Replace String CharArray with internal uint16_t array.

Summary of high level changes:
  - Adds compiler inliner support to identify string init methods
  - Adds compiler support (quick & optimizing) with new invoke code path
    that calls method off the thread pointer
  - Adds thread entrypoints for all string init methods
  - Adds map to verifier to log when receiver of string init has been
    copied to other registers. used by compiler and interpreter

Change-Id: I797b992a8feb566f9ad73060011ab6f51eb7ce01
diff --git a/compiler/dex/bb_optimizations.h b/compiler/dex/bb_optimizations.h
index b948afd..72919b6 100644
--- a/compiler/dex/bb_optimizations.h
+++ b/compiler/dex/bb_optimizations.h
@@ -26,6 +26,30 @@
 namespace art {
 
 /**
+ * @class String Change
+ * @brief Converts calls to String.<init> to StringFactory instead.
+ */
+class StringChange : public PassME {
+ public:
+  StringChange() : PassME("StringChange", kNoNodes) {
+  }
+
+  void Start(PassDataHolder* data) const {
+    DCHECK(data != nullptr);
+    CompilationUnit* c_unit = down_cast<PassMEDataHolder*>(data)->c_unit;
+    DCHECK(c_unit != nullptr);
+    c_unit->mir_graph->StringChange();
+  }
+
+  bool Gate(const PassDataHolder* data) const {
+    DCHECK(data != nullptr);
+    CompilationUnit* c_unit = down_cast<const PassMEDataHolder*>(data)->c_unit;
+    DCHECK(c_unit != nullptr);
+    return c_unit->mir_graph->HasInvokes();
+  }
+};
+
+/**
  * @class CacheFieldLoweringInfo
  * @brief Cache the lowering info for fields used by IGET/IPUT/SGET/SPUT insns.
  */
diff --git a/compiler/dex/mir_graph.h b/compiler/dex/mir_graph.h
index 7bfbb34..7385a8b 100644
--- a/compiler/dex/mir_graph.h
+++ b/compiler/dex/mir_graph.h
@@ -519,6 +519,7 @@
   bool is_range;
   DexOffset offset;       // Offset in code units.
   MIR* mir;
+  int32_t string_init_offset;
 };
 
 
@@ -723,6 +724,8 @@
   void BasicBlockOptimization();
   void BasicBlockOptimizationEnd();
 
+  void StringChange();
+
   const ArenaVector<BasicBlockId>& GetTopologicalSortOrder() {
     DCHECK(!topological_order_.empty());
     return topological_order_;
diff --git a/compiler/dex/mir_method_info.cc b/compiler/dex/mir_method_info.cc
index 0c84b82..5654604 100644
--- a/compiler/dex/mir_method_info.cc
+++ b/compiler/dex/mir_method_info.cc
@@ -16,6 +16,7 @@
 
 # include "mir_method_info.h"
 
+#include "dex/compiler_ir.h"
 #include "dex/quick/dex_file_method_inliner.h"
 #include "dex/quick/dex_file_to_method_inliner_map.h"
 #include "dex/verified_method.h"
@@ -83,6 +84,13 @@
     MethodReference* devirt_target = (it->target_dex_file_ != nullptr) ? &devirt_ref : nullptr;
     InvokeType invoke_type = it->GetInvokeType();
     mirror::ArtMethod* resolved_method = nullptr;
+
+    bool string_init = false;
+    if (default_inliner->IsStringInitMethodIndex(it->MethodIndex())) {
+      string_init = true;
+      invoke_type = kDirect;
+    }
+
     if (!it->IsQuickened()) {
       it->target_dex_file_ = dex_file;
       it->target_method_idx_ = it->MethodIndex();
@@ -170,6 +178,9 @@
     it->target_dex_file_ = target_method.dex_file;
     it->target_method_idx_ = target_method.dex_method_index;
     it->stats_flags_ = fast_path_flags;
+    if (string_init) {
+      it->direct_code_ = 0;
+    }
   }
 }
 
diff --git a/compiler/dex/mir_optimization.cc b/compiler/dex/mir_optimization.cc
index 3482602..25c159f 100644
--- a/compiler/dex/mir_optimization.cc
+++ b/compiler/dex/mir_optimization.cc
@@ -18,6 +18,7 @@
 #include "base/logging.h"
 #include "base/scoped_arena_containers.h"
 #include "dataflow_iterator-inl.h"
+#include "dex/verified_method.h"
 #include "dex_flags.h"
 #include "driver/compiler_driver.h"
 #include "driver/dex_compilation_unit.h"
@@ -25,10 +26,11 @@
 #include "gvn_dead_code_elimination.h"
 #include "local_value_numbering.h"
 #include "mir_field_info.h"
-#include "type_inference.h"
+#include "mirror/string.h"
 #include "quick/dex_file_method_inliner.h"
 #include "quick/dex_file_to_method_inliner_map.h"
 #include "stack.h"
+#include "type_inference.h"
 
 namespace art {
 
@@ -1660,6 +1662,77 @@
   temp_scoped_alloc_.reset();
 }
 
+void MIRGraph::StringChange() {
+  AllNodesIterator iter(this);
+  for (BasicBlock* bb = iter.Next(); bb != nullptr; bb = iter.Next()) {
+    for (MIR* mir = bb->first_mir_insn; mir != nullptr; mir = mir->next) {
+      // Look for new instance opcodes, skip otherwise
+      Instruction::Code opcode = mir->dalvikInsn.opcode;
+      if (opcode == Instruction::NEW_INSTANCE) {
+        uint32_t type_idx = mir->dalvikInsn.vB;
+        if (cu_->compiler_driver->IsStringTypeIndex(type_idx, cu_->dex_file)) {
+          // Change NEW_INSTANCE and throwing half of the insn (if it exists) into CONST_4 of 0
+          mir->dalvikInsn.opcode = Instruction::CONST_4;
+          mir->dalvikInsn.vB = 0;
+          MIR* check_mir = GetBasicBlock(bb->predecessors[0])->last_mir_insn;
+          if (check_mir != nullptr &&
+              static_cast<int>(check_mir->dalvikInsn.opcode) == kMirOpCheck) {
+            check_mir->dalvikInsn.opcode = static_cast<Instruction::Code>(kMirOpNop);
+            check_mir->dalvikInsn.vB = 0;
+          }
+        }
+      } else if ((opcode == Instruction::INVOKE_DIRECT) ||
+                 (opcode == Instruction::INVOKE_DIRECT_RANGE)) {
+        uint32_t method_idx = mir->dalvikInsn.vB;
+        DexFileMethodInliner* inliner =
+            cu_->compiler_driver->GetMethodInlinerMap()->GetMethodInliner(cu_->dex_file);
+        if (inliner->IsStringInitMethodIndex(method_idx)) {
+          bool is_range = (opcode == Instruction::INVOKE_DIRECT_RANGE);
+          uint32_t orig_this_reg = is_range ? mir->dalvikInsn.vC : mir->dalvikInsn.arg[0];
+          // Remove this pointer from string init and change to static call.
+          mir->dalvikInsn.vA--;
+          if (!is_range) {
+            mir->dalvikInsn.opcode = Instruction::INVOKE_STATIC;
+            for (uint32_t i = 0; i < mir->dalvikInsn.vA; i++) {
+              mir->dalvikInsn.arg[i] = mir->dalvikInsn.arg[i + 1];
+            }
+          } else {
+            mir->dalvikInsn.opcode = Instruction::INVOKE_STATIC_RANGE;
+            mir->dalvikInsn.vC++;
+          }
+          // Insert a move-result instruction to the original this pointer reg.
+          MIR* move_result_mir = static_cast<MIR *>(arena_->Alloc(sizeof(MIR), kArenaAllocMIR));
+          move_result_mir->dalvikInsn.opcode = Instruction::MOVE_RESULT_OBJECT;
+          move_result_mir->dalvikInsn.vA = orig_this_reg;
+          move_result_mir->offset = mir->offset;
+          move_result_mir->m_unit_index = mir->m_unit_index;
+          bb->InsertMIRAfter(mir, move_result_mir);
+          // Add additional moves if this pointer was copied to other registers.
+          const VerifiedMethod* verified_method =
+              cu_->compiler_driver->GetVerifiedMethod(cu_->dex_file, cu_->method_idx);
+          DCHECK(verified_method != nullptr);
+          const SafeMap<uint32_t, std::set<uint32_t>>& string_init_map =
+              verified_method->GetStringInitPcRegMap();
+          auto map_it = string_init_map.find(mir->offset);
+          if (map_it != string_init_map.end()) {
+            const std::set<uint32_t>& reg_set = map_it->second;
+            for (auto set_it = reg_set.begin(); set_it != reg_set.end(); ++set_it) {
+              MIR* move_mir = static_cast<MIR *>(arena_->Alloc(sizeof(MIR), kArenaAllocMIR));
+              move_mir->dalvikInsn.opcode = Instruction::MOVE_OBJECT;
+              move_mir->dalvikInsn.vA = *set_it;
+              move_mir->dalvikInsn.vB = orig_this_reg;
+              move_mir->offset = mir->offset;
+              move_mir->m_unit_index = mir->m_unit_index;
+              bb->InsertMIRAfter(move_result_mir, move_mir);
+            }
+          }
+        }
+      }
+    }
+  }
+}
+
+
 bool MIRGraph::EliminateSuspendChecksGate() {
   if ((cu_->disable_opt & (1 << kSuspendCheckElimination)) != 0 ||  // Disabled.
       GetMaxNestedLoops() == 0u ||   // Nothing to do.
diff --git a/compiler/dex/pass_driver_me_opts.cc b/compiler/dex/pass_driver_me_opts.cc
index 3e193b4..375003b 100644
--- a/compiler/dex/pass_driver_me_opts.cc
+++ b/compiler/dex/pass_driver_me_opts.cc
@@ -35,6 +35,7 @@
    * Disadvantage is the passes can't change their internal states depending on CompilationUnit:
    *   - This is not yet an issue: no current pass would require it.
    */
+  pass_manager->AddPass(new StringChange);
   pass_manager->AddPass(new CacheFieldLoweringInfo);
   pass_manager->AddPass(new CacheMethodLoweringInfo);
   pass_manager->AddPass(new CalculatePredecessors);
diff --git a/compiler/dex/quick/arm/call_arm.cc b/compiler/dex/quick/arm/call_arm.cc
index 6ba4016..2b2d6af 100644
--- a/compiler/dex/quick/arm/call_arm.cc
+++ b/compiler/dex/quick/arm/call_arm.cc
@@ -21,6 +21,7 @@
 #include "arm_lir.h"
 #include "base/logging.h"
 #include "dex/mir_graph.h"
+#include "dex/quick/dex_file_to_method_inliner_map.h"
 #include "dex/quick/mir_to_lir-inl.h"
 #include "driver/compiler_driver.h"
 #include "driver/compiler_options.h"
@@ -619,13 +620,31 @@
  * Bit of a hack here - in the absence of a real scheduling pass,
  * emit the next instruction in static & direct invoke sequences.
  */
-int ArmMir2Lir::ArmNextSDCallInsn(CompilationUnit* cu, CallInfo* info ATTRIBUTE_UNUSED,
+int ArmMir2Lir::ArmNextSDCallInsn(CompilationUnit* cu, CallInfo* info,
                                   int state, const MethodReference& target_method,
                                   uint32_t unused_idx ATTRIBUTE_UNUSED,
                                   uintptr_t direct_code, uintptr_t direct_method,
                                   InvokeType type) {
   ArmMir2Lir* cg = static_cast<ArmMir2Lir*>(cu->cg.get());
-  if (direct_code != 0 && direct_method != 0) {
+  if (info->string_init_offset != 0) {
+    RegStorage arg0_ref = cg->TargetReg(kArg0, kRef);
+    switch (state) {
+    case 0: {  // Grab target method* from thread pointer
+      cg->LoadRefDisp(rs_rARM_SELF, info->string_init_offset, arg0_ref, kNotVolatile);
+      break;
+    }
+    case 1:  // Grab the code from the method*
+      if (direct_code == 0) {
+        // kInvokeTgt := arg0_ref->entrypoint
+        cg->LoadWordDisp(arg0_ref,
+                         mirror::ArtMethod::EntryPointFromQuickCompiledCodeOffset(
+                             kArmPointerSize).Int32Value(), cg->TargetPtrReg(kInvokeTgt));
+      }
+      break;
+    default:
+      return -1;
+    }
+  } else if (direct_code != 0 && direct_method != 0) {
     switch (state) {
     case 0:  // Get the current Method* [sets kArg0]
       if (direct_code != static_cast<uintptr_t>(-1)) {
diff --git a/compiler/dex/quick/arm64/call_arm64.cc b/compiler/dex/quick/arm64/call_arm64.cc
index 9a7c2ad..e49e40d 100644
--- a/compiler/dex/quick/arm64/call_arm64.cc
+++ b/compiler/dex/quick/arm64/call_arm64.cc
@@ -21,6 +21,7 @@
 #include "arm64_lir.h"
 #include "base/logging.h"
 #include "dex/mir_graph.h"
+#include "dex/quick/dex_file_to_method_inliner_map.h"
 #include "dex/quick/mir_to_lir-inl.h"
 #include "driver/compiler_driver.h"
 #include "driver/compiler_options.h"
@@ -460,7 +461,25 @@
                                       InvokeType type) {
   UNUSED(info, unused_idx);
   Arm64Mir2Lir* cg = static_cast<Arm64Mir2Lir*>(cu->cg.get());
-  if (direct_code != 0 && direct_method != 0) {
+  if (info->string_init_offset != 0) {
+    RegStorage arg0_ref = cg->TargetReg(kArg0, kRef);
+    switch (state) {
+    case 0: {  // Grab target method* from thread pointer
+      cg->LoadRefDisp(rs_xSELF, info->string_init_offset, arg0_ref, kNotVolatile);
+      break;
+    }
+    case 1:  // Grab the code from the method*
+      if (direct_code == 0) {
+        // kInvokeTgt := arg0_ref->entrypoint
+        cg->LoadWordDisp(arg0_ref,
+                         mirror::ArtMethod::EntryPointFromQuickCompiledCodeOffset(
+                             kArm64PointerSize).Int32Value(), cg->TargetPtrReg(kInvokeTgt));
+      }
+      break;
+    default:
+      return -1;
+    }
+  } else if (direct_code != 0 && direct_method != 0) {
     switch (state) {
     case 0:  // Get the current Method* [sets kArg0]
       if (direct_code != static_cast<uintptr_t>(-1)) {
diff --git a/compiler/dex/quick/dex_file_method_inliner.cc b/compiler/dex/quick/dex_file_method_inliner.cc
index f5e6c09..2568ee3 100644
--- a/compiler/dex/quick/dex_file_method_inliner.cc
+++ b/compiler/dex/quick/dex_file_method_inliner.cc
@@ -55,8 +55,12 @@
     false,  // kIntrinsicReferenceGetReferent
     false,  // kIntrinsicCharAt
     false,  // kIntrinsicCompareTo
+    false,  // kIntrinsicGetCharsNoCheck
     false,  // kIntrinsicIsEmptyOrLength
     false,  // kIntrinsicIndexOf
+    true,   // kIntrinsicNewStringFromBytes
+    true,   // kIntrinsicNewStringFromChars
+    true,   // kIntrinsicNewStringFromString
     true,   // kIntrinsicCurrentThread
     true,   // kIntrinsicPeek
     true,   // kIntrinsicPoke
@@ -88,8 +92,15 @@
 static_assert(!kIntrinsicIsStatic[kIntrinsicReferenceGetReferent], "Get must not be static");
 static_assert(!kIntrinsicIsStatic[kIntrinsicCharAt], "CharAt must not be static");
 static_assert(!kIntrinsicIsStatic[kIntrinsicCompareTo], "CompareTo must not be static");
+static_assert(!kIntrinsicIsStatic[kIntrinsicGetCharsNoCheck], "GetCharsNoCheck must not be static");
 static_assert(!kIntrinsicIsStatic[kIntrinsicIsEmptyOrLength], "IsEmptyOrLength must not be static");
 static_assert(!kIntrinsicIsStatic[kIntrinsicIndexOf], "IndexOf must not be static");
+static_assert(kIntrinsicIsStatic[kIntrinsicNewStringFromBytes],
+              "NewStringFromBytes must be static");
+static_assert(kIntrinsicIsStatic[kIntrinsicNewStringFromChars],
+              "NewStringFromChars must be static");
+static_assert(kIntrinsicIsStatic[kIntrinsicNewStringFromString],
+              "NewStringFromString must be static");
 static_assert(kIntrinsicIsStatic[kIntrinsicCurrentThread], "CurrentThread must be static");
 static_assert(kIntrinsicIsStatic[kIntrinsicPeek], "Peek must be static");
 static_assert(kIntrinsicIsStatic[kIntrinsicPoke], "Poke must be static");
@@ -137,9 +148,15 @@
     "F",                       // kClassCacheFloat
     "D",                       // kClassCacheDouble
     "V",                       // kClassCacheVoid
+    "[B",                      // kClassCacheJavaLangByteArray
+    "[C",                      // kClassCacheJavaLangCharArray
+    "[I",                      // kClassCacheJavaLangIntArray
     "Ljava/lang/Object;",      // kClassCacheJavaLangObject
-    "Ljava/lang/ref/Reference;",  // kClassCacheJavaLangRefReference
+    "Ljava/lang/ref/Reference;",   // kClassCacheJavaLangRefReference
     "Ljava/lang/String;",      // kClassCacheJavaLangString
+    "Ljava/lang/StringBuffer;",    // kClassCacheJavaLangStringBuffer
+    "Ljava/lang/StringBuilder;",   // kClassCacheJavaLangStringBuilder
+    "Ljava/lang/StringFactory;",   // kClassCacheJavaLangStringFactory
     "Ljava/lang/Double;",      // kClassCacheJavaLangDouble
     "Ljava/lang/Float;",       // kClassCacheJavaLangFloat
     "Ljava/lang/Integer;",     // kClassCacheJavaLangInteger
@@ -148,10 +165,10 @@
     "Ljava/lang/Math;",        // kClassCacheJavaLangMath
     "Ljava/lang/StrictMath;",  // kClassCacheJavaLangStrictMath
     "Ljava/lang/Thread;",      // kClassCacheJavaLangThread
+    "Ljava/nio/charset/Charset;",  // kClassCacheJavaNioCharsetCharset
     "Llibcore/io/Memory;",     // kClassCacheLibcoreIoMemory
     "Lsun/misc/Unsafe;",       // kClassCacheSunMiscUnsafe
     "Ljava/lang/System;",      // kClassCacheJavaLangSystem
-    "[C"                       // kClassCacheJavaLangCharArray
 };
 
 const char* const DexFileMethodInliner::kNameCacheNames[] = {
@@ -172,9 +189,14 @@
     "getReferent",           // kNameCacheReferenceGet
     "charAt",                // kNameCacheCharAt
     "compareTo",             // kNameCacheCompareTo
+    "getCharsNoCheck",       // kNameCacheGetCharsNoCheck
     "isEmpty",               // kNameCacheIsEmpty
     "indexOf",               // kNameCacheIndexOf
     "length",                // kNameCacheLength
+    "<init>",                // kNameCacheInit
+    "newStringFromBytes",    // kNameCacheNewStringFromBytes
+    "newStringFromChars",    // kNameCacheNewStringFromChars
+    "newStringFromString",   // kNameCacheNewStringFromString
     "currentThread",         // kNameCacheCurrentThread
     "peekByte",              // kNameCachePeekByte
     "peekIntNative",         // kNameCachePeekIntNative
@@ -282,7 +304,53 @@
         kClassCacheJavaLangObject } },
     // kProtoCacheCharArrayICharArrayII_V
     { kClassCacheVoid, 5, {kClassCacheJavaLangCharArray, kClassCacheInt,
-                kClassCacheJavaLangCharArray, kClassCacheInt, kClassCacheInt}}
+        kClassCacheJavaLangCharArray, kClassCacheInt, kClassCacheInt} },
+    // kProtoCacheIICharArrayI_V
+    { kClassCacheVoid, 4, { kClassCacheInt, kClassCacheInt, kClassCacheJavaLangCharArray,
+        kClassCacheInt } },
+    // kProtoCacheByteArrayIII_String
+    { kClassCacheJavaLangString, 4, { kClassCacheJavaLangByteArray, kClassCacheInt, kClassCacheInt,
+        kClassCacheInt } },
+    // kProtoCacheIICharArray_String
+    { kClassCacheJavaLangString, 3, { kClassCacheInt, kClassCacheInt,
+        kClassCacheJavaLangCharArray } },
+    // kProtoCacheString_String
+    { kClassCacheJavaLangString, 1, { kClassCacheJavaLangString } },
+    // kProtoCache_V
+    { kClassCacheVoid, 0, { } },
+    // kProtoCacheByteArray_V
+    { kClassCacheVoid, 1, { kClassCacheJavaLangByteArray } },
+    // kProtoCacheByteArrayI_V
+    { kClassCacheVoid, 2, { kClassCacheJavaLangByteArray, kClassCacheInt } },
+    // kProtoCacheByteArrayII_V
+    { kClassCacheVoid, 3, { kClassCacheJavaLangByteArray, kClassCacheInt, kClassCacheInt } },
+    // kProtoCacheByteArrayIII_V
+    { kClassCacheVoid, 4, { kClassCacheJavaLangByteArray, kClassCacheInt, kClassCacheInt,
+        kClassCacheInt } },
+    // kProtoCacheByteArrayIIString_V
+    { kClassCacheVoid, 4, { kClassCacheJavaLangByteArray, kClassCacheInt, kClassCacheInt,
+        kClassCacheJavaLangString } },
+    // kProtoCacheByteArrayString_V
+    { kClassCacheVoid, 2, { kClassCacheJavaLangByteArray, kClassCacheJavaLangString } },
+    // kProtoCacheByteArrayIICharset_V
+    { kClassCacheVoid, 4, { kClassCacheJavaLangByteArray, kClassCacheInt, kClassCacheInt,
+        kClassCacheJavaNioCharsetCharset } },
+    // kProtoCacheByteArrayCharset_V
+    { kClassCacheVoid, 2, { kClassCacheJavaLangByteArray, kClassCacheJavaNioCharsetCharset } },
+    // kProtoCacheCharArray_V
+    { kClassCacheVoid, 1, { kClassCacheJavaLangCharArray } },
+    // kProtoCacheCharArrayII_V
+    { kClassCacheVoid, 3, { kClassCacheJavaLangCharArray, kClassCacheInt, kClassCacheInt } },
+    // kProtoCacheIICharArray_V
+    { kClassCacheVoid, 3, { kClassCacheInt, kClassCacheInt, kClassCacheJavaLangCharArray } },
+    // kProtoCacheIntArrayII_V
+    { kClassCacheVoid, 3, { kClassCacheJavaLangIntArray, kClassCacheInt, kClassCacheInt } },
+    // kProtoCacheString_V
+    { kClassCacheVoid, 1, { kClassCacheJavaLangString } },
+    // kProtoCacheStringBuffer_V
+    { kClassCacheVoid, 1, { kClassCacheJavaLangStringBuffer } },
+    // kProtoCacheStringBuilder_V
+    { kClassCacheVoid, 1, { kClassCacheJavaLangStringBuilder } },
 };
 
 const DexFileMethodInliner::IntrinsicDef DexFileMethodInliner::kIntrinsicMethods[] = {
@@ -343,6 +411,7 @@
 
     INTRINSIC(JavaLangString, CharAt, I_C, kIntrinsicCharAt, 0),
     INTRINSIC(JavaLangString, CompareTo, String_I, kIntrinsicCompareTo, 0),
+    INTRINSIC(JavaLangString, GetCharsNoCheck, IICharArrayI_V, kIntrinsicGetCharsNoCheck, 0),
     INTRINSIC(JavaLangString, IsEmpty, _Z, kIntrinsicIsEmptyOrLength, kIntrinsicFlagIsEmpty),
     INTRINSIC(JavaLangString, IndexOf, II_I, kIntrinsicIndexOf, kIntrinsicFlagNone),
     INTRINSIC(JavaLangString, IndexOf, I_I, kIntrinsicIndexOf, kIntrinsicFlagBase0),
@@ -386,8 +455,29 @@
     INTRINSIC(JavaLangSystem, ArrayCopy, CharArrayICharArrayII_V , kIntrinsicSystemArrayCopyCharArray,
               0),
 
-
 #undef INTRINSIC
+
+#define SPECIAL(c, n, p, o, d) \
+    { { kClassCache ## c, kNameCache ## n, kProtoCache ## p }, { o, kInlineSpecial, { d } } }
+
+    SPECIAL(JavaLangString, Init, _V, kInlineStringInit, 0),
+    SPECIAL(JavaLangString, Init, ByteArray_V, kInlineStringInit, 1),
+    SPECIAL(JavaLangString, Init, ByteArrayI_V, kInlineStringInit, 2),
+    SPECIAL(JavaLangString, Init, ByteArrayII_V, kInlineStringInit, 3),
+    SPECIAL(JavaLangString, Init, ByteArrayIII_V, kInlineStringInit, 4),
+    SPECIAL(JavaLangString, Init, ByteArrayIIString_V, kInlineStringInit, 5),
+    SPECIAL(JavaLangString, Init, ByteArrayString_V, kInlineStringInit, 6),
+    SPECIAL(JavaLangString, Init, ByteArrayIICharset_V, kInlineStringInit, 7),
+    SPECIAL(JavaLangString, Init, ByteArrayCharset_V, kInlineStringInit, 8),
+    SPECIAL(JavaLangString, Init, CharArray_V, kInlineStringInit, 9),
+    SPECIAL(JavaLangString, Init, CharArrayII_V, kInlineStringInit, 10),
+    SPECIAL(JavaLangString, Init, IICharArray_V, kInlineStringInit, 11),
+    SPECIAL(JavaLangString, Init, IntArrayII_V, kInlineStringInit, 12),
+    SPECIAL(JavaLangString, Init, String_V, kInlineStringInit, 13),
+    SPECIAL(JavaLangString, Init, StringBuffer_V, kInlineStringInit, 14),
+    SPECIAL(JavaLangString, Init, StringBuilder_V, kInlineStringInit, 15),
+
+#undef SPECIAL
 };
 
 DexFileMethodInliner::DexFileMethodInliner()
@@ -491,11 +581,19 @@
       return backend->GenInlinedCharAt(info);
     case kIntrinsicCompareTo:
       return backend->GenInlinedStringCompareTo(info);
+    case kIntrinsicGetCharsNoCheck:
+      return backend->GenInlinedStringGetCharsNoCheck(info);
     case kIntrinsicIsEmptyOrLength:
       return backend->GenInlinedStringIsEmptyOrLength(
           info, intrinsic.d.data & kIntrinsicFlagIsEmpty);
     case kIntrinsicIndexOf:
       return backend->GenInlinedIndexOf(info, intrinsic.d.data & kIntrinsicFlagBase0);
+    case kIntrinsicNewStringFromBytes:
+      return backend->GenInlinedStringFactoryNewStringFromBytes(info);
+    case kIntrinsicNewStringFromChars:
+      return backend->GenInlinedStringFactoryNewStringFromChars(info);
+    case kIntrinsicNewStringFromString:
+      return backend->GenInlinedStringFactoryNewStringFromString(info);
     case kIntrinsicCurrentThread:
       return backend->GenInlinedCurrentThread(info);
     case kIntrinsicPeek:
@@ -574,6 +672,8 @@
       move_result = mir_graph->FindMoveResult(bb, invoke);
       result = GenInlineIPut(mir_graph, bb, invoke, move_result, method);
       break;
+    case kInlineStringInit:
+      return false;
     default:
       LOG(FATAL) << "Unexpected inline op: " << method.opcode;
       break;
@@ -921,4 +1021,21 @@
   return true;
 }
 
+uint32_t DexFileMethodInliner::GetOffsetForStringInit(uint32_t method_index, size_t pointer_size) {
+  ReaderMutexLock mu(Thread::Current(), lock_);
+  auto it = inline_methods_.find(method_index);
+  if (it != inline_methods_.end() && (it->second.opcode == kInlineStringInit)) {
+    uint32_t string_init_base_offset = Thread::QuickEntryPointOffsetWithSize(
+              OFFSETOF_MEMBER(QuickEntryPoints, pNewEmptyString), pointer_size);
+    return string_init_base_offset + it->second.d.data * pointer_size;
+  }
+  return 0;
+}
+
+bool DexFileMethodInliner::IsStringInitMethodIndex(uint32_t method_index) {
+  ReaderMutexLock mu(Thread::Current(), lock_);
+  auto it = inline_methods_.find(method_index);
+  return (it != inline_methods_.end()) && (it->second.opcode == kInlineStringInit);
+}
+
 }  // namespace art
diff --git a/compiler/dex/quick/dex_file_method_inliner.h b/compiler/dex/quick/dex_file_method_inliner.h
index d1e5621..26b41bf 100644
--- a/compiler/dex/quick/dex_file_method_inliner.h
+++ b/compiler/dex/quick/dex_file_method_inliner.h
@@ -96,6 +96,17 @@
         LOCKS_EXCLUDED(lock_);
 
     /**
+     * Gets the thread pointer entrypoint offset for a string init method index and pointer size.
+     */
+    uint32_t GetOffsetForStringInit(uint32_t method_index, size_t pointer_size)
+        LOCKS_EXCLUDED(lock_);
+
+    /**
+     * Check whether a particular method index is a string init.
+     */
+    bool IsStringInitMethodIndex(uint32_t method_index) LOCKS_EXCLUDED(lock_);
+
+    /**
      * To avoid multiple lookups of a class by its descriptor, we cache its
      * type index in the IndexCache. These are the indexes into the IndexCache
      * class_indexes array.
@@ -111,9 +122,15 @@
       kClassCacheFloat,
       kClassCacheDouble,
       kClassCacheVoid,
+      kClassCacheJavaLangByteArray,
+      kClassCacheJavaLangCharArray,
+      kClassCacheJavaLangIntArray,
       kClassCacheJavaLangObject,
       kClassCacheJavaLangRefReference,
       kClassCacheJavaLangString,
+      kClassCacheJavaLangStringBuffer,
+      kClassCacheJavaLangStringBuilder,
+      kClassCacheJavaLangStringFactory,
       kClassCacheJavaLangDouble,
       kClassCacheJavaLangFloat,
       kClassCacheJavaLangInteger,
@@ -122,10 +139,10 @@
       kClassCacheJavaLangMath,
       kClassCacheJavaLangStrictMath,
       kClassCacheJavaLangThread,
+      kClassCacheJavaNioCharsetCharset,
       kClassCacheLibcoreIoMemory,
       kClassCacheSunMiscUnsafe,
       kClassCacheJavaLangSystem,
-      kClassCacheJavaLangCharArray,
       kClassCacheLast
     };
 
@@ -153,9 +170,14 @@
       kNameCacheReferenceGetReferent,
       kNameCacheCharAt,
       kNameCacheCompareTo,
+      kNameCacheGetCharsNoCheck,
       kNameCacheIsEmpty,
       kNameCacheIndexOf,
       kNameCacheLength,
+      kNameCacheInit,
+      kNameCacheNewStringFromBytes,
+      kNameCacheNewStringFromChars,
+      kNameCacheNewStringFromString,
       kNameCacheCurrentThread,
       kNameCachePeekByte,
       kNameCachePeekIntNative,
@@ -230,6 +252,26 @@
       kProtoCacheObjectJ_Object,
       kProtoCacheObjectJObject_V,
       kProtoCacheCharArrayICharArrayII_V,
+      kProtoCacheIICharArrayI_V,
+      kProtoCacheByteArrayIII_String,
+      kProtoCacheIICharArray_String,
+      kProtoCacheString_String,
+      kProtoCache_V,
+      kProtoCacheByteArray_V,
+      kProtoCacheByteArrayI_V,
+      kProtoCacheByteArrayII_V,
+      kProtoCacheByteArrayIII_V,
+      kProtoCacheByteArrayIIString_V,
+      kProtoCacheByteArrayString_V,
+      kProtoCacheByteArrayIICharset_V,
+      kProtoCacheByteArrayCharset_V,
+      kProtoCacheCharArray_V,
+      kProtoCacheCharArrayII_V,
+      kProtoCacheIICharArray_V,
+      kProtoCacheIntArrayII_V,
+      kProtoCacheString_V,
+      kProtoCacheStringBuffer_V,
+      kProtoCacheStringBuilder_V,
       kProtoCacheLast
     };
 
diff --git a/compiler/dex/quick/gen_invoke.cc b/compiler/dex/quick/gen_invoke.cc
index 1eb3a5f..ab011fc 100755
--- a/compiler/dex/quick/gen_invoke.cc
+++ b/compiler/dex/quick/gen_invoke.cc
@@ -375,6 +375,18 @@
   CallHelper(r_tgt, trampoline, safepoint_pc);
 }
 
+void Mir2Lir::CallRuntimeHelperRegLocationRegLocationRegLocationRegLocation(
+    QuickEntrypointEnum trampoline, RegLocation arg0, RegLocation arg1, RegLocation arg2,
+    RegLocation arg3, bool safepoint_pc) {
+  RegStorage r_tgt = CallHelperSetup(trampoline);
+  LoadValueDirectFixed(arg0, TargetReg(kArg0, arg0));
+  LoadValueDirectFixed(arg1, TargetReg(kArg1, arg1));
+  LoadValueDirectFixed(arg2, TargetReg(kArg2, arg2));
+  LoadValueDirectFixed(arg3, TargetReg(kArg3, arg3));
+  ClobberCallerSave();
+  CallHelper(r_tgt, trampoline, safepoint_pc);
+}
+
 /*
  * If there are any ins passed in registers that have not been promoted
  * to a callee-save register, flush them to the frame.  Perform initial
@@ -966,14 +978,10 @@
 }
 
 bool Mir2Lir::GenInlinedCharAt(CallInfo* info) {
-  // Location of reference to data array
+  // Location of char array data
   int value_offset = mirror::String::ValueOffset().Int32Value();
   // Location of count
   int count_offset = mirror::String::CountOffset().Int32Value();
-  // Starting offset within data array
-  int offset_offset = mirror::String::OffsetOffset().Int32Value();
-  // Start of char data with array_
-  int data_offset = mirror::Array::DataOffset(sizeof(uint16_t)).Int32Value();
 
   RegLocation rl_obj = info->args[0];
   RegLocation rl_idx = info->args[1];
@@ -983,38 +991,21 @@
   GenNullCheck(rl_obj.reg, info->opt_flags);
   bool range_check = (!(info->opt_flags & MIR_IGNORE_RANGE_CHECK));
   LIR* range_check_branch = nullptr;
-  RegStorage reg_off;
-  RegStorage reg_ptr;
-  reg_off = AllocTemp();
-  reg_ptr = AllocTempRef();
   if (range_check) {
     reg_max = AllocTemp();
     Load32Disp(rl_obj.reg, count_offset, reg_max);
     MarkPossibleNullPointerException(info->opt_flags);
-  }
-  Load32Disp(rl_obj.reg, offset_offset, reg_off);
-  MarkPossibleNullPointerException(info->opt_flags);
-  LoadRefDisp(rl_obj.reg, value_offset, reg_ptr, kNotVolatile);
-  if (range_check) {
-    // Set up a slow path to allow retry in case of bounds violation */
+    // Set up a slow path to allow retry in case of bounds violation
     OpRegReg(kOpCmp, rl_idx.reg, reg_max);
     FreeTemp(reg_max);
     range_check_branch = OpCondBranch(kCondUge, nullptr);
   }
-  OpRegImm(kOpAdd, reg_ptr, data_offset);
-  if (rl_idx.is_const) {
-    OpRegImm(kOpAdd, reg_off, mir_graph_->ConstantValue(rl_idx.orig_sreg));
-  } else {
-    OpRegReg(kOpAdd, reg_off, rl_idx.reg);
-  }
+  RegStorage reg_ptr = AllocTempRef();
+  OpRegRegImm(kOpAdd, reg_ptr, rl_obj.reg, value_offset);
   FreeTemp(rl_obj.reg);
-  if (rl_idx.location == kLocPhysReg) {
-    FreeTemp(rl_idx.reg);
-  }
   RegLocation rl_dest = InlineTarget(info);
   RegLocation rl_result = EvalLoc(rl_dest, kCoreReg, true);
-  LoadBaseIndexed(reg_ptr, reg_off, rl_result.reg, 1, kUnsignedHalf);
-  FreeTemp(reg_off);
+  LoadBaseIndexed(reg_ptr, rl_idx.reg, rl_result.reg, 1, kUnsignedHalf);
   FreeTemp(reg_ptr);
   StoreValue(rl_dest, rl_result);
   if (range_check) {
@@ -1025,6 +1016,59 @@
   return true;
 }
 
+bool Mir2Lir::GenInlinedStringGetCharsNoCheck(CallInfo* info) {
+  if (cu_->instruction_set == kMips) {
+    // TODO - add Mips implementation
+    return false;
+  }
+  size_t char_component_size = Primitive::ComponentSize(Primitive::kPrimChar);
+  // Location of data in char array buffer
+  int data_offset = mirror::Array::DataOffset(char_component_size).Int32Value();
+  // Location of char array data in string
+  int value_offset = mirror::String::ValueOffset().Int32Value();
+
+  RegLocation rl_obj = info->args[0];
+  RegLocation rl_start = info->args[1];
+  RegLocation rl_end = info->args[2];
+  RegLocation rl_buffer = info->args[3];
+  RegLocation rl_index = info->args[4];
+
+  ClobberCallerSave();
+  LockCallTemps();  // Using fixed registers
+  RegStorage reg_dst_ptr = TargetReg(kArg0, kRef);
+  RegStorage reg_src_ptr = TargetReg(kArg1, kRef);
+  RegStorage reg_length = TargetReg(kArg2, kNotWide);
+  RegStorage reg_tmp = TargetReg(kArg3, kNotWide);
+  RegStorage reg_tmp_ptr = RegStorage(RegStorage::k64BitSolo, reg_tmp.GetRawBits() & RegStorage::kRegTypeMask);
+
+  LoadValueDirectFixed(rl_buffer, reg_dst_ptr);
+  OpRegImm(kOpAdd, reg_dst_ptr, data_offset);
+  LoadValueDirectFixed(rl_index, reg_tmp);
+  OpRegRegImm(kOpLsl, reg_tmp, reg_tmp, 1);
+  OpRegReg(kOpAdd, reg_dst_ptr, cu_->instruction_set == kArm64 ? reg_tmp_ptr : reg_tmp);
+
+  LoadValueDirectFixed(rl_start, reg_tmp);
+  LoadValueDirectFixed(rl_end, reg_length);
+  OpRegReg(kOpSub, reg_length, reg_tmp);
+  OpRegRegImm(kOpLsl, reg_length, reg_length, 1);
+  LoadValueDirectFixed(rl_obj, reg_src_ptr);
+
+  OpRegImm(kOpAdd, reg_src_ptr, value_offset);
+  OpRegRegImm(kOpLsl, reg_tmp, reg_tmp, 1);
+  OpRegReg(kOpAdd, reg_src_ptr, cu_->instruction_set == kArm64 ? reg_tmp_ptr : reg_tmp);
+
+  RegStorage r_tgt;
+  if (cu_->instruction_set != kX86 && cu_->instruction_set != kX86_64) {
+    r_tgt = LoadHelper(kQuickMemcpy);
+  } else {
+    r_tgt = RegStorage::InvalidReg();
+  }
+  // NOTE: not a safepoint
+  CallHelper(r_tgt, kQuickMemcpy, false, true);
+
+  return true;
+}
+
 // Generates an inlined String.is_empty or String.length.
 bool Mir2Lir::GenInlinedStringIsEmptyOrLength(CallInfo* info, bool is_empty) {
   if (cu_->instruction_set == kMips || cu_->instruction_set == kMips64) {
@@ -1058,6 +1102,58 @@
   return true;
 }
 
+bool Mir2Lir::GenInlinedStringFactoryNewStringFromBytes(CallInfo* info) {
+  if (cu_->instruction_set == kMips) {
+    // TODO - add Mips implementation
+    return false;
+  }
+  RegLocation rl_data = info->args[0];
+  RegLocation rl_high = info->args[1];
+  RegLocation rl_offset = info->args[2];
+  RegLocation rl_count = info->args[3];
+  rl_data = LoadValue(rl_data, kRefReg);
+  LIR* data_null_check_branch = OpCmpImmBranch(kCondEq, rl_data.reg, 0, nullptr);
+  AddIntrinsicSlowPath(info, data_null_check_branch);
+  CallRuntimeHelperRegLocationRegLocationRegLocationRegLocation(
+      kQuickAllocStringFromBytes, rl_data, rl_high, rl_offset, rl_count, true);
+  RegLocation rl_return = GetReturn(kRefReg);
+  RegLocation rl_dest = InlineTarget(info);
+  StoreValue(rl_dest, rl_return);
+  return true;
+}
+
+bool Mir2Lir::GenInlinedStringFactoryNewStringFromChars(CallInfo* info) {
+  if (cu_->instruction_set == kMips) {
+    // TODO - add Mips implementation
+    return false;
+  }
+  RegLocation rl_offset = info->args[0];
+  RegLocation rl_count = info->args[1];
+  RegLocation rl_data = info->args[2];
+  CallRuntimeHelperRegLocationRegLocationRegLocation(
+      kQuickAllocStringFromChars, rl_offset, rl_count, rl_data, true);
+  RegLocation rl_return = GetReturn(kRefReg);
+  RegLocation rl_dest = InlineTarget(info);
+  StoreValue(rl_dest, rl_return);
+  return true;
+}
+
+bool Mir2Lir::GenInlinedStringFactoryNewStringFromString(CallInfo* info) {
+  if (cu_->instruction_set == kMips) {
+    // TODO - add Mips implementation
+    return false;
+  }
+  RegLocation rl_string = info->args[0];
+  rl_string = LoadValue(rl_string, kRefReg);
+  LIR* string_null_check_branch = OpCmpImmBranch(kCondEq, rl_string.reg, 0, nullptr);
+  AddIntrinsicSlowPath(info, string_null_check_branch);
+  CallRuntimeHelperRegLocation(kQuickAllocStringFromString, rl_string, true);
+  RegLocation rl_return = GetReturn(kRefReg);
+  RegLocation rl_dest = InlineTarget(info);
+  StoreValue(rl_dest, rl_return);
+  return true;
+}
+
 bool Mir2Lir::GenInlinedReverseBytes(CallInfo* info, OpSize size) {
   if (cu_->instruction_set == kMips || cu_->instruction_set == kMips64) {
     // TODO: add Mips and Mips64 implementations.
@@ -1451,9 +1547,22 @@
   LockCallTemps();
 
   const MirMethodLoweringInfo& method_info = mir_graph_->GetMethodLoweringInfo(info->mir);
+  MethodReference target_method = method_info.GetTargetMethod();
   cu_->compiler_driver->ProcessedInvoke(method_info.GetInvokeType(), method_info.StatsFlags());
   InvokeType original_type = static_cast<InvokeType>(method_info.GetInvokeType());
   info->type = method_info.GetSharpType();
+  bool is_string_init = false;
+  if (method_info.IsSpecial()) {
+    DexFileMethodInliner* inliner = cu_->compiler_driver->GetMethodInlinerMap()->GetMethodInliner(
+        target_method.dex_file);
+    if (inliner->IsStringInitMethodIndex(target_method.dex_method_index)) {
+      is_string_init = true;
+      size_t pointer_size = GetInstructionSetPointerSize(cu_->instruction_set);
+      info->string_init_offset = inliner->GetOffsetForStringInit(target_method.dex_method_index,
+                                                                 pointer_size);
+      info->type = kStatic;
+    }
+  }
   bool fast_path = method_info.FastPath();
   bool skip_this;
 
@@ -1478,7 +1587,6 @@
     next_call_insn = fast_path ? NextVCallInsn : NextVCallInsnSP;
     skip_this = fast_path;
   }
-  MethodReference target_method = method_info.GetTargetMethod();
   call_state = GenDalvikArgs(info, call_state, p_null_ck,
                              next_call_insn, target_method, method_info.VTableIndex(),
                              method_info.DirectCode(), method_info.DirectMethod(),
@@ -1495,7 +1603,7 @@
   FreeCallTemps();
   if (info->result.location != kLocInvalid) {
     // We have a following MOVE_RESULT - do it now.
-    RegisterClass reg_class =
+    RegisterClass reg_class = is_string_init ? kRefReg :
         ShortyToRegClass(mir_graph_->GetShortyFromMethodReference(info->method_ref)[0]);
     if (info->result.wide) {
       RegLocation ret_loc = GetReturnWide(reg_class);
diff --git a/compiler/dex/quick/mips/call_mips.cc b/compiler/dex/quick/mips/call_mips.cc
index 39b9cc7..3d25384 100644
--- a/compiler/dex/quick/mips/call_mips.cc
+++ b/compiler/dex/quick/mips/call_mips.cc
@@ -20,7 +20,9 @@
 
 #include "base/logging.h"
 #include "dex/mir_graph.h"
+#include "dex/quick/dex_file_to_method_inliner_map.h"
 #include "dex/quick/mir_to_lir-inl.h"
+#include "driver/compiler_driver.h"
 #include "entrypoints/quick/quick_entrypoints.h"
 #include "gc/accounting/card_table.h"
 #include "mips_lir.h"
@@ -397,11 +399,28 @@
  * Bit of a hack here - in the absence of a real scheduling pass,
  * emit the next instruction in static & direct invoke sequences.
  */
-static int NextSDCallInsn(CompilationUnit* cu, CallInfo* info ATTRIBUTE_UNUSED, int state,
+static int NextSDCallInsn(CompilationUnit* cu, CallInfo* info, int state,
                           const MethodReference& target_method, uint32_t, uintptr_t direct_code,
                           uintptr_t direct_method, InvokeType type) {
   Mir2Lir* cg = static_cast<Mir2Lir*>(cu->cg.get());
-  if (direct_code != 0 && direct_method != 0) {
+  if (info->string_init_offset != 0) {
+    RegStorage arg0_ref = cg->TargetReg(kArg0, kRef);
+    switch (state) {
+    case 0: {  // Grab target method* from thread pointer
+      cg->LoadRefDisp(cg->TargetPtrReg(kSelf), info->string_init_offset, arg0_ref, kNotVolatile);
+      break;
+    }
+    case 1:  // Grab the code from the method*
+      if (direct_code == 0) {
+        int32_t offset = mirror::ArtMethod::EntryPointFromQuickCompiledCodeOffset(
+            InstructionSetPointerSize(cu->instruction_set)).Int32Value();
+        cg->LoadWordDisp(arg0_ref, offset, cg->TargetPtrReg(kInvokeTgt));
+      }
+      break;
+    default:
+      return -1;
+    }
+  } else if (direct_code != 0 && direct_method != 0) {
     switch (state) {
       case 0:  // Get the current Method* [sets kArg0]
         if (direct_code != static_cast<uintptr_t>(-1)) {
diff --git a/compiler/dex/quick/mir_to_lir.h b/compiler/dex/quick/mir_to_lir.h
index 6f227fc..a07274f 100644
--- a/compiler/dex/quick/mir_to_lir.h
+++ b/compiler/dex/quick/mir_to_lir.h
@@ -897,6 +897,10 @@
                                                             RegLocation arg0, RegLocation arg1,
                                                             RegLocation arg2,
                                                             bool safepoint_pc);
+    void CallRuntimeHelperRegLocationRegLocationRegLocationRegLocation(
+        QuickEntrypointEnum trampoline, RegLocation arg0, RegLocation arg1,
+        RegLocation arg2, RegLocation arg3, bool safepoint_pc);
+
     void GenInvoke(CallInfo* info);
     void GenInvokeNoInline(CallInfo* info);
     virtual NextCallInsn GetNextSDCallInsn() = 0;
@@ -937,7 +941,11 @@
 
     bool GenInlinedReferenceGetReferent(CallInfo* info);
     virtual bool GenInlinedCharAt(CallInfo* info);
+    bool GenInlinedStringGetCharsNoCheck(CallInfo* info);
     bool GenInlinedStringIsEmptyOrLength(CallInfo* info, bool is_empty);
+    bool GenInlinedStringFactoryNewStringFromBytes(CallInfo* info);
+    bool GenInlinedStringFactoryNewStringFromChars(CallInfo* info);
+    bool GenInlinedStringFactoryNewStringFromString(CallInfo* info);
     virtual bool GenInlinedReverseBits(CallInfo* info, OpSize size);
     bool GenInlinedReverseBytes(CallInfo* info, OpSize size);
     virtual bool GenInlinedAbsInt(CallInfo* info);
diff --git a/compiler/dex/quick/x86/call_x86.cc b/compiler/dex/quick/x86/call_x86.cc
index e2364d8..2495757 100644
--- a/compiler/dex/quick/x86/call_x86.cc
+++ b/compiler/dex/quick/x86/call_x86.cc
@@ -19,6 +19,7 @@
 #include "codegen_x86.h"
 
 #include "base/logging.h"
+#include "dex/quick/dex_file_to_method_inliner_map.h"
 #include "dex/quick/mir_to_lir-inl.h"
 #include "driver/compiler_driver.h"
 #include "driver/compiler_options.h"
@@ -343,11 +344,20 @@
 int X86Mir2Lir::X86NextSDCallInsn(CompilationUnit* cu, CallInfo* info,
                                   int state, const MethodReference& target_method,
                                   uint32_t,
-                                  uintptr_t direct_code, uintptr_t direct_method,
+                                  uintptr_t direct_code ATTRIBUTE_UNUSED, uintptr_t direct_method,
                                   InvokeType type) {
-  UNUSED(info, direct_code);
   X86Mir2Lir* cg = static_cast<X86Mir2Lir*>(cu->cg.get());
-  if (direct_method != 0) {
+  if (info->string_init_offset != 0) {
+    RegStorage arg0_ref = cg->TargetReg(kArg0, kRef);
+    switch (state) {
+    case 0: {  // Grab target method* from thread pointer
+      cg->NewLIR2(kX86Mov32RT, arg0_ref.GetReg(), info->string_init_offset);
+      break;
+    }
+    default:
+      return -1;
+    }
+  } else if (direct_method != 0) {
     switch (state) {
     case 0:  // Get the current Method* [sets kArg0]
       if (direct_method != static_cast<uintptr_t>(-1)) {
diff --git a/compiler/dex/quick/x86/target_x86.cc b/compiler/dex/quick/x86/target_x86.cc
index b460379..2f211da 100755
--- a/compiler/dex/quick/x86/target_x86.cc
+++ b/compiler/dex/quick/x86/target_x86.cc
@@ -1302,10 +1302,6 @@
   int value_offset = mirror::String::ValueOffset().Int32Value();
   // Location of count within the String object.
   int count_offset = mirror::String::CountOffset().Int32Value();
-  // Starting offset within data array.
-  int offset_offset = mirror::String::OffsetOffset().Int32Value();
-  // Start of char data with array_.
-  int data_offset = mirror::Array::DataOffset(sizeof(uint16_t)).Int32Value();
 
   // Compute the number of words to search in to rCX.
   Load32Disp(rs_rDX, count_offset, rs_rCX);
@@ -1388,15 +1384,13 @@
 
   // Load the address of the string into EDI.
   // In case of start index we have to add the address to existing value in EDI.
-  // The string starts at VALUE(String) + 2 * OFFSET(String) + DATA_OFFSET.
   if (zero_based || (!zero_based && rl_start.is_const && start_value == 0)) {
-    Load32Disp(rs_rDX, offset_offset, rs_rDI);
+    OpRegRegImm(kOpAdd, rs_rDI, rs_rDX, value_offset);
   } else {
-    OpRegMem(kOpAdd, rs_rDI, rs_rDX, offset_offset);
+    OpRegImm(kOpLsl, rs_rDI, 1);
+    OpRegReg(kOpAdd, rs_rDI, rs_rDX);
+    OpRegImm(kOpAdd, rs_rDI, value_offset);
   }
-  OpRegImm(kOpLsl, rs_rDI, 1);
-  OpRegMem(kOpAdd, rs_rDI, rs_rDX, value_offset);
-  OpRegImm(kOpAdd, rs_rDI, data_offset);
 
   // EDI now contains the start of the string to be searched.
   // We are all prepared to do the search for the character.
@@ -2423,24 +2417,15 @@
   int value_offset = mirror::String::ValueOffset().Int32Value();
   // Location of count
   int count_offset = mirror::String::CountOffset().Int32Value();
-  // Starting offset within data array
-  int offset_offset = mirror::String::OffsetOffset().Int32Value();
-  // Start of char data with array_
-  int data_offset = mirror::Array::DataOffset(sizeof(uint16_t)).Int32Value();
 
   RegLocation rl_obj = info->args[0];
   RegLocation rl_idx = info->args[1];
   rl_obj = LoadValue(rl_obj, kRefReg);
-  // X86 wants to avoid putting a constant index into a register.
-  if (!rl_idx.is_const) {
-    rl_idx = LoadValue(rl_idx, kCoreReg);
-  }
+  rl_idx = LoadValue(rl_idx, kCoreReg);
   RegStorage reg_max;
   GenNullCheck(rl_obj.reg, info->opt_flags);
   bool range_check = (!(info->opt_flags & MIR_IGNORE_RANGE_CHECK));
   LIR* range_check_branch = nullptr;
-  RegStorage reg_off;
-  RegStorage reg_ptr;
   if (range_check) {
     // On x86, we can compare to memory directly
     // Set up a launch pad to allow retry in case of bounds violation */
@@ -2456,24 +2441,11 @@
       range_check_branch = OpCondBranch(kCondUge, nullptr);
     }
   }
-  reg_off = AllocTemp();
-  reg_ptr = AllocTempRef();
-  Load32Disp(rl_obj.reg, offset_offset, reg_off);
-  LoadRefDisp(rl_obj.reg, value_offset, reg_ptr, kNotVolatile);
-  if (rl_idx.is_const) {
-    OpRegImm(kOpAdd, reg_off, mir_graph_->ConstantValue(rl_idx.orig_sreg));
-  } else {
-    OpRegReg(kOpAdd, reg_off, rl_idx.reg);
-  }
-  FreeTemp(rl_obj.reg);
-  if (rl_idx.location == kLocPhysReg) {
-    FreeTemp(rl_idx.reg);
-  }
   RegLocation rl_dest = InlineTarget(info);
   RegLocation rl_result = EvalLoc(rl_dest, kCoreReg, true);
-  LoadBaseIndexedDisp(reg_ptr, reg_off, 1, data_offset, rl_result.reg, kUnsignedHalf);
-  FreeTemp(reg_off);
-  FreeTemp(reg_ptr);
+  LoadBaseIndexedDisp(rl_obj.reg, rl_idx.reg, 1, value_offset, rl_result.reg, kUnsignedHalf);
+  FreeTemp(rl_idx.reg);
+  FreeTemp(rl_obj.reg);
   StoreValue(rl_dest, rl_result);
   if (range_check) {
     DCHECK(range_check_branch != nullptr);
diff --git a/compiler/dex/verified_method.cc b/compiler/dex/verified_method.cc
index 7eba515..e788261 100644
--- a/compiler/dex/verified_method.cc
+++ b/compiler/dex/verified_method.cc
@@ -64,6 +64,9 @@
   if (method_verifier->HasCheckCasts()) {
     verified_method->GenerateSafeCastSet(method_verifier);
   }
+
+  verified_method->SetStringInitPcRegMap(method_verifier->GetStringInitPcRegMap());
+
   return verified_method.release();
 }
 
diff --git a/compiler/dex/verified_method.h b/compiler/dex/verified_method.h
index ad07639..242e3df 100644
--- a/compiler/dex/verified_method.h
+++ b/compiler/dex/verified_method.h
@@ -75,6 +75,13 @@
     return has_verification_failures_;
   }
 
+  void SetStringInitPcRegMap(SafeMap<uint32_t, std::set<uint32_t>>& string_init_pc_reg_map) {
+    string_init_pc_reg_map_ = string_init_pc_reg_map;
+  }
+  const SafeMap<uint32_t, std::set<uint32_t>>& GetStringInitPcRegMap() const {
+    return string_init_pc_reg_map_;
+  }
+
  private:
   VerifiedMethod() = default;
 
@@ -114,6 +121,10 @@
   SafeCastSet safe_cast_set_;
 
   bool has_verification_failures_;
+
+  // Copy of mapping generated by verifier of dex PCs of string init invocations
+  // to the set of other registers that the receiver has been copied into.
+  SafeMap<uint32_t, std::set<uint32_t>> string_init_pc_reg_map_;
 };
 
 }  // namespace art
diff --git a/compiler/driver/compiler_driver.cc b/compiler/driver/compiler_driver.cc
index c858326..47288b5 100644
--- a/compiler/driver/compiler_driver.cc
+++ b/compiler/driver/compiler_driver.cc
@@ -40,6 +40,7 @@
 #include "dex/verification_results.h"
 #include "dex/verified_method.h"
 #include "dex/quick/dex_file_method_inliner.h"
+#include "dex/quick/dex_file_to_method_inliner_map.h"
 #include "driver/compiler_options.h"
 #include "elf_writer_quick.h"
 #include "jni_internal.h"
@@ -2485,4 +2486,16 @@
   return oss.str();
 }
 
+bool CompilerDriver::IsStringTypeIndex(uint16_t type_index, const DexFile* dex_file) {
+  const char* type = dex_file->GetTypeDescriptor(dex_file->GetTypeId(type_index));
+  return strcmp(type, "Ljava/lang/String;") == 0;
+}
+
+bool CompilerDriver::IsStringInit(uint32_t method_index, const DexFile* dex_file, int32_t* offset) {
+  DexFileMethodInliner* inliner = GetMethodInlinerMap()->GetMethodInliner(dex_file);
+  size_t pointer_size = InstructionSetPointerSize(GetInstructionSet());
+  *offset = inliner->GetOffsetForStringInit(method_index, pointer_size);
+  return inliner->IsStringInitMethodIndex(method_index);
+}
+
 }  // namespace art
diff --git a/compiler/driver/compiler_driver.h b/compiler/driver/compiler_driver.h
index 02de11e..2b0985a 100644
--- a/compiler/driver/compiler_driver.h
+++ b/compiler/driver/compiler_driver.h
@@ -466,6 +466,9 @@
   // Get memory usage during compilation.
   std::string GetMemoryUsageString(bool extended) const;
 
+  bool IsStringTypeIndex(uint16_t type_index, const DexFile* dex_file);
+  bool IsStringInit(uint32_t method_index, const DexFile* dex_file, int32_t* offset);
+
   void SetHadHardVerifierFailure() {
     had_hard_verifier_failure_ = true;
   }
diff --git a/compiler/image_writer.cc b/compiler/image_writer.cc
index fc70d8f..4dc7509 100644
--- a/compiler/image_writer.cc
+++ b/compiler/image_writer.cc
@@ -89,7 +89,12 @@
     Thread::Current()->TransitionFromSuspendedToRunnable();
     PruneNonImageClasses();  // Remove junk
     ComputeLazyFieldsForImageClasses();  // Add useful information
-    ProcessStrings();
+
+    // Calling this can in theory fill in some resolved strings. However, in practice it seems to
+    // never resolve any.
+    if (kComputeEagerResolvedStrings) {
+      ComputeEagerResolvedStrings();
+    }
     Thread::Current()->TransitionFromRunnableToSuspended(kNative);
   }
   gc::Heap* heap = Runtime::Current()->GetHeap();
@@ -529,14 +534,6 @@
   return true;
 }
 
-// Count the number of strings in the heap and put the result in arg as a size_t pointer.
-static void CountStringsCallback(Object* obj, void* arg)
-    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-  if (obj->GetClass()->IsStringClass()) {
-    ++*reinterpret_cast<size_t*>(arg);
-  }
-}
-
 // Collect all the java.lang.String in the heap and put them in the output strings_ array.
 class StringCollector {
  public:
@@ -566,99 +563,19 @@
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
     mirror::String* lhs_s = lhs.AsMirrorPtr();
     mirror::String* rhs_s = rhs.AsMirrorPtr();
-    uint16_t* lhs_begin = lhs_s->GetCharArray()->GetData() + lhs_s->GetOffset();
-    uint16_t* rhs_begin = rhs_s->GetCharArray()->GetData() + rhs_s->GetOffset();
+    uint16_t* lhs_begin = lhs_s->GetValue();
+    uint16_t* rhs_begin = rhs_s->GetValue();
     return std::lexicographical_compare(lhs_begin, lhs_begin + lhs_s->GetLength(),
                                         rhs_begin, rhs_begin + rhs_s->GetLength());
   }
 };
 
-static bool IsPrefix(mirror::String* pref, mirror::String* full)
-    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-  if (pref->GetLength() > full->GetLength()) {
-    return false;
-  }
-  uint16_t* pref_begin = pref->GetCharArray()->GetData() + pref->GetOffset();
-  uint16_t* full_begin = full->GetCharArray()->GetData() + full->GetOffset();
-  return std::equal(pref_begin, pref_begin + pref->GetLength(), full_begin);
-}
-
-void ImageWriter::ProcessStrings() {
-  size_t total_strings = 0;
-  gc::Heap* heap = Runtime::Current()->GetHeap();
-  ClassLinker* cl = Runtime::Current()->GetClassLinker();
-  // Count the strings.
-  heap->VisitObjects(CountStringsCallback, &total_strings);
-  Thread* self = Thread::Current();
-  StackHandleScope<1> hs(self);
-  auto strings = hs.NewHandle(cl->AllocStringArray(self, total_strings));
-  StringCollector string_collector(strings, 0U);
-  // Read strings into the array.
-  heap->VisitObjects(StringCollector::Callback, &string_collector);
-  // Some strings could have gotten freed if AllocStringArray caused a GC.
-  CHECK_LE(string_collector.GetIndex(), total_strings);
-  total_strings = string_collector.GetIndex();
-  auto* strings_begin = reinterpret_cast<mirror::HeapReference<mirror::String>*>(
-          strings->GetRawData(sizeof(mirror::HeapReference<mirror::String>), 0));
-  std::sort(strings_begin, strings_begin + total_strings, LexicographicalStringComparator());
-  // Characters of strings which are non equal prefix of another string (not the same string).
-  // We don't count the savings from equal strings since these would get interned later anyways.
-  size_t prefix_saved_chars = 0;
-  // Count characters needed for the strings.
-  size_t num_chars = 0u;
-  mirror::String* prev_s = nullptr;
-  for (size_t idx = 0; idx != total_strings; ++idx) {
-    mirror::String* s = strings->GetWithoutChecks(idx);
-    size_t length = s->GetLength();
-    num_chars += length;
-    if (prev_s != nullptr && IsPrefix(prev_s, s)) {
-      size_t prev_length = prev_s->GetLength();
-      num_chars -= prev_length;
-      if (prev_length != length) {
-        prefix_saved_chars += prev_length;
-      }
-    }
-    prev_s = s;
-  }
-  // Create character array, copy characters and point the strings there.
-  mirror::CharArray* array = mirror::CharArray::Alloc(self, num_chars);
-  string_data_array_ = array;
-  uint16_t* array_data = array->GetData();
-  size_t pos = 0u;
-  prev_s = nullptr;
-  for (size_t idx = 0; idx != total_strings; ++idx) {
-    mirror::String* s = strings->GetWithoutChecks(idx);
-    uint16_t* s_data = s->GetCharArray()->GetData() + s->GetOffset();
-    int32_t s_length = s->GetLength();
-    int32_t prefix_length = 0u;
-    if (idx != 0u && IsPrefix(prev_s, s)) {
-      prefix_length = prev_s->GetLength();
-    }
-    memcpy(array_data + pos, s_data + prefix_length, (s_length - prefix_length) * sizeof(*s_data));
-    s->SetOffset(pos - prefix_length);
-    s->SetArray(array);
-    pos += s_length - prefix_length;
-    prev_s = s;
-  }
-  CHECK_EQ(pos, num_chars);
-
-  if (kIsDebugBuild || VLOG_IS_ON(compiler)) {
-    LOG(INFO) << "Total # image strings=" << total_strings << " combined length="
-        << num_chars << " prefix saved chars=" << prefix_saved_chars;
-  }
-  // Calling this can in theory fill in some resolved strings. However, in practice it seems to
-  // never resolve any.
-  if (kComputeEagerResolvedStrings) {
-    ComputeEagerResolvedStrings();
-  }
-}
-
 void ImageWriter::ComputeEagerResolvedStringsCallback(Object* obj, void* arg ATTRIBUTE_UNUSED) {
   if (!obj->GetClass()->IsStringClass()) {
     return;
   }
   mirror::String* string = obj->AsString();
-  const uint16_t* utf16_string = string->GetCharArray()->GetData() + string->GetOffset();
+  const uint16_t* utf16_string = string->GetValue();
   size_t utf16_length = static_cast<size_t>(string->GetLength());
   ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
   ReaderMutexLock mu(Thread::Current(), *class_linker->DexLock());
diff --git a/compiler/image_writer.h b/compiler/image_writer.h
index a2d99ee..c0cffa5 100644
--- a/compiler/image_writer.h
+++ b/compiler/image_writer.h
@@ -220,9 +220,6 @@
   static void ComputeEagerResolvedStringsCallback(mirror::Object* obj, void* arg)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
-  // Combine string char arrays.
-  void ProcessStrings() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
-
   // Remove unwanted classes from various roots.
   void PruneNonImageClasses() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
   static bool NonImageClassesVisitor(mirror::Class* c, void* arg)
diff --git a/compiler/oat_test.cc b/compiler/oat_test.cc
index 925b507..dbdcc96 100644
--- a/compiler/oat_test.cc
+++ b/compiler/oat_test.cc
@@ -176,7 +176,7 @@
   EXPECT_EQ(72U, sizeof(OatHeader));
   EXPECT_EQ(4U, sizeof(OatMethodOffsets));
   EXPECT_EQ(28U, sizeof(OatQuickMethodHeader));
-  EXPECT_EQ(92 * GetInstructionSetPointerSize(kRuntimeISA), sizeof(QuickEntryPoints));
+  EXPECT_EQ(111 * GetInstructionSetPointerSize(kRuntimeISA), sizeof(QuickEntryPoints));
 }
 
 TEST_F(OatTest, OatHeaderIsValid) {
diff --git a/compiler/optimizing/builder.cc b/compiler/optimizing/builder.cc
index 96e08fd..a883bd0 100644
--- a/compiler/optimizing/builder.cc
+++ b/compiler/optimizing/builder.cc
@@ -19,6 +19,7 @@
 #include "art_field-inl.h"
 #include "base/logging.h"
 #include "class_linker.h"
+#include "dex/verified_method.h"
 #include "dex_file-inl.h"
 #include "dex_instruction-inl.h"
 #include "dex/verified_method.h"
@@ -612,6 +613,16 @@
       HInvokeStaticOrDirect::ClinitCheckRequirement::kImplicit;
   // Potential class initialization check, in the case of a static method call.
   HClinitCheck* clinit_check = nullptr;
+  // Replace calls to String.<init> with StringFactory.
+  int32_t string_init_offset = 0;
+  bool is_string_init = compiler_driver_->IsStringInit(method_idx, dex_file_, &string_init_offset);
+  if (is_string_init) {
+    return_type = Primitive::kPrimNot;
+    is_instance_call = false;
+    number_of_arguments--;
+    invoke_type = kStatic;
+    optimized_invoke_type = kStatic;
+  }
 
   HInvoke* invoke = nullptr;
 
@@ -698,7 +709,8 @@
 
     invoke = new (arena_) HInvokeStaticOrDirect(
         arena_, number_of_arguments, return_type, dex_pc, target_method.dex_method_index,
-        is_recursive, invoke_type, optimized_invoke_type, clinit_check_requirement);
+        is_recursive, string_init_offset, invoke_type, optimized_invoke_type,
+        clinit_check_requirement);
   }
 
   size_t start_index = 0;
@@ -714,6 +726,9 @@
 
   uint32_t descriptor_index = 1;
   uint32_t argument_index = start_index;
+  if (is_string_init) {
+    start_index = 1;
+  }
   for (size_t i = start_index; i < number_of_vreg_arguments; i++, argument_index++) {
     Primitive::Type type = Primitive::GetType(descriptor[descriptor_index++]);
     bool is_wide = (type == Primitive::kPrimLong) || (type == Primitive::kPrimDouble);
@@ -740,6 +755,28 @@
   DCHECK_EQ(argument_index, number_of_arguments);
   current_block_->AddInstruction(invoke);
   latest_result_ = invoke;
+
+  // Add move-result for StringFactory method.
+  if (is_string_init) {
+    uint32_t orig_this_reg = is_range ? register_index : args[0];
+    const VerifiedMethod* verified_method =
+        compiler_driver_->GetVerifiedMethod(dex_file_, dex_compilation_unit_->GetDexMethodIndex());
+    if (verified_method == nullptr) {
+      LOG(WARNING) << "No verified method for method calling String.<init>: "
+                   << PrettyMethod(dex_compilation_unit_->GetDexMethodIndex(), *dex_file_);
+      return false;
+    }
+    const SafeMap<uint32_t, std::set<uint32_t>>& string_init_map =
+        verified_method->GetStringInitPcRegMap();
+    auto map_it = string_init_map.find(dex_pc);
+    if (map_it != string_init_map.end()) {
+      std::set<uint32_t> reg_set = map_it->second;
+      for (auto set_it = reg_set.begin(); set_it != reg_set.end(); ++set_it) {
+        UpdateLocal(*set_it, invoke);
+      }
+    }
+    UpdateLocal(orig_this_reg, invoke);
+  }
   return true;
 }
 
@@ -1916,12 +1953,19 @@
 
     case Instruction::NEW_INSTANCE: {
       uint16_t type_index = instruction.VRegB_21c();
-      QuickEntrypointEnum entrypoint = NeedsAccessCheck(type_index)
-          ? kQuickAllocObjectWithAccessCheck
-          : kQuickAllocObject;
+      if (compiler_driver_->IsStringTypeIndex(type_index, dex_file_)) {
+        // Turn new-instance of string into a const 0.
+        int32_t register_index = instruction.VRegA();
+        HNullConstant* constant = graph_->GetNullConstant();
+        UpdateLocal(register_index, constant);
+      } else {
+        QuickEntrypointEnum entrypoint = NeedsAccessCheck(type_index)
+            ? kQuickAllocObjectWithAccessCheck
+            : kQuickAllocObject;
 
-      current_block_->AddInstruction(new (arena_) HNewInstance(dex_pc, type_index, entrypoint));
-      UpdateLocal(instruction.VRegA(), current_block_->GetLastInstruction());
+        current_block_->AddInstruction(new (arena_) HNewInstance(dex_pc, type_index, entrypoint));
+        UpdateLocal(instruction.VRegA(), current_block_->GetLastInstruction());
+      }
       break;
     }
 
diff --git a/compiler/optimizing/code_generator_arm.cc b/compiler/optimizing/code_generator_arm.cc
index 01748a9..bcdfccd 100644
--- a/compiler/optimizing/code_generator_arm.cc
+++ b/compiler/optimizing/code_generator_arm.cc
@@ -4071,15 +4071,9 @@
   //
   // 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()));
+  if (invoke->IsStringInit()) {
+    // temp = thread->string_init_entrypoint
+    __ LoadFromOffset(kLoadWord, temp, TR, invoke->GetStringInitOffset());
     // LR = temp[offset_of_quick_compiled_code]
     __ LoadFromOffset(kLoadWord, LR, temp,
                       mirror::ArtMethod::EntryPointFromQuickCompiledCodeOffset(
@@ -4087,7 +4081,24 @@
     // LR()
     __ blx(LR);
   } else {
-    __ bl(GetFrameEntryLabel());
+    // 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());
+    }
   }
 
   DCHECK(!IsLeafMethod());
diff --git a/compiler/optimizing/code_generator_arm64.cc b/compiler/optimizing/code_generator_arm64.cc
index dada4ce..0d963d7 100644
--- a/compiler/optimizing/code_generator_arm64.cc
+++ b/compiler/optimizing/code_generator_arm64.cc
@@ -2006,20 +2006,30 @@
   //
   // 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_;
-    __ Ldr(temp, HeapOperand(temp, mirror::ArtMethod::DexCacheResolvedMethodsOffset()));
-    // temp = temp[index_in_cache];
-    __ Ldr(temp, HeapOperand(temp, index_in_cache));
-    // lr = temp->entry_point_from_quick_compiled_code_;
+  if (invoke->IsStringInit()) {
+    // temp = thread->string_init_entrypoint
+    __ Ldr(temp, HeapOperand(tr, invoke->GetStringInitOffset()));
+    // LR = temp->entry_point_from_quick_compiled_code_;
     __ Ldr(lr, HeapOperand(temp, mirror::ArtMethod::EntryPointFromQuickCompiledCodeOffset(
         kArm64WordSize)));
-    // lr();
+    // lr()
     __ Blr(lr);
   } else {
-    __ Bl(&frame_entry_label_);
+    // temp = method;
+    LoadCurrentMethod(temp);
+    if (!invoke->IsRecursive()) {
+      // temp = temp->dex_cache_resolved_methods_;
+      __ Ldr(temp, HeapOperand(temp, mirror::ArtMethod::DexCacheResolvedMethodsOffset()));
+      // temp = temp[index_in_cache];
+      __ Ldr(temp, HeapOperand(temp, index_in_cache));
+      // lr = temp->entry_point_from_quick_compiled_code_;
+      __ Ldr(lr, HeapOperand(temp, mirror::ArtMethod::EntryPointFromQuickCompiledCodeOffset(
+          kArm64WordSize)));
+      // lr();
+      __ Blr(lr);
+    } else {
+      __ Bl(&frame_entry_label_);
+    }
   }
 
   DCHECK(!IsLeafMethod());
diff --git a/compiler/optimizing/code_generator_x86.cc b/compiler/optimizing/code_generator_x86.cc
index 04999be..a037040 100644
--- a/compiler/optimizing/code_generator_x86.cc
+++ b/compiler/optimizing/code_generator_x86.cc
@@ -3114,18 +3114,27 @@
   // 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_;
-    __ movl(temp, Address(temp, mirror::ArtMethod::DexCacheResolvedMethodsOffset().Int32Value()));
-    // temp = temp[index_in_cache]
-    __ movl(temp, Address(temp, CodeGenerator::GetCacheOffset(invoke->GetDexMethodIndex())));
+
+  if (invoke->IsStringInit()) {
+    // temp = thread->string_init_entrypoint
+    __ fs()->movl(temp, Address::Absolute(invoke->GetStringInitOffset()));
     // (temp + offset_of_quick_compiled_code)()
     __ call(Address(
         temp, mirror::ArtMethod::EntryPointFromQuickCompiledCodeOffset(kX86WordSize).Int32Value()));
   } else {
-    __ call(GetFrameEntryLabel());
+    // temp = method;
+    LoadCurrentMethod(temp);
+    if (!invoke->IsRecursive()) {
+      // temp = temp->dex_cache_resolved_methods_;
+      __ movl(temp, Address(temp, mirror::ArtMethod::DexCacheResolvedMethodsOffset().Int32Value()));
+      // temp = temp[index_in_cache]
+      __ movl(temp, Address(temp, CodeGenerator::GetCacheOffset(invoke->GetDexMethodIndex())));
+      // (temp + offset_of_quick_compiled_code)()
+      __ call(Address(temp,
+          mirror::ArtMethod::EntryPointFromQuickCompiledCodeOffset(kX86WordSize).Int32Value()));
+    } else {
+      __ call(GetFrameEntryLabel());
+    }
   }
 
   DCHECK(!IsLeafMethod());
diff --git a/compiler/optimizing/code_generator_x86_64.cc b/compiler/optimizing/code_generator_x86_64.cc
index 5ce9329..f175283 100644
--- a/compiler/optimizing/code_generator_x86_64.cc
+++ b/compiler/optimizing/code_generator_x86_64.cc
@@ -366,18 +366,26 @@
   //
   // 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_;
-    __ movl(temp, Address(temp, mirror::ArtMethod::DexCacheResolvedMethodsOffset().SizeValue()));
-    // temp = temp[index_in_cache]
-    __ movl(temp, Address(temp, CodeGenerator::GetCacheOffset(invoke->GetDexMethodIndex())));
+  if (invoke->IsStringInit()) {
+    // temp = thread->string_init_entrypoint
+    __ gs()->movl(temp, Address::Absolute(invoke->GetStringInitOffset()));
     // (temp + offset_of_quick_compiled_code)()
     __ call(Address(temp, mirror::ArtMethod::EntryPointFromQuickCompiledCodeOffset(
         kX86_64WordSize).SizeValue()));
   } else {
-    __ call(&frame_entry_label_);
+    // temp = method;
+    LoadCurrentMethod(temp);
+    if (!invoke->IsRecursive()) {
+      // temp = temp->dex_cache_resolved_methods_;
+      __ movl(temp, Address(temp, mirror::ArtMethod::DexCacheResolvedMethodsOffset().SizeValue()));
+      // temp = temp[index_in_cache]
+      __ movl(temp, Address(temp, CodeGenerator::GetCacheOffset(invoke->GetDexMethodIndex())));
+      // (temp + offset_of_quick_compiled_code)()
+      __ call(Address(temp, mirror::ArtMethod::EntryPointFromQuickCompiledCodeOffset(
+          kX86_64WordSize).SizeValue()));
+    } else {
+      __ call(&frame_entry_label_);
+    }
   }
 
   DCHECK(!IsLeafMethod());
diff --git a/compiler/optimizing/code_generator_x86_64.h b/compiler/optimizing/code_generator_x86_64.h
index 6cdc822..e3fd5d7 100644
--- a/compiler/optimizing/code_generator_x86_64.h
+++ b/compiler/optimizing/code_generator_x86_64.h
@@ -37,7 +37,7 @@
 static constexpr size_t kParameterCoreRegistersLength = arraysize(kParameterCoreRegisters);
 static constexpr size_t kParameterFloatRegistersLength = arraysize(kParameterFloatRegisters);
 
-static constexpr Register kRuntimeParameterCoreRegisters[] = { RDI, RSI, RDX };
+static constexpr Register kRuntimeParameterCoreRegisters[] = { RDI, RSI, RDX, RCX };
 static constexpr size_t kRuntimeParameterCoreRegistersLength =
     arraysize(kRuntimeParameterCoreRegisters);
 static constexpr FloatRegister kRuntimeParameterFpuRegisters[] = { XMM0, XMM1 };
diff --git a/compiler/optimizing/intrinsics.cc b/compiler/optimizing/intrinsics.cc
index 20aa45f..5d3db5c 100644
--- a/compiler/optimizing/intrinsics.cc
+++ b/compiler/optimizing/intrinsics.cc
@@ -186,6 +186,8 @@
       return Intrinsics::kStringCharAt;
     case kIntrinsicCompareTo:
       return Intrinsics::kStringCompareTo;
+    case kIntrinsicGetCharsNoCheck:
+      return Intrinsics::kStringGetCharsNoCheck;
     case kIntrinsicIsEmptyOrLength:
       // The inliner can handle these two cases - and this is the preferred approach
       // since after inlining the call is no longer visible (as opposed to waiting
@@ -194,6 +196,12 @@
     case kIntrinsicIndexOf:
       return ((method.d.data & kIntrinsicFlagBase0) == 0) ?
           Intrinsics::kStringIndexOfAfter : Intrinsics::kStringIndexOf;
+    case kIntrinsicNewStringFromBytes:
+      return Intrinsics::kStringNewStringFromBytes;
+    case kIntrinsicNewStringFromChars:
+      return Intrinsics::kStringNewStringFromChars;
+    case kIntrinsicNewStringFromString:
+      return Intrinsics::kStringNewStringFromString;
 
     case kIntrinsicCas:
       switch (GetType(method.d.data, false)) {
@@ -280,6 +288,11 @@
     case kInlineOpIPut:
       return Intrinsics::kNone;
 
+    // String init cases, not intrinsics.
+
+    case kInlineStringInit:
+      return Intrinsics::kNone;
+
     // No default case to make the compiler warn on missing cases.
   }
   return Intrinsics::kNone;
diff --git a/compiler/optimizing/intrinsics_arm.cc b/compiler/optimizing/intrinsics_arm.cc
index abdf04e..27d2d43 100644
--- a/compiler/optimizing/intrinsics_arm.cc
+++ b/compiler/optimizing/intrinsics_arm.cc
@@ -48,7 +48,7 @@
 
   DCHECK_NE(type, Primitive::kPrimVoid);
 
-  if (Primitive::IsIntegralType(type)) {
+  if (Primitive::IsIntegralType(type) || type == Primitive::kPrimNot) {
     if (type == Primitive::kPrimLong) {
       Register trg_reg_lo = trg.AsRegisterPairLow<Register>();
       Register trg_reg_hi = trg.AsRegisterPairHigh<Register>();
@@ -810,10 +810,6 @@
   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.
@@ -835,15 +831,10 @@
   __ 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));
+  __ add(array_temp, obj, ShifterOperand(value_offset.Int32Value()));  // array_temp := str.value.
 
   // Load the value.
-  __ ldrh(out, Address(array_temp, temp, LSL, 1));                // out := array_temp[temp].
+  __ ldrh(out, Address(array_temp, idx, LSL, 1));                 // out := array_temp[idx].
 
   __ Bind(slow_path->GetExitLabel());
 }
@@ -878,6 +869,81 @@
   __ Bind(slow_path->GetExitLabel());
 }
 
+void IntrinsicLocationsBuilderARM::VisitStringNewStringFromBytes(HInvoke* invoke) {
+  LocationSummary* locations = new (arena_) LocationSummary(invoke,
+                                                            LocationSummary::kCall,
+                                                            kIntrinsified);
+  InvokeRuntimeCallingConvention calling_convention;
+  locations->SetInAt(0, Location::RegisterLocation(calling_convention.GetRegisterAt(0)));
+  locations->SetInAt(1, Location::RegisterLocation(calling_convention.GetRegisterAt(1)));
+  locations->SetInAt(2, Location::RegisterLocation(calling_convention.GetRegisterAt(2)));
+  locations->SetInAt(3, Location::RegisterLocation(calling_convention.GetRegisterAt(3)));
+  locations->SetOut(Location::RegisterLocation(R0));
+}
+
+void IntrinsicCodeGeneratorARM::VisitStringNewStringFromBytes(HInvoke* invoke) {
+  ArmAssembler* assembler = GetAssembler();
+  LocationSummary* locations = invoke->GetLocations();
+
+  Register byte_array = locations->InAt(0).AsRegister<Register>();
+  __ cmp(byte_array, ShifterOperand(0));
+  SlowPathCodeARM* slow_path = new (GetAllocator()) IntrinsicSlowPathARM(invoke);
+  codegen_->AddSlowPath(slow_path);
+  __ b(slow_path->GetEntryLabel(), EQ);
+
+  __ LoadFromOffset(
+      kLoadWord, LR, TR, QUICK_ENTRYPOINT_OFFSET(kArmWordSize, pAllocStringFromBytes).Int32Value());
+  codegen_->RecordPcInfo(invoke, invoke->GetDexPc());
+  __ blx(LR);
+  __ Bind(slow_path->GetExitLabel());
+}
+
+void IntrinsicLocationsBuilderARM::VisitStringNewStringFromChars(HInvoke* invoke) {
+  LocationSummary* locations = new (arena_) LocationSummary(invoke,
+                                                            LocationSummary::kCall,
+                                                            kIntrinsified);
+  InvokeRuntimeCallingConvention calling_convention;
+  locations->SetInAt(0, Location::RegisterLocation(calling_convention.GetRegisterAt(0)));
+  locations->SetInAt(1, Location::RegisterLocation(calling_convention.GetRegisterAt(1)));
+  locations->SetInAt(2, Location::RegisterLocation(calling_convention.GetRegisterAt(2)));
+  locations->SetOut(Location::RegisterLocation(R0));
+}
+
+void IntrinsicCodeGeneratorARM::VisitStringNewStringFromChars(HInvoke* invoke) {
+  ArmAssembler* assembler = GetAssembler();
+
+  __ LoadFromOffset(
+      kLoadWord, LR, TR, QUICK_ENTRYPOINT_OFFSET(kArmWordSize, pAllocStringFromChars).Int32Value());
+  codegen_->RecordPcInfo(invoke, invoke->GetDexPc());
+  __ blx(LR);
+}
+
+void IntrinsicLocationsBuilderARM::VisitStringNewStringFromString(HInvoke* invoke) {
+  LocationSummary* locations = new (arena_) LocationSummary(invoke,
+                                                            LocationSummary::kCall,
+                                                            kIntrinsified);
+  InvokeRuntimeCallingConvention calling_convention;
+  locations->SetInAt(0, Location::RegisterLocation(calling_convention.GetRegisterAt(0)));
+  locations->SetOut(Location::RegisterLocation(R0));
+}
+
+void IntrinsicCodeGeneratorARM::VisitStringNewStringFromString(HInvoke* invoke) {
+  ArmAssembler* assembler = GetAssembler();
+  LocationSummary* locations = invoke->GetLocations();
+
+  Register string_to_copy = locations->InAt(0).AsRegister<Register>();
+  __ cmp(string_to_copy, ShifterOperand(0));
+  SlowPathCodeARM* slow_path = new (GetAllocator()) IntrinsicSlowPathARM(invoke);
+  codegen_->AddSlowPath(slow_path);
+  __ b(slow_path->GetEntryLabel(), EQ);
+
+  __ LoadFromOffset(kLoadWord,
+      LR, TR, QUICK_ENTRYPOINT_OFFSET(kArmWordSize, pAllocStringFromString).Int32Value());
+  codegen_->RecordPcInfo(invoke, invoke->GetDexPc());
+  __ blx(LR);
+  __ Bind(slow_path->GetExitLabel());
+}
+
 // Unimplemented intrinsics.
 
 #define UNIMPLEMENTED_INTRINSIC(Name)                                                  \
@@ -907,6 +973,7 @@
 UNIMPLEMENTED_INTRINSIC(StringIndexOf)
 UNIMPLEMENTED_INTRINSIC(StringIndexOfAfter)
 UNIMPLEMENTED_INTRINSIC(ReferenceGetReferent)
+UNIMPLEMENTED_INTRINSIC(StringGetCharsNoCheck)
 
 }  // namespace arm
 }  // namespace art
diff --git a/compiler/optimizing/intrinsics_arm64.cc b/compiler/optimizing/intrinsics_arm64.cc
index 7a753b2..4f008e7 100644
--- a/compiler/optimizing/intrinsics_arm64.cc
+++ b/compiler/optimizing/intrinsics_arm64.cc
@@ -75,7 +75,7 @@
 
   DCHECK_NE(type, Primitive::kPrimVoid);
 
-  if (Primitive::IsIntegralType(type)) {
+  if (Primitive::IsIntegralType(type) || type == Primitive::kPrimNot) {
     Register trg_reg = RegisterFrom(trg, type);
     Register res_reg = RegisterFrom(ARM64ReturnLocation(type), type);
     __ Mov(trg_reg, res_reg, kDiscardForSameWReg);
@@ -953,10 +953,6 @@
   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 = WRegisterFrom(locations->InAt(0));  // String object pointer.
   Register idx = WRegisterFrom(locations->InAt(1));  // Index of character.
@@ -979,21 +975,15 @@
   __ Cmp(idx, temp);
   __ B(hs, slow_path->GetEntryLabel());
 
-  // Index computation.
-  __ Ldr(temp, HeapOperand(obj, offset_offset));         // temp := str.offset.
-  __ Ldr(array_temp, HeapOperand(obj, value_offset));    // array_temp := str.offset.
-  __ Add(temp, temp, idx);
-  DCHECK_EQ(data_offset.Int32Value() % 2, 0);            // We'll compensate by shifting.
-  __ Add(temp, temp, Operand(data_offset.Int32Value() / 2));
+  __ Add(array_temp, obj, Operand(value_offset.Int32Value()));  // array_temp := str.value.
 
   // Load the value.
-  __ Ldrh(out, MemOperand(array_temp.X(), temp, UXTW, 1));  // out := array_temp[temp].
+  __ Ldrh(out, MemOperand(array_temp.X(), idx, UXTW, 1));  // out := array_temp[idx].
 
   __ Bind(slow_path->GetExitLabel());
 }
 
 void IntrinsicLocationsBuilderARM64::VisitStringCompareTo(HInvoke* invoke) {
-  // The inputs plus one temp.
   LocationSummary* locations = new (arena_) LocationSummary(invoke,
                                                             LocationSummary::kCall,
                                                             kIntrinsified);
@@ -1022,6 +1012,84 @@
   __ Bind(slow_path->GetExitLabel());
 }
 
+void IntrinsicLocationsBuilderARM64::VisitStringNewStringFromBytes(HInvoke* invoke) {
+  LocationSummary* locations = new (arena_) LocationSummary(invoke,
+                                                            LocationSummary::kCall,
+                                                            kIntrinsified);
+  InvokeRuntimeCallingConvention calling_convention;
+  locations->SetInAt(0, LocationFrom(calling_convention.GetRegisterAt(0)));
+  locations->SetInAt(1, LocationFrom(calling_convention.GetRegisterAt(1)));
+  locations->SetInAt(2, LocationFrom(calling_convention.GetRegisterAt(2)));
+  locations->SetInAt(3, LocationFrom(calling_convention.GetRegisterAt(3)));
+  locations->SetOut(calling_convention.GetReturnLocation(Primitive::kPrimNot));
+}
+
+void IntrinsicCodeGeneratorARM64::VisitStringNewStringFromBytes(HInvoke* invoke) {
+  vixl::MacroAssembler* masm = GetVIXLAssembler();
+  LocationSummary* locations = invoke->GetLocations();
+
+  Register byte_array = WRegisterFrom(locations->InAt(0));
+  __ Cmp(byte_array, 0);
+  SlowPathCodeARM64* slow_path = new (GetAllocator()) IntrinsicSlowPathARM64(invoke);
+  codegen_->AddSlowPath(slow_path);
+  __ B(eq, slow_path->GetEntryLabel());
+
+  __ Ldr(lr,
+      MemOperand(tr, QUICK_ENTRYPOINT_OFFSET(kArm64WordSize, pAllocStringFromBytes).Int32Value()));
+  codegen_->RecordPcInfo(invoke, invoke->GetDexPc());
+  __ Blr(lr);
+  __ Bind(slow_path->GetExitLabel());
+}
+
+void IntrinsicLocationsBuilderARM64::VisitStringNewStringFromChars(HInvoke* invoke) {
+  LocationSummary* locations = new (arena_) LocationSummary(invoke,
+                                                            LocationSummary::kCall,
+                                                            kIntrinsified);
+  InvokeRuntimeCallingConvention calling_convention;
+  locations->SetInAt(0, LocationFrom(calling_convention.GetRegisterAt(0)));
+  locations->SetInAt(1, LocationFrom(calling_convention.GetRegisterAt(1)));
+  locations->SetInAt(2, LocationFrom(calling_convention.GetRegisterAt(2)));
+  locations->SetOut(calling_convention.GetReturnLocation(Primitive::kPrimNot));
+}
+
+void IntrinsicCodeGeneratorARM64::VisitStringNewStringFromChars(HInvoke* invoke) {
+  vixl::MacroAssembler* masm = GetVIXLAssembler();
+
+  __ Ldr(lr,
+      MemOperand(tr, QUICK_ENTRYPOINT_OFFSET(kArm64WordSize, pAllocStringFromChars).Int32Value()));
+  codegen_->RecordPcInfo(invoke, invoke->GetDexPc());
+  __ Blr(lr);
+}
+
+void IntrinsicLocationsBuilderARM64::VisitStringNewStringFromString(HInvoke* invoke) {
+  // The inputs plus one temp.
+  LocationSummary* locations = new (arena_) LocationSummary(invoke,
+                                                            LocationSummary::kCall,
+                                                            kIntrinsified);
+  InvokeRuntimeCallingConvention calling_convention;
+  locations->SetInAt(0, LocationFrom(calling_convention.GetRegisterAt(0)));
+  locations->SetInAt(1, LocationFrom(calling_convention.GetRegisterAt(1)));
+  locations->SetInAt(2, LocationFrom(calling_convention.GetRegisterAt(2)));
+  locations->SetOut(calling_convention.GetReturnLocation(Primitive::kPrimNot));
+}
+
+void IntrinsicCodeGeneratorARM64::VisitStringNewStringFromString(HInvoke* invoke) {
+  vixl::MacroAssembler* masm = GetVIXLAssembler();
+  LocationSummary* locations = invoke->GetLocations();
+
+  Register string_to_copy = WRegisterFrom(locations->InAt(0));
+  __ Cmp(string_to_copy, 0);
+  SlowPathCodeARM64* slow_path = new (GetAllocator()) IntrinsicSlowPathARM64(invoke);
+  codegen_->AddSlowPath(slow_path);
+  __ B(eq, slow_path->GetEntryLabel());
+
+  __ Ldr(lr,
+      MemOperand(tr, QUICK_ENTRYPOINT_OFFSET(kArm64WordSize, pAllocStringFromString).Int32Value()));
+  codegen_->RecordPcInfo(invoke, invoke->GetDexPc());
+  __ Blr(lr);
+  __ Bind(slow_path->GetExitLabel());
+}
+
 // Unimplemented intrinsics.
 
 #define UNIMPLEMENTED_INTRINSIC(Name)                                                  \
@@ -1034,6 +1102,7 @@
 UNIMPLEMENTED_INTRINSIC(StringIndexOf)
 UNIMPLEMENTED_INTRINSIC(StringIndexOfAfter)
 UNIMPLEMENTED_INTRINSIC(ReferenceGetReferent)
+UNIMPLEMENTED_INTRINSIC(StringGetCharsNoCheck)
 
 }  // namespace arm64
 }  // namespace art
diff --git a/compiler/optimizing/intrinsics_list.h b/compiler/optimizing/intrinsics_list.h
index 10f6e1d..2c9248f 100644
--- a/compiler/optimizing/intrinsics_list.h
+++ b/compiler/optimizing/intrinsics_list.h
@@ -60,8 +60,12 @@
   V(MemoryPokeShortNative, kStatic) \
   V(StringCharAt, kDirect) \
   V(StringCompareTo, kDirect) \
+  V(StringGetCharsNoCheck, kDirect) \
   V(StringIndexOf, kDirect) \
   V(StringIndexOfAfter, kDirect) \
+  V(StringNewStringFromBytes, kStatic) \
+  V(StringNewStringFromChars, kStatic) \
+  V(StringNewStringFromString, kStatic) \
   V(UnsafeCASInt, kDirect) \
   V(UnsafeCASLong, kDirect) \
   V(UnsafeCASObject, kDirect) \
diff --git a/compiler/optimizing/intrinsics_x86.cc b/compiler/optimizing/intrinsics_x86.cc
index 7275edb..b3e821c 100644
--- a/compiler/optimizing/intrinsics_x86.cc
+++ b/compiler/optimizing/intrinsics_x86.cc
@@ -910,23 +910,18 @@
   const int32_t value_offset = mirror::String::ValueOffset().Int32Value();
   // Location of count
   const int32_t count_offset = mirror::String::CountOffset().Int32Value();
-  // Starting offset within data array
-  const int32_t offset_offset = mirror::String::OffsetOffset().Int32Value();
-  // Start of char data with array_
-  const int32_t data_offset = mirror::Array::DataOffset(sizeof(uint16_t)).Int32Value();
 
   Register obj = locations->InAt(0).AsRegister<Register>();
   Register idx = locations->InAt(1).AsRegister<Register>();
   Register out = locations->Out().AsRegister<Register>();
-  Location temp_loc = locations->GetTemp(0);
-  Register temp = temp_loc.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).
 
-  SlowPathCodeX86* slow_path = new (GetAllocator()) IntrinsicSlowPathX86(invoke, temp);
+  SlowPathCodeX86* slow_path = new (GetAllocator()) IntrinsicSlowPathX86(
+      invoke, locations->GetTemp(0).AsRegister<Register>());
   codegen_->AddSlowPath(slow_path);
 
   X86Assembler* assembler = GetAssembler();
@@ -935,12 +930,8 @@
   codegen_->MaybeRecordImplicitNullCheck(invoke);
   __ j(kAboveEqual, slow_path->GetEntryLabel());
 
-  // Get the actual element.
-  __ movl(temp, idx);                          // temp := idx.
-  __ addl(temp, Address(obj, offset_offset));  // temp := offset + idx.
-  __ movl(out, Address(obj, value_offset));    // obj := obj.array.
-  // out = out[2*temp].
-  __ movzxw(out, Address(out, temp, ScaleFactor::TIMES_2, data_offset));
+  // out = out[2*idx].
+  __ movzxw(out, Address(out, idx, ScaleFactor::TIMES_2, value_offset));
 
   __ Bind(slow_path->GetExitLabel());
 }
@@ -976,6 +967,81 @@
   __ Bind(slow_path->GetExitLabel());
 }
 
+void IntrinsicLocationsBuilderX86::VisitStringNewStringFromBytes(HInvoke* invoke) {
+  LocationSummary* locations = new (arena_) LocationSummary(invoke,
+                                                            LocationSummary::kCall,
+                                                            kIntrinsified);
+  InvokeRuntimeCallingConvention calling_convention;
+  locations->SetInAt(0, Location::RegisterLocation(calling_convention.GetRegisterAt(0)));
+  locations->SetInAt(1, Location::RegisterLocation(calling_convention.GetRegisterAt(1)));
+  locations->SetInAt(2, Location::RegisterLocation(calling_convention.GetRegisterAt(2)));
+  locations->SetInAt(3, Location::RegisterLocation(calling_convention.GetRegisterAt(3)));
+  locations->SetOut(Location::RegisterLocation(EAX));
+  // Needs to be EAX for the invoke.
+  locations->AddTemp(Location::RegisterLocation(EAX));
+}
+
+void IntrinsicCodeGeneratorX86::VisitStringNewStringFromBytes(HInvoke* invoke) {
+  X86Assembler* assembler = GetAssembler();
+  LocationSummary* locations = invoke->GetLocations();
+
+  Register byte_array = locations->InAt(0).AsRegister<Register>();
+  __ testl(byte_array, byte_array);
+  SlowPathCodeX86* slow_path = new (GetAllocator()) IntrinsicSlowPathX86(
+      invoke, locations->GetTemp(0).AsRegister<Register>());
+  codegen_->AddSlowPath(slow_path);
+  __ j(kEqual, slow_path->GetEntryLabel());
+
+  __ fs()->call(Address::Absolute(QUICK_ENTRYPOINT_OFFSET(kX86WordSize, pAllocStringFromBytes)));
+  codegen_->RecordPcInfo(invoke, invoke->GetDexPc());
+  __ Bind(slow_path->GetExitLabel());
+}
+
+void IntrinsicLocationsBuilderX86::VisitStringNewStringFromChars(HInvoke* invoke) {
+  LocationSummary* locations = new (arena_) LocationSummary(invoke,
+                                                            LocationSummary::kCall,
+                                                            kIntrinsified);
+  InvokeRuntimeCallingConvention calling_convention;
+  locations->SetInAt(0, Location::RegisterLocation(calling_convention.GetRegisterAt(0)));
+  locations->SetInAt(1, Location::RegisterLocation(calling_convention.GetRegisterAt(1)));
+  locations->SetInAt(2, Location::RegisterLocation(calling_convention.GetRegisterAt(2)));
+  locations->SetOut(Location::RegisterLocation(EAX));
+}
+
+void IntrinsicCodeGeneratorX86::VisitStringNewStringFromChars(HInvoke* invoke) {
+  X86Assembler* assembler = GetAssembler();
+
+  __ fs()->call(Address::Absolute(QUICK_ENTRYPOINT_OFFSET(kX86WordSize, pAllocStringFromChars)));
+  codegen_->RecordPcInfo(invoke, invoke->GetDexPc());
+}
+
+void IntrinsicLocationsBuilderX86::VisitStringNewStringFromString(HInvoke* invoke) {
+  LocationSummary* locations = new (arena_) LocationSummary(invoke,
+                                                            LocationSummary::kCall,
+                                                            kIntrinsified);
+  InvokeRuntimeCallingConvention calling_convention;
+  locations->SetInAt(0, Location::RegisterLocation(calling_convention.GetRegisterAt(0)));
+  locations->SetOut(Location::RegisterLocation(EAX));
+  // Needs to be EAX for the invoke.
+  locations->AddTemp(Location::RegisterLocation(EAX));
+}
+
+void IntrinsicCodeGeneratorX86::VisitStringNewStringFromString(HInvoke* invoke) {
+  X86Assembler* assembler = GetAssembler();
+  LocationSummary* locations = invoke->GetLocations();
+
+  Register string_to_copy = locations->InAt(0).AsRegister<Register>();
+  __ testl(string_to_copy, string_to_copy);
+  SlowPathCodeX86* slow_path = new (GetAllocator()) IntrinsicSlowPathX86(
+      invoke, locations->GetTemp(0).AsRegister<Register>());
+  codegen_->AddSlowPath(slow_path);
+  __ j(kEqual, slow_path->GetEntryLabel());
+
+  __ fs()->call(Address::Absolute(QUICK_ENTRYPOINT_OFFSET(kX86WordSize, pAllocStringFromString)));
+  codegen_->RecordPcInfo(invoke, invoke->GetDexPc());
+  __ Bind(slow_path->GetExitLabel());
+}
+
 static void GenPeek(LocationSummary* locations, Primitive::Type size, X86Assembler* assembler) {
   Register address = locations->InAt(0).AsRegisterPairLow<Register>();
   Location out_loc = locations->Out();
@@ -1536,6 +1602,7 @@
 }
 
 UNIMPLEMENTED_INTRINSIC(MathRoundDouble)
+UNIMPLEMENTED_INTRINSIC(StringGetCharsNoCheck)
 UNIMPLEMENTED_INTRINSIC(StringIndexOf)
 UNIMPLEMENTED_INTRINSIC(StringIndexOfAfter)
 UNIMPLEMENTED_INTRINSIC(SystemArrayCopyChar)
diff --git a/compiler/optimizing/intrinsics_x86_64.cc b/compiler/optimizing/intrinsics_x86_64.cc
index 35daaf6..5779b9c 100644
--- a/compiler/optimizing/intrinsics_x86_64.cc
+++ b/compiler/optimizing/intrinsics_x86_64.cc
@@ -824,16 +824,10 @@
   const int32_t value_offset = mirror::String::ValueOffset().Int32Value();
   // Location of count
   const int32_t count_offset = mirror::String::CountOffset().Int32Value();
-  // Starting offset within data array
-  const int32_t offset_offset = mirror::String::OffsetOffset().Int32Value();
-  // Start of char data with array_
-  const int32_t data_offset = mirror::Array::DataOffset(sizeof(uint16_t)).Int32Value();
 
   CpuRegister obj = locations->InAt(0).AsRegister<CpuRegister>();
   CpuRegister idx = locations->InAt(1).AsRegister<CpuRegister>();
   CpuRegister out = locations->Out().AsRegister<CpuRegister>();
-  Location temp_loc = locations->GetTemp(0);
-  CpuRegister temp = temp_loc.AsRegister<CpuRegister>();
 
   // TODO: Maybe we can support range check elimination. Overall, though, I think it's not worth
   //       the cost.
@@ -849,12 +843,8 @@
   codegen_->MaybeRecordImplicitNullCheck(invoke);
   __ j(kAboveEqual, slow_path->GetEntryLabel());
 
-  // Get the actual element.
-  __ movl(temp, idx);                          // temp := idx.
-  __ addl(temp, Address(obj, offset_offset));  // temp := offset + idx.
-  __ movl(out, Address(obj, value_offset));    // obj := obj.array.
-  // out = out[2*temp].
-  __ movzxw(out, Address(out, temp, ScaleFactor::TIMES_2, data_offset));
+  // out = out[2*idx].
+  __ movzxw(out, Address(out, idx, ScaleFactor::TIMES_2, value_offset));
 
   __ Bind(slow_path->GetExitLabel());
 }
@@ -887,6 +877,78 @@
   __ Bind(slow_path->GetExitLabel());
 }
 
+void IntrinsicLocationsBuilderX86_64::VisitStringNewStringFromBytes(HInvoke* invoke) {
+  LocationSummary* locations = new (arena_) LocationSummary(invoke,
+                                                            LocationSummary::kCall,
+                                                            kIntrinsified);
+  InvokeRuntimeCallingConvention calling_convention;
+  locations->SetInAt(0, Location::RegisterLocation(calling_convention.GetRegisterAt(0)));
+  locations->SetInAt(1, Location::RegisterLocation(calling_convention.GetRegisterAt(1)));
+  locations->SetInAt(2, Location::RegisterLocation(calling_convention.GetRegisterAt(2)));
+  locations->SetInAt(3, Location::RegisterLocation(calling_convention.GetRegisterAt(3)));
+  locations->SetOut(Location::RegisterLocation(RAX));
+}
+
+void IntrinsicCodeGeneratorX86_64::VisitStringNewStringFromBytes(HInvoke* invoke) {
+  X86_64Assembler* assembler = GetAssembler();
+  LocationSummary* locations = invoke->GetLocations();
+
+  CpuRegister byte_array = locations->InAt(0).AsRegister<CpuRegister>();
+  __ testl(byte_array, byte_array);
+  SlowPathCodeX86_64* slow_path = new (GetAllocator()) IntrinsicSlowPathX86_64(invoke);
+  codegen_->AddSlowPath(slow_path);
+  __ j(kEqual, slow_path->GetEntryLabel());
+
+  __ gs()->call(Address::Absolute(
+        QUICK_ENTRYPOINT_OFFSET(kX86_64WordSize, pAllocStringFromBytes), true));
+  codegen_->RecordPcInfo(invoke, invoke->GetDexPc());
+  __ Bind(slow_path->GetExitLabel());
+}
+
+void IntrinsicLocationsBuilderX86_64::VisitStringNewStringFromChars(HInvoke* invoke) {
+  LocationSummary* locations = new (arena_) LocationSummary(invoke,
+                                                            LocationSummary::kCall,
+                                                            kIntrinsified);
+  InvokeRuntimeCallingConvention calling_convention;
+  locations->SetInAt(0, Location::RegisterLocation(calling_convention.GetRegisterAt(0)));
+  locations->SetInAt(1, Location::RegisterLocation(calling_convention.GetRegisterAt(1)));
+  locations->SetInAt(2, Location::RegisterLocation(calling_convention.GetRegisterAt(2)));
+  locations->SetOut(Location::RegisterLocation(RAX));
+}
+
+void IntrinsicCodeGeneratorX86_64::VisitStringNewStringFromChars(HInvoke* invoke) {
+  X86_64Assembler* assembler = GetAssembler();
+
+  __ gs()->call(Address::Absolute(
+        QUICK_ENTRYPOINT_OFFSET(kX86_64WordSize, pAllocStringFromChars), true));
+  codegen_->RecordPcInfo(invoke, invoke->GetDexPc());
+}
+
+void IntrinsicLocationsBuilderX86_64::VisitStringNewStringFromString(HInvoke* invoke) {
+  LocationSummary* locations = new (arena_) LocationSummary(invoke,
+                                                            LocationSummary::kCall,
+                                                            kIntrinsified);
+  InvokeRuntimeCallingConvention calling_convention;
+  locations->SetInAt(0, Location::RegisterLocation(calling_convention.GetRegisterAt(0)));
+  locations->SetOut(Location::RegisterLocation(RAX));
+}
+
+void IntrinsicCodeGeneratorX86_64::VisitStringNewStringFromString(HInvoke* invoke) {
+  X86_64Assembler* assembler = GetAssembler();
+  LocationSummary* locations = invoke->GetLocations();
+
+  CpuRegister string_to_copy = locations->InAt(0).AsRegister<CpuRegister>();
+  __ testl(string_to_copy, string_to_copy);
+  SlowPathCodeX86_64* slow_path = new (GetAllocator()) IntrinsicSlowPathX86_64(invoke);
+  codegen_->AddSlowPath(slow_path);
+  __ j(kEqual, slow_path->GetEntryLabel());
+
+  __ gs()->call(Address::Absolute(
+        QUICK_ENTRYPOINT_OFFSET(kX86_64WordSize, pAllocStringFromString), true));
+  codegen_->RecordPcInfo(invoke, invoke->GetDexPc());
+  __ Bind(slow_path->GetExitLabel());
+}
+
 static void GenPeek(LocationSummary* locations, Primitive::Type size, X86_64Assembler* assembler) {
   CpuRegister address = locations->InAt(0).AsRegister<CpuRegister>();
   CpuRegister out = locations->Out().AsRegister<CpuRegister>();  // == address, here for clarity.
@@ -1390,6 +1452,7 @@
 void IntrinsicCodeGeneratorX86_64::Visit ## Name(HInvoke* invoke ATTRIBUTE_UNUSED) {    \
 }
 
+UNIMPLEMENTED_INTRINSIC(StringGetCharsNoCheck)
 UNIMPLEMENTED_INTRINSIC(StringIndexOf)
 UNIMPLEMENTED_INTRINSIC(StringIndexOfAfter)
 UNIMPLEMENTED_INTRINSIC(SystemArrayCopyChar)
diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index 0533bff..9e8df04 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -2292,6 +2292,7 @@
                         uint32_t dex_pc,
                         uint32_t dex_method_index,
                         bool is_recursive,
+                        int32_t string_init_offset,
                         InvokeType original_invoke_type,
                         InvokeType invoke_type,
                         ClinitCheckRequirement clinit_check_requirement)
@@ -2299,7 +2300,8 @@
         original_invoke_type_(original_invoke_type),
         invoke_type_(invoke_type),
         is_recursive_(is_recursive),
-        clinit_check_requirement_(clinit_check_requirement) {}
+        clinit_check_requirement_(clinit_check_requirement),
+        string_init_offset_(string_init_offset) {}
 
   bool CanDoImplicitNullCheckOn(HInstruction* obj) const OVERRIDE {
     UNUSED(obj);
@@ -2312,6 +2314,8 @@
   InvokeType GetInvokeType() const { return invoke_type_; }
   bool IsRecursive() const { return is_recursive_; }
   bool NeedsDexCache() const OVERRIDE { return !IsRecursive(); }
+  bool IsStringInit() const { return string_init_offset_ != 0; }
+  int32_t GetStringInitOffset() const { return string_init_offset_; }
 
   // Is this instruction a call to a static method?
   bool IsStatic() const {
@@ -2367,6 +2371,9 @@
   const InvokeType invoke_type_;
   const bool is_recursive_;
   ClinitCheckRequirement clinit_check_requirement_;
+  // Thread entrypoint offset for string init method if this is a string init invoke.
+  // Note that there are multiple string init methods, each having its own offset.
+  int32_t string_init_offset_;
 
   DISALLOW_COPY_AND_ASSIGN(HInvokeStaticOrDirect);
 };