 (Different from ARM).
diff --git a/compiler/utils/arm/assembler_thumb2_test.cc b/compiler/utils/arm/assembler_thumb2_test.cc
index e571e72402..ebea9d4262 100644
--- a/compiler/utils/arm/assembler_thumb2_test.cc
+++ b/compiler/utils/arm/assembler_thumb2_test.cc
@@ -198,6 +198,18 @@ TEST_F(AssemblerThumb2Test, strexd) {
   DriverStr(expected, "strexd");
 }
 
+TEST_F(AssemblerThumb2Test, LdrdStrd) {
+  GetAssembler()->ldrd(arm::R0, arm::Address(arm::R2, 8));
+  GetAssembler()->ldrd(arm::R0, arm::Address(arm::R12));
+  GetAssembler()->strd(arm::R0, arm::Address(arm::R2, 8));
+
+  const char* expected =
+      "ldrd r0, r1, [r2, #8]\n"
+      "ldrd r0, r1, [r12]\n"
+      "strd r0, r1, [r2, #8]\n";
+  DriverStr(expected, "ldrdstrd");
+}
+
 TEST_F(AssemblerThumb2Test, eor) {
 #define __ GetAssembler()->
   __ eor(arm::R1, arm::R1, arm::ShifterOperand(arm::R0));