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| 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 #include "v8.h" |
| 29 |
| 30 #include "codegen-inl.h" |
| 31 #include "register-allocator-inl.h" |
| 32 #include "scopes.h" |
| 33 |
| 34 namespace v8 { namespace internal { |
| 35 |
| 36 #define __ ACCESS_MASM(masm_) |
| 37 |
| 38 // ------------------------------------------------------------------------- |
| 39 // VirtualFrame implementation. |
| 40 |
| 41 // On entry to a function, the virtual frame already contains the receiver, |
| 42 // the parameters, and a return address. All frame elements are in memory. |
| 43 VirtualFrame::VirtualFrame(CodeGenerator* cgen) |
| 44 : cgen_(cgen), |
| 45 masm_(cgen->masm()), |
| 46 elements_(cgen->scope()->num_parameters() |
| 47 + cgen->scope()->num_stack_slots() |
| 48 + kPreallocatedElements), |
| 49 parameter_count_(cgen->scope()->num_parameters()), |
| 50 local_count_(0), |
| 51 stack_pointer_(parameter_count_ + 1), // 0-based index of TOS. |
| 52 frame_pointer_(kIllegalIndex) { |
| 53 for (int i = 0; i < parameter_count_ + 2; i++) { |
| 54 elements_.Add(FrameElement::MemoryElement()); |
| 55 } |
| 56 for (int i = 0; i < kNumRegisters; i++) { |
| 57 register_locations_[i] = kIllegalIndex; |
| 58 } |
| 59 } |
| 60 |
| 61 |
| 62 void VirtualFrame::SyncElementBelowStackPointer(int index) { |
| 63 // Emit code to write elements below the stack pointer to their |
| 64 // (already allocated) stack address. |
| 65 ASSERT(index <= stack_pointer_); |
| 66 FrameElement element = elements_[index]; |
| 67 ASSERT(!element.is_synced()); |
| 68 switch (element.type()) { |
| 69 case FrameElement::INVALID: |
| 70 break; |
| 71 |
| 72 case FrameElement::MEMORY: |
| 73 // This function should not be called with synced elements. |
| 74 // (memory elements are always synced). |
| 75 UNREACHABLE(); |
| 76 break; |
| 77 |
| 78 case FrameElement::REGISTER: |
| 79 __ mov(Operand(ebp, fp_relative(index)), element.reg()); |
| 80 break; |
| 81 |
| 82 case FrameElement::CONSTANT: |
| 83 if (cgen_->IsUnsafeSmi(element.handle())) { |
| 84 Result temp = cgen_->allocator()->Allocate(); |
| 85 ASSERT(temp.is_valid()); |
| 86 cgen_->LoadUnsafeSmi(temp.reg(), element.handle()); |
| 87 __ mov(Operand(ebp, fp_relative(index)), temp.reg()); |
| 88 } else { |
| 89 __ Set(Operand(ebp, fp_relative(index)), |
| 90 Immediate(element.handle())); |
| 91 } |
| 92 break; |
| 93 |
| 94 case FrameElement::COPY: { |
| 95 int backing_index = element.index(); |
| 96 FrameElement backing_element = elements_[backing_index]; |
| 97 if (backing_element.is_memory()) { |
| 98 Result temp = cgen_->allocator()->Allocate(); |
| 99 ASSERT(temp.is_valid()); |
| 100 __ mov(temp.reg(), Operand(ebp, fp_relative(backing_index))); |
| 101 __ mov(Operand(ebp, fp_relative(index)), temp.reg()); |
| 102 } else { |
| 103 ASSERT(backing_element.is_register()); |
| 104 __ mov(Operand(ebp, fp_relative(index)), backing_element.reg()); |
| 105 } |
| 106 break; |
| 107 } |
| 108 } |
| 109 elements_[index].set_sync(); |
| 110 } |
| 111 |
| 112 |
| 113 void VirtualFrame::SyncElementByPushing(int index) { |
| 114 // Sync an element of the frame that is just above the stack pointer |
| 115 // by pushing it. |
| 116 ASSERT(index == stack_pointer_ + 1); |
| 117 stack_pointer_++; |
| 118 FrameElement element = elements_[index]; |
| 119 |
| 120 switch (element.type()) { |
| 121 case FrameElement::INVALID: |
| 122 __ push(Immediate(Smi::FromInt(0))); |
| 123 break; |
| 124 |
| 125 case FrameElement::MEMORY: |
| 126 // No memory elements exist above the stack pointer. |
| 127 UNREACHABLE(); |
| 128 break; |
| 129 |
| 130 case FrameElement::REGISTER: |
| 131 __ push(element.reg()); |
| 132 break; |
| 133 |
| 134 case FrameElement::CONSTANT: |
| 135 if (cgen_->IsUnsafeSmi(element.handle())) { |
| 136 Result temp = cgen_->allocator()->Allocate(); |
| 137 ASSERT(temp.is_valid()); |
| 138 cgen_->LoadUnsafeSmi(temp.reg(), element.handle()); |
| 139 __ push(temp.reg()); |
| 140 } else { |
| 141 __ push(Immediate(element.handle())); |
| 142 } |
| 143 break; |
| 144 |
| 145 case FrameElement::COPY: { |
| 146 int backing_index = element.index(); |
| 147 FrameElement backing = elements_[backing_index]; |
| 148 ASSERT(backing.is_memory() || backing.is_register()); |
| 149 if (backing.is_memory()) { |
| 150 __ push(Operand(ebp, fp_relative(backing_index))); |
| 151 } else { |
| 152 __ push(backing.reg()); |
| 153 } |
| 154 break; |
| 155 } |
| 156 } |
| 157 elements_[index].set_sync(); |
| 158 } |
| 159 |
| 160 |
| 161 void VirtualFrame::MergeTo(VirtualFrame* expected) { |
| 162 Comment cmnt(masm_, "[ Merge frame"); |
| 163 // We should always be merging the code generator's current frame to an |
| 164 // expected frame. |
| 165 ASSERT(cgen_->frame() == this); |
| 166 |
| 167 // Adjust the stack pointer upward (toward the top of the virtual |
| 168 // frame) if necessary. |
| 169 if (stack_pointer_ < expected->stack_pointer_) { |
| 170 int difference = expected->stack_pointer_ - stack_pointer_; |
| 171 stack_pointer_ = expected->stack_pointer_; |
| 172 __ sub(Operand(esp), Immediate(difference * kPointerSize)); |
| 173 } |
| 174 |
| 175 MergeMoveRegistersToMemory(expected); |
| 176 MergeMoveRegistersToRegisters(expected); |
| 177 MergeMoveMemoryToRegisters(expected); |
| 178 |
| 179 // Fix any sync flag problems from the bottom-up and make the copied |
| 180 // flags exact. This assumes that the backing store of copies is |
| 181 // always lower in the frame. |
| 182 for (int i = 0; i < elements_.length(); i++) { |
| 183 FrameElement source = elements_[i]; |
| 184 FrameElement target = expected->elements_[i]; |
| 185 if (source.is_synced() && !target.is_synced()) { |
| 186 elements_[i].clear_sync(); |
| 187 } else if (!source.is_synced() && target.is_synced()) { |
| 188 SyncElementAt(i); |
| 189 } |
| 190 elements_[i].clear_copied(); |
| 191 if (elements_[i].is_copy()) { |
| 192 elements_[elements_[i].index()].set_copied(); |
| 193 } |
| 194 } |
| 195 |
| 196 // Adjust the stack pointer downward if necessary. |
| 197 if (stack_pointer_ > expected->stack_pointer_) { |
| 198 int difference = stack_pointer_ - expected->stack_pointer_; |
| 199 stack_pointer_ = expected->stack_pointer_; |
| 200 __ add(Operand(esp), Immediate(difference * kPointerSize)); |
| 201 } |
| 202 |
| 203 // At this point, the frames should be identical. |
| 204 ASSERT(Equals(expected)); |
| 205 } |
| 206 |
| 207 |
| 208 void VirtualFrame::MergeMoveRegistersToMemory(VirtualFrame* expected) { |
| 209 ASSERT(stack_pointer_ >= expected->stack_pointer_); |
| 210 |
| 211 // Move registers, constants, and copies to memory. Perform moves |
| 212 // from the top downward in the frame in order to leave the backing |
| 213 // stores of copies in registers. |
| 214 // |
| 215 // Moving memory-backed copies to memory requires a spare register |
| 216 // for the memory-to-memory moves. Since we are performing a merge, |
| 217 // we use esi (which is already saved in the frame). We keep track |
| 218 // of the index of the frame element esi is caching or kIllegalIndex |
| 219 // if esi has not been disturbed. |
| 220 int esi_caches = kIllegalIndex; |
| 221 // A "singleton" memory element. |
| 222 FrameElement memory_element = FrameElement::MemoryElement(); |
| 223 // Loop downward from the stack pointer or the top of the frame if |
| 224 // the stack pointer is floating above the frame. |
| 225 int start = Min(stack_pointer_, elements_.length() - 1); |
| 226 for (int i = start; i >= 0; i--) { |
| 227 FrameElement target = expected->elements_[i]; |
| 228 if (target.is_memory()) { |
| 229 FrameElement source = elements_[i]; |
| 230 switch (source.type()) { |
| 231 case FrameElement::INVALID: |
| 232 // Not a legal merge move. |
| 233 UNREACHABLE(); |
| 234 break; |
| 235 |
| 236 case FrameElement::MEMORY: |
| 237 // Already in place. |
| 238 break; |
| 239 |
| 240 case FrameElement::REGISTER: |
| 241 Unuse(source.reg()); |
| 242 if (!source.is_synced()) { |
| 243 __ mov(Operand(ebp, fp_relative(i)), source.reg()); |
| 244 } |
| 245 break; |
| 246 |
| 247 case FrameElement::CONSTANT: |
| 248 if (!source.is_synced()) { |
| 249 if (cgen_->IsUnsafeSmi(source.handle())) { |
| 250 esi_caches = i; |
| 251 cgen_->LoadUnsafeSmi(esi, source.handle()); |
| 252 __ mov(Operand(ebp, fp_relative(i)), esi); |
| 253 } else { |
| 254 __ Set(Operand(ebp, fp_relative(i)), Immediate(source.handle())); |
| 255 } |
| 256 } |
| 257 break; |
| 258 |
| 259 case FrameElement::COPY: |
| 260 if (!source.is_synced()) { |
| 261 int backing_index = source.index(); |
| 262 FrameElement backing_element = elements_[backing_index]; |
| 263 if (backing_element.is_memory()) { |
| 264 // If we have to spill a register, we spill esi. |
| 265 if (esi_caches != backing_index) { |
| 266 esi_caches = backing_index; |
| 267 __ mov(esi, Operand(ebp, fp_relative(backing_index))); |
| 268 } |
| 269 __ mov(Operand(ebp, fp_relative(i)), esi); |
| 270 } else { |
| 271 ASSERT(backing_element.is_register()); |
| 272 __ mov(Operand(ebp, fp_relative(i)), backing_element.reg()); |
| 273 } |
| 274 } |
| 275 break; |
| 276 } |
| 277 elements_[i] = memory_element; |
| 278 } |
| 279 } |
| 280 |
| 281 if (esi_caches != kIllegalIndex) { |
| 282 __ mov(esi, Operand(ebp, fp_relative(context_index()))); |
| 283 } |
| 284 } |
| 285 |
| 286 |
| 287 void VirtualFrame::MergeMoveRegistersToRegisters(VirtualFrame* expected) { |
| 288 // We have already done X-to-memory moves. |
| 289 ASSERT(stack_pointer_ >= expected->stack_pointer_); |
| 290 |
| 291 // Perform register-to-register moves. |
| 292 int start = 0; |
| 293 int end = elements_.length() - 1; |
| 294 bool any_moves_blocked; // Did we fail to make some moves this iteration? |
| 295 bool should_break_cycles = false; |
| 296 bool any_moves_made; // Did we make any progress this iteration? |
| 297 do { |
| 298 any_moves_blocked = false; |
| 299 any_moves_made = false; |
| 300 int first_move_blocked = kIllegalIndex; |
| 301 int last_move_blocked = kIllegalIndex; |
| 302 for (int i = start; i <= end; i++) { |
| 303 FrameElement source = elements_[i]; |
| 304 FrameElement target = expected->elements_[i]; |
| 305 if (source.is_register() && target.is_register()) { |
| 306 if (target.reg().is(source.reg())) { |
| 307 if (target.is_synced() && !source.is_synced()) { |
| 308 __ mov(Operand(ebp, fp_relative(i)), source.reg()); |
| 309 } |
| 310 elements_[i] = target; |
| 311 } else { |
| 312 // We need to move source to target. |
| 313 if (is_used(target.reg())) { |
| 314 // The move is blocked because the target contains valid data. |
| 315 // If we are stuck with only cycles remaining, then we spill source. |
| 316 // Otherwise, we just need more iterations. |
| 317 if (should_break_cycles) { |
| 318 SpillElementAt(i); |
| 319 should_break_cycles = false; |
| 320 } else { // Record a blocked move. |
| 321 if (!any_moves_blocked) { |
| 322 first_move_blocked = i; |
| 323 } |
| 324 last_move_blocked = i; |
| 325 any_moves_blocked = true; |
| 326 } |
| 327 } else { |
| 328 // The move is not blocked. This frame element can be moved from |
| 329 // its source register to its target register. |
| 330 if (target.is_synced() && !source.is_synced()) { |
| 331 SyncElementAt(i); |
| 332 } |
| 333 Use(target.reg(), i); |
| 334 Unuse(source.reg()); |
| 335 elements_[i] = target; |
| 336 __ mov(target.reg(), source.reg()); |
| 337 any_moves_made = true; |
| 338 } |
| 339 } |
| 340 } |
| 341 } |
| 342 // Update control flags for next iteration. |
| 343 should_break_cycles = (any_moves_blocked && !any_moves_made); |
| 344 if (any_moves_blocked) { |
| 345 start = first_move_blocked; |
| 346 end = last_move_blocked; |
| 347 } |
| 348 } while (any_moves_blocked); |
| 349 } |
| 350 |
| 351 |
| 352 void VirtualFrame::MergeMoveMemoryToRegisters(VirtualFrame *expected) { |
| 353 // Move memory, constants, and copies to registers. This is the |
| 354 // final step and is done from the bottom up so that the backing |
| 355 // elements of copies are in their correct locations when we |
| 356 // encounter the copies. |
| 357 for (int i = 0; i < elements_.length(); i++) { |
| 358 FrameElement source = elements_[i]; |
| 359 FrameElement target = expected->elements_[i]; |
| 360 if (target.is_register() && !source.is_register()) { |
| 361 switch (source.type()) { |
| 362 case FrameElement::INVALID: // Fall through. |
| 363 case FrameElement::REGISTER: |
| 364 UNREACHABLE(); |
| 365 break; |
| 366 |
| 367 case FrameElement::MEMORY: |
| 368 ASSERT(i <= stack_pointer_); |
| 369 __ mov(target.reg(), Operand(ebp, fp_relative(i))); |
| 370 break; |
| 371 |
| 372 case FrameElement::CONSTANT: |
| 373 if (cgen_->IsUnsafeSmi(source.handle())) { |
| 374 cgen_->LoadUnsafeSmi(target.reg(), source.handle()); |
| 375 } else { |
| 376 __ Set(target.reg(), Immediate(source.handle())); |
| 377 } |
| 378 break; |
| 379 |
| 380 case FrameElement::COPY: { |
| 381 FrameElement backing = elements_[source.index()]; |
| 382 ASSERT(backing.is_memory() || backing.is_register()); |
| 383 if (backing.is_memory()) { |
| 384 ASSERT(source.index() <= stack_pointer_); |
| 385 __ mov(target.reg(), Operand(ebp, fp_relative(source.index()))); |
| 386 } else { |
| 387 __ mov(target.reg(), backing.reg()); |
| 388 } |
| 389 } |
| 390 } |
| 391 // Ensure the proper sync state. If the source was memory no |
| 392 // code needs to be emitted. |
| 393 if (target.is_synced() && !source.is_memory()) { |
| 394 SyncElementAt(i); |
| 395 } |
| 396 Use(target.reg(), i); |
| 397 elements_[i] = target; |
| 398 } |
| 399 } |
| 400 } |
| 401 |
| 402 |
| 403 void VirtualFrame::Enter() { |
| 404 // Registers live on entry: esp, ebp, esi, edi. |
| 405 Comment cmnt(masm_, "[ Enter JS frame"); |
| 406 |
| 407 #ifdef DEBUG |
| 408 // Verify that edi contains a JS function. The following code |
| 409 // relies on eax being available for use. |
| 410 __ test(edi, Immediate(kSmiTagMask)); |
| 411 __ Check(not_zero, |
| 412 "VirtualFrame::Enter - edi is not a function (smi check)."); |
| 413 __ CmpObjectType(edi, JS_FUNCTION_TYPE, eax); |
| 414 __ Check(equal, |
| 415 "VirtualFrame::Enter - edi is not a function (map check)."); |
| 416 #endif |
| 417 |
| 418 EmitPush(ebp); |
| 419 |
| 420 frame_pointer_ = stack_pointer_; |
| 421 __ mov(ebp, Operand(esp)); |
| 422 |
| 423 // Store the context in the frame. The context is kept in esi and a |
| 424 // copy is stored in the frame. The external reference to esi |
| 425 // remains. |
| 426 EmitPush(esi); |
| 427 |
| 428 // Store the function in the frame. The frame owns the register |
| 429 // reference now (ie, it can keep it in edi or spill it later). |
| 430 Push(edi); |
| 431 SyncElementAt(elements_.length() - 1); |
| 432 cgen_->allocator()->Unuse(edi); |
| 433 } |
| 434 |
| 435 |
| 436 void VirtualFrame::Exit() { |
| 437 Comment cmnt(masm_, "[ Exit JS frame"); |
| 438 // Record the location of the JS exit code for patching when setting |
| 439 // break point. |
| 440 __ RecordJSReturn(); |
| 441 |
| 442 // Avoid using the leave instruction here, because it is too |
| 443 // short. We need the return sequence to be a least the size of a |
| 444 // call instruction to support patching the exit code in the |
| 445 // debugger. See VisitReturnStatement for the full return sequence. |
| 446 __ mov(esp, Operand(ebp)); |
| 447 stack_pointer_ = frame_pointer_; |
| 448 for (int i = elements_.length() - 1; i > stack_pointer_; i--) { |
| 449 FrameElement last = elements_.RemoveLast(); |
| 450 if (last.is_register()) { |
| 451 Unuse(last.reg()); |
| 452 } |
| 453 } |
| 454 |
| 455 frame_pointer_ = kIllegalIndex; |
| 456 EmitPop(ebp); |
| 457 } |
| 458 |
| 459 |
| 460 void VirtualFrame::AllocateStackSlots(int count) { |
| 461 ASSERT(height() == 0); |
| 462 local_count_ = count; |
| 463 |
| 464 if (count > 0) { |
| 465 Comment cmnt(masm_, "[ Allocate space for locals"); |
| 466 // The locals are initialized to a constant (the undefined value), but |
| 467 // we sync them with the actual frame to allocate space for spilling |
| 468 // them later. First sync everything above the stack pointer so we can |
| 469 // use pushes to allocate and initialize the locals. |
| 470 SyncRange(stack_pointer_ + 1, elements_.length()); |
| 471 Handle<Object> undefined = Factory::undefined_value(); |
| 472 FrameElement initial_value = |
| 473 FrameElement::ConstantElement(undefined, FrameElement::SYNCED); |
| 474 Result temp = cgen_->allocator()->Allocate(); |
| 475 ASSERT(temp.is_valid()); |
| 476 __ Set(temp.reg(), Immediate(undefined)); |
| 477 for (int i = 0; i < count; i++) { |
| 478 elements_.Add(initial_value); |
| 479 stack_pointer_++; |
| 480 __ push(temp.reg()); |
| 481 } |
| 482 } |
| 483 } |
| 484 |
| 485 |
| 486 void VirtualFrame::SaveContextRegister() { |
| 487 ASSERT(elements_[context_index()].is_memory()); |
| 488 __ mov(Operand(ebp, fp_relative(context_index())), esi); |
| 489 } |
| 490 |
| 491 |
| 492 void VirtualFrame::RestoreContextRegister() { |
| 493 ASSERT(elements_[context_index()].is_memory()); |
| 494 __ mov(esi, Operand(ebp, fp_relative(context_index()))); |
| 495 } |
| 496 |
| 497 |
| 498 void VirtualFrame::PushReceiverSlotAddress() { |
| 499 Result temp = cgen_->allocator()->Allocate(); |
| 500 ASSERT(temp.is_valid()); |
| 501 __ lea(temp.reg(), ParameterAt(-1)); |
| 502 Push(&temp); |
| 503 } |
| 504 |
| 505 |
| 506 int VirtualFrame::InvalidateFrameSlotAt(int index) { |
| 507 FrameElement original = elements_[index]; |
| 508 |
| 509 // Is this element the backing store of any copies? |
| 510 int new_backing_index = kIllegalIndex; |
| 511 if (original.is_copied()) { |
| 512 // Verify it is copied, and find first copy. |
| 513 for (int i = index + 1; i < elements_.length(); i++) { |
| 514 if (elements_[i].is_copy() && elements_[i].index() == index) { |
| 515 new_backing_index = i; |
| 516 break; |
| 517 } |
| 518 } |
| 519 } |
| 520 |
| 521 if (new_backing_index == kIllegalIndex) { |
| 522 // No copies found, return kIllegalIndex. |
| 523 if (original.is_register()) { |
| 524 Unuse(original.reg()); |
| 525 } |
| 526 elements_[index] = FrameElement::InvalidElement(); |
| 527 return kIllegalIndex; |
| 528 } |
| 529 |
| 530 // This is the backing store of copies. |
| 531 Register backing_reg; |
| 532 if (original.is_memory()) { |
| 533 Result fresh = cgen_->allocator()->Allocate(); |
| 534 ASSERT(fresh.is_valid()); |
| 535 Use(fresh.reg(), new_backing_index); |
| 536 backing_reg = fresh.reg(); |
| 537 __ mov(backing_reg, Operand(ebp, fp_relative(index))); |
| 538 } else { |
| 539 // The original was in a register. |
| 540 backing_reg = original.reg(); |
| 541 register_locations_[backing_reg.code()] = new_backing_index; |
| 542 } |
| 543 // Invalidate the element at index. |
| 544 elements_[index] = FrameElement::InvalidElement(); |
| 545 // Set the new backing element. |
| 546 if (elements_[new_backing_index].is_synced()) { |
| 547 elements_[new_backing_index] = |
| 548 FrameElement::RegisterElement(backing_reg, FrameElement::SYNCED); |
| 549 } else { |
| 550 elements_[new_backing_index] = |
| 551 FrameElement::RegisterElement(backing_reg, FrameElement::NOT_SYNCED); |
| 552 } |
| 553 // Update the other copies. |
| 554 for (int i = new_backing_index + 1; i < elements_.length(); i++) { |
| 555 if (elements_[i].is_copy() && elements_[i].index() == index) { |
| 556 elements_[i].set_index(new_backing_index); |
| 557 elements_[new_backing_index].set_copied(); |
| 558 } |
| 559 } |
| 560 return new_backing_index; |
| 561 } |
| 562 |
| 563 |
| 564 void VirtualFrame::TakeFrameSlotAt(int index) { |
| 565 ASSERT(index >= 0); |
| 566 ASSERT(index <= elements_.length()); |
| 567 FrameElement original = elements_[index]; |
| 568 int new_backing_store_index = InvalidateFrameSlotAt(index); |
| 569 if (new_backing_store_index != kIllegalIndex) { |
| 570 elements_.Add(CopyElementAt(new_backing_store_index)); |
| 571 return; |
| 572 } |
| 573 |
| 574 switch (original.type()) { |
| 575 case FrameElement::MEMORY: { |
| 576 // Emit code to load the original element's data into a register. |
| 577 // Push that register as a FrameElement on top of the frame. |
| 578 Result fresh = cgen_->allocator()->Allocate(); |
| 579 ASSERT(fresh.is_valid()); |
| 580 FrameElement new_element = |
| 581 FrameElement::RegisterElement(fresh.reg(), |
| 582 FrameElement::NOT_SYNCED); |
| 583 Use(fresh.reg(), elements_.length()); |
| 584 elements_.Add(new_element); |
| 585 __ mov(fresh.reg(), Operand(ebp, fp_relative(index))); |
| 586 break; |
| 587 } |
| 588 case FrameElement::REGISTER: |
| 589 Use(original.reg(), elements_.length()); |
| 590 // Fall through. |
| 591 case FrameElement::CONSTANT: |
| 592 case FrameElement::COPY: |
| 593 original.clear_sync(); |
| 594 elements_.Add(original); |
| 595 break; |
| 596 case FrameElement::INVALID: |
| 597 UNREACHABLE(); |
| 598 break; |
| 599 } |
| 600 } |
| 601 |
| 602 |
| 603 void VirtualFrame::StoreToFrameSlotAt(int index) { |
| 604 // Store the value on top of the frame to the virtual frame slot at |
| 605 // a given index. The value on top of the frame is left in place. |
| 606 // This is a duplicating operation, so it can create copies. |
| 607 ASSERT(index >= 0); |
| 608 ASSERT(index < elements_.length()); |
| 609 |
| 610 int top_index = elements_.length() - 1; |
| 611 FrameElement top = elements_[top_index]; |
| 612 FrameElement original = elements_[index]; |
| 613 if (top.is_copy() && top.index() == index) return; |
| 614 ASSERT(top.is_valid()); |
| 615 |
| 616 InvalidateFrameSlotAt(index); |
| 617 |
| 618 if (top.is_copy()) { |
| 619 // There are two cases based on the relative positions of the |
| 620 // stored-to slot and the backing slot of the top element. |
| 621 int backing_index = top.index(); |
| 622 ASSERT(backing_index != index); |
| 623 if (backing_index < index) { |
| 624 // 1. The top element is a copy of a slot below the stored-to |
| 625 // slot. The stored-to slot becomes an unsynced copy of that |
| 626 // same backing slot. |
| 627 elements_[index] = CopyElementAt(backing_index); |
| 628 } else { |
| 629 // 2. The top element is a copy of a slot above the stored-to |
| 630 // slot. The stored-to slot becomes the new (unsynced) backing |
| 631 // slot and both the top element and the element at the former |
| 632 // backing slot become copies of it. The sync state of the top |
| 633 // and former backing elements is preserved. |
| 634 FrameElement backing_element = elements_[backing_index]; |
| 635 ASSERT(backing_element.is_memory() || backing_element.is_register()); |
| 636 if (backing_element.is_memory()) { |
| 637 // Because sets of copies are canonicalized to be backed by |
| 638 // their lowest frame element, and because memory frame |
| 639 // elements are backed by the corresponding stack address, we |
| 640 // have to move the actual value down in the stack. |
| 641 // |
| 642 // TODO(209): considering allocating the stored-to slot to the |
| 643 // temp register. Alternatively, allow copies to appear in |
| 644 // any order in the frame and lazily move the value down to |
| 645 // the slot. |
| 646 Result temp = cgen_->allocator()->Allocate(); |
| 647 ASSERT(temp.is_valid()); |
| 648 __ mov(temp.reg(), Operand(ebp, fp_relative(backing_index))); |
| 649 __ mov(Operand(ebp, fp_relative(index)), temp.reg()); |
| 650 } else { |
| 651 register_locations_[backing_element.reg().code()] = index; |
| 652 if (backing_element.is_synced()) { |
| 653 // If the element is a register, we will not actually move |
| 654 // anything on the stack but only update the virtual frame |
| 655 // element. |
| 656 backing_element.clear_sync(); |
| 657 } |
| 658 } |
| 659 elements_[index] = backing_element; |
| 660 |
| 661 // The old backing element becomes a copy of the new backing |
| 662 // element. |
| 663 FrameElement new_element = CopyElementAt(index); |
| 664 elements_[backing_index] = new_element; |
| 665 if (backing_element.is_synced()) { |
| 666 elements_[backing_index].set_sync(); |
| 667 } |
| 668 |
| 669 // All the copies of the old backing element (including the top |
| 670 // element) become copies of the new backing element. |
| 671 for (int i = backing_index + 1; i < elements_.length(); i++) { |
| 672 if (elements_[i].is_copy() && elements_[i].index() == backing_index) { |
| 673 elements_[i].set_index(index); |
| 674 } |
| 675 } |
| 676 } |
| 677 return; |
| 678 } |
| 679 |
| 680 // Move the top element to the stored-to slot and replace it (the |
| 681 // top element) with a copy. |
| 682 elements_[index] = top; |
| 683 if (top.is_memory()) { |
| 684 // TODO(209): consider allocating the stored-to slot to the temp |
| 685 // register. Alternatively, allow copies to appear in any order |
| 686 // in the frame and lazily move the value down to the slot. |
| 687 FrameElement new_top = CopyElementAt(index); |
| 688 new_top.set_sync(); |
| 689 elements_[top_index] = new_top; |
| 690 |
| 691 // The sync state of the former top element is correct (synced). |
| 692 // Emit code to move the value down in the frame. |
| 693 Result temp = cgen_->allocator()->Allocate(); |
| 694 ASSERT(temp.is_valid()); |
| 695 __ mov(temp.reg(), Operand(esp, 0)); |
| 696 __ mov(Operand(ebp, fp_relative(index)), temp.reg()); |
| 697 } else if (top.is_register()) { |
| 698 register_locations_[top.reg().code()] = index; |
| 699 // The stored-to slot has the (unsynced) register reference and |
| 700 // the top element becomes a copy. The sync state of the top is |
| 701 // preserved. |
| 702 FrameElement new_top = CopyElementAt(index); |
| 703 if (top.is_synced()) { |
| 704 new_top.set_sync(); |
| 705 elements_[index].clear_sync(); |
| 706 } |
| 707 elements_[top_index] = new_top; |
| 708 } else { |
| 709 // The stored-to slot holds the same value as the top but |
| 710 // unsynced. (We do not have copies of constants yet.) |
| 711 ASSERT(top.is_constant()); |
| 712 elements_[index].clear_sync(); |
| 713 } |
| 714 } |
| 715 |
| 716 |
| 717 void VirtualFrame::PushTryHandler(HandlerType type) { |
| 718 ASSERT(cgen_->HasValidEntryRegisters()); |
| 719 // Grow the expression stack by handler size less two (the return address |
| 720 // is already pushed by a call instruction, and PushTryHandler from the |
| 721 // macro assembler will leave the top of stack in the eax register to be |
| 722 // pushed separately). |
| 723 Adjust(kHandlerSize - 2); |
| 724 __ PushTryHandler(IN_JAVASCRIPT, type); |
| 725 // TODO(1222589): remove the reliance of PushTryHandler on a cached TOS |
| 726 EmitPush(eax); |
| 727 } |
| 728 |
| 729 |
| 730 Result VirtualFrame::RawCallStub(CodeStub* stub) { |
| 731 ASSERT(cgen_->HasValidEntryRegisters()); |
| 732 __ CallStub(stub); |
| 733 Result result = cgen_->allocator()->Allocate(eax); |
| 734 ASSERT(result.is_valid()); |
| 735 return result; |
| 736 } |
| 737 |
| 738 |
| 739 Result VirtualFrame::CallStub(CodeStub* stub, Result* arg) { |
| 740 PrepareForCall(0, 0); |
| 741 arg->ToRegister(eax); |
| 742 arg->Unuse(); |
| 743 return RawCallStub(stub); |
| 744 } |
| 745 |
| 746 |
| 747 Result VirtualFrame::CallStub(CodeStub* stub, Result* arg0, Result* arg1) { |
| 748 PrepareForCall(0, 0); |
| 749 |
| 750 if (arg0->is_register() && arg0->reg().is(eax)) { |
| 751 if (arg1->is_register() && arg1->reg().is(edx)) { |
| 752 // Wrong registers. |
| 753 __ xchg(eax, edx); |
| 754 } else { |
| 755 // Register edx is free for arg0, which frees eax for arg1. |
| 756 arg0->ToRegister(edx); |
| 757 arg1->ToRegister(eax); |
| 758 } |
| 759 } else { |
| 760 // Register eax is free for arg1, which guarantees edx is free for |
| 761 // arg0. |
| 762 arg1->ToRegister(eax); |
| 763 arg0->ToRegister(edx); |
| 764 } |
| 765 |
| 766 arg0->Unuse(); |
| 767 arg1->Unuse(); |
| 768 return RawCallStub(stub); |
| 769 } |
| 770 |
| 771 |
| 772 Result VirtualFrame::CallRuntime(Runtime::Function* f, int arg_count) { |
| 773 PrepareForCall(arg_count, arg_count); |
| 774 ASSERT(cgen_->HasValidEntryRegisters()); |
| 775 __ CallRuntime(f, arg_count); |
| 776 Result result = cgen_->allocator()->Allocate(eax); |
| 777 ASSERT(result.is_valid()); |
| 778 return result; |
| 779 } |
| 780 |
| 781 |
| 782 Result VirtualFrame::CallRuntime(Runtime::FunctionId id, int arg_count) { |
| 783 PrepareForCall(arg_count, arg_count); |
| 784 ASSERT(cgen_->HasValidEntryRegisters()); |
| 785 __ CallRuntime(id, arg_count); |
| 786 Result result = cgen_->allocator()->Allocate(eax); |
| 787 ASSERT(result.is_valid()); |
| 788 return result; |
| 789 } |
| 790 |
| 791 |
| 792 Result VirtualFrame::InvokeBuiltin(Builtins::JavaScript id, |
| 793 InvokeFlag flag, |
| 794 int arg_count) { |
| 795 PrepareForCall(arg_count, arg_count); |
| 796 ASSERT(cgen_->HasValidEntryRegisters()); |
| 797 __ InvokeBuiltin(id, flag); |
| 798 Result result = cgen_->allocator()->Allocate(eax); |
| 799 ASSERT(result.is_valid()); |
| 800 return result; |
| 801 } |
| 802 |
| 803 |
| 804 Result VirtualFrame::RawCallCodeObject(Handle<Code> code, |
| 805 RelocInfo::Mode rmode) { |
| 806 ASSERT(cgen_->HasValidEntryRegisters()); |
| 807 __ call(code, rmode); |
| 808 Result result = cgen_->allocator()->Allocate(eax); |
| 809 ASSERT(result.is_valid()); |
| 810 return result; |
| 811 } |
| 812 |
| 813 |
| 814 Result VirtualFrame::CallLoadIC(RelocInfo::Mode mode) { |
| 815 // Name and receiver are on the top of the frame. The IC expects |
| 816 // name in ecx and receiver on the stack. It does not drop the |
| 817 // receiver. |
| 818 Handle<Code> ic(Builtins::builtin(Builtins::LoadIC_Initialize)); |
| 819 Result name = Pop(); |
| 820 PrepareForCall(1, 0); // One stack arg, not callee-dropped. |
| 821 name.ToRegister(ecx); |
| 822 name.Unuse(); |
| 823 return RawCallCodeObject(ic, mode); |
| 824 } |
| 825 |
| 826 |
| 827 Result VirtualFrame::CallKeyedLoadIC(RelocInfo::Mode mode) { |
| 828 // Key and receiver are on top of the frame. The IC expects them on |
| 829 // the stack. It does not drop them. |
| 830 Handle<Code> ic(Builtins::builtin(Builtins::KeyedLoadIC_Initialize)); |
| 831 PrepareForCall(2, 0); // Two stack args, neither callee-dropped. |
| 832 return RawCallCodeObject(ic, mode); |
| 833 } |
| 834 |
| 835 |
| 836 Result VirtualFrame::CallStoreIC() { |
| 837 // Name, value, and receiver are on top of the frame. The IC |
| 838 // expects name in ecx, value in eax, and receiver on the stack. It |
| 839 // does not drop the receiver. |
| 840 Handle<Code> ic(Builtins::builtin(Builtins::StoreIC_Initialize)); |
| 841 Result name = Pop(); |
| 842 Result value = Pop(); |
| 843 PrepareForCall(1, 0); // One stack arg, not callee-dropped. |
| 844 |
| 845 if (value.is_register() && value.reg().is(ecx)) { |
| 846 if (name.is_register() && name.reg().is(eax)) { |
| 847 // Wrong registers. |
| 848 __ xchg(eax, ecx); |
| 849 } else { |
| 850 // Register eax is free for value, which frees ecx for name. |
| 851 value.ToRegister(eax); |
| 852 name.ToRegister(ecx); |
| 853 } |
| 854 } else { |
| 855 // Register ecx is free for name, which guarantees eax is free for |
| 856 // value. |
| 857 name.ToRegister(ecx); |
| 858 value.ToRegister(eax); |
| 859 } |
| 860 |
| 861 name.Unuse(); |
| 862 value.Unuse(); |
| 863 return RawCallCodeObject(ic, RelocInfo::CODE_TARGET); |
| 864 } |
| 865 |
| 866 |
| 867 Result VirtualFrame::CallKeyedStoreIC() { |
| 868 // Value, key, and receiver are on the top of the frame. The IC |
| 869 // expects value in eax and key and receiver on the stack. It does |
| 870 // not drop the key and receiver. |
| 871 Handle<Code> ic(Builtins::builtin(Builtins::KeyedStoreIC_Initialize)); |
| 872 // TODO(1222589): Make the IC grab the values from the stack. |
| 873 Result value = Pop(); |
| 874 PrepareForCall(2, 0); // Two stack args, neither callee-dropped. |
| 875 value.ToRegister(eax); |
| 876 value.Unuse(); |
| 877 return RawCallCodeObject(ic, RelocInfo::CODE_TARGET); |
| 878 } |
| 879 |
| 880 |
| 881 Result VirtualFrame::CallCallIC(RelocInfo::Mode mode, |
| 882 int arg_count, |
| 883 int loop_nesting) { |
| 884 // Arguments, receiver, and function name are on top of the frame. |
| 885 // The IC expects them on the stack. It does not drop the function |
| 886 // name slot (but it does drop the rest). |
| 887 Handle<Code> ic = (loop_nesting > 0) |
| 888 ? cgen_->ComputeCallInitializeInLoop(arg_count) |
| 889 : cgen_->ComputeCallInitialize(arg_count); |
| 890 // Spill args, receiver, and function. The call will drop args and |
| 891 // receiver. |
| 892 PrepareForCall(arg_count + 2, arg_count + 1); |
| 893 return RawCallCodeObject(ic, mode); |
| 894 } |
| 895 |
| 896 |
| 897 Result VirtualFrame::CallConstructor(int arg_count) { |
| 898 // Arguments, receiver, and function are on top of the frame. The |
| 899 // IC expects arg count in eax, function in edi, and the arguments |
| 900 // and receiver on the stack. |
| 901 Handle<Code> ic(Builtins::builtin(Builtins::JSConstructCall)); |
| 902 // Duplicate the function before preparing the frame. |
| 903 PushElementAt(arg_count + 1); |
| 904 Result function = Pop(); |
| 905 PrepareForCall(arg_count + 1, arg_count + 1); // Spill args and receiver. |
| 906 function.ToRegister(edi); |
| 907 |
| 908 // Constructors are called with the number of arguments in register |
| 909 // eax for now. Another option would be to have separate construct |
| 910 // call trampolines per different arguments counts encountered. |
| 911 Result num_args = cgen_->allocator()->Allocate(eax); |
| 912 ASSERT(num_args.is_valid()); |
| 913 __ Set(num_args.reg(), Immediate(arg_count)); |
| 914 |
| 915 function.Unuse(); |
| 916 num_args.Unuse(); |
| 917 return RawCallCodeObject(ic, RelocInfo::CONSTRUCT_CALL); |
| 918 } |
| 919 |
| 920 |
| 921 void VirtualFrame::Drop(int count) { |
| 922 ASSERT(height() >= count); |
| 923 int num_virtual_elements = (elements_.length() - 1) - stack_pointer_; |
| 924 |
| 925 // Emit code to lower the stack pointer if necessary. |
| 926 if (num_virtual_elements < count) { |
| 927 int num_dropped = count - num_virtual_elements; |
| 928 stack_pointer_ -= num_dropped; |
| 929 __ add(Operand(esp), Immediate(num_dropped * kPointerSize)); |
| 930 } |
| 931 |
| 932 // Discard elements from the virtual frame and free any registers. |
| 933 for (int i = 0; i < count; i++) { |
| 934 FrameElement dropped = elements_.RemoveLast(); |
| 935 if (dropped.is_register()) { |
| 936 Unuse(dropped.reg()); |
| 937 } |
| 938 } |
| 939 } |
| 940 |
| 941 |
| 942 Result VirtualFrame::Pop() { |
| 943 FrameElement element = elements_.RemoveLast(); |
| 944 int index = elements_.length(); |
| 945 ASSERT(element.is_valid()); |
| 946 |
| 947 bool pop_needed = (stack_pointer_ == index); |
| 948 if (pop_needed) { |
| 949 stack_pointer_--; |
| 950 if (element.is_memory()) { |
| 951 Result temp = cgen_->allocator()->Allocate(); |
| 952 ASSERT(temp.is_valid()); |
| 953 temp.set_static_type(element.static_type()); |
| 954 __ pop(temp.reg()); |
| 955 return temp; |
| 956 } |
| 957 |
| 958 __ add(Operand(esp), Immediate(kPointerSize)); |
| 959 } |
| 960 ASSERT(!element.is_memory()); |
| 961 |
| 962 // The top element is a register, constant, or a copy. Unuse |
| 963 // registers and follow copies to their backing store. |
| 964 if (element.is_register()) { |
| 965 Unuse(element.reg()); |
| 966 } else if (element.is_copy()) { |
| 967 ASSERT(element.index() < index); |
| 968 index = element.index(); |
| 969 element = elements_[index]; |
| 970 } |
| 971 ASSERT(!element.is_copy()); |
| 972 |
| 973 // The element is memory, a register, or a constant. |
| 974 if (element.is_memory()) { |
| 975 // Memory elements could only be the backing store of a copy. |
| 976 // Allocate the original to a register. |
| 977 ASSERT(index <= stack_pointer_); |
| 978 Result temp = cgen_->allocator()->Allocate(); |
| 979 ASSERT(temp.is_valid()); |
| 980 Use(temp.reg(), index); |
| 981 FrameElement new_element = |
| 982 FrameElement::RegisterElement(temp.reg(), FrameElement::SYNCED); |
| 983 // Preserve the copy flag on the element. |
| 984 if (element.is_copied()) new_element.set_copied(); |
| 985 new_element.set_static_type(element.static_type()); |
| 986 elements_[index] = new_element; |
| 987 __ mov(temp.reg(), Operand(ebp, fp_relative(index))); |
| 988 return Result(temp.reg(), cgen_, element.static_type()); |
| 989 } else if (element.is_register()) { |
| 990 return Result(element.reg(), cgen_, element.static_type()); |
| 991 } else { |
| 992 ASSERT(element.is_constant()); |
| 993 return Result(element.handle(), cgen_); |
| 994 } |
| 995 } |
| 996 |
| 997 |
| 998 void VirtualFrame::EmitPop(Register reg) { |
| 999 ASSERT(stack_pointer_ == elements_.length() - 1); |
| 1000 stack_pointer_--; |
| 1001 elements_.RemoveLast(); |
| 1002 __ pop(reg); |
| 1003 } |
| 1004 |
| 1005 |
| 1006 void VirtualFrame::EmitPop(Operand operand) { |
| 1007 ASSERT(stack_pointer_ == elements_.length() - 1); |
| 1008 stack_pointer_--; |
| 1009 elements_.RemoveLast(); |
| 1010 __ pop(operand); |
| 1011 } |
| 1012 |
| 1013 |
| 1014 void VirtualFrame::EmitPush(Register reg) { |
| 1015 ASSERT(stack_pointer_ == elements_.length() - 1); |
| 1016 elements_.Add(FrameElement::MemoryElement()); |
| 1017 stack_pointer_++; |
| 1018 __ push(reg); |
| 1019 } |
| 1020 |
| 1021 |
| 1022 void VirtualFrame::EmitPush(Operand operand) { |
| 1023 ASSERT(stack_pointer_ == elements_.length() - 1); |
| 1024 elements_.Add(FrameElement::MemoryElement()); |
| 1025 stack_pointer_++; |
| 1026 __ push(operand); |
| 1027 } |
| 1028 |
| 1029 |
| 1030 void VirtualFrame::EmitPush(Immediate immediate) { |
| 1031 ASSERT(stack_pointer_ == elements_.length() - 1); |
| 1032 elements_.Add(FrameElement::MemoryElement()); |
| 1033 stack_pointer_++; |
| 1034 __ push(immediate); |
| 1035 } |
| 1036 |
| 1037 |
| 1038 #undef __ |
| 1039 |
| 1040 } } // namespace v8::internal |
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