1// Copyright 2012 the V8 project authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef V8_ARM_MACRO_ASSEMBLER_ARM_H_
6#define V8_ARM_MACRO_ASSEMBLER_ARM_H_
7
8#include "src/assembler.h"
9#include "src/bailout-reason.h"
10#include "src/frames.h"
11#include "src/globals.h"
12
13namespace v8 {
14namespace internal {
15
16// ----------------------------------------------------------------------------
17// Static helper functions
18
19// Generate a MemOperand for loading a field from an object.
20inline MemOperand FieldMemOperand(Register object, int offset) {
21  return MemOperand(object, offset - kHeapObjectTag);
22}
23
24
25// Give alias names to registers
26const Register cp = { kRegister_r7_Code };  // JavaScript context pointer.
27const Register pp = { kRegister_r8_Code };  // Constant pool pointer.
28const Register kRootRegister = { kRegister_r10_Code };  // Roots array pointer.
29
30// Flags used for AllocateHeapNumber
31enum TaggingMode {
32  // Tag the result.
33  TAG_RESULT,
34  // Don't tag
35  DONT_TAG_RESULT
36};
37
38
39enum RememberedSetAction { EMIT_REMEMBERED_SET, OMIT_REMEMBERED_SET };
40enum SmiCheck { INLINE_SMI_CHECK, OMIT_SMI_CHECK };
41enum PointersToHereCheck {
42  kPointersToHereMaybeInteresting,
43  kPointersToHereAreAlwaysInteresting
44};
45enum LinkRegisterStatus { kLRHasNotBeenSaved, kLRHasBeenSaved };
46
47
48Register GetRegisterThatIsNotOneOf(Register reg1,
49                                   Register reg2 = no_reg,
50                                   Register reg3 = no_reg,
51                                   Register reg4 = no_reg,
52                                   Register reg5 = no_reg,
53                                   Register reg6 = no_reg);
54
55
56#ifdef DEBUG
57bool AreAliased(Register reg1,
58                Register reg2,
59                Register reg3 = no_reg,
60                Register reg4 = no_reg,
61                Register reg5 = no_reg,
62                Register reg6 = no_reg,
63                Register reg7 = no_reg,
64                Register reg8 = no_reg);
65#endif
66
67
68enum TargetAddressStorageMode {
69  CAN_INLINE_TARGET_ADDRESS,
70  NEVER_INLINE_TARGET_ADDRESS
71};
72
73// MacroAssembler implements a collection of frequently used macros.
74class MacroAssembler: public Assembler {
75 public:
76  // The isolate parameter can be NULL if the macro assembler should
77  // not use isolate-dependent functionality. In this case, it's the
78  // responsibility of the caller to never invoke such function on the
79  // macro assembler.
80  MacroAssembler(Isolate* isolate, void* buffer, int size);
81
82
83  // Returns the size of a call in instructions. Note, the value returned is
84  // only valid as long as no entries are added to the constant pool between
85  // checking the call size and emitting the actual call.
86  static int CallSize(Register target, Condition cond = al);
87  int CallSize(Address target, RelocInfo::Mode rmode, Condition cond = al);
88  int CallStubSize(CodeStub* stub,
89                   TypeFeedbackId ast_id = TypeFeedbackId::None(),
90                   Condition cond = al);
91  static int CallSizeNotPredictableCodeSize(Isolate* isolate,
92                                            Address target,
93                                            RelocInfo::Mode rmode,
94                                            Condition cond = al);
95
96  // Jump, Call, and Ret pseudo instructions implementing inter-working.
97  void Jump(Register target, Condition cond = al);
98  void Jump(Address target, RelocInfo::Mode rmode, Condition cond = al);
99  void Jump(Handle<Code> code, RelocInfo::Mode rmode, Condition cond = al);
100  void Call(Register target, Condition cond = al);
101  void Call(Address target, RelocInfo::Mode rmode,
102            Condition cond = al,
103            TargetAddressStorageMode mode = CAN_INLINE_TARGET_ADDRESS);
104  int CallSize(Handle<Code> code,
105               RelocInfo::Mode rmode = RelocInfo::CODE_TARGET,
106               TypeFeedbackId ast_id = TypeFeedbackId::None(),
107               Condition cond = al);
108  void Call(Handle<Code> code,
109            RelocInfo::Mode rmode = RelocInfo::CODE_TARGET,
110            TypeFeedbackId ast_id = TypeFeedbackId::None(),
111            Condition cond = al,
112            TargetAddressStorageMode mode = CAN_INLINE_TARGET_ADDRESS);
113  void Ret(Condition cond = al);
114
115  // Emit code to discard a non-negative number of pointer-sized elements
116  // from the stack, clobbering only the sp register.
117  void Drop(int count, Condition cond = al);
118
119  void Ret(int drop, Condition cond = al);
120
121  // Swap two registers.  If the scratch register is omitted then a slightly
122  // less efficient form using xor instead of mov is emitted.
123  void Swap(Register reg1,
124            Register reg2,
125            Register scratch = no_reg,
126            Condition cond = al);
127
128  void Mls(Register dst, Register src1, Register src2, Register srcA,
129           Condition cond = al);
130  void And(Register dst, Register src1, const Operand& src2,
131           Condition cond = al);
132  void Ubfx(Register dst, Register src, int lsb, int width,
133            Condition cond = al);
134  void Sbfx(Register dst, Register src, int lsb, int width,
135            Condition cond = al);
136  // The scratch register is not used for ARMv7.
137  // scratch can be the same register as src (in which case it is trashed), but
138  // not the same as dst.
139  void Bfi(Register dst,
140           Register src,
141           Register scratch,
142           int lsb,
143           int width,
144           Condition cond = al);
145  void Bfc(Register dst, Register src, int lsb, int width, Condition cond = al);
146  void Usat(Register dst, int satpos, const Operand& src,
147            Condition cond = al);
148
149  void Call(Label* target);
150  void Push(Register src) { push(src); }
151  void Pop(Register dst) { pop(dst); }
152
153  // Register move. May do nothing if the registers are identical.
154  void Move(Register dst, Handle<Object> value);
155  void Move(Register dst, Register src, Condition cond = al);
156  void Move(Register dst, const Operand& src, SBit sbit = LeaveCC,
157            Condition cond = al) {
158    if (!src.is_reg() || !src.rm().is(dst) || sbit != LeaveCC) {
159      mov(dst, src, sbit, cond);
160    }
161  }
162  void Move(DwVfpRegister dst, DwVfpRegister src);
163
164  void Load(Register dst, const MemOperand& src, Representation r);
165  void Store(Register src, const MemOperand& dst, Representation r);
166
167  // Load an object from the root table.
168  void LoadRoot(Register destination,
169                Heap::RootListIndex index,
170                Condition cond = al);
171  // Store an object to the root table.
172  void StoreRoot(Register source,
173                 Heap::RootListIndex index,
174                 Condition cond = al);
175
176  // ---------------------------------------------------------------------------
177  // GC Support
178
179  void IncrementalMarkingRecordWriteHelper(Register object,
180                                           Register value,
181                                           Register address);
182
183  enum RememberedSetFinalAction {
184    kReturnAtEnd,
185    kFallThroughAtEnd
186  };
187
188  // Record in the remembered set the fact that we have a pointer to new space
189  // at the address pointed to by the addr register.  Only works if addr is not
190  // in new space.
191  void RememberedSetHelper(Register object,  // Used for debug code.
192                           Register addr,
193                           Register scratch,
194                           SaveFPRegsMode save_fp,
195                           RememberedSetFinalAction and_then);
196
197  void CheckPageFlag(Register object,
198                     Register scratch,
199                     int mask,
200                     Condition cc,
201                     Label* condition_met);
202
203  void CheckMapDeprecated(Handle<Map> map,
204                          Register scratch,
205                          Label* if_deprecated);
206
207  // Check if object is in new space.  Jumps if the object is not in new space.
208  // The register scratch can be object itself, but scratch will be clobbered.
209  void JumpIfNotInNewSpace(Register object,
210                           Register scratch,
211                           Label* branch) {
212    InNewSpace(object, scratch, ne, branch);
213  }
214
215  // Check if object is in new space.  Jumps if the object is in new space.
216  // The register scratch can be object itself, but it will be clobbered.
217  void JumpIfInNewSpace(Register object,
218                        Register scratch,
219                        Label* branch) {
220    InNewSpace(object, scratch, eq, branch);
221  }
222
223  // Check if an object has a given incremental marking color.
224  void HasColor(Register object,
225                Register scratch0,
226                Register scratch1,
227                Label* has_color,
228                int first_bit,
229                int second_bit);
230
231  void JumpIfBlack(Register object,
232                   Register scratch0,
233                   Register scratch1,
234                   Label* on_black);
235
236  // Checks the color of an object.  If the object is already grey or black
237  // then we just fall through, since it is already live.  If it is white and
238  // we can determine that it doesn't need to be scanned, then we just mark it
239  // black and fall through.  For the rest we jump to the label so the
240  // incremental marker can fix its assumptions.
241  void EnsureNotWhite(Register object,
242                      Register scratch1,
243                      Register scratch2,
244                      Register scratch3,
245                      Label* object_is_white_and_not_data);
246
247  // Detects conservatively whether an object is data-only, i.e. it does need to
248  // be scanned by the garbage collector.
249  void JumpIfDataObject(Register value,
250                        Register scratch,
251                        Label* not_data_object);
252
253  // Notify the garbage collector that we wrote a pointer into an object.
254  // |object| is the object being stored into, |value| is the object being
255  // stored.  value and scratch registers are clobbered by the operation.
256  // The offset is the offset from the start of the object, not the offset from
257  // the tagged HeapObject pointer.  For use with FieldOperand(reg, off).
258  void RecordWriteField(
259      Register object,
260      int offset,
261      Register value,
262      Register scratch,
263      LinkRegisterStatus lr_status,
264      SaveFPRegsMode save_fp,
265      RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
266      SmiCheck smi_check = INLINE_SMI_CHECK,
267      PointersToHereCheck pointers_to_here_check_for_value =
268          kPointersToHereMaybeInteresting);
269
270  // As above, but the offset has the tag presubtracted.  For use with
271  // MemOperand(reg, off).
272  inline void RecordWriteContextSlot(
273      Register context,
274      int offset,
275      Register value,
276      Register scratch,
277      LinkRegisterStatus lr_status,
278      SaveFPRegsMode save_fp,
279      RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
280      SmiCheck smi_check = INLINE_SMI_CHECK,
281      PointersToHereCheck pointers_to_here_check_for_value =
282          kPointersToHereMaybeInteresting) {
283    RecordWriteField(context,
284                     offset + kHeapObjectTag,
285                     value,
286                     scratch,
287                     lr_status,
288                     save_fp,
289                     remembered_set_action,
290                     smi_check,
291                     pointers_to_here_check_for_value);
292  }
293
294  void RecordWriteForMap(
295      Register object,
296      Register map,
297      Register dst,
298      LinkRegisterStatus lr_status,
299      SaveFPRegsMode save_fp);
300
301  // For a given |object| notify the garbage collector that the slot |address|
302  // has been written.  |value| is the object being stored. The value and
303  // address registers are clobbered by the operation.
304  void RecordWrite(
305      Register object,
306      Register address,
307      Register value,
308      LinkRegisterStatus lr_status,
309      SaveFPRegsMode save_fp,
310      RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
311      SmiCheck smi_check = INLINE_SMI_CHECK,
312      PointersToHereCheck pointers_to_here_check_for_value =
313          kPointersToHereMaybeInteresting);
314
315  // Push a handle.
316  void Push(Handle<Object> handle);
317  void Push(Smi* smi) { Push(Handle<Smi>(smi, isolate())); }
318
319  // Push two registers.  Pushes leftmost register first (to highest address).
320  void Push(Register src1, Register src2, Condition cond = al) {
321    DCHECK(!src1.is(src2));
322    if (src1.code() > src2.code()) {
323      stm(db_w, sp, src1.bit() | src2.bit(), cond);
324    } else {
325      str(src1, MemOperand(sp, 4, NegPreIndex), cond);
326      str(src2, MemOperand(sp, 4, NegPreIndex), cond);
327    }
328  }
329
330  // Push three registers.  Pushes leftmost register first (to highest address).
331  void Push(Register src1, Register src2, Register src3, Condition cond = al) {
332    DCHECK(!src1.is(src2));
333    DCHECK(!src2.is(src3));
334    DCHECK(!src1.is(src3));
335    if (src1.code() > src2.code()) {
336      if (src2.code() > src3.code()) {
337        stm(db_w, sp, src1.bit() | src2.bit() | src3.bit(), cond);
338      } else {
339        stm(db_w, sp, src1.bit() | src2.bit(), cond);
340        str(src3, MemOperand(sp, 4, NegPreIndex), cond);
341      }
342    } else {
343      str(src1, MemOperand(sp, 4, NegPreIndex), cond);
344      Push(src2, src3, cond);
345    }
346  }
347
348  // Push four registers.  Pushes leftmost register first (to highest address).
349  void Push(Register src1,
350            Register src2,
351            Register src3,
352            Register src4,
353            Condition cond = al) {
354    DCHECK(!src1.is(src2));
355    DCHECK(!src2.is(src3));
356    DCHECK(!src1.is(src3));
357    DCHECK(!src1.is(src4));
358    DCHECK(!src2.is(src4));
359    DCHECK(!src3.is(src4));
360    if (src1.code() > src2.code()) {
361      if (src2.code() > src3.code()) {
362        if (src3.code() > src4.code()) {
363          stm(db_w,
364              sp,
365              src1.bit() | src2.bit() | src3.bit() | src4.bit(),
366              cond);
367        } else {
368          stm(db_w, sp, src1.bit() | src2.bit() | src3.bit(), cond);
369          str(src4, MemOperand(sp, 4, NegPreIndex), cond);
370        }
371      } else {
372        stm(db_w, sp, src1.bit() | src2.bit(), cond);
373        Push(src3, src4, cond);
374      }
375    } else {
376      str(src1, MemOperand(sp, 4, NegPreIndex), cond);
377      Push(src2, src3, src4, cond);
378    }
379  }
380
381  // Pop two registers. Pops rightmost register first (from lower address).
382  void Pop(Register src1, Register src2, Condition cond = al) {
383    DCHECK(!src1.is(src2));
384    if (src1.code() > src2.code()) {
385      ldm(ia_w, sp, src1.bit() | src2.bit(), cond);
386    } else {
387      ldr(src2, MemOperand(sp, 4, PostIndex), cond);
388      ldr(src1, MemOperand(sp, 4, PostIndex), cond);
389    }
390  }
391
392  // Pop three registers.  Pops rightmost register first (from lower address).
393  void Pop(Register src1, Register src2, Register src3, Condition cond = al) {
394    DCHECK(!src1.is(src2));
395    DCHECK(!src2.is(src3));
396    DCHECK(!src1.is(src3));
397    if (src1.code() > src2.code()) {
398      if (src2.code() > src3.code()) {
399        ldm(ia_w, sp, src1.bit() | src2.bit() | src3.bit(), cond);
400      } else {
401        ldr(src3, MemOperand(sp, 4, PostIndex), cond);
402        ldm(ia_w, sp, src1.bit() | src2.bit(), cond);
403      }
404    } else {
405      Pop(src2, src3, cond);
406      ldr(src1, MemOperand(sp, 4, PostIndex), cond);
407    }
408  }
409
410  // Pop four registers.  Pops rightmost register first (from lower address).
411  void Pop(Register src1,
412           Register src2,
413           Register src3,
414           Register src4,
415           Condition cond = al) {
416    DCHECK(!src1.is(src2));
417    DCHECK(!src2.is(src3));
418    DCHECK(!src1.is(src3));
419    DCHECK(!src1.is(src4));
420    DCHECK(!src2.is(src4));
421    DCHECK(!src3.is(src4));
422    if (src1.code() > src2.code()) {
423      if (src2.code() > src3.code()) {
424        if (src3.code() > src4.code()) {
425          ldm(ia_w,
426              sp,
427              src1.bit() | src2.bit() | src3.bit() | src4.bit(),
428              cond);
429        } else {
430          ldr(src4, MemOperand(sp, 4, PostIndex), cond);
431          ldm(ia_w, sp, src1.bit() | src2.bit() | src3.bit(), cond);
432        }
433      } else {
434        Pop(src3, src4, cond);
435        ldm(ia_w, sp, src1.bit() | src2.bit(), cond);
436      }
437    } else {
438      Pop(src2, src3, src4, cond);
439      ldr(src1, MemOperand(sp, 4, PostIndex), cond);
440    }
441  }
442
443  // Push a fixed frame, consisting of lr, fp, constant pool (if
444  // FLAG_enable_ool_constant_pool), context and JS function / marker id if
445  // marker_reg is a valid register.
446  void PushFixedFrame(Register marker_reg = no_reg);
447  void PopFixedFrame(Register marker_reg = no_reg);
448
449  // Push and pop the registers that can hold pointers, as defined by the
450  // RegList constant kSafepointSavedRegisters.
451  void PushSafepointRegisters();
452  void PopSafepointRegisters();
453  // Store value in register src in the safepoint stack slot for
454  // register dst.
455  void StoreToSafepointRegisterSlot(Register src, Register dst);
456  // Load the value of the src register from its safepoint stack slot
457  // into register dst.
458  void LoadFromSafepointRegisterSlot(Register dst, Register src);
459
460  // Load two consecutive registers with two consecutive memory locations.
461  void Ldrd(Register dst1,
462            Register dst2,
463            const MemOperand& src,
464            Condition cond = al);
465
466  // Store two consecutive registers to two consecutive memory locations.
467  void Strd(Register src1,
468            Register src2,
469            const MemOperand& dst,
470            Condition cond = al);
471
472  // Ensure that FPSCR contains values needed by JavaScript.
473  // We need the NaNModeControlBit to be sure that operations like
474  // vadd and vsub generate the Canonical NaN (if a NaN must be generated).
475  // In VFP3 it will be always the Canonical NaN.
476  // In VFP2 it will be either the Canonical NaN or the negative version
477  // of the Canonical NaN. It doesn't matter if we have two values. The aim
478  // is to be sure to never generate the hole NaN.
479  void VFPEnsureFPSCRState(Register scratch);
480
481  // If the value is a NaN, canonicalize the value else, do nothing.
482  void VFPCanonicalizeNaN(const DwVfpRegister dst,
483                          const DwVfpRegister src,
484                          const Condition cond = al);
485  void VFPCanonicalizeNaN(const DwVfpRegister value,
486                          const Condition cond = al) {
487    VFPCanonicalizeNaN(value, value, cond);
488  }
489
490  // Compare double values and move the result to the normal condition flags.
491  void VFPCompareAndSetFlags(const DwVfpRegister src1,
492                             const DwVfpRegister src2,
493                             const Condition cond = al);
494  void VFPCompareAndSetFlags(const DwVfpRegister src1,
495                             const double src2,
496                             const Condition cond = al);
497
498  // Compare double values and then load the fpscr flags to a register.
499  void VFPCompareAndLoadFlags(const DwVfpRegister src1,
500                              const DwVfpRegister src2,
501                              const Register fpscr_flags,
502                              const Condition cond = al);
503  void VFPCompareAndLoadFlags(const DwVfpRegister src1,
504                              const double src2,
505                              const Register fpscr_flags,
506                              const Condition cond = al);
507
508  void Vmov(const DwVfpRegister dst,
509            const double imm,
510            const Register scratch = no_reg);
511
512  void VmovHigh(Register dst, DwVfpRegister src);
513  void VmovHigh(DwVfpRegister dst, Register src);
514  void VmovLow(Register dst, DwVfpRegister src);
515  void VmovLow(DwVfpRegister dst, Register src);
516
517  // Loads the number from object into dst register.
518  // If |object| is neither smi nor heap number, |not_number| is jumped to
519  // with |object| still intact.
520  void LoadNumber(Register object,
521                  LowDwVfpRegister dst,
522                  Register heap_number_map,
523                  Register scratch,
524                  Label* not_number);
525
526  // Loads the number from object into double_dst in the double format.
527  // Control will jump to not_int32 if the value cannot be exactly represented
528  // by a 32-bit integer.
529  // Floating point value in the 32-bit integer range that are not exact integer
530  // won't be loaded.
531  void LoadNumberAsInt32Double(Register object,
532                               DwVfpRegister double_dst,
533                               Register heap_number_map,
534                               Register scratch,
535                               LowDwVfpRegister double_scratch,
536                               Label* not_int32);
537
538  // Loads the number from object into dst as a 32-bit integer.
539  // Control will jump to not_int32 if the object cannot be exactly represented
540  // by a 32-bit integer.
541  // Floating point value in the 32-bit integer range that are not exact integer
542  // won't be converted.
543  void LoadNumberAsInt32(Register object,
544                         Register dst,
545                         Register heap_number_map,
546                         Register scratch,
547                         DwVfpRegister double_scratch0,
548                         LowDwVfpRegister double_scratch1,
549                         Label* not_int32);
550
551  // Generates function and stub prologue code.
552  void StubPrologue();
553  void Prologue(bool code_pre_aging);
554
555  // Enter exit frame.
556  // stack_space - extra stack space, used for alignment before call to C.
557  void EnterExitFrame(bool save_doubles, int stack_space = 0);
558
559  // Leave the current exit frame. Expects the return value in r0.
560  // Expect the number of values, pushed prior to the exit frame, to
561  // remove in a register (or no_reg, if there is nothing to remove).
562  void LeaveExitFrame(bool save_doubles,
563                      Register argument_count,
564                      bool restore_context);
565
566  // Get the actual activation frame alignment for target environment.
567  static int ActivationFrameAlignment();
568
569  void LoadContext(Register dst, int context_chain_length);
570
571  // Conditionally load the cached Array transitioned map of type
572  // transitioned_kind from the native context if the map in register
573  // map_in_out is the cached Array map in the native context of
574  // expected_kind.
575  void LoadTransitionedArrayMapConditional(
576      ElementsKind expected_kind,
577      ElementsKind transitioned_kind,
578      Register map_in_out,
579      Register scratch,
580      Label* no_map_match);
581
582  void LoadGlobalFunction(int index, Register function);
583
584  // Load the initial map from the global function. The registers
585  // function and map can be the same, function is then overwritten.
586  void LoadGlobalFunctionInitialMap(Register function,
587                                    Register map,
588                                    Register scratch);
589
590  void InitializeRootRegister() {
591    ExternalReference roots_array_start =
592        ExternalReference::roots_array_start(isolate());
593    mov(kRootRegister, Operand(roots_array_start));
594  }
595
596  // ---------------------------------------------------------------------------
597  // JavaScript invokes
598
599  // Invoke the JavaScript function code by either calling or jumping.
600  void InvokeCode(Register code,
601                  const ParameterCount& expected,
602                  const ParameterCount& actual,
603                  InvokeFlag flag,
604                  const CallWrapper& call_wrapper);
605
606  // Invoke the JavaScript function in the given register. Changes the
607  // current context to the context in the function before invoking.
608  void InvokeFunction(Register function,
609                      const ParameterCount& actual,
610                      InvokeFlag flag,
611                      const CallWrapper& call_wrapper);
612
613  void InvokeFunction(Register function,
614                      const ParameterCount& expected,
615                      const ParameterCount& actual,
616                      InvokeFlag flag,
617                      const CallWrapper& call_wrapper);
618
619  void InvokeFunction(Handle<JSFunction> function,
620                      const ParameterCount& expected,
621                      const ParameterCount& actual,
622                      InvokeFlag flag,
623                      const CallWrapper& call_wrapper);
624
625  void IsObjectJSObjectType(Register heap_object,
626                            Register map,
627                            Register scratch,
628                            Label* fail);
629
630  void IsInstanceJSObjectType(Register map,
631                              Register scratch,
632                              Label* fail);
633
634  void IsObjectJSStringType(Register object,
635                            Register scratch,
636                            Label* fail);
637
638  void IsObjectNameType(Register object,
639                        Register scratch,
640                        Label* fail);
641
642  // ---------------------------------------------------------------------------
643  // Debugger Support
644
645  void DebugBreak();
646
647  // ---------------------------------------------------------------------------
648  // Exception handling
649
650  // Push a new try handler and link into try handler chain.
651  void PushTryHandler(StackHandler::Kind kind, int handler_index);
652
653  // Unlink the stack handler on top of the stack from the try handler chain.
654  // Must preserve the result register.
655  void PopTryHandler();
656
657  // Passes thrown value to the handler of top of the try handler chain.
658  void Throw(Register value);
659
660  // Propagates an uncatchable exception to the top of the current JS stack's
661  // handler chain.
662  void ThrowUncatchable(Register value);
663
664  // ---------------------------------------------------------------------------
665  // Inline caching support
666
667  // Generate code for checking access rights - used for security checks
668  // on access to global objects across environments. The holder register
669  // is left untouched, whereas both scratch registers are clobbered.
670  void CheckAccessGlobalProxy(Register holder_reg,
671                              Register scratch,
672                              Label* miss);
673
674  void GetNumberHash(Register t0, Register scratch);
675
676  void LoadFromNumberDictionary(Label* miss,
677                                Register elements,
678                                Register key,
679                                Register result,
680                                Register t0,
681                                Register t1,
682                                Register t2);
683
684
685  inline void MarkCode(NopMarkerTypes type) {
686    nop(type);
687  }
688
689  // Check if the given instruction is a 'type' marker.
690  // i.e. check if is is a mov r<type>, r<type> (referenced as nop(type))
691  // These instructions are generated to mark special location in the code,
692  // like some special IC code.
693  static inline bool IsMarkedCode(Instr instr, int type) {
694    DCHECK((FIRST_IC_MARKER <= type) && (type < LAST_CODE_MARKER));
695    return IsNop(instr, type);
696  }
697
698
699  static inline int GetCodeMarker(Instr instr) {
700    int dst_reg_offset = 12;
701    int dst_mask = 0xf << dst_reg_offset;
702    int src_mask = 0xf;
703    int dst_reg = (instr & dst_mask) >> dst_reg_offset;
704    int src_reg = instr & src_mask;
705    uint32_t non_register_mask = ~(dst_mask | src_mask);
706    uint32_t mov_mask = al | 13 << 21;
707
708    // Return <n> if we have a mov rn rn, else return -1.
709    int type = ((instr & non_register_mask) == mov_mask) &&
710               (dst_reg == src_reg) &&
711               (FIRST_IC_MARKER <= dst_reg) && (dst_reg < LAST_CODE_MARKER)
712                   ? src_reg
713                   : -1;
714    DCHECK((type == -1) ||
715           ((FIRST_IC_MARKER <= type) && (type < LAST_CODE_MARKER)));
716    return type;
717  }
718
719
720  // ---------------------------------------------------------------------------
721  // Allocation support
722
723  // Allocate an object in new space or old pointer space. The object_size is
724  // specified either in bytes or in words if the allocation flag SIZE_IN_WORDS
725  // is passed. If the space is exhausted control continues at the gc_required
726  // label. The allocated object is returned in result. If the flag
727  // tag_allocated_object is true the result is tagged as as a heap object.
728  // All registers are clobbered also when control continues at the gc_required
729  // label.
730  void Allocate(int object_size,
731                Register result,
732                Register scratch1,
733                Register scratch2,
734                Label* gc_required,
735                AllocationFlags flags);
736
737  void Allocate(Register object_size,
738                Register result,
739                Register scratch1,
740                Register scratch2,
741                Label* gc_required,
742                AllocationFlags flags);
743
744  // Undo allocation in new space. The object passed and objects allocated after
745  // it will no longer be allocated. The caller must make sure that no pointers
746  // are left to the object(s) no longer allocated as they would be invalid when
747  // allocation is undone.
748  void UndoAllocationInNewSpace(Register object, Register scratch);
749
750
751  void AllocateTwoByteString(Register result,
752                             Register length,
753                             Register scratch1,
754                             Register scratch2,
755                             Register scratch3,
756                             Label* gc_required);
757  void AllocateOneByteString(Register result, Register length,
758                             Register scratch1, Register scratch2,
759                             Register scratch3, Label* gc_required);
760  void AllocateTwoByteConsString(Register result,
761                                 Register length,
762                                 Register scratch1,
763                                 Register scratch2,
764                                 Label* gc_required);
765  void AllocateOneByteConsString(Register result, Register length,
766                                 Register scratch1, Register scratch2,
767                                 Label* gc_required);
768  void AllocateTwoByteSlicedString(Register result,
769                                   Register length,
770                                   Register scratch1,
771                                   Register scratch2,
772                                   Label* gc_required);
773  void AllocateOneByteSlicedString(Register result, Register length,
774                                   Register scratch1, Register scratch2,
775                                   Label* gc_required);
776
777  // Allocates a heap number or jumps to the gc_required label if the young
778  // space is full and a scavenge is needed. All registers are clobbered also
779  // when control continues at the gc_required label.
780  void AllocateHeapNumber(Register result,
781                          Register scratch1,
782                          Register scratch2,
783                          Register heap_number_map,
784                          Label* gc_required,
785                          TaggingMode tagging_mode = TAG_RESULT,
786                          MutableMode mode = IMMUTABLE);
787  void AllocateHeapNumberWithValue(Register result,
788                                   DwVfpRegister value,
789                                   Register scratch1,
790                                   Register scratch2,
791                                   Register heap_number_map,
792                                   Label* gc_required);
793
794  // Copies a fixed number of fields of heap objects from src to dst.
795  void CopyFields(Register dst,
796                  Register src,
797                  LowDwVfpRegister double_scratch,
798                  int field_count);
799
800  // Copies a number of bytes from src to dst. All registers are clobbered. On
801  // exit src and dst will point to the place just after where the last byte was
802  // read or written and length will be zero.
803  void CopyBytes(Register src,
804                 Register dst,
805                 Register length,
806                 Register scratch);
807
808  // Initialize fields with filler values.  Fields starting at |start_offset|
809  // not including end_offset are overwritten with the value in |filler|.  At
810  // the end the loop, |start_offset| takes the value of |end_offset|.
811  void InitializeFieldsWithFiller(Register start_offset,
812                                  Register end_offset,
813                                  Register filler);
814
815  // ---------------------------------------------------------------------------
816  // Support functions.
817
818  // Try to get function prototype of a function and puts the value in
819  // the result register. Checks that the function really is a
820  // function and jumps to the miss label if the fast checks fail. The
821  // function register will be untouched; the other registers may be
822  // clobbered.
823  void TryGetFunctionPrototype(Register function,
824                               Register result,
825                               Register scratch,
826                               Label* miss,
827                               bool miss_on_bound_function = false);
828
829  // Compare object type for heap object.  heap_object contains a non-Smi
830  // whose object type should be compared with the given type.  This both
831  // sets the flags and leaves the object type in the type_reg register.
832  // It leaves the map in the map register (unless the type_reg and map register
833  // are the same register).  It leaves the heap object in the heap_object
834  // register unless the heap_object register is the same register as one of the
835  // other registers.
836  // Type_reg can be no_reg. In that case ip is used.
837  void CompareObjectType(Register heap_object,
838                         Register map,
839                         Register type_reg,
840                         InstanceType type);
841
842  // Compare object type for heap object. Branch to false_label if type
843  // is lower than min_type or greater than max_type.
844  // Load map into the register map.
845  void CheckObjectTypeRange(Register heap_object,
846                            Register map,
847                            InstanceType min_type,
848                            InstanceType max_type,
849                            Label* false_label);
850
851  // Compare instance type in a map.  map contains a valid map object whose
852  // object type should be compared with the given type.  This both
853  // sets the flags and leaves the object type in the type_reg register.
854  void CompareInstanceType(Register map,
855                           Register type_reg,
856                           InstanceType type);
857
858
859  // Check if a map for a JSObject indicates that the object has fast elements.
860  // Jump to the specified label if it does not.
861  void CheckFastElements(Register map,
862                         Register scratch,
863                         Label* fail);
864
865  // Check if a map for a JSObject indicates that the object can have both smi
866  // and HeapObject elements.  Jump to the specified label if it does not.
867  void CheckFastObjectElements(Register map,
868                               Register scratch,
869                               Label* fail);
870
871  // Check if a map for a JSObject indicates that the object has fast smi only
872  // elements.  Jump to the specified label if it does not.
873  void CheckFastSmiElements(Register map,
874                            Register scratch,
875                            Label* fail);
876
877  // Check to see if maybe_number can be stored as a double in
878  // FastDoubleElements. If it can, store it at the index specified by key in
879  // the FastDoubleElements array elements. Otherwise jump to fail.
880  void StoreNumberToDoubleElements(Register value_reg,
881                                   Register key_reg,
882                                   Register elements_reg,
883                                   Register scratch1,
884                                   LowDwVfpRegister double_scratch,
885                                   Label* fail,
886                                   int elements_offset = 0);
887
888  // Compare an object's map with the specified map and its transitioned
889  // elements maps if mode is ALLOW_ELEMENT_TRANSITION_MAPS. Condition flags are
890  // set with result of map compare. If multiple map compares are required, the
891  // compare sequences branches to early_success.
892  void CompareMap(Register obj,
893                  Register scratch,
894                  Handle<Map> map,
895                  Label* early_success);
896
897  // As above, but the map of the object is already loaded into the register
898  // which is preserved by the code generated.
899  void CompareMap(Register obj_map,
900                  Handle<Map> map,
901                  Label* early_success);
902
903  // Check if the map of an object is equal to a specified map and branch to
904  // label if not. Skip the smi check if not required (object is known to be a
905  // heap object). If mode is ALLOW_ELEMENT_TRANSITION_MAPS, then also match
906  // against maps that are ElementsKind transition maps of the specified map.
907  void CheckMap(Register obj,
908                Register scratch,
909                Handle<Map> map,
910                Label* fail,
911                SmiCheckType smi_check_type);
912
913
914  void CheckMap(Register obj,
915                Register scratch,
916                Heap::RootListIndex index,
917                Label* fail,
918                SmiCheckType smi_check_type);
919
920
921  // Check if the map of an object is equal to a specified map and branch to a
922  // specified target if equal. Skip the smi check if not required (object is
923  // known to be a heap object)
924  void DispatchMap(Register obj,
925                   Register scratch,
926                   Handle<Map> map,
927                   Handle<Code> success,
928                   SmiCheckType smi_check_type);
929
930
931  // Compare the object in a register to a value from the root list.
932  // Uses the ip register as scratch.
933  void CompareRoot(Register obj, Heap::RootListIndex index);
934
935
936  // Load and check the instance type of an object for being a string.
937  // Loads the type into the second argument register.
938  // Returns a condition that will be enabled if the object was a string
939  // and the passed-in condition passed. If the passed-in condition failed
940  // then flags remain unchanged.
941  Condition IsObjectStringType(Register obj,
942                               Register type,
943                               Condition cond = al) {
944    ldr(type, FieldMemOperand(obj, HeapObject::kMapOffset), cond);
945    ldrb(type, FieldMemOperand(type, Map::kInstanceTypeOffset), cond);
946    tst(type, Operand(kIsNotStringMask), cond);
947    DCHECK_EQ(0, kStringTag);
948    return eq;
949  }
950
951
952  // Picks out an array index from the hash field.
953  // Register use:
954  //   hash - holds the index's hash. Clobbered.
955  //   index - holds the overwritten index on exit.
956  void IndexFromHash(Register hash, Register index);
957
958  // Get the number of least significant bits from a register
959  void GetLeastBitsFromSmi(Register dst, Register src, int num_least_bits);
960  void GetLeastBitsFromInt32(Register dst, Register src, int mun_least_bits);
961
962  // Load the value of a smi object into a double register.
963  // The register value must be between d0 and d15.
964  void SmiToDouble(LowDwVfpRegister value, Register smi);
965
966  // Check if a double can be exactly represented as a signed 32-bit integer.
967  // Z flag set to one if true.
968  void TestDoubleIsInt32(DwVfpRegister double_input,
969                         LowDwVfpRegister double_scratch);
970
971  // Try to convert a double to a signed 32-bit integer.
972  // Z flag set to one and result assigned if the conversion is exact.
973  void TryDoubleToInt32Exact(Register result,
974                             DwVfpRegister double_input,
975                             LowDwVfpRegister double_scratch);
976
977  // Floor a double and writes the value to the result register.
978  // Go to exact if the conversion is exact (to be able to test -0),
979  // fall through calling code if an overflow occurred, else go to done.
980  // In return, input_high is loaded with high bits of input.
981  void TryInt32Floor(Register result,
982                     DwVfpRegister double_input,
983                     Register input_high,
984                     LowDwVfpRegister double_scratch,
985                     Label* done,
986                     Label* exact);
987
988  // Performs a truncating conversion of a floating point number as used by
989  // the JS bitwise operations. See ECMA-262 9.5: ToInt32. Goes to 'done' if it
990  // succeeds, otherwise falls through if result is saturated. On return
991  // 'result' either holds answer, or is clobbered on fall through.
992  //
993  // Only public for the test code in test-code-stubs-arm.cc.
994  void TryInlineTruncateDoubleToI(Register result,
995                                  DwVfpRegister input,
996                                  Label* done);
997
998  // Performs a truncating conversion of a floating point number as used by
999  // the JS bitwise operations. See ECMA-262 9.5: ToInt32.
1000  // Exits with 'result' holding the answer.
1001  void TruncateDoubleToI(Register result, DwVfpRegister double_input);
1002
1003  // Performs a truncating conversion of a heap number as used by
1004  // the JS bitwise operations. See ECMA-262 9.5: ToInt32. 'result' and 'input'
1005  // must be different registers.  Exits with 'result' holding the answer.
1006  void TruncateHeapNumberToI(Register result, Register object);
1007
1008  // Converts the smi or heap number in object to an int32 using the rules
1009  // for ToInt32 as described in ECMAScript 9.5.: the value is truncated
1010  // and brought into the range -2^31 .. +2^31 - 1. 'result' and 'input' must be
1011  // different registers.
1012  void TruncateNumberToI(Register object,
1013                         Register result,
1014                         Register heap_number_map,
1015                         Register scratch1,
1016                         Label* not_int32);
1017
1018  // Check whether d16-d31 are available on the CPU. The result is given by the
1019  // Z condition flag: Z==0 if d16-d31 available, Z==1 otherwise.
1020  void CheckFor32DRegs(Register scratch);
1021
1022  // Does a runtime check for 16/32 FP registers. Either way, pushes 32 double
1023  // values to location, saving [d0..(d15|d31)].
1024  void SaveFPRegs(Register location, Register scratch);
1025
1026  // Does a runtime check for 16/32 FP registers. Either way, pops 32 double
1027  // values to location, restoring [d0..(d15|d31)].
1028  void RestoreFPRegs(Register location, Register scratch);
1029
1030  // ---------------------------------------------------------------------------
1031  // Runtime calls
1032
1033  // Call a code stub.
1034  void CallStub(CodeStub* stub,
1035                TypeFeedbackId ast_id = TypeFeedbackId::None(),
1036                Condition cond = al);
1037
1038  // Call a code stub.
1039  void TailCallStub(CodeStub* stub, Condition cond = al);
1040
1041  // Call a runtime routine.
1042  void CallRuntime(const Runtime::Function* f,
1043                   int num_arguments,
1044                   SaveFPRegsMode save_doubles = kDontSaveFPRegs);
1045  void CallRuntimeSaveDoubles(Runtime::FunctionId id) {
1046    const Runtime::Function* function = Runtime::FunctionForId(id);
1047    CallRuntime(function, function->nargs, kSaveFPRegs);
1048  }
1049
1050  // Convenience function: Same as above, but takes the fid instead.
1051  void CallRuntime(Runtime::FunctionId id,
1052                   int num_arguments,
1053                   SaveFPRegsMode save_doubles = kDontSaveFPRegs) {
1054    CallRuntime(Runtime::FunctionForId(id), num_arguments, save_doubles);
1055  }
1056
1057  // Convenience function: call an external reference.
1058  void CallExternalReference(const ExternalReference& ext,
1059                             int num_arguments);
1060
1061  // Tail call of a runtime routine (jump).
1062  // Like JumpToExternalReference, but also takes care of passing the number
1063  // of parameters.
1064  void TailCallExternalReference(const ExternalReference& ext,
1065                                 int num_arguments,
1066                                 int result_size);
1067
1068  // Convenience function: tail call a runtime routine (jump).
1069  void TailCallRuntime(Runtime::FunctionId fid,
1070                       int num_arguments,
1071                       int result_size);
1072
1073  int CalculateStackPassedWords(int num_reg_arguments,
1074                                int num_double_arguments);
1075
1076  // Before calling a C-function from generated code, align arguments on stack.
1077  // After aligning the frame, non-register arguments must be stored in
1078  // sp[0], sp[4], etc., not pushed. The argument count assumes all arguments
1079  // are word sized. If double arguments are used, this function assumes that
1080  // all double arguments are stored before core registers; otherwise the
1081  // correct alignment of the double values is not guaranteed.
1082  // Some compilers/platforms require the stack to be aligned when calling
1083  // C++ code.
1084  // Needs a scratch register to do some arithmetic. This register will be
1085  // trashed.
1086  void PrepareCallCFunction(int num_reg_arguments,
1087                            int num_double_registers,
1088                            Register scratch);
1089  void PrepareCallCFunction(int num_reg_arguments,
1090                            Register scratch);
1091
1092  // There are two ways of passing double arguments on ARM, depending on
1093  // whether soft or hard floating point ABI is used. These functions
1094  // abstract parameter passing for the three different ways we call
1095  // C functions from generated code.
1096  void MovToFloatParameter(DwVfpRegister src);
1097  void MovToFloatParameters(DwVfpRegister src1, DwVfpRegister src2);
1098  void MovToFloatResult(DwVfpRegister src);
1099
1100  // Calls a C function and cleans up the space for arguments allocated
1101  // by PrepareCallCFunction. The called function is not allowed to trigger a
1102  // garbage collection, since that might move the code and invalidate the
1103  // return address (unless this is somehow accounted for by the called
1104  // function).
1105  void CallCFunction(ExternalReference function, int num_arguments);
1106  void CallCFunction(Register function, int num_arguments);
1107  void CallCFunction(ExternalReference function,
1108                     int num_reg_arguments,
1109                     int num_double_arguments);
1110  void CallCFunction(Register function,
1111                     int num_reg_arguments,
1112                     int num_double_arguments);
1113
1114  void MovFromFloatParameter(DwVfpRegister dst);
1115  void MovFromFloatResult(DwVfpRegister dst);
1116
1117  // Calls an API function.  Allocates HandleScope, extracts returned value
1118  // from handle and propagates exceptions.  Restores context.  stack_space
1119  // - space to be unwound on exit (includes the call JS arguments space and
1120  // the additional space allocated for the fast call).
1121  void CallApiFunctionAndReturn(Register function_address,
1122                                ExternalReference thunk_ref,
1123                                int stack_space,
1124                                MemOperand return_value_operand,
1125                                MemOperand* context_restore_operand);
1126
1127  // Jump to a runtime routine.
1128  void JumpToExternalReference(const ExternalReference& builtin);
1129
1130  // Invoke specified builtin JavaScript function. Adds an entry to
1131  // the unresolved list if the name does not resolve.
1132  void InvokeBuiltin(Builtins::JavaScript id,
1133                     InvokeFlag flag,
1134                     const CallWrapper& call_wrapper = NullCallWrapper());
1135
1136  // Store the code object for the given builtin in the target register and
1137  // setup the function in r1.
1138  void GetBuiltinEntry(Register target, Builtins::JavaScript id);
1139
1140  // Store the function for the given builtin in the target register.
1141  void GetBuiltinFunction(Register target, Builtins::JavaScript id);
1142
1143  Handle<Object> CodeObject() {
1144    DCHECK(!code_object_.is_null());
1145    return code_object_;
1146  }
1147
1148
1149  // Emit code for a truncating division by a constant. The dividend register is
1150  // unchanged and ip gets clobbered. Dividend and result must be different.
1151  void TruncatingDiv(Register result, Register dividend, int32_t divisor);
1152
1153  // ---------------------------------------------------------------------------
1154  // StatsCounter support
1155
1156  void SetCounter(StatsCounter* counter, int value,
1157                  Register scratch1, Register scratch2);
1158  void IncrementCounter(StatsCounter* counter, int value,
1159                        Register scratch1, Register scratch2);
1160  void DecrementCounter(StatsCounter* counter, int value,
1161                        Register scratch1, Register scratch2);
1162
1163
1164  // ---------------------------------------------------------------------------
1165  // Debugging
1166
1167  // Calls Abort(msg) if the condition cond is not satisfied.
1168  // Use --debug_code to enable.
1169  void Assert(Condition cond, BailoutReason reason);
1170  void AssertFastElements(Register elements);
1171
1172  // Like Assert(), but always enabled.
1173  void Check(Condition cond, BailoutReason reason);
1174
1175  // Print a message to stdout and abort execution.
1176  void Abort(BailoutReason msg);
1177
1178  // Verify restrictions about code generated in stubs.
1179  void set_generating_stub(bool value) { generating_stub_ = value; }
1180  bool generating_stub() { return generating_stub_; }
1181  void set_has_frame(bool value) { has_frame_ = value; }
1182  bool has_frame() { return has_frame_; }
1183  inline bool AllowThisStubCall(CodeStub* stub);
1184
1185  // EABI variant for double arguments in use.
1186  bool use_eabi_hardfloat() {
1187#ifdef __arm__
1188    return base::OS::ArmUsingHardFloat();
1189#elif USE_EABI_HARDFLOAT
1190    return true;
1191#else
1192    return false;
1193#endif
1194  }
1195
1196  // ---------------------------------------------------------------------------
1197  // Number utilities
1198
1199  // Check whether the value of reg is a power of two and not zero. If not
1200  // control continues at the label not_power_of_two. If reg is a power of two
1201  // the register scratch contains the value of (reg - 1) when control falls
1202  // through.
1203  void JumpIfNotPowerOfTwoOrZero(Register reg,
1204                                 Register scratch,
1205                                 Label* not_power_of_two_or_zero);
1206  // Check whether the value of reg is a power of two and not zero.
1207  // Control falls through if it is, with scratch containing the mask
1208  // value (reg - 1).
1209  // Otherwise control jumps to the 'zero_and_neg' label if the value of reg is
1210  // zero or negative, or jumps to the 'not_power_of_two' label if the value is
1211  // strictly positive but not a power of two.
1212  void JumpIfNotPowerOfTwoOrZeroAndNeg(Register reg,
1213                                       Register scratch,
1214                                       Label* zero_and_neg,
1215                                       Label* not_power_of_two);
1216
1217  // ---------------------------------------------------------------------------
1218  // Smi utilities
1219
1220  void SmiTag(Register reg, SBit s = LeaveCC) {
1221    add(reg, reg, Operand(reg), s);
1222  }
1223  void SmiTag(Register dst, Register src, SBit s = LeaveCC) {
1224    add(dst, src, Operand(src), s);
1225  }
1226
1227  // Try to convert int32 to smi. If the value is to large, preserve
1228  // the original value and jump to not_a_smi. Destroys scratch and
1229  // sets flags.
1230  void TrySmiTag(Register reg, Label* not_a_smi) {
1231    TrySmiTag(reg, reg, not_a_smi);
1232  }
1233  void TrySmiTag(Register reg, Register src, Label* not_a_smi) {
1234    SmiTag(ip, src, SetCC);
1235    b(vs, not_a_smi);
1236    mov(reg, ip);
1237  }
1238
1239
1240  void SmiUntag(Register reg, SBit s = LeaveCC) {
1241    mov(reg, Operand::SmiUntag(reg), s);
1242  }
1243  void SmiUntag(Register dst, Register src, SBit s = LeaveCC) {
1244    mov(dst, Operand::SmiUntag(src), s);
1245  }
1246
1247  // Untag the source value into destination and jump if source is a smi.
1248  // Souce and destination can be the same register.
1249  void UntagAndJumpIfSmi(Register dst, Register src, Label* smi_case);
1250
1251  // Untag the source value into destination and jump if source is not a smi.
1252  // Souce and destination can be the same register.
1253  void UntagAndJumpIfNotSmi(Register dst, Register src, Label* non_smi_case);
1254
1255  // Test if the register contains a smi (Z == 0 (eq) if true).
1256  inline void SmiTst(Register value) {
1257    tst(value, Operand(kSmiTagMask));
1258  }
1259  inline void NonNegativeSmiTst(Register value) {
1260    tst(value, Operand(kSmiTagMask | kSmiSignMask));
1261  }
1262  // Jump if the register contains a smi.
1263  inline void JumpIfSmi(Register value, Label* smi_label) {
1264    tst(value, Operand(kSmiTagMask));
1265    b(eq, smi_label);
1266  }
1267  // Jump if either of the registers contain a non-smi.
1268  inline void JumpIfNotSmi(Register value, Label* not_smi_label) {
1269    tst(value, Operand(kSmiTagMask));
1270    b(ne, not_smi_label);
1271  }
1272  // Jump if either of the registers contain a non-smi.
1273  void JumpIfNotBothSmi(Register reg1, Register reg2, Label* on_not_both_smi);
1274  // Jump if either of the registers contain a smi.
1275  void JumpIfEitherSmi(Register reg1, Register reg2, Label* on_either_smi);
1276
1277  // Abort execution if argument is a smi, enabled via --debug-code.
1278  void AssertNotSmi(Register object);
1279  void AssertSmi(Register object);
1280
1281  // Abort execution if argument is not a string, enabled via --debug-code.
1282  void AssertString(Register object);
1283
1284  // Abort execution if argument is not a name, enabled via --debug-code.
1285  void AssertName(Register object);
1286
1287  // Abort execution if argument is not undefined or an AllocationSite, enabled
1288  // via --debug-code.
1289  void AssertUndefinedOrAllocationSite(Register object, Register scratch);
1290
1291  // Abort execution if reg is not the root value with the given index,
1292  // enabled via --debug-code.
1293  void AssertIsRoot(Register reg, Heap::RootListIndex index);
1294
1295  // ---------------------------------------------------------------------------
1296  // HeapNumber utilities
1297
1298  void JumpIfNotHeapNumber(Register object,
1299                           Register heap_number_map,
1300                           Register scratch,
1301                           Label* on_not_heap_number);
1302
1303  // ---------------------------------------------------------------------------
1304  // String utilities
1305
1306  // Generate code to do a lookup in the number string cache. If the number in
1307  // the register object is found in the cache the generated code falls through
1308  // with the result in the result register. The object and the result register
1309  // can be the same. If the number is not found in the cache the code jumps to
1310  // the label not_found with only the content of register object unchanged.
1311  void LookupNumberStringCache(Register object,
1312                               Register result,
1313                               Register scratch1,
1314                               Register scratch2,
1315                               Register scratch3,
1316                               Label* not_found);
1317
1318  // Checks if both objects are sequential one-byte strings and jumps to label
1319  // if either is not. Assumes that neither object is a smi.
1320  void JumpIfNonSmisNotBothSequentialOneByteStrings(Register object1,
1321                                                    Register object2,
1322                                                    Register scratch1,
1323                                                    Register scratch2,
1324                                                    Label* failure);
1325
1326  // Checks if both objects are sequential one-byte strings and jumps to label
1327  // if either is not.
1328  void JumpIfNotBothSequentialOneByteStrings(Register first, Register second,
1329                                             Register scratch1,
1330                                             Register scratch2,
1331                                             Label* not_flat_one_byte_strings);
1332
1333  // Checks if both instance types are sequential one-byte strings and jumps to
1334  // label if either is not.
1335  void JumpIfBothInstanceTypesAreNotSequentialOneByte(
1336      Register first_object_instance_type, Register second_object_instance_type,
1337      Register scratch1, Register scratch2, Label* failure);
1338
1339  // Check if instance type is sequential one-byte string and jump to label if
1340  // it is not.
1341  void JumpIfInstanceTypeIsNotSequentialOneByte(Register type, Register scratch,
1342                                                Label* failure);
1343
1344  void JumpIfNotUniqueNameInstanceType(Register reg, Label* not_unique_name);
1345
1346  void EmitSeqStringSetCharCheck(Register string,
1347                                 Register index,
1348                                 Register value,
1349                                 uint32_t encoding_mask);
1350
1351  // ---------------------------------------------------------------------------
1352  // Patching helpers.
1353
1354  // Get the location of a relocated constant (its address in the constant pool)
1355  // from its load site.
1356  void GetRelocatedValueLocation(Register ldr_location, Register result,
1357                                 Register scratch);
1358
1359
1360  void ClampUint8(Register output_reg, Register input_reg);
1361
1362  void ClampDoubleToUint8(Register result_reg,
1363                          DwVfpRegister input_reg,
1364                          LowDwVfpRegister double_scratch);
1365
1366
1367  void LoadInstanceDescriptors(Register map, Register descriptors);
1368  void EnumLength(Register dst, Register map);
1369  void NumberOfOwnDescriptors(Register dst, Register map);
1370
1371  template<typename Field>
1372  void DecodeField(Register dst, Register src) {
1373    Ubfx(dst, src, Field::kShift, Field::kSize);
1374  }
1375
1376  template<typename Field>
1377  void DecodeField(Register reg) {
1378    DecodeField<Field>(reg, reg);
1379  }
1380
1381  template<typename Field>
1382  void DecodeFieldToSmi(Register dst, Register src) {
1383    static const int shift = Field::kShift;
1384    static const int mask = Field::kMask >> shift << kSmiTagSize;
1385    STATIC_ASSERT((mask & (0x80000000u >> (kSmiTagSize - 1))) == 0);
1386    STATIC_ASSERT(kSmiTag == 0);
1387    if (shift < kSmiTagSize) {
1388      mov(dst, Operand(src, LSL, kSmiTagSize - shift));
1389      and_(dst, dst, Operand(mask));
1390    } else if (shift > kSmiTagSize) {
1391      mov(dst, Operand(src, LSR, shift - kSmiTagSize));
1392      and_(dst, dst, Operand(mask));
1393    } else {
1394      and_(dst, src, Operand(mask));
1395    }
1396  }
1397
1398  template<typename Field>
1399  void DecodeFieldToSmi(Register reg) {
1400    DecodeField<Field>(reg, reg);
1401  }
1402
1403  // Activation support.
1404  void EnterFrame(StackFrame::Type type, bool load_constant_pool = false);
1405  // Returns the pc offset at which the frame ends.
1406  int LeaveFrame(StackFrame::Type type);
1407
1408  // Expects object in r0 and returns map with validated enum cache
1409  // in r0.  Assumes that any other register can be used as a scratch.
1410  void CheckEnumCache(Register null_value, Label* call_runtime);
1411
1412  // AllocationMemento support. Arrays may have an associated
1413  // AllocationMemento object that can be checked for in order to pretransition
1414  // to another type.
1415  // On entry, receiver_reg should point to the array object.
1416  // scratch_reg gets clobbered.
1417  // If allocation info is present, condition flags are set to eq.
1418  void TestJSArrayForAllocationMemento(Register receiver_reg,
1419                                       Register scratch_reg,
1420                                       Label* no_memento_found);
1421
1422  void JumpIfJSArrayHasAllocationMemento(Register receiver_reg,
1423                                         Register scratch_reg,
1424                                         Label* memento_found) {
1425    Label no_memento_found;
1426    TestJSArrayForAllocationMemento(receiver_reg, scratch_reg,
1427                                    &no_memento_found);
1428    b(eq, memento_found);
1429    bind(&no_memento_found);
1430  }
1431
1432  // Jumps to found label if a prototype map has dictionary elements.
1433  void JumpIfDictionaryInPrototypeChain(Register object, Register scratch0,
1434                                        Register scratch1, Label* found);
1435
1436 private:
1437  void CallCFunctionHelper(Register function,
1438                           int num_reg_arguments,
1439                           int num_double_arguments);
1440
1441  void Jump(intptr_t target, RelocInfo::Mode rmode, Condition cond = al);
1442
1443  // Helper functions for generating invokes.
1444  void InvokePrologue(const ParameterCount& expected,
1445                      const ParameterCount& actual,
1446                      Handle<Code> code_constant,
1447                      Register code_reg,
1448                      Label* done,
1449                      bool* definitely_mismatches,
1450                      InvokeFlag flag,
1451                      const CallWrapper& call_wrapper);
1452
1453  void InitializeNewString(Register string,
1454                           Register length,
1455                           Heap::RootListIndex map_index,
1456                           Register scratch1,
1457                           Register scratch2);
1458
1459  // Helper for implementing JumpIfNotInNewSpace and JumpIfInNewSpace.
1460  void InNewSpace(Register object,
1461                  Register scratch,
1462                  Condition cond,  // eq for new space, ne otherwise.
1463                  Label* branch);
1464
1465  // Helper for finding the mark bits for an address.  Afterwards, the
1466  // bitmap register points at the word with the mark bits and the mask
1467  // the position of the first bit.  Leaves addr_reg unchanged.
1468  inline void GetMarkBits(Register addr_reg,
1469                          Register bitmap_reg,
1470                          Register mask_reg);
1471
1472  // Helper for throwing exceptions.  Compute a handler address and jump to
1473  // it.  See the implementation for register usage.
1474  void JumpToHandlerEntry();
1475
1476  // Compute memory operands for safepoint stack slots.
1477  static int SafepointRegisterStackIndex(int reg_code);
1478  MemOperand SafepointRegisterSlot(Register reg);
1479  MemOperand SafepointRegistersAndDoublesSlot(Register reg);
1480
1481  // Loads the constant pool pointer (pp) register.
1482  void LoadConstantPoolPointerRegister();
1483
1484  bool generating_stub_;
1485  bool has_frame_;
1486  // This handle will be patched with the code object on installation.
1487  Handle<Object> code_object_;
1488
1489  // Needs access to SafepointRegisterStackIndex for compiled frame
1490  // traversal.
1491  friend class StandardFrame;
1492};
1493
1494
1495// The code patcher is used to patch (typically) small parts of code e.g. for
1496// debugging and other types of instrumentation. When using the code patcher
1497// the exact number of bytes specified must be emitted. It is not legal to emit
1498// relocation information. If any of these constraints are violated it causes
1499// an assertion to fail.
1500class CodePatcher {
1501 public:
1502  enum FlushICache {
1503    FLUSH,
1504    DONT_FLUSH
1505  };
1506
1507  CodePatcher(byte* address,
1508              int instructions,
1509              FlushICache flush_cache = FLUSH);
1510  virtual ~CodePatcher();
1511
1512  // Macro assembler to emit code.
1513  MacroAssembler* masm() { return &masm_; }
1514
1515  // Emit an instruction directly.
1516  void Emit(Instr instr);
1517
1518  // Emit an address directly.
1519  void Emit(Address addr);
1520
1521  // Emit the condition part of an instruction leaving the rest of the current
1522  // instruction unchanged.
1523  void EmitCondition(Condition cond);
1524
1525 private:
1526  byte* address_;  // The address of the code being patched.
1527  int size_;  // Number of bytes of the expected patch size.
1528  MacroAssembler masm_;  // Macro assembler used to generate the code.
1529  FlushICache flush_cache_;  // Whether to flush the I cache after patching.
1530};
1531
1532
1533class FrameAndConstantPoolScope {
1534 public:
1535  FrameAndConstantPoolScope(MacroAssembler* masm, StackFrame::Type type)
1536      : masm_(masm),
1537        type_(type),
1538        old_has_frame_(masm->has_frame()),
1539        old_constant_pool_available_(masm->is_constant_pool_available())  {
1540    // We only want to enable constant pool access for non-manual frame scopes
1541    // to ensure the constant pool pointer is valid throughout the scope.
1542    DCHECK(type_ != StackFrame::MANUAL && type_ != StackFrame::NONE);
1543    masm->set_has_frame(true);
1544    masm->set_constant_pool_available(true);
1545    masm->EnterFrame(type, !old_constant_pool_available_);
1546  }
1547
1548  ~FrameAndConstantPoolScope() {
1549    masm_->LeaveFrame(type_);
1550    masm_->set_has_frame(old_has_frame_);
1551    masm_->set_constant_pool_available(old_constant_pool_available_);
1552  }
1553
1554  // Normally we generate the leave-frame code when this object goes
1555  // out of scope.  Sometimes we may need to generate the code somewhere else
1556  // in addition.  Calling this will achieve that, but the object stays in
1557  // scope, the MacroAssembler is still marked as being in a frame scope, and
1558  // the code will be generated again when it goes out of scope.
1559  void GenerateLeaveFrame() {
1560    DCHECK(type_ != StackFrame::MANUAL && type_ != StackFrame::NONE);
1561    masm_->LeaveFrame(type_);
1562  }
1563
1564 private:
1565  MacroAssembler* masm_;
1566  StackFrame::Type type_;
1567  bool old_has_frame_;
1568  bool old_constant_pool_available_;
1569
1570  DISALLOW_IMPLICIT_CONSTRUCTORS(FrameAndConstantPoolScope);
1571};
1572
1573
1574// Class for scoping the the unavailability of constant pool access.
1575class ConstantPoolUnavailableScope {
1576 public:
1577  explicit ConstantPoolUnavailableScope(MacroAssembler* masm)
1578     : masm_(masm),
1579       old_constant_pool_available_(masm->is_constant_pool_available()) {
1580    if (FLAG_enable_ool_constant_pool) {
1581      masm_->set_constant_pool_available(false);
1582    }
1583  }
1584  ~ConstantPoolUnavailableScope() {
1585    if (FLAG_enable_ool_constant_pool) {
1586     masm_->set_constant_pool_available(old_constant_pool_available_);
1587    }
1588  }
1589
1590 private:
1591  MacroAssembler* masm_;
1592  int old_constant_pool_available_;
1593
1594  DISALLOW_IMPLICIT_CONSTRUCTORS(ConstantPoolUnavailableScope);
1595};
1596
1597
1598// -----------------------------------------------------------------------------
1599// Static helper functions.
1600
1601inline MemOperand ContextOperand(Register context, int index) {
1602  return MemOperand(context, Context::SlotOffset(index));
1603}
1604
1605
1606inline MemOperand GlobalObjectOperand()  {
1607  return ContextOperand(cp, Context::GLOBAL_OBJECT_INDEX);
1608}
1609
1610
1611#ifdef GENERATED_CODE_COVERAGE
1612#define CODE_COVERAGE_STRINGIFY(x) #x
1613#define CODE_COVERAGE_TOSTRING(x) CODE_COVERAGE_STRINGIFY(x)
1614#define __FILE_LINE__ __FILE__ ":" CODE_COVERAGE_TOSTRING(__LINE__)
1615#define ACCESS_MASM(masm) masm->stop(__FILE_LINE__); masm->
1616#else
1617#define ACCESS_MASM(masm) masm->
1618#endif
1619
1620
1621} }  // namespace v8::internal
1622
1623#endif  // V8_ARM_MACRO_ASSEMBLER_ARM_H_
1624