Version 3.2.6

src/mips/assembler-mips.h

Index: src/mips/assembler-mips.h
diff --git a/src/mips/assembler-mips.h b/src/mips/assembler-mips.h
index a687c2b8fbc26c68ebb7af4451bfb8eb72c6091a..5a6e271556955c247d9bb6dd4cefc940a19b1deb 100644
--- a/src/mips/assembler-mips.h
+++ b/src/mips/assembler-mips.h
@@ -41,8 +41,6 @@
 #include "constants-mips.h"
 #include "serialize.h"
 
-using namespace assembler::mips;
-
 namespace v8 {
 namespace internal {
 
@@ -73,6 +71,44 @@ namespace internal {
 
 // Core register.
 struct Register {
+  static const int kNumRegisters = v8::internal::kNumRegisters;
+  static const int kNumAllocatableRegisters = 14;  // v0 through t7
+
+  static int ToAllocationIndex(Register reg) {
+    return reg.code() - 2;  // zero_reg and 'at' are skipped.
+  }
+
+  static Register FromAllocationIndex(int index) {
+    ASSERT(index >= 0 && index < kNumAllocatableRegisters);
+    return from_code(index + 2);  // zero_reg and 'at' are skipped.
+  }
+
+  static const char* AllocationIndexToString(int index) {
+    ASSERT(index >= 0 && index < kNumAllocatableRegisters);
+    const char* const names[] = {
+      "v0",
+      "v1",
+      "a0",
+      "a1",
+      "a2",
+      "a3",
+      "t0",
+      "t1",
+      "t2",
+      "t3",
+      "t4",
+      "t5",
+      "t6",
+      "t7",
+    };
+    return names[index];
+  }
+
+  static Register from_code(int code) {
+    Register r = { code };
+    return r;
+  }
+
   bool is_valid() const { return 0 <= code_ && code_ < kNumRegisters; }
   bool is(Register reg) const { return code_ == reg.code_; }
   int code() const {
@@ -88,40 +124,41 @@ struct Register {
   int code_;
 };
 
-extern const Register no_reg;
-
-extern const Register zero_reg;
-extern const Register at;
-extern const Register v0;
-extern const Register v1;
-extern const Register a0;
-extern const Register a1;
-extern const Register a2;
-extern const Register a3;
-extern const Register t0;
-extern const Register t1;
-extern const Register t2;
-extern const Register t3;
-extern const Register t4;
-extern const Register t5;
-extern const Register t6;
-extern const Register t7;
-extern const Register s0;
-extern const Register s1;
-extern const Register s2;
-extern const Register s3;
-extern const Register s4;
-extern const Register s5;
-extern const Register s6;
-extern const Register s7;
-extern const Register t8;
-extern const Register t9;
-extern const Register k0;
-extern const Register k1;
-extern const Register gp;
-extern const Register sp;
-extern const Register s8_fp;
-extern const Register ra;
+const Register no_reg = { -1 };
+
+const Register zero_reg = { 0 };
+const Register at = { 1 };
+const Register v0 = { 2 };
+const Register v1 = { 3 };
+const Register a0 = { 4 };
+const Register a1 = { 5 };
+const Register a2 = { 6 };
+const Register a3 = { 7 };
+const Register t0 = { 8 };
+const Register t1 = { 9 };
+const Register t2 = { 10 };
+const Register t3 = { 11 };
+const Register t4 = { 12 };
+const Register t5 = { 13 };
+const Register t6 = { 14 };
+const Register t7 = { 15 };
+const Register s0 = { 16 };
+const Register s1 = { 17 };
+const Register s2 = { 18 };
+const Register s3 = { 19 };
+const Register s4 = { 20 };
+const Register s5 = { 21 };
+const Register s6 = { 22 };
+const Register s7 = { 23 };
+const Register t8 = { 24 };
+const Register t9 = { 25 };
+const Register k0 = { 26 };
+const Register k1 = { 27 };
+const Register gp = { 28 };
+const Register sp = { 29 };
+const Register s8_fp = { 30 };
+const Register ra = { 31 };
+
 
 int ToNumber(Register reg);
 
@@ -129,7 +166,50 @@ Register ToRegister(int num);
 
 // Coprocessor register.
 struct FPURegister {
-  bool is_valid() const { return 0 <= code_ && code_ < kNumFPURegister ; }
+  static const int kNumRegisters = v8::internal::kNumFPURegisters;
+  // f0 has been excluded from allocation. This is following ia32
+  // where xmm0 is excluded.
+  static const int kNumAllocatableRegisters = 15;
+
+  static int ToAllocationIndex(FPURegister reg) {
+    ASSERT(reg.code() != 0);
+    ASSERT(reg.code() % 2 == 0);
+    return (reg.code() / 2) - 1;
+  }
+
+  static FPURegister FromAllocationIndex(int index) {
+    ASSERT(index >= 0 && index < kNumAllocatableRegisters);
+    return from_code((index + 1) * 2);
+  }
+
+  static const char* AllocationIndexToString(int index) {
+    ASSERT(index >= 0 && index < kNumAllocatableRegisters);
+    const char* const names[] = {
+      "f2",
+      "f4",
+      "f6",
+      "f8",
+      "f10",
+      "f12",
+      "f14",
+      "f16",
+      "f18",
+      "f20",
+      "f22",
+      "f24",
+      "f26",
+      "f28",
+      "f30"
+    };
+    return names[index];
+  }
+
+  static FPURegister from_code(int code) {
+    FPURegister r = { code };
+    return r;
+  }
+
+  bool is_valid() const { return 0 <= code_ && code_ < kNumFPURegisters ; }
   bool is(FPURegister creg) const { return code_ == creg.code_; }
   int code() const {
     ASSERT(is_valid());
@@ -139,84 +219,77 @@ struct FPURegister {
     ASSERT(is_valid());
     return 1 << code_;
   }
-
+  void setcode(int f) {
+    code_ = f;
+    ASSERT(is_valid());
+  }
   // Unfortunately we can't make this private in a struct.
   int code_;
 };
 
-extern const FPURegister no_creg;
-
-extern const FPURegister f0;
-extern const FPURegister f1;
-extern const FPURegister f2;
-extern const FPURegister f3;
-extern const FPURegister f4;
-extern const FPURegister f5;
-extern const FPURegister f6;
-extern const FPURegister f7;
-extern const FPURegister f8;
-extern const FPURegister f9;
-extern const FPURegister f10;
-extern const FPURegister f11;
-extern const FPURegister f12;  // arg
-extern const FPURegister f13;
-extern const FPURegister f14;  // arg
-extern const FPURegister f15;
-extern const FPURegister f16;
-extern const FPURegister f17;
-extern const FPURegister f18;
-extern const FPURegister f19;
-extern const FPURegister f20;
-extern const FPURegister f21;
-extern const FPURegister f22;
-extern const FPURegister f23;
-extern const FPURegister f24;
-extern const FPURegister f25;
-extern const FPURegister f26;
-extern const FPURegister f27;
-extern const FPURegister f28;
-extern const FPURegister f29;
-extern const FPURegister f30;
-extern const FPURegister f31;
-
-
-// Returns the equivalent of !cc.
-// Negation of the default no_condition (-1) results in a non-default
-// no_condition value (-2). As long as tests for no_condition check
-// for condition < 0, this will work as expected.
-inline Condition NegateCondition(Condition cc);
-
-inline Condition ReverseCondition(Condition cc) {
-  switch (cc) {
-    case Uless:
-      return Ugreater;
-    case Ugreater:
-      return Uless;
-    case Ugreater_equal:
-      return Uless_equal;
-    case Uless_equal:
-      return Ugreater_equal;
-    case less:
-      return greater;
-    case greater:
-      return less;
-    case greater_equal:
-      return less_equal;
-    case less_equal:
-      return greater_equal;
-    default:
-      return cc;
-  };
-}
-
-
-enum Hint {
-  no_hint = 0
+typedef FPURegister DoubleRegister;
+
+const FPURegister no_creg = { -1 };
+
+const FPURegister f0 = { 0 };  // Return value in hard float mode.
+const FPURegister f1 = { 1 };
+const FPURegister f2 = { 2 };
+const FPURegister f3 = { 3 };
+const FPURegister f4 = { 4 };
+const FPURegister f5 = { 5 };
+const FPURegister f6 = { 6 };
+const FPURegister f7 = { 7 };
+const FPURegister f8 = { 8 };
+const FPURegister f9 = { 9 };
+const FPURegister f10 = { 10 };
+const FPURegister f11 = { 11 };
+const FPURegister f12 = { 12 };  // Arg 0 in hard float mode.
+const FPURegister f13 = { 13 };
+const FPURegister f14 = { 14 };  // Arg 1 in hard float mode.
+const FPURegister f15 = { 15 };
+const FPURegister f16 = { 16 };
+const FPURegister f17 = { 17 };
+const FPURegister f18 = { 18 };
+const FPURegister f19 = { 19 };
+const FPURegister f20 = { 20 };
+const FPURegister f21 = { 21 };
+const FPURegister f22 = { 22 };
+const FPURegister f23 = { 23 };
+const FPURegister f24 = { 24 };
+const FPURegister f25 = { 25 };
+const FPURegister f26 = { 26 };
+const FPURegister f27 = { 27 };
+const FPURegister f28 = { 28 };
+const FPURegister f29 = { 29 };
+const FPURegister f30 = { 30 };
+const FPURegister f31 = { 31 };
+
+// FPU (coprocessor 1) control registers.
+// Currently only FCSR (#31) is implemented.
+struct FPUControlRegister {
+  static const int kFCSRRegister = 31;
+  static const int kInvalidFPUControlRegister = -1;
+
+  bool is_valid() const { return code_ == kFCSRRegister; }
+  bool is(FPUControlRegister creg) const { return code_ == creg.code_; }
+  int code() const {
+    ASSERT(is_valid());
+    return code_;
+  }
+  int bit() const {
+    ASSERT(is_valid());
+    return 1 << code_;
+  }
+  void setcode(int f) {
+    code_ = f;
+    ASSERT(is_valid());
+  }
+  // Unfortunately we can't make this private in a struct.
+  int code_;
 };
 
-inline Hint NegateHint(Hint hint) {
-  return no_hint;
-}
+const FPUControlRegister no_fpucreg = { -1 };
+const FPUControlRegister FCSR = { kFCSRRegister };
 
 
 // -----------------------------------------------------------------------------
@@ -258,16 +331,75 @@ class Operand BASE_EMBEDDED {
 class MemOperand : public Operand {
  public:
 
-  explicit MemOperand(Register rn, int16_t offset = 0);
+  explicit MemOperand(Register rn, int32_t offset = 0);
 
  private:
-  int16_t offset_;
+  int32_t offset_;
 
   friend class Assembler;
 };
 
 
-class Assembler : public Malloced {
+// CpuFeatures keeps track of which features are supported by the target CPU.
+// Supported features must be enabled by a Scope before use.
+class CpuFeatures {
+ public:
+  // Detect features of the target CPU. Set safe defaults if the serializer
+  // is enabled (snapshots must be portable).
+  void Probe(bool portable);
+
+  // Check whether a feature is supported by the target CPU.
+  bool IsSupported(CpuFeature f) const {
+    if (f == FPU && !FLAG_enable_fpu) return false;
+    return (supported_ & (1u << f)) != 0;
+  }
+
+  // Check whether a feature is currently enabled.
+  bool IsEnabled(CpuFeature f) const {
+    return (enabled_ & (1u << f)) != 0;
+  }
+
+  // Enable a specified feature within a scope.
+  class Scope BASE_EMBEDDED {
+#ifdef DEBUG
+   public:
+    explicit Scope(CpuFeature f)
+        : cpu_features_(Isolate::Current()->cpu_features()),
+          isolate_(Isolate::Current()) {
+      ASSERT(cpu_features_->IsSupported(f));
+      ASSERT(!Serializer::enabled() ||
+             (cpu_features_->found_by_runtime_probing_ & (1u << f)) == 0);
+      old_enabled_ = cpu_features_->enabled_;
+      cpu_features_->enabled_ |= 1u << f;
+    }
+    ~Scope() {
+      ASSERT_EQ(Isolate::Current(), isolate_);
+      cpu_features_->enabled_ = old_enabled_;
+     }
+   private:
+    unsigned old_enabled_;
+    CpuFeatures* cpu_features_;
+    Isolate* isolate_;
+#else
+   public:
+    explicit Scope(CpuFeature f) {}
+#endif
+  };
+
+ private:
+  CpuFeatures();
+
+  unsigned supported_;
+  unsigned enabled_;
+  unsigned found_by_runtime_probing_;
+
+  friend class Isolate;
+
+  DISALLOW_COPY_AND_ASSIGN(CpuFeatures);
+};
+
+
+class Assembler : public AssemblerBase {
  public:
   // Create an assembler. Instructions and relocation information are emitted
   // into a buffer, with the instructions starting from the beginning and the
@@ -285,6 +417,9 @@ class Assembler : public Malloced {
   Assembler(void* buffer, int buffer_size);
   ~Assembler();
 
+  // Overrides the default provided by FLAG_debug_code.
+  void set_emit_debug_code(bool value) { emit_debug_code_ = value; }
+
   // GetCode emits any pending (non-emitted) code and fills the descriptor
   // desc. GetCode() is idempotent; it returns the same result if no other
   // Assembler functions are invoked in between GetCode() calls.
@@ -320,12 +455,6 @@ class Assembler : public Malloced {
   // The high 8 bits are set to zero.
   void label_at_put(Label* L, int at_offset);
 
-  // Size of an instruction.
-  static const int kInstrSize = sizeof(Instr);
-
-  // Difference between address of current opcode and target address offset.
-  static const int kBranchPCOffset = 4;
-
   // Read/Modify the code target address in the branch/call instruction at pc.
   static Address target_address_at(Address pc);
   static void set_target_address_at(Address pc, Address target);
@@ -344,8 +473,25 @@ class Assembler : public Malloced {
     set_target_address_at(instruction_payload, target);
   }
 
-  static const int kCallTargetSize = 3 * kPointerSize;
-  static const int kExternalTargetSize = 3 * kPointerSize;
+  // Size of an instruction.
+  static const int kInstrSize = sizeof(Instr);
+
+  // Difference between address of current opcode and target address offset.
+  static const int kBranchPCOffset = 4;
+
+  // Here we are patching the address in the LUI/ORI instruction pair.
+  // These values are used in the serialization process and must be zero for
+  // MIPS platform, as Code, Embedded Object or External-reference pointers
+  // are split across two consecutive instructions and don't exist separately
+  // in the code, so the serializer should not step forwards in memory after
+  // a target is resolved and written.
+  static const int kCallTargetSize = 0 * kInstrSize;
+  static const int kExternalTargetSize = 0 * kInstrSize;
+
+  // Number of consecutive instructions used to store 32bit constant.
+  // Used in RelocInfo::target_address_address() function to tell serializer
+  // address of the instruction that follows LUI/ORI instruction pair.
+  static const int kInstructionsFor32BitConstant = 2;
 
   // Distance between the instruction referring to the address of the call
   // target and the return address.
@@ -353,16 +499,53 @@ class Assembler : public Malloced {
 
   // Distance between start of patched return sequence and the emitted address
   // to jump to.
-  static const int kPatchReturnSequenceAddressOffset = kInstrSize;
+  static const int kPatchReturnSequenceAddressOffset = 0;
 
   // Distance between start of patched debug break slot and the emitted address
   // to jump to.
-  static const int kPatchDebugBreakSlotAddressOffset = kInstrSize;
+  static const int kPatchDebugBreakSlotAddressOffset =  0 * kInstrSize;
+
+  // Difference between address of current opcode and value read from pc
+  // register.
+  static const int kPcLoadDelta = 4;
+
+  // Number of instructions used for the JS return sequence. The constant is
+  // used by the debugger to patch the JS return sequence.
+  static const int kJSReturnSequenceInstructions = 7;
+  static const int kDebugBreakSlotInstructions = 4;
+  static const int kDebugBreakSlotLength =
+      kDebugBreakSlotInstructions * kInstrSize;
+
 
   // ---------------------------------------------------------------------------
   // Code generation.
 
-  void nop() { sll(zero_reg, zero_reg, 0); }
+  // Insert the smallest number of nop instructions
+  // possible to align the pc offset to a multiple
+  // of m. m must be a power of 2 (>= 4).
+  void Align(int m);
+  // Aligns code to something that's optimal for a jump target for the platform.
+  void CodeTargetAlign();
+
+  // Different nop operations are used by the code generator to detect certain
+  // states of the generated code.
+  enum NopMarkerTypes {
+    NON_MARKING_NOP = 0,
+    DEBUG_BREAK_NOP,
+    // IC markers.
+    PROPERTY_ACCESS_INLINED,
+    PROPERTY_ACCESS_INLINED_CONTEXT,
+    PROPERTY_ACCESS_INLINED_CONTEXT_DONT_DELETE,
+    // Helper values.
+    LAST_CODE_MARKER,
+    FIRST_IC_MARKER = PROPERTY_ACCESS_INLINED
+  };
+
+  // type == 0 is the default non-marking type.
+  void nop(unsigned int type = 0) {
+    ASSERT(type < 32);
+    sll(zero_reg, zero_reg, type, true);
+  }
 
 
   //------- Branch and jump  instructions --------
@@ -400,9 +583,7 @@ class Assembler : public Malloced {
   //-------Data-processing-instructions---------
 
   // Arithmetic.
-  void add(Register rd, Register rs, Register rt);
   void addu(Register rd, Register rs, Register rt);
-  void sub(Register rd, Register rs, Register rt);
   void subu(Register rd, Register rs, Register rt);
   void mult(Register rs, Register rt);
   void multu(Register rs, Register rt);
@@ -410,7 +591,6 @@ class Assembler : public Malloced {
   void divu(Register rs, Register rt);
   void mul(Register rd, Register rs, Register rt);
 
-  void addi(Register rd, Register rs, int32_t j);
   void addiu(Register rd, Register rs, int32_t j);
 
   // Logical.
@@ -425,21 +605,33 @@ class Assembler : public Malloced {
   void lui(Register rd, int32_t j);
 
   // Shifts.
-  void sll(Register rd, Register rt, uint16_t sa);
+  // Please note: sll(zero_reg, zero_reg, x) instructions are reserved as nop
+  // and may cause problems in normal code. coming_from_nop makes sure this
+  // doesn't happen.
+  void sll(Register rd, Register rt, uint16_t sa, bool coming_from_nop = false);
   void sllv(Register rd, Register rt, Register rs);
   void srl(Register rd, Register rt, uint16_t sa);
   void srlv(Register rd, Register rt, Register rs);
   void sra(Register rt, Register rd, uint16_t sa);
   void srav(Register rt, Register rd, Register rs);
+  void rotr(Register rd, Register rt, uint16_t sa);
+  void rotrv(Register rd, Register rt, Register rs);
 
 
   //------------Memory-instructions-------------
 
   void lb(Register rd, const MemOperand& rs);
   void lbu(Register rd, const MemOperand& rs);
+  void lh(Register rd, const MemOperand& rs);
+  void lhu(Register rd, const MemOperand& rs);
   void lw(Register rd, const MemOperand& rs);
+  void lwl(Register rd, const MemOperand& rs);
+  void lwr(Register rd, const MemOperand& rs);
   void sb(Register rd, const MemOperand& rs);
+  void sh(Register rd, const MemOperand& rs);
   void sw(Register rd, const MemOperand& rs);
+  void swl(Register rd, const MemOperand& rs);
+  void swr(Register rd, const MemOperand& rs);
 
 
   //-------------Misc-instructions--------------
@@ -463,6 +655,16 @@ class Assembler : public Malloced {
   void slti(Register rd, Register rs, int32_t j);
   void sltiu(Register rd, Register rs, int32_t j);
 
+  // Conditional move.
+  void movz(Register rd, Register rs, Register rt);
+  void movn(Register rd, Register rs, Register rt);
+  void movt(Register rd, Register rs, uint16_t cc = 0);
+  void movf(Register rd, Register rs, uint16_t cc = 0);
+
+  // Bit twiddling.
+  void clz(Register rd, Register rs);
+  void ins_(Register rt, Register rs, uint16_t pos, uint16_t size);
+  void ext_(Register rt, Register rs, uint16_t pos, uint16_t size);
 
   //--------Coprocessor-instructions----------------
 
@@ -473,19 +675,44 @@ class Assembler : public Malloced {
   void swc1(FPURegister fs, const MemOperand& dst);
   void sdc1(FPURegister fs, const MemOperand& dst);
 
-  // When paired with MTC1 to write a value to a 64-bit FPR, the MTC1 must be
-  // executed first, followed by the MTHC1.
-  void mtc1(FPURegister fs, Register rt);
-  void mthc1(FPURegister fs, Register rt);
-  void mfc1(FPURegister fs, Register rt);
-  void mfhc1(FPURegister fs, Register rt);
+  void mtc1(Register rt, FPURegister fs);
+  void mfc1(Register rt, FPURegister fs);
+
+  void ctc1(Register rt, FPUControlRegister fs);
+  void cfc1(Register rt, FPUControlRegister fs);
+
+  // Arithmetic.
+  void add_d(FPURegister fd, FPURegister fs, FPURegister ft);
+  void sub_d(FPURegister fd, FPURegister fs, FPURegister ft);
+  void mul_d(FPURegister fd, FPURegister fs, FPURegister ft);
+  void div_d(FPURegister fd, FPURegister fs, FPURegister ft);
+  void abs_d(FPURegister fd, FPURegister fs);
+  void mov_d(FPURegister fd, FPURegister fs);
+  void neg_d(FPURegister fd, FPURegister fs);
+  void sqrt_d(FPURegister fd, FPURegister fs);
 
   // Conversion.
   void cvt_w_s(FPURegister fd, FPURegister fs);
   void cvt_w_d(FPURegister fd, FPURegister fs);
+  void trunc_w_s(FPURegister fd, FPURegister fs);
+  void trunc_w_d(FPURegister fd, FPURegister fs);
+  void round_w_s(FPURegister fd, FPURegister fs);
+  void round_w_d(FPURegister fd, FPURegister fs);
+  void floor_w_s(FPURegister fd, FPURegister fs);
+  void floor_w_d(FPURegister fd, FPURegister fs);
+  void ceil_w_s(FPURegister fd, FPURegister fs);
+  void ceil_w_d(FPURegister fd, FPURegister fs);
 
   void cvt_l_s(FPURegister fd, FPURegister fs);
   void cvt_l_d(FPURegister fd, FPURegister fs);
+  void trunc_l_s(FPURegister fd, FPURegister fs);
+  void trunc_l_d(FPURegister fd, FPURegister fs);
+  void round_l_s(FPURegister fd, FPURegister fs);
+  void round_l_d(FPURegister fd, FPURegister fs);
+  void floor_l_s(FPURegister fd, FPURegister fs);
+  void floor_l_d(FPURegister fd, FPURegister fs);
+  void ceil_l_s(FPURegister fd, FPURegister fs);
+  void ceil_l_d(FPURegister fd, FPURegister fs);
 
   void cvt_s_w(FPURegister fd, FPURegister fs);
   void cvt_s_l(FPURegister fd, FPURegister fs);
@@ -503,32 +730,60 @@ class Assembler : public Malloced {
   void bc1f(Label* L, uint16_t cc = 0) { bc1f(branch_offset(L, false)>>2, cc); }
   void bc1t(int16_t offset, uint16_t cc = 0);
   void bc1t(Label* L, uint16_t cc = 0) { bc1t(branch_offset(L, false)>>2, cc); }
-
+  void fcmp(FPURegister src1, const double src2, FPUCondition cond);
 
   // Check the code size generated from label to here.
   int InstructionsGeneratedSince(Label* l) {
     return (pc_offset() - l->pos()) / kInstrSize;
   }
 
+  // Class for scoping postponing the trampoline pool generation.
+  class BlockTrampolinePoolScope {
+   public:
+    explicit BlockTrampolinePoolScope(Assembler* assem) : assem_(assem) {
+      assem_->StartBlockTrampolinePool();
+    }
+    ~BlockTrampolinePoolScope() {
+      assem_->EndBlockTrampolinePool();
+    }
+
+   private:
+    Assembler* assem_;
+
+    DISALLOW_IMPLICIT_CONSTRUCTORS(BlockTrampolinePoolScope);
+  };
+
   // Debugging.
 
   // Mark address of the ExitJSFrame code.
   void RecordJSReturn();
 
+  // Mark address of a debug break slot.
+  void RecordDebugBreakSlot();
+
   // Record a comment relocation entry that can be used by a disassembler.
-  // Use --debug_code to enable.
+  // Use --code-comments to enable.
   void RecordComment(const char* msg);
 
-  void RecordPosition(int pos);
-  void RecordStatementPosition(int pos);
-  bool WriteRecordedPositions();
+  // Writes a single byte or word of data in the code stream.  Used for
+  // inline tables, e.g., jump-tables.
+  void db(uint8_t data);
+  void dd(uint32_t data);
 
   int32_t pc_offset() const { return pc_ - buffer_; }
-  int32_t current_position() const { return current_position_; }
-  int32_t current_statement_position() const {
-    return current_statement_position_;
+
+  PositionsRecorder* positions_recorder() { return &positions_recorder_; }
+
+  bool can_peephole_optimize(int instructions) {
+    if (!allow_peephole_optimization_) return false;
+    if (last_bound_pos_ > pc_offset() - instructions * kInstrSize) return false;
+    return reloc_info_writer.last_pc() <= pc_ - instructions * kInstrSize;
   }
 
+  // Postpone the generation of the trampoline pool for the specified number of
+  // instructions.
+  void BlockTrampolinePoolFor(int instructions);
+
   // Check if there is less than kGap bytes available in the buffer.
   // If this is the case, we need to grow the buffer before emitting
   // an instruction or relocation information.
@@ -537,12 +792,9 @@ class Assembler : public Malloced {
   // Get the number of bytes available in the buffer.
   inline int available_space() const { return reloc_info_writer.pos() - pc_; }
 
- protected:
-  int32_t buffer_space() const { return reloc_info_writer.pos() - pc_; }
-
   // Read/patch instructions.
   static Instr instr_at(byte* pc) { return *reinterpret_cast<Instr*>(pc); }
-  void instr_at_put(byte* pc, Instr instr) {
+  static void instr_at_put(byte* pc, Instr instr) {
     *reinterpret_cast<Instr*>(pc) = instr;
   }
   Instr instr_at(int pos) { return *reinterpret_cast<Instr*>(buffer_ + pos); }
@@ -551,7 +803,34 @@ class Assembler : public Malloced {
   }
 
   // Check if an instruction is a branch of some kind.
-  bool is_branch(Instr instr);
+  static bool IsBranch(Instr instr);
+
+  static bool IsNop(Instr instr, unsigned int type);
+  static bool IsPop(Instr instr);
+  static bool IsPush(Instr instr);
+  static bool IsLwRegFpOffset(Instr instr);
+  static bool IsSwRegFpOffset(Instr instr);
+  static bool IsLwRegFpNegOffset(Instr instr);
+  static bool IsSwRegFpNegOffset(Instr instr);
+
+  static Register GetRt(Instr instr);
+
+  static int32_t GetBranchOffset(Instr instr);
+  static bool IsLw(Instr instr);
+  static int16_t GetLwOffset(Instr instr);
+  static Instr SetLwOffset(Instr instr, int16_t offset);
+
+  static bool IsSw(Instr instr);
+  static Instr SetSwOffset(Instr instr, int16_t offset);
+  static bool IsAddImmediate(Instr instr);
+  static Instr SetAddImmediateOffset(Instr instr, int16_t offset);
+
+  void CheckTrampolinePool(bool force_emit = false);
+
+ protected:
+  bool emit_debug_code() const { return emit_debug_code_; }
+
+  int32_t buffer_space() const { return reloc_info_writer.pos() - pc_; }
 
   // Decode branch instruction at pos and return branch target pos.
   int target_at(int32_t pos);
@@ -560,11 +839,28 @@ class Assembler : public Malloced {
   void target_at_put(int32_t pos, int32_t target_pos);
 
   // Say if we need to relocate with this mode.
-  bool MustUseAt(RelocInfo::Mode rmode);
+  bool MustUseReg(RelocInfo::Mode rmode);
 
   // Record reloc info for current pc_.
   void RecordRelocInfo(RelocInfo::Mode rmode, intptr_t data = 0);
 
+  // Block the emission of the trampoline pool before pc_offset.
+  void BlockTrampolinePoolBefore(int pc_offset) {
+    if (no_trampoline_pool_before_ < pc_offset)
+      no_trampoline_pool_before_ = pc_offset;
+  }
+
+  void StartBlockTrampolinePool() {
+    trampoline_pool_blocked_nesting_++;
+  }
+  void EndBlockTrampolinePool() {
+    trampoline_pool_blocked_nesting_--;
+  }
+
+  bool is_trampoline_pool_blocked() const {
+    return trampoline_pool_blocked_nesting_ > 0;
+  }
+
  private:
   // Code buffer:
   // The buffer into which code and relocation info are generated.
@@ -585,6 +881,22 @@ class Assembler : public Malloced {
   static const int kGap = 32;
   byte* pc_;  // The program counter - moves forward.
 
+
+  // Repeated checking whether the trampoline pool should be emitted is rather
+  // expensive. By default we only check again once a number of instructions
+  // has been generated.
+  static const int kCheckConstIntervalInst = 32;
+  static const int kCheckConstInterval = kCheckConstIntervalInst * kInstrSize;
+
+  int next_buffer_check_;  // pc offset of next buffer check.
+
+  // Emission of the trampoline pool may be blocked in some code sequences.
+  int trampoline_pool_blocked_nesting_;  // Block emission if this is not zero.
+  int no_trampoline_pool_before_;  // Block emission before this pc offset.
+
+  // Keep track of the last emitted pool to guarantee a maximal distance.
+  int last_trampoline_pool_end_;  // pc offset of the end of the last pool.
+
   // Relocation information generation.
   // Each relocation is encoded as a variable size value.
   static const int kMaxRelocSize = RelocInfoWriter::kMaxSize;
@@ -593,16 +905,11 @@ class Assembler : public Malloced {
   // The bound position, before this we cannot do instruction elimination.
   int last_bound_pos_;
 
-  // Source position information.
-  int current_position_;
-  int current_statement_position_;
-  int written_position_;
-  int written_statement_position_;
-
   // Code emission.
   inline void CheckBuffer();
   void GrowBuffer();
   inline void emit(Instr x);
+  inline void CheckTrampolinePoolQuick();
 
   // Instruction generation.
   // We have 3 different kind of encoding layout on MIPS.
@@ -620,6 +927,13 @@ class Assembler : public Malloced {
                         SecondaryField func = NULLSF);
 
   void GenInstrRegister(Opcode opcode,
+                        Register rs,
+                        Register rt,
+                        uint16_t msb,
+                        uint16_t lsb,
+                        SecondaryField func);
+
+  void GenInstrRegister(Opcode opcode,
                         SecondaryField fmt,
                         FPURegister ft,
                         FPURegister fs,
@@ -633,6 +947,12 @@ class Assembler : public Malloced {
                         FPURegister fd,
                         SecondaryField func = NULLSF);
 
+  void GenInstrRegister(Opcode opcode,
+                        SecondaryField fmt,
+                        Register rt,
+                        FPUControlRegister fs,
+                        SecondaryField func = NULLSF);
+
 
   void GenInstrImmediate(Opcode opcode,
                          Register rs,
@@ -651,6 +971,8 @@ class Assembler : public Malloced {
   void GenInstrJump(Opcode opcode,
                      uint32_t address);
 
+  // Helpers.
+  void LoadRegPlusOffsetToAt(const MemOperand& src);
 
   // Labels.
   void print(Label* L);
@@ -658,8 +980,85 @@ class Assembler : public Malloced {
   void link_to(Label* L, Label* appendix);
   void next(Label* L);
 
+  // One trampoline consists of:
+  // - space for trampoline slots,
+  // - space for labels.
+  //
+  // Space for trampoline slots is equal to slot_count * 2 * kInstrSize.
+  // Space for trampoline slots preceeds space for labels. Each label is of one
+  // instruction size, so total amount for labels is equal to
+  // label_count *  kInstrSize.
+  class Trampoline {
+   public:
+    Trampoline(int start, int slot_count, int label_count) {
+      start_ = start;
+      next_slot_ = start;
+      free_slot_count_ = slot_count;
+      next_label_ = start + slot_count * 2 * kInstrSize;
+      free_label_count_ = label_count;
+      end_ = next_label_ + (label_count - 1) * kInstrSize;
+    }
+    int start() {
+      return start_;
+    }
+    int end() {
+      return end_;
+    }
+    int take_slot() {
+      int trampoline_slot = next_slot_;
+      ASSERT(free_slot_count_ > 0);
+      free_slot_count_--;
+      next_slot_ += 2 * kInstrSize;
+      return trampoline_slot;
+    }
+    int take_label() {
+      int label_pos = next_label_;
+      ASSERT(free_label_count_ > 0);
+      free_label_count_--;
+      next_label_ += kInstrSize;
+      return label_pos;
+    }
+   private:
+    int start_;
+    int end_;
+    int next_slot_;
+    int free_slot_count_;
+    int next_label_;
+    int free_label_count_;
+  };
+
+  int32_t get_label_entry(int32_t pos, bool next_pool = true);
+  int32_t get_trampoline_entry(int32_t pos, bool next_pool = true);
+
+  static const int kSlotsPerTrampoline = 2304;
+  static const int kLabelsPerTrampoline = 8;
+  static const int kTrampolineInst =
+      2 * kSlotsPerTrampoline + kLabelsPerTrampoline;
+  static const int kTrampolineSize = kTrampolineInst * kInstrSize;
+  static const int kMaxBranchOffset = (1 << (18 - 1)) - 1;
+  static const int kMaxDistBetweenPools =
+      kMaxBranchOffset - 2 * kTrampolineSize;
+
+  List<Trampoline> trampolines_;
+
   friend class RegExpMacroAssemblerMIPS;
   friend class RelocInfo;
+  friend class CodePatcher;
+  friend class BlockTrampolinePoolScope;
+
+  PositionsRecorder positions_recorder_;
+  bool allow_peephole_optimization_;
+  bool emit_debug_code_;
+  friend class PositionsRecorder;
+  friend class EnsureSpace;
+};
+
+
+class EnsureSpace BASE_EMBEDDED {
+ public:
+  explicit EnsureSpace(Assembler* assembler) {
+    assembler->CheckBuffer();
+  }
 };
 
 } }  // namespace v8::internal