OLD | NEW |
(Empty) | |
| 1 // Copyright 2009 the V8 project authors. All rights reserved. |
| 2 // Redistribution and use in source and binary forms, with or without |
| 3 // modification, are permitted provided that the following conditions are |
| 4 // met: |
| 5 // |
| 6 // * Redistributions of source code must retain the above copyright |
| 7 // notice, this list of conditions and the following disclaimer. |
| 8 // * Redistributions in binary form must reproduce the above |
| 9 // copyright notice, this list of conditions and the following |
| 10 // disclaimer in the documentation and/or other materials provided |
| 11 // with the distribution. |
| 12 // * Neither the name of Google Inc. nor the names of its |
| 13 // contributors may be used to endorse or promote products derived |
| 14 // from this software without specific prior written permission. |
| 15 // |
| 16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 27 |
| 28 #ifndef V8_VIRTUAL_FRAME_ARM_H_ |
| 29 #define V8_VIRTUAL_FRAME_ARM_H_ |
| 30 |
| 31 #include "register-allocator.h" |
| 32 |
| 33 namespace v8 { namespace internal { |
| 34 |
| 35 // ------------------------------------------------------------------------- |
| 36 // Virtual frames |
| 37 // |
| 38 // The virtual frame is an abstraction of the physical stack frame. It |
| 39 // encapsulates the parameters, frame-allocated locals, and the expression |
| 40 // stack. It supports push/pop operations on the expression stack, as well |
| 41 // as random access to the expression stack elements, locals, and |
| 42 // parameters. |
| 43 |
| 44 class VirtualFrame : public Malloced { |
| 45 public: |
| 46 // A utility class to introduce a scope where the virtual frame is |
| 47 // expected to remain spilled. The constructor spills the code |
| 48 // generator's current frame, but no attempt is made to require it |
| 49 // to stay spilled. It is intended as documentation while the code |
| 50 // generator is being transformed. |
| 51 class SpilledScope BASE_EMBEDDED { |
| 52 public: |
| 53 explicit SpilledScope(CodeGenerator* cgen); |
| 54 |
| 55 ~SpilledScope(); |
| 56 |
| 57 private: |
| 58 CodeGenerator* cgen_; |
| 59 bool previous_state_; |
| 60 }; |
| 61 |
| 62 // An illegal index into the virtual frame. |
| 63 static const int kIllegalIndex = -1; |
| 64 |
| 65 // Construct an initial virtual frame on entry to a JS function. |
| 66 explicit VirtualFrame(CodeGenerator* cgen); |
| 67 |
| 68 // Construct a virtual frame as a clone of an existing one. |
| 69 explicit VirtualFrame(VirtualFrame* original); |
| 70 |
| 71 // Create a duplicate of an existing valid frame element. |
| 72 FrameElement CopyElementAt(int index); |
| 73 |
| 74 // The height of the virtual expression stack. |
| 75 int height() const { |
| 76 return elements_.length() - expression_base_index(); |
| 77 } |
| 78 |
| 79 int register_index(Register reg) { |
| 80 return register_locations_[reg.code()]; |
| 81 } |
| 82 |
| 83 bool is_used(int reg_code) { |
| 84 return register_locations_[reg_code] != kIllegalIndex; |
| 85 } |
| 86 |
| 87 bool is_used(Register reg) { |
| 88 return is_used(reg.code()); |
| 89 } |
| 90 |
| 91 // Add extra in-memory elements to the top of the frame to match an actual |
| 92 // frame (eg, the frame after an exception handler is pushed). No code is |
| 93 // emitted. |
| 94 void Adjust(int count); |
| 95 |
| 96 // Forget elements from the top of the frame to match an actual frame (eg, |
| 97 // the frame after a runtime call). No code is emitted. |
| 98 void Forget(int count); |
| 99 |
| 100 // Forget count elements from the top of the frame without adjusting |
| 101 // the stack pointer downward. This is used, for example, before |
| 102 // merging frames at break, continue, and return targets. |
| 103 void ForgetElements(int count); |
| 104 |
| 105 // Spill all values from the frame to memory. |
| 106 void SpillAll(); |
| 107 |
| 108 // Spill all occurrences of a specific register from the frame. |
| 109 void Spill(Register reg); |
| 110 |
| 111 // Spill all occurrences of an arbitrary register if possible. Return the |
| 112 // register spilled or no_reg if it was not possible to free any register |
| 113 // (ie, they all have frame-external references). |
| 114 Register SpillAnyRegister(); |
| 115 |
| 116 // Prepare this virtual frame for merging to an expected frame by |
| 117 // performing some state changes that do not require generating |
| 118 // code. It is guaranteed that no code will be generated. |
| 119 void PrepareMergeTo(VirtualFrame* expected); |
| 120 |
| 121 // Make this virtual frame have a state identical to an expected virtual |
| 122 // frame. As a side effect, code may be emitted to make this frame match |
| 123 // the expected one. |
| 124 void MergeTo(VirtualFrame* expected); |
| 125 |
| 126 // Detach a frame from its code generator, perhaps temporarily. This |
| 127 // tells the register allocator that it is free to use frame-internal |
| 128 // registers. Used when the code generator's frame is switched from this |
| 129 // one to NULL by an unconditional jump. |
| 130 void DetachFromCodeGenerator(); |
| 131 |
| 132 // (Re)attach a frame to its code generator. This informs the register |
| 133 // allocator that the frame-internal register references are active again. |
| 134 // Used when a code generator's frame is switched from NULL to this one by |
| 135 // binding a label. |
| 136 void AttachToCodeGenerator(); |
| 137 |
| 138 // Emit code for the physical JS entry and exit frame sequences. After |
| 139 // calling Enter, the virtual frame is ready for use; and after calling |
| 140 // Exit it should not be used. Note that Enter does not allocate space in |
| 141 // the physical frame for storing frame-allocated locals. |
| 142 void Enter(); |
| 143 void Exit(); |
| 144 |
| 145 // Prepare for returning from the frame by spilling locals and |
| 146 // dropping all non-locals elements in the virtual frame. This |
| 147 // avoids generating unnecessary merge code when jumping to the |
| 148 // shared return site. Emits code for spills. |
| 149 void PrepareForReturn(); |
| 150 |
| 151 // Allocate and initialize the frame-allocated locals. |
| 152 void AllocateStackSlots(int count); |
| 153 |
| 154 // The current top of the expression stack as an assembly operand. |
| 155 MemOperand Top() const { return MemOperand(sp, 0); } |
| 156 |
| 157 // An element of the expression stack as an assembly operand. |
| 158 MemOperand ElementAt(int index) const { |
| 159 return MemOperand(sp, index * kPointerSize); |
| 160 } |
| 161 |
| 162 // Random-access store to a frame-top relative frame element. The result |
| 163 // becomes owned by the frame and is invalidated. |
| 164 void SetElementAt(int index, Result* value); |
| 165 |
| 166 // Set a frame element to a constant. The index is frame-top relative. |
| 167 void SetElementAt(int index, Handle<Object> value) { |
| 168 Result temp(value, cgen_); |
| 169 SetElementAt(index, &temp); |
| 170 } |
| 171 |
| 172 void PushElementAt(int index) { |
| 173 PushFrameSlotAt(elements_.length() - index - 1); |
| 174 } |
| 175 |
| 176 // A frame-allocated local as an assembly operand. |
| 177 MemOperand LocalAt(int index) const { |
| 178 ASSERT(0 <= index); |
| 179 ASSERT(index < local_count_); |
| 180 return MemOperand(fp, kLocal0Offset - index * kPointerSize); |
| 181 } |
| 182 |
| 183 // Push a copy of the value of a local frame slot on top of the frame. |
| 184 void PushLocalAt(int index) { |
| 185 PushFrameSlotAt(local0_index() + index); |
| 186 } |
| 187 |
| 188 // Push the value of a local frame slot on top of the frame and invalidate |
| 189 // the local slot. The slot should be written to before trying to read |
| 190 // from it again. |
| 191 void TakeLocalAt(int index) { |
| 192 TakeFrameSlotAt(local0_index() + index); |
| 193 } |
| 194 |
| 195 // Store the top value on the virtual frame into a local frame slot. The |
| 196 // value is left in place on top of the frame. |
| 197 void StoreToLocalAt(int index) { |
| 198 StoreToFrameSlotAt(local0_index() + index); |
| 199 } |
| 200 |
| 201 // Push the address of the receiver slot on the frame. |
| 202 void PushReceiverSlotAddress(); |
| 203 |
| 204 // The function frame slot. |
| 205 MemOperand Function() const { return MemOperand(fp, kFunctionOffset); } |
| 206 |
| 207 // Push the function on top of the frame. |
| 208 void PushFunction() { PushFrameSlotAt(function_index()); } |
| 209 |
| 210 // The context frame slot. |
| 211 MemOperand Context() const { return MemOperand(fp, kContextOffset); } |
| 212 |
| 213 // Save the value of the esi register to the context frame slot. |
| 214 void SaveContextRegister(); |
| 215 |
| 216 // Restore the esi register from the value of the context frame |
| 217 // slot. |
| 218 void RestoreContextRegister(); |
| 219 |
| 220 // A parameter as an assembly operand. |
| 221 MemOperand ParameterAt(int index) const { |
| 222 // Index -1 corresponds to the receiver. |
| 223 ASSERT(-1 <= index && index <= parameter_count_); |
| 224 return MemOperand(fp, (1 + parameter_count_ - index) * kPointerSize); |
| 225 } |
| 226 |
| 227 // Push a copy of the value of a parameter frame slot on top of the frame. |
| 228 void PushParameterAt(int index) { |
| 229 PushFrameSlotAt(param0_index() + index); |
| 230 } |
| 231 |
| 232 // Push the value of a paramter frame slot on top of the frame and |
| 233 // invalidate the parameter slot. The slot should be written to before |
| 234 // trying to read from it again. |
| 235 void TakeParameterAt(int index) { |
| 236 TakeFrameSlotAt(param0_index() + index); |
| 237 } |
| 238 |
| 239 // Store the top value on the virtual frame into a parameter frame slot. |
| 240 // The value is left in place on top of the frame. |
| 241 void StoreToParameterAt(int index) { |
| 242 StoreToFrameSlotAt(param0_index() + index); |
| 243 } |
| 244 |
| 245 // The receiver frame slot. |
| 246 MemOperand Receiver() const { return ParameterAt(-1); } |
| 247 |
| 248 // Push a try-catch or try-finally handler on top of the virtual frame. |
| 249 void PushTryHandler(HandlerType type); |
| 250 |
| 251 // Call stub given the number of arguments it expects on (and |
| 252 // removes from) the stack. |
| 253 Result CallStub(CodeStub* stub, int arg_count); |
| 254 |
| 255 // Call stub that expects its argument in r0. The argument is given |
| 256 // as a result which must be the register r0. |
| 257 Result CallStub(CodeStub* stub, Result* arg); |
| 258 |
| 259 // Call stub that expects its arguments in r1 and r0. The arguments |
| 260 // are given as results which must be the appropriate registers. |
| 261 Result CallStub(CodeStub* stub, Result* arg0, Result* arg1); |
| 262 |
| 263 // Call runtime given the number of arguments expected on (and |
| 264 // removed from) the stack. |
| 265 Result CallRuntime(Runtime::Function* f, int arg_count); |
| 266 Result CallRuntime(Runtime::FunctionId id, int arg_count); |
| 267 |
| 268 // Invoke builtin given the number of arguments it expects on (and |
| 269 // removes from) the stack. |
| 270 Result InvokeBuiltin(Builtins::JavaScript id, |
| 271 InvokeJSFlags flag, |
| 272 Result* arg_count_register, |
| 273 int arg_count); |
| 274 |
| 275 // Call into an IC stub given the number of arguments it removes |
| 276 // from the stack. Register arguments are passed as results and |
| 277 // consumed by the call. |
| 278 Result CallCodeObject(Handle<Code> ic, |
| 279 RelocInfo::Mode rmode, |
| 280 int dropped_args); |
| 281 Result CallCodeObject(Handle<Code> ic, |
| 282 RelocInfo::Mode rmode, |
| 283 Result* arg, |
| 284 int dropped_args); |
| 285 Result CallCodeObject(Handle<Code> ic, |
| 286 RelocInfo::Mode rmode, |
| 287 Result* arg0, |
| 288 Result* arg1, |
| 289 int dropped_args); |
| 290 |
| 291 // Drop a number of elements from the top of the expression stack. May |
| 292 // emit code to affect the physical frame. Does not clobber any registers |
| 293 // excepting possibly the stack pointer. |
| 294 void Drop(int count); |
| 295 |
| 296 // Drop one element. |
| 297 void Drop() { Drop(1); } |
| 298 |
| 299 // Duplicate the top element of the frame. |
| 300 void Dup() { PushFrameSlotAt(elements_.length() - 1); } |
| 301 |
| 302 // Pop an element from the top of the expression stack. Returns a |
| 303 // Result, which may be a constant or a register. |
| 304 Result Pop(); |
| 305 |
| 306 // Pop and save an element from the top of the expression stack and |
| 307 // emit a corresponding pop instruction. |
| 308 void EmitPop(Register reg); |
| 309 |
| 310 // Push an element on top of the expression stack and emit a |
| 311 // corresponding push instruction. |
| 312 void EmitPush(Register reg); |
| 313 |
| 314 // Push an element on the virtual frame. |
| 315 void Push(Register reg, StaticType static_type = StaticType()); |
| 316 void Push(Handle<Object> value); |
| 317 void Push(Smi* value) { Push(Handle<Object>(value)); } |
| 318 |
| 319 // Pushing a result invalidates it (its contents become owned by the frame). |
| 320 void Push(Result* result); |
| 321 |
| 322 // Nip removes zero or more elements from immediately below the top |
| 323 // of the frame, leaving the previous top-of-frame value on top of |
| 324 // the frame. Nip(k) is equivalent to x = Pop(), Drop(k), Push(x). |
| 325 void Nip(int num_dropped); |
| 326 |
| 327 private: |
| 328 static const int kLocal0Offset = JavaScriptFrameConstants::kLocal0Offset; |
| 329 static const int kFunctionOffset = JavaScriptFrameConstants::kFunctionOffset; |
| 330 static const int kContextOffset = StandardFrameConstants::kContextOffset; |
| 331 |
| 332 static const int kHandlerSize = StackHandlerConstants::kSize / kPointerSize; |
| 333 static const int kPreallocatedElements = 5 + 8; // 8 expression stack slots. |
| 334 |
| 335 CodeGenerator* cgen_; |
| 336 MacroAssembler* masm_; |
| 337 |
| 338 List<FrameElement> elements_; |
| 339 |
| 340 // The number of frame-allocated locals and parameters respectively. |
| 341 int parameter_count_; |
| 342 int local_count_; |
| 343 |
| 344 // The index of the element that is at the processor's stack pointer |
| 345 // (the sp register). |
| 346 int stack_pointer_; |
| 347 |
| 348 // The index of the element that is at the processor's frame pointer |
| 349 // (the fp register). |
| 350 int frame_pointer_; |
| 351 |
| 352 // The index of the register frame element using each register, or |
| 353 // kIllegalIndex if a register is not on the frame. |
| 354 int register_locations_[kNumRegisters]; |
| 355 |
| 356 // The index of the first parameter. The receiver lies below the first |
| 357 // parameter. |
| 358 int param0_index() const { return 1; } |
| 359 |
| 360 // The index of the context slot in the frame. |
| 361 int context_index() const { |
| 362 ASSERT(frame_pointer_ != kIllegalIndex); |
| 363 return frame_pointer_ - 1; |
| 364 } |
| 365 |
| 366 // The index of the function slot in the frame. It lies above the context |
| 367 // slot. |
| 368 int function_index() const { |
| 369 ASSERT(frame_pointer_ != kIllegalIndex); |
| 370 return frame_pointer_ - 2; |
| 371 } |
| 372 |
| 373 // The index of the first local. Between the parameters and the locals |
| 374 // lie the return address, the saved frame pointer, the context, and the |
| 375 // function. |
| 376 int local0_index() const { |
| 377 ASSERT(frame_pointer_ != kIllegalIndex); |
| 378 return frame_pointer_ + 2; |
| 379 } |
| 380 |
| 381 // The index of the base of the expression stack. |
| 382 int expression_base_index() const { return local0_index() + local_count_; } |
| 383 |
| 384 // Convert a frame index into a frame pointer relative offset into the |
| 385 // actual stack. |
| 386 int fp_relative(int index) const { |
| 387 return (frame_pointer_ - index) * kPointerSize; |
| 388 } |
| 389 |
| 390 // Record an occurrence of a register in the virtual frame. This has the |
| 391 // effect of incrementing the register's external reference count and |
| 392 // of updating the index of the register's location in the frame. |
| 393 void Use(Register reg, int index); |
| 394 |
| 395 // Record that a register reference has been dropped from the frame. This |
| 396 // decrements the register's external reference count and invalidates the |
| 397 // index of the register's location in the frame. |
| 398 void Unuse(Register reg); |
| 399 |
| 400 // Spill the element at a particular index---write it to memory if |
| 401 // necessary, free any associated register, and forget its value if |
| 402 // constant. |
| 403 void SpillElementAt(int index); |
| 404 |
| 405 // Sync the element at a particular index. If it is a register or |
| 406 // constant that disagrees with the value on the stack, write it to memory. |
| 407 // Keep the element type as register or constant, and clear the dirty bit. |
| 408 void SyncElementAt(int index); |
| 409 |
| 410 // Sync the range of elements in [begin, end). |
| 411 void SyncRange(int begin, int end); |
| 412 |
| 413 // Sync a single unsynced element that lies beneath or at the stack pointer. |
| 414 void SyncElementBelowStackPointer(int index); |
| 415 |
| 416 // Sync a single unsynced element that lies just above the stack pointer. |
| 417 void SyncElementByPushing(int index); |
| 418 |
| 419 // Push a copy of a frame slot (typically a local or parameter) on top of |
| 420 // the frame. |
| 421 void PushFrameSlotAt(int index); |
| 422 |
| 423 // Push a the value of a frame slot (typically a local or parameter) on |
| 424 // top of the frame and invalidate the slot. |
| 425 void TakeFrameSlotAt(int index); |
| 426 |
| 427 // Store the value on top of the frame to a frame slot (typically a local |
| 428 // or parameter). |
| 429 void StoreToFrameSlotAt(int index); |
| 430 |
| 431 // Spill all elements in registers. Spill the top spilled_args elements |
| 432 // on the frame. Sync all other frame elements. |
| 433 // Then drop dropped_args elements from the virtual frame, to match |
| 434 // the effect of an upcoming call that will drop them from the stack. |
| 435 void PrepareForCall(int spilled_args, int dropped_args); |
| 436 |
| 437 // Move frame elements currently in registers or constants, that |
| 438 // should be in memory in the expected frame, to memory. |
| 439 void MergeMoveRegistersToMemory(VirtualFrame* expected); |
| 440 |
| 441 // Make the register-to-register moves necessary to |
| 442 // merge this frame with the expected frame. |
| 443 // Register to memory moves must already have been made, |
| 444 // and memory to register moves must follow this call. |
| 445 // This is because some new memory-to-register moves are |
| 446 // created in order to break cycles of register moves. |
| 447 // Used in the implementation of MergeTo(). |
| 448 void MergeMoveRegistersToRegisters(VirtualFrame* expected); |
| 449 |
| 450 // Make the memory-to-register and constant-to-register moves |
| 451 // needed to make this frame equal the expected frame. |
| 452 // Called after all register-to-memory and register-to-register |
| 453 // moves have been made. After this function returns, the frames |
| 454 // should be equal. |
| 455 void MergeMoveMemoryToRegisters(VirtualFrame* expected); |
| 456 |
| 457 // Invalidates a frame slot (puts an invalid frame element in it). |
| 458 // Copies on the frame are correctly handled, and if this slot was |
| 459 // the backing store of copies, the index of the new backing store |
| 460 // is returned. Otherwise, returns kIllegalIndex. |
| 461 // Register counts are correctly updated. |
| 462 int InvalidateFrameSlotAt(int index); |
| 463 |
| 464 // Call a code stub that has already been prepared for calling (via |
| 465 // PrepareForCall). |
| 466 Result RawCallStub(CodeStub* stub); |
| 467 |
| 468 // Calls a code object which has already been prepared for calling |
| 469 // (via PrepareForCall). |
| 470 Result RawCallCodeObject(Handle<Code> code, RelocInfo::Mode rmode); |
| 471 |
| 472 bool Equals(VirtualFrame* other); |
| 473 |
| 474 friend class JumpTarget; |
| 475 }; |
| 476 |
| 477 |
| 478 } } // namespace v8::internal |
| 479 |
| 480 #endif // V8_VIRTUAL_FRAME_ARM_H_ |
OLD | NEW |