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| 1 // Copyright 2006-2008 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 "bootstrapper.h" |
| 31 #include "codegen-inl.h" |
| 32 #include "debug.h" |
| 33 #include "runtime.h" |
| 34 #include "serialize.h" |
| 35 |
| 36 namespace v8 { namespace internal { |
| 37 |
| 38 // ------------------------------------------------------------------------- |
| 39 // MacroAssembler implementation. |
| 40 |
| 41 MacroAssembler::MacroAssembler(void* buffer, int size) |
| 42 : Assembler(buffer, size), |
| 43 unresolved_(0), |
| 44 generating_stub_(false), |
| 45 allow_stub_calls_(true), |
| 46 code_object_(Heap::undefined_value()) { |
| 47 } |
| 48 |
| 49 |
| 50 static void RecordWriteHelper(MacroAssembler* masm, |
| 51 Register object, |
| 52 Register addr, |
| 53 Register scratch) { |
| 54 Label fast; |
| 55 |
| 56 // Compute the page address from the heap object pointer, leave it |
| 57 // in 'object'. |
| 58 masm->and_(object, ~Page::kPageAlignmentMask); |
| 59 |
| 60 // Compute the bit addr in the remembered set, leave it in "addr". |
| 61 masm->sub(addr, Operand(object)); |
| 62 masm->shr(addr, kObjectAlignmentBits); |
| 63 |
| 64 // If the bit offset lies beyond the normal remembered set range, it is in |
| 65 // the extra remembered set area of a large object. |
| 66 masm->cmp(addr, Page::kPageSize / kPointerSize); |
| 67 masm->j(less, &fast); |
| 68 |
| 69 // Adjust 'addr' to be relative to the start of the extra remembered set |
| 70 // and the page address in 'object' to be the address of the extra |
| 71 // remembered set. |
| 72 masm->sub(Operand(addr), Immediate(Page::kPageSize / kPointerSize)); |
| 73 // Load the array length into 'scratch' and multiply by four to get the |
| 74 // size in bytes of the elements. |
| 75 masm->mov(scratch, Operand(object, Page::kObjectStartOffset |
| 76 + FixedArray::kLengthOffset)); |
| 77 masm->shl(scratch, kObjectAlignmentBits); |
| 78 // Add the page header, array header, and array body size to the page |
| 79 // address. |
| 80 masm->add(Operand(object), Immediate(Page::kObjectStartOffset |
| 81 + Array::kHeaderSize)); |
| 82 masm->add(object, Operand(scratch)); |
| 83 |
| 84 |
| 85 // NOTE: For now, we use the bit-test-and-set (bts) x86 instruction |
| 86 // to limit code size. We should probably evaluate this decision by |
| 87 // measuring the performance of an equivalent implementation using |
| 88 // "simpler" instructions |
| 89 masm->bind(&fast); |
| 90 masm->bts(Operand(object, 0), addr); |
| 91 } |
| 92 |
| 93 |
| 94 class RecordWriteStub : public CodeStub { |
| 95 public: |
| 96 RecordWriteStub(Register object, Register addr, Register scratch) |
| 97 : object_(object), addr_(addr), scratch_(scratch) { } |
| 98 |
| 99 void Generate(MacroAssembler* masm); |
| 100 |
| 101 private: |
| 102 Register object_; |
| 103 Register addr_; |
| 104 Register scratch_; |
| 105 |
| 106 #ifdef DEBUG |
| 107 void Print() { |
| 108 PrintF("RecordWriteStub (object reg %d), (addr reg %d), (scratch reg %d)\n", |
| 109 object_.code(), addr_.code(), scratch_.code()); |
| 110 } |
| 111 #endif |
| 112 |
| 113 // Minor key encoding in 12 bits of three registers (object, address and |
| 114 // scratch) OOOOAAAASSSS. |
| 115 class ScratchBits: public BitField<uint32_t, 0, 4> {}; |
| 116 class AddressBits: public BitField<uint32_t, 4, 4> {}; |
| 117 class ObjectBits: public BitField<uint32_t, 8, 4> {}; |
| 118 |
| 119 Major MajorKey() { return RecordWrite; } |
| 120 |
| 121 int MinorKey() { |
| 122 // Encode the registers. |
| 123 return ObjectBits::encode(object_.code()) | |
| 124 AddressBits::encode(addr_.code()) | |
| 125 ScratchBits::encode(scratch_.code()); |
| 126 } |
| 127 }; |
| 128 |
| 129 |
| 130 void RecordWriteStub::Generate(MacroAssembler* masm) { |
| 131 RecordWriteHelper(masm, object_, addr_, scratch_); |
| 132 masm->ret(0); |
| 133 } |
| 134 |
| 135 |
| 136 // Set the remembered set bit for [object+offset]. |
| 137 // object is the object being stored into, value is the object being stored. |
| 138 // If offset is zero, then the scratch register contains the array index into |
| 139 // the elements array represented as a Smi. |
| 140 // All registers are clobbered by the operation. |
| 141 void MacroAssembler::RecordWrite(Register object, int offset, |
| 142 Register value, Register scratch) { |
| 143 // First, check if a remembered set write is even needed. The tests below |
| 144 // catch stores of Smis and stores into young gen (which does not have space |
| 145 // for the remembered set bits. |
| 146 Label done; |
| 147 |
| 148 // This optimization cannot survive serialization and deserialization, |
| 149 // so we disable as long as serialization can take place. |
| 150 int32_t new_space_start = |
| 151 reinterpret_cast<int32_t>(ExternalReference::new_space_start().address()); |
| 152 if (Serializer::enabled() || new_space_start < 0) { |
| 153 // Cannot do smart bit-twiddling. Need to do two consecutive checks. |
| 154 // Check for Smi first. |
| 155 test(value, Immediate(kSmiTagMask)); |
| 156 j(zero, &done); |
| 157 // Test that the object address is not in the new space. We cannot |
| 158 // set remembered set bits in the new space. |
| 159 mov(value, Operand(object)); |
| 160 and_(value, Heap::NewSpaceMask()); |
| 161 cmp(Operand(value), Immediate(ExternalReference::new_space_start())); |
| 162 j(equal, &done); |
| 163 } else { |
| 164 // move the value SmiTag into the sign bit |
| 165 shl(value, 31); |
| 166 // combine the object with value SmiTag |
| 167 or_(value, Operand(object)); |
| 168 // remove the uninteresing bits inside the page |
| 169 and_(value, Heap::NewSpaceMask() | (1 << 31)); |
| 170 // xor has two effects: |
| 171 // - if the value was a smi, then the result will be negative |
| 172 // - if the object is pointing into new space area the page bits will |
| 173 // all be zero |
| 174 xor_(value, new_space_start | (1 << 31)); |
| 175 // Check for both conditions in one branch |
| 176 j(less_equal, &done); |
| 177 } |
| 178 |
| 179 if ((offset > 0) && (offset < Page::kMaxHeapObjectSize)) { |
| 180 // Compute the bit offset in the remembered set, leave it in 'value'. |
| 181 mov(value, Operand(object)); |
| 182 and_(value, Page::kPageAlignmentMask); |
| 183 add(Operand(value), Immediate(offset)); |
| 184 shr(value, kObjectAlignmentBits); |
| 185 |
| 186 // Compute the page address from the heap object pointer, leave it in |
| 187 // 'object'. |
| 188 and_(object, ~Page::kPageAlignmentMask); |
| 189 |
| 190 // NOTE: For now, we use the bit-test-and-set (bts) x86 instruction |
| 191 // to limit code size. We should probably evaluate this decision by |
| 192 // measuring the performance of an equivalent implementation using |
| 193 // "simpler" instructions |
| 194 bts(Operand(object, 0), value); |
| 195 } else { |
| 196 Register dst = scratch; |
| 197 if (offset != 0) { |
| 198 lea(dst, Operand(object, offset)); |
| 199 } else { |
| 200 // array access: calculate the destination address in the same manner as |
| 201 // KeyedStoreIC::GenerateGeneric |
| 202 lea(dst, |
| 203 Operand(object, dst, times_2, Array::kHeaderSize - kHeapObjectTag)); |
| 204 } |
| 205 // If we are already generating a shared stub, not inlining the |
| 206 // record write code isn't going to save us any memory. |
| 207 if (generating_stub()) { |
| 208 RecordWriteHelper(this, object, dst, value); |
| 209 } else { |
| 210 RecordWriteStub stub(object, dst, value); |
| 211 CallStub(&stub); |
| 212 } |
| 213 } |
| 214 |
| 215 bind(&done); |
| 216 } |
| 217 |
| 218 |
| 219 #ifdef ENABLE_DEBUGGER_SUPPORT |
| 220 void MacroAssembler::SaveRegistersToMemory(RegList regs) { |
| 221 ASSERT((regs & ~kJSCallerSaved) == 0); |
| 222 // Copy the content of registers to memory location. |
| 223 for (int i = 0; i < kNumJSCallerSaved; i++) { |
| 224 int r = JSCallerSavedCode(i); |
| 225 if ((regs & (1 << r)) != 0) { |
| 226 Register reg = { r }; |
| 227 ExternalReference reg_addr = |
| 228 ExternalReference(Debug_Address::Register(i)); |
| 229 mov(Operand::StaticVariable(reg_addr), reg); |
| 230 } |
| 231 } |
| 232 } |
| 233 |
| 234 |
| 235 void MacroAssembler::RestoreRegistersFromMemory(RegList regs) { |
| 236 ASSERT((regs & ~kJSCallerSaved) == 0); |
| 237 // Copy the content of memory location to registers. |
| 238 for (int i = kNumJSCallerSaved; --i >= 0;) { |
| 239 int r = JSCallerSavedCode(i); |
| 240 if ((regs & (1 << r)) != 0) { |
| 241 Register reg = { r }; |
| 242 ExternalReference reg_addr = |
| 243 ExternalReference(Debug_Address::Register(i)); |
| 244 mov(reg, Operand::StaticVariable(reg_addr)); |
| 245 } |
| 246 } |
| 247 } |
| 248 |
| 249 |
| 250 void MacroAssembler::PushRegistersFromMemory(RegList regs) { |
| 251 ASSERT((regs & ~kJSCallerSaved) == 0); |
| 252 // Push the content of the memory location to the stack. |
| 253 for (int i = 0; i < kNumJSCallerSaved; i++) { |
| 254 int r = JSCallerSavedCode(i); |
| 255 if ((regs & (1 << r)) != 0) { |
| 256 ExternalReference reg_addr = |
| 257 ExternalReference(Debug_Address::Register(i)); |
| 258 push(Operand::StaticVariable(reg_addr)); |
| 259 } |
| 260 } |
| 261 } |
| 262 |
| 263 |
| 264 void MacroAssembler::PopRegistersToMemory(RegList regs) { |
| 265 ASSERT((regs & ~kJSCallerSaved) == 0); |
| 266 // Pop the content from the stack to the memory location. |
| 267 for (int i = kNumJSCallerSaved; --i >= 0;) { |
| 268 int r = JSCallerSavedCode(i); |
| 269 if ((regs & (1 << r)) != 0) { |
| 270 ExternalReference reg_addr = |
| 271 ExternalReference(Debug_Address::Register(i)); |
| 272 pop(Operand::StaticVariable(reg_addr)); |
| 273 } |
| 274 } |
| 275 } |
| 276 |
| 277 |
| 278 void MacroAssembler::CopyRegistersFromStackToMemory(Register base, |
| 279 Register scratch, |
| 280 RegList regs) { |
| 281 ASSERT((regs & ~kJSCallerSaved) == 0); |
| 282 // Copy the content of the stack to the memory location and adjust base. |
| 283 for (int i = kNumJSCallerSaved; --i >= 0;) { |
| 284 int r = JSCallerSavedCode(i); |
| 285 if ((regs & (1 << r)) != 0) { |
| 286 mov(scratch, Operand(base, 0)); |
| 287 ExternalReference reg_addr = |
| 288 ExternalReference(Debug_Address::Register(i)); |
| 289 mov(Operand::StaticVariable(reg_addr), scratch); |
| 290 lea(base, Operand(base, kPointerSize)); |
| 291 } |
| 292 } |
| 293 } |
| 294 #endif |
| 295 |
| 296 void MacroAssembler::Set(Register dst, const Immediate& x) { |
| 297 if (x.is_zero()) { |
| 298 xor_(dst, Operand(dst)); // shorter than mov |
| 299 } else { |
| 300 mov(dst, x); |
| 301 } |
| 302 } |
| 303 |
| 304 |
| 305 void MacroAssembler::Set(const Operand& dst, const Immediate& x) { |
| 306 mov(dst, x); |
| 307 } |
| 308 |
| 309 |
| 310 void MacroAssembler::CmpObjectType(Register heap_object, |
| 311 InstanceType type, |
| 312 Register map) { |
| 313 mov(map, FieldOperand(heap_object, HeapObject::kMapOffset)); |
| 314 CmpInstanceType(map, type); |
| 315 } |
| 316 |
| 317 |
| 318 void MacroAssembler::CmpInstanceType(Register map, InstanceType type) { |
| 319 cmpb(FieldOperand(map, Map::kInstanceTypeOffset), |
| 320 static_cast<int8_t>(type)); |
| 321 } |
| 322 |
| 323 |
| 324 void MacroAssembler::FCmp() { |
| 325 fcompp(); |
| 326 push(eax); |
| 327 fnstsw_ax(); |
| 328 sahf(); |
| 329 pop(eax); |
| 330 } |
| 331 |
| 332 |
| 333 void MacroAssembler::EnterFrame(StackFrame::Type type) { |
| 334 push(ebp); |
| 335 mov(ebp, Operand(esp)); |
| 336 push(esi); |
| 337 push(Immediate(Smi::FromInt(type))); |
| 338 push(Immediate(CodeObject())); |
| 339 if (FLAG_debug_code) { |
| 340 cmp(Operand(esp, 0), Immediate(Factory::undefined_value())); |
| 341 Check(not_equal, "code object not properly patched"); |
| 342 } |
| 343 } |
| 344 |
| 345 |
| 346 void MacroAssembler::LeaveFrame(StackFrame::Type type) { |
| 347 if (FLAG_debug_code) { |
| 348 cmp(Operand(ebp, StandardFrameConstants::kMarkerOffset), |
| 349 Immediate(Smi::FromInt(type))); |
| 350 Check(equal, "stack frame types must match"); |
| 351 } |
| 352 leave(); |
| 353 } |
| 354 |
| 355 |
| 356 void MacroAssembler::EnterExitFrame(StackFrame::Type type) { |
| 357 ASSERT(type == StackFrame::EXIT || type == StackFrame::EXIT_DEBUG); |
| 358 |
| 359 // Setup the frame structure on the stack. |
| 360 ASSERT(ExitFrameConstants::kPPDisplacement == +2 * kPointerSize); |
| 361 ASSERT(ExitFrameConstants::kCallerPCOffset == +1 * kPointerSize); |
| 362 ASSERT(ExitFrameConstants::kCallerFPOffset == 0 * kPointerSize); |
| 363 push(ebp); |
| 364 mov(ebp, Operand(esp)); |
| 365 |
| 366 // Reserve room for entry stack pointer and push the debug marker. |
| 367 ASSERT(ExitFrameConstants::kSPOffset == -1 * kPointerSize); |
| 368 push(Immediate(0)); // saved entry sp, patched before call |
| 369 push(Immediate(type == StackFrame::EXIT_DEBUG ? 1 : 0)); |
| 370 |
| 371 // Save the frame pointer and the context in top. |
| 372 ExternalReference c_entry_fp_address(Top::k_c_entry_fp_address); |
| 373 ExternalReference context_address(Top::k_context_address); |
| 374 mov(Operand::StaticVariable(c_entry_fp_address), ebp); |
| 375 mov(Operand::StaticVariable(context_address), esi); |
| 376 |
| 377 // Setup argc and argv in callee-saved registers. |
| 378 int offset = StandardFrameConstants::kCallerSPOffset - kPointerSize; |
| 379 mov(edi, Operand(eax)); |
| 380 lea(esi, Operand(ebp, eax, times_4, offset)); |
| 381 |
| 382 #ifdef ENABLE_DEBUGGER_SUPPORT |
| 383 // Save the state of all registers to the stack from the memory |
| 384 // location. This is needed to allow nested break points. |
| 385 if (type == StackFrame::EXIT_DEBUG) { |
| 386 // TODO(1243899): This should be symmetric to |
| 387 // CopyRegistersFromStackToMemory() but it isn't! esp is assumed |
| 388 // correct here, but computed for the other call. Very error |
| 389 // prone! FIX THIS. Actually there are deeper problems with |
| 390 // register saving than this asymmetry (see the bug report |
| 391 // associated with this issue). |
| 392 PushRegistersFromMemory(kJSCallerSaved); |
| 393 } |
| 394 #endif |
| 395 |
| 396 // Reserve space for two arguments: argc and argv. |
| 397 sub(Operand(esp), Immediate(2 * kPointerSize)); |
| 398 |
| 399 // Get the required frame alignment for the OS. |
| 400 static const int kFrameAlignment = OS::ActivationFrameAlignment(); |
| 401 if (kFrameAlignment > 0) { |
| 402 ASSERT(IsPowerOf2(kFrameAlignment)); |
| 403 and_(esp, -kFrameAlignment); |
| 404 } |
| 405 |
| 406 // Patch the saved entry sp. |
| 407 mov(Operand(ebp, ExitFrameConstants::kSPOffset), esp); |
| 408 } |
| 409 |
| 410 |
| 411 void MacroAssembler::LeaveExitFrame(StackFrame::Type type) { |
| 412 #ifdef ENABLE_DEBUGGER_SUPPORT |
| 413 // Restore the memory copy of the registers by digging them out from |
| 414 // the stack. This is needed to allow nested break points. |
| 415 if (type == StackFrame::EXIT_DEBUG) { |
| 416 // It's okay to clobber register ebx below because we don't need |
| 417 // the function pointer after this. |
| 418 const int kCallerSavedSize = kNumJSCallerSaved * kPointerSize; |
| 419 int kOffset = ExitFrameConstants::kDebugMarkOffset - kCallerSavedSize; |
| 420 lea(ebx, Operand(ebp, kOffset)); |
| 421 CopyRegistersFromStackToMemory(ebx, ecx, kJSCallerSaved); |
| 422 } |
| 423 #endif |
| 424 |
| 425 // Get the return address from the stack and restore the frame pointer. |
| 426 mov(ecx, Operand(ebp, 1 * kPointerSize)); |
| 427 mov(ebp, Operand(ebp, 0 * kPointerSize)); |
| 428 |
| 429 // Pop the arguments and the receiver from the caller stack. |
| 430 lea(esp, Operand(esi, 1 * kPointerSize)); |
| 431 |
| 432 // Restore current context from top and clear it in debug mode. |
| 433 ExternalReference context_address(Top::k_context_address); |
| 434 mov(esi, Operand::StaticVariable(context_address)); |
| 435 #ifdef DEBUG |
| 436 mov(Operand::StaticVariable(context_address), Immediate(0)); |
| 437 #endif |
| 438 |
| 439 // Push the return address to get ready to return. |
| 440 push(ecx); |
| 441 |
| 442 // Clear the top frame. |
| 443 ExternalReference c_entry_fp_address(Top::k_c_entry_fp_address); |
| 444 mov(Operand::StaticVariable(c_entry_fp_address), Immediate(0)); |
| 445 } |
| 446 |
| 447 |
| 448 void MacroAssembler::PushTryHandler(CodeLocation try_location, |
| 449 HandlerType type) { |
| 450 ASSERT(StackHandlerConstants::kSize == 6 * kPointerSize); // adjust this code |
| 451 // The pc (return address) is already on TOS. |
| 452 if (try_location == IN_JAVASCRIPT) { |
| 453 if (type == TRY_CATCH_HANDLER) { |
| 454 push(Immediate(StackHandler::TRY_CATCH)); |
| 455 } else { |
| 456 push(Immediate(StackHandler::TRY_FINALLY)); |
| 457 } |
| 458 push(Immediate(Smi::FromInt(StackHandler::kCodeNotPresent))); |
| 459 push(ebp); |
| 460 push(edi); |
| 461 } else { |
| 462 ASSERT(try_location == IN_JS_ENTRY); |
| 463 // The parameter pointer is meaningless here and ebp does not |
| 464 // point to a JS frame. So we save NULL for both pp and ebp. We |
| 465 // expect the code throwing an exception to check ebp before |
| 466 // dereferencing it to restore the context. |
| 467 push(Immediate(StackHandler::ENTRY)); |
| 468 push(Immediate(Smi::FromInt(StackHandler::kCodeNotPresent))); |
| 469 push(Immediate(0)); // NULL frame pointer |
| 470 push(Immediate(0)); // NULL parameter pointer |
| 471 } |
| 472 // Cached TOS. |
| 473 mov(eax, Operand::StaticVariable(ExternalReference(Top::k_handler_address))); |
| 474 // Link this handler. |
| 475 mov(Operand::StaticVariable(ExternalReference(Top::k_handler_address)), esp); |
| 476 } |
| 477 |
| 478 |
| 479 Register MacroAssembler::CheckMaps(JSObject* object, Register object_reg, |
| 480 JSObject* holder, Register holder_reg, |
| 481 Register scratch, |
| 482 Label* miss) { |
| 483 // Make sure there's no overlap between scratch and the other |
| 484 // registers. |
| 485 ASSERT(!scratch.is(object_reg) && !scratch.is(holder_reg)); |
| 486 |
| 487 // Keep track of the current object in register reg. |
| 488 Register reg = object_reg; |
| 489 int depth = 1; |
| 490 |
| 491 // Check the maps in the prototype chain. |
| 492 // Traverse the prototype chain from the object and do map checks. |
| 493 while (object != holder) { |
| 494 depth++; |
| 495 |
| 496 // Only global objects and objects that do not require access |
| 497 // checks are allowed in stubs. |
| 498 ASSERT(object->IsJSGlobalProxy() || !object->IsAccessCheckNeeded()); |
| 499 |
| 500 JSObject* prototype = JSObject::cast(object->GetPrototype()); |
| 501 if (Heap::InNewSpace(prototype)) { |
| 502 // Get the map of the current object. |
| 503 mov(scratch, FieldOperand(reg, HeapObject::kMapOffset)); |
| 504 cmp(Operand(scratch), Immediate(Handle<Map>(object->map()))); |
| 505 // Branch on the result of the map check. |
| 506 j(not_equal, miss, not_taken); |
| 507 // Check access rights to the global object. This has to happen |
| 508 // after the map check so that we know that the object is |
| 509 // actually a global object. |
| 510 if (object->IsJSGlobalProxy()) { |
| 511 CheckAccessGlobalProxy(reg, scratch, miss); |
| 512 |
| 513 // Restore scratch register to be the map of the object. |
| 514 // We load the prototype from the map in the scratch register. |
| 515 mov(scratch, FieldOperand(reg, HeapObject::kMapOffset)); |
| 516 } |
| 517 // The prototype is in new space; we cannot store a reference |
| 518 // to it in the code. Load it from the map. |
| 519 reg = holder_reg; // from now the object is in holder_reg |
| 520 mov(reg, FieldOperand(scratch, Map::kPrototypeOffset)); |
| 521 |
| 522 } else { |
| 523 // Check the map of the current object. |
| 524 cmp(FieldOperand(reg, HeapObject::kMapOffset), |
| 525 Immediate(Handle<Map>(object->map()))); |
| 526 // Branch on the result of the map check. |
| 527 j(not_equal, miss, not_taken); |
| 528 // Check access rights to the global object. This has to happen |
| 529 // after the map check so that we know that the object is |
| 530 // actually a global object. |
| 531 if (object->IsJSGlobalProxy()) { |
| 532 CheckAccessGlobalProxy(reg, scratch, miss); |
| 533 } |
| 534 // The prototype is in old space; load it directly. |
| 535 reg = holder_reg; // from now the object is in holder_reg |
| 536 mov(reg, Handle<JSObject>(prototype)); |
| 537 } |
| 538 |
| 539 // Go to the next object in the prototype chain. |
| 540 object = prototype; |
| 541 } |
| 542 |
| 543 // Check the holder map. |
| 544 cmp(FieldOperand(reg, HeapObject::kMapOffset), |
| 545 Immediate(Handle<Map>(holder->map()))); |
| 546 j(not_equal, miss, not_taken); |
| 547 |
| 548 // Log the check depth. |
| 549 LOG(IntEvent("check-maps-depth", depth)); |
| 550 |
| 551 // Perform security check for access to the global object and return |
| 552 // the holder register. |
| 553 ASSERT(object == holder); |
| 554 ASSERT(object->IsJSGlobalProxy() || !object->IsAccessCheckNeeded()); |
| 555 if (object->IsJSGlobalProxy()) { |
| 556 CheckAccessGlobalProxy(reg, scratch, miss); |
| 557 } |
| 558 return reg; |
| 559 } |
| 560 |
| 561 |
| 562 void MacroAssembler::CheckAccessGlobalProxy(Register holder_reg, |
| 563 Register scratch, |
| 564 Label* miss) { |
| 565 Label same_contexts; |
| 566 |
| 567 ASSERT(!holder_reg.is(scratch)); |
| 568 |
| 569 // Load current lexical context from the stack frame. |
| 570 mov(scratch, Operand(ebp, StandardFrameConstants::kContextOffset)); |
| 571 |
| 572 // When generating debug code, make sure the lexical context is set. |
| 573 if (FLAG_debug_code) { |
| 574 cmp(Operand(scratch), Immediate(0)); |
| 575 Check(not_equal, "we should not have an empty lexical context"); |
| 576 } |
| 577 // Load the global context of the current context. |
| 578 int offset = Context::kHeaderSize + Context::GLOBAL_INDEX * kPointerSize; |
| 579 mov(scratch, FieldOperand(scratch, offset)); |
| 580 mov(scratch, FieldOperand(scratch, GlobalObject::kGlobalContextOffset)); |
| 581 |
| 582 // Check the context is a global context. |
| 583 if (FLAG_debug_code) { |
| 584 push(scratch); |
| 585 // Read the first word and compare to global_context_map. |
| 586 mov(scratch, FieldOperand(scratch, HeapObject::kMapOffset)); |
| 587 cmp(scratch, Factory::global_context_map()); |
| 588 Check(equal, "JSGlobalObject::global_context should be a global context."); |
| 589 pop(scratch); |
| 590 } |
| 591 |
| 592 // Check if both contexts are the same. |
| 593 cmp(scratch, FieldOperand(holder_reg, JSGlobalProxy::kContextOffset)); |
| 594 j(equal, &same_contexts, taken); |
| 595 |
| 596 // Compare security tokens, save holder_reg on the stack so we can use it |
| 597 // as a temporary register. |
| 598 // |
| 599 // TODO(119): avoid push(holder_reg)/pop(holder_reg) |
| 600 push(holder_reg); |
| 601 // Check that the security token in the calling global object is |
| 602 // compatible with the security token in the receiving global |
| 603 // object. |
| 604 mov(holder_reg, FieldOperand(holder_reg, JSGlobalProxy::kContextOffset)); |
| 605 |
| 606 // Check the context is a global context. |
| 607 if (FLAG_debug_code) { |
| 608 cmp(holder_reg, Factory::null_value()); |
| 609 Check(not_equal, "JSGlobalProxy::context() should not be null."); |
| 610 |
| 611 push(holder_reg); |
| 612 // Read the first word and compare to global_context_map(), |
| 613 mov(holder_reg, FieldOperand(holder_reg, HeapObject::kMapOffset)); |
| 614 cmp(holder_reg, Factory::global_context_map()); |
| 615 Check(equal, "JSGlobalObject::global_context should be a global context."); |
| 616 pop(holder_reg); |
| 617 } |
| 618 |
| 619 int token_offset = Context::kHeaderSize + |
| 620 Context::SECURITY_TOKEN_INDEX * kPointerSize; |
| 621 mov(scratch, FieldOperand(scratch, token_offset)); |
| 622 cmp(scratch, FieldOperand(holder_reg, token_offset)); |
| 623 pop(holder_reg); |
| 624 j(not_equal, miss, not_taken); |
| 625 |
| 626 bind(&same_contexts); |
| 627 } |
| 628 |
| 629 |
| 630 void MacroAssembler::NegativeZeroTest(CodeGenerator* cgen, |
| 631 Register result, |
| 632 Register op, |
| 633 JumpTarget* then_target) { |
| 634 JumpTarget ok(cgen); |
| 635 test(result, Operand(result)); |
| 636 ok.Branch(not_zero, taken); |
| 637 test(op, Operand(op)); |
| 638 then_target->Branch(sign, not_taken); |
| 639 ok.Bind(); |
| 640 } |
| 641 |
| 642 |
| 643 void MacroAssembler::NegativeZeroTest(Register result, |
| 644 Register op, |
| 645 Label* then_label) { |
| 646 Label ok; |
| 647 test(result, Operand(result)); |
| 648 j(not_zero, &ok, taken); |
| 649 test(op, Operand(op)); |
| 650 j(sign, then_label, not_taken); |
| 651 bind(&ok); |
| 652 } |
| 653 |
| 654 |
| 655 void MacroAssembler::NegativeZeroTest(Register result, |
| 656 Register op1, |
| 657 Register op2, |
| 658 Register scratch, |
| 659 Label* then_label) { |
| 660 Label ok; |
| 661 test(result, Operand(result)); |
| 662 j(not_zero, &ok, taken); |
| 663 mov(scratch, Operand(op1)); |
| 664 or_(scratch, Operand(op2)); |
| 665 j(sign, then_label, not_taken); |
| 666 bind(&ok); |
| 667 } |
| 668 |
| 669 |
| 670 void MacroAssembler::TryGetFunctionPrototype(Register function, |
| 671 Register result, |
| 672 Register scratch, |
| 673 Label* miss) { |
| 674 // Check that the receiver isn't a smi. |
| 675 test(function, Immediate(kSmiTagMask)); |
| 676 j(zero, miss, not_taken); |
| 677 |
| 678 // Check that the function really is a function. |
| 679 CmpObjectType(function, JS_FUNCTION_TYPE, result); |
| 680 j(not_equal, miss, not_taken); |
| 681 |
| 682 // Make sure that the function has an instance prototype. |
| 683 Label non_instance; |
| 684 movzx_b(scratch, FieldOperand(result, Map::kBitFieldOffset)); |
| 685 test(scratch, Immediate(1 << Map::kHasNonInstancePrototype)); |
| 686 j(not_zero, &non_instance, not_taken); |
| 687 |
| 688 // Get the prototype or initial map from the function. |
| 689 mov(result, |
| 690 FieldOperand(function, JSFunction::kPrototypeOrInitialMapOffset)); |
| 691 |
| 692 // If the prototype or initial map is the hole, don't return it and |
| 693 // simply miss the cache instead. This will allow us to allocate a |
| 694 // prototype object on-demand in the runtime system. |
| 695 cmp(Operand(result), Immediate(Factory::the_hole_value())); |
| 696 j(equal, miss, not_taken); |
| 697 |
| 698 // If the function does not have an initial map, we're done. |
| 699 Label done; |
| 700 CmpObjectType(result, MAP_TYPE, scratch); |
| 701 j(not_equal, &done); |
| 702 |
| 703 // Get the prototype from the initial map. |
| 704 mov(result, FieldOperand(result, Map::kPrototypeOffset)); |
| 705 jmp(&done); |
| 706 |
| 707 // Non-instance prototype: Fetch prototype from constructor field |
| 708 // in initial map. |
| 709 bind(&non_instance); |
| 710 mov(result, FieldOperand(result, Map::kConstructorOffset)); |
| 711 |
| 712 // All done. |
| 713 bind(&done); |
| 714 } |
| 715 |
| 716 |
| 717 void MacroAssembler::CallStub(CodeStub* stub) { |
| 718 ASSERT(allow_stub_calls()); // calls are not allowed in some stubs |
| 719 call(stub->GetCode(), RelocInfo::CODE_TARGET); |
| 720 } |
| 721 |
| 722 |
| 723 void MacroAssembler::StubReturn(int argc) { |
| 724 ASSERT(argc >= 1 && generating_stub()); |
| 725 ret((argc - 1) * kPointerSize); |
| 726 } |
| 727 |
| 728 |
| 729 void MacroAssembler::IllegalOperation(int num_arguments) { |
| 730 if (num_arguments > 0) { |
| 731 add(Operand(esp), Immediate(num_arguments * kPointerSize)); |
| 732 } |
| 733 mov(eax, Immediate(Factory::undefined_value())); |
| 734 } |
| 735 |
| 736 |
| 737 void MacroAssembler::CallRuntime(Runtime::FunctionId id, int num_arguments) { |
| 738 CallRuntime(Runtime::FunctionForId(id), num_arguments); |
| 739 } |
| 740 |
| 741 |
| 742 void MacroAssembler::CallRuntime(Runtime::Function* f, int num_arguments) { |
| 743 // If the expected number of arguments of the runtime function is |
| 744 // constant, we check that the actual number of arguments match the |
| 745 // expectation. |
| 746 if (f->nargs >= 0 && f->nargs != num_arguments) { |
| 747 IllegalOperation(num_arguments); |
| 748 return; |
| 749 } |
| 750 |
| 751 Runtime::FunctionId function_id = |
| 752 static_cast<Runtime::FunctionId>(f->stub_id); |
| 753 RuntimeStub stub(function_id, num_arguments); |
| 754 CallStub(&stub); |
| 755 } |
| 756 |
| 757 |
| 758 void MacroAssembler::TailCallRuntime(const ExternalReference& ext, |
| 759 int num_arguments) { |
| 760 // TODO(1236192): Most runtime routines don't need the number of |
| 761 // arguments passed in because it is constant. At some point we |
| 762 // should remove this need and make the runtime routine entry code |
| 763 // smarter. |
| 764 Set(eax, Immediate(num_arguments)); |
| 765 JumpToBuiltin(ext); |
| 766 } |
| 767 |
| 768 |
| 769 void MacroAssembler::JumpToBuiltin(const ExternalReference& ext) { |
| 770 // Set the entry point and jump to the C entry runtime stub. |
| 771 mov(ebx, Immediate(ext)); |
| 772 CEntryStub ces; |
| 773 jmp(ces.GetCode(), RelocInfo::CODE_TARGET); |
| 774 } |
| 775 |
| 776 |
| 777 void MacroAssembler::InvokePrologue(const ParameterCount& expected, |
| 778 const ParameterCount& actual, |
| 779 Handle<Code> code_constant, |
| 780 const Operand& code_operand, |
| 781 Label* done, |
| 782 InvokeFlag flag) { |
| 783 bool definitely_matches = false; |
| 784 Label invoke; |
| 785 if (expected.is_immediate()) { |
| 786 ASSERT(actual.is_immediate()); |
| 787 if (expected.immediate() == actual.immediate()) { |
| 788 definitely_matches = true; |
| 789 } else { |
| 790 mov(eax, actual.immediate()); |
| 791 const int sentinel = SharedFunctionInfo::kDontAdaptArgumentsSentinel; |
| 792 if (expected.immediate() == sentinel) { |
| 793 // Don't worry about adapting arguments for builtins that |
| 794 // don't want that done. Skip adaption code by making it look |
| 795 // like we have a match between expected and actual number of |
| 796 // arguments. |
| 797 definitely_matches = true; |
| 798 } else { |
| 799 mov(ebx, expected.immediate()); |
| 800 } |
| 801 } |
| 802 } else { |
| 803 if (actual.is_immediate()) { |
| 804 // Expected is in register, actual is immediate. This is the |
| 805 // case when we invoke function values without going through the |
| 806 // IC mechanism. |
| 807 cmp(expected.reg(), actual.immediate()); |
| 808 j(equal, &invoke); |
| 809 ASSERT(expected.reg().is(ebx)); |
| 810 mov(eax, actual.immediate()); |
| 811 } else if (!expected.reg().is(actual.reg())) { |
| 812 // Both expected and actual are in (different) registers. This |
| 813 // is the case when we invoke functions using call and apply. |
| 814 cmp(expected.reg(), Operand(actual.reg())); |
| 815 j(equal, &invoke); |
| 816 ASSERT(actual.reg().is(eax)); |
| 817 ASSERT(expected.reg().is(ebx)); |
| 818 } |
| 819 } |
| 820 |
| 821 if (!definitely_matches) { |
| 822 Handle<Code> adaptor = |
| 823 Handle<Code>(Builtins::builtin(Builtins::ArgumentsAdaptorTrampoline)); |
| 824 if (!code_constant.is_null()) { |
| 825 mov(edx, Immediate(code_constant)); |
| 826 add(Operand(edx), Immediate(Code::kHeaderSize - kHeapObjectTag)); |
| 827 } else if (!code_operand.is_reg(edx)) { |
| 828 mov(edx, code_operand); |
| 829 } |
| 830 |
| 831 if (flag == CALL_FUNCTION) { |
| 832 call(adaptor, RelocInfo::CODE_TARGET); |
| 833 jmp(done); |
| 834 } else { |
| 835 jmp(adaptor, RelocInfo::CODE_TARGET); |
| 836 } |
| 837 bind(&invoke); |
| 838 } |
| 839 } |
| 840 |
| 841 |
| 842 void MacroAssembler::InvokeCode(const Operand& code, |
| 843 const ParameterCount& expected, |
| 844 const ParameterCount& actual, |
| 845 InvokeFlag flag) { |
| 846 Label done; |
| 847 InvokePrologue(expected, actual, Handle<Code>::null(), code, &done, flag); |
| 848 if (flag == CALL_FUNCTION) { |
| 849 call(code); |
| 850 } else { |
| 851 ASSERT(flag == JUMP_FUNCTION); |
| 852 jmp(code); |
| 853 } |
| 854 bind(&done); |
| 855 } |
| 856 |
| 857 |
| 858 void MacroAssembler::InvokeCode(Handle<Code> code, |
| 859 const ParameterCount& expected, |
| 860 const ParameterCount& actual, |
| 861 RelocInfo::Mode rmode, |
| 862 InvokeFlag flag) { |
| 863 Label done; |
| 864 Operand dummy(eax); |
| 865 InvokePrologue(expected, actual, code, dummy, &done, flag); |
| 866 if (flag == CALL_FUNCTION) { |
| 867 call(code, rmode); |
| 868 } else { |
| 869 ASSERT(flag == JUMP_FUNCTION); |
| 870 jmp(code, rmode); |
| 871 } |
| 872 bind(&done); |
| 873 } |
| 874 |
| 875 |
| 876 void MacroAssembler::InvokeFunction(Register fun, |
| 877 const ParameterCount& actual, |
| 878 InvokeFlag flag) { |
| 879 ASSERT(fun.is(edi)); |
| 880 mov(edx, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset)); |
| 881 mov(esi, FieldOperand(edi, JSFunction::kContextOffset)); |
| 882 mov(ebx, FieldOperand(edx, SharedFunctionInfo::kFormalParameterCountOffset)); |
| 883 mov(edx, FieldOperand(edx, SharedFunctionInfo::kCodeOffset)); |
| 884 lea(edx, FieldOperand(edx, Code::kHeaderSize)); |
| 885 |
| 886 ParameterCount expected(ebx); |
| 887 InvokeCode(Operand(edx), expected, actual, flag); |
| 888 } |
| 889 |
| 890 |
| 891 void MacroAssembler::InvokeBuiltin(Builtins::JavaScript id, InvokeFlag flag) { |
| 892 bool resolved; |
| 893 Handle<Code> code = ResolveBuiltin(id, &resolved); |
| 894 |
| 895 // Calls are not allowed in some stubs. |
| 896 ASSERT(flag == JUMP_FUNCTION || allow_stub_calls()); |
| 897 |
| 898 // Rely on the assertion to check that the number of provided |
| 899 // arguments match the expected number of arguments. Fake a |
| 900 // parameter count to avoid emitting code to do the check. |
| 901 ParameterCount expected(0); |
| 902 InvokeCode(Handle<Code>(code), expected, expected, |
| 903 RelocInfo::CODE_TARGET, flag); |
| 904 |
| 905 const char* name = Builtins::GetName(id); |
| 906 int argc = Builtins::GetArgumentsCount(id); |
| 907 |
| 908 if (!resolved) { |
| 909 uint32_t flags = |
| 910 Bootstrapper::FixupFlagsArgumentsCount::encode(argc) | |
| 911 Bootstrapper::FixupFlagsIsPCRelative::encode(true) | |
| 912 Bootstrapper::FixupFlagsUseCodeObject::encode(false); |
| 913 Unresolved entry = { pc_offset() - sizeof(int32_t), flags, name }; |
| 914 unresolved_.Add(entry); |
| 915 } |
| 916 } |
| 917 |
| 918 |
| 919 void MacroAssembler::GetBuiltinEntry(Register target, Builtins::JavaScript id) { |
| 920 bool resolved; |
| 921 Handle<Code> code = ResolveBuiltin(id, &resolved); |
| 922 |
| 923 const char* name = Builtins::GetName(id); |
| 924 int argc = Builtins::GetArgumentsCount(id); |
| 925 |
| 926 mov(Operand(target), Immediate(code)); |
| 927 if (!resolved) { |
| 928 uint32_t flags = |
| 929 Bootstrapper::FixupFlagsArgumentsCount::encode(argc) | |
| 930 Bootstrapper::FixupFlagsIsPCRelative::encode(false) | |
| 931 Bootstrapper::FixupFlagsUseCodeObject::encode(true); |
| 932 Unresolved entry = { pc_offset() - sizeof(int32_t), flags, name }; |
| 933 unresolved_.Add(entry); |
| 934 } |
| 935 add(Operand(target), Immediate(Code::kHeaderSize - kHeapObjectTag)); |
| 936 } |
| 937 |
| 938 |
| 939 Handle<Code> MacroAssembler::ResolveBuiltin(Builtins::JavaScript id, |
| 940 bool* resolved) { |
| 941 // Move the builtin function into the temporary function slot by |
| 942 // reading it from the builtins object. NOTE: We should be able to |
| 943 // reduce this to two instructions by putting the function table in |
| 944 // the global object instead of the "builtins" object and by using a |
| 945 // real register for the function. |
| 946 mov(edx, Operand(esi, Context::SlotOffset(Context::GLOBAL_INDEX))); |
| 947 mov(edx, FieldOperand(edx, GlobalObject::kBuiltinsOffset)); |
| 948 int builtins_offset = |
| 949 JSBuiltinsObject::kJSBuiltinsOffset + (id * kPointerSize); |
| 950 mov(edi, FieldOperand(edx, builtins_offset)); |
| 951 |
| 952 |
| 953 return Builtins::GetCode(id, resolved); |
| 954 } |
| 955 |
| 956 |
| 957 void MacroAssembler::Ret() { |
| 958 ret(0); |
| 959 } |
| 960 |
| 961 |
| 962 void MacroAssembler::SetCounter(StatsCounter* counter, int value) { |
| 963 if (FLAG_native_code_counters && counter->Enabled()) { |
| 964 mov(Operand::StaticVariable(ExternalReference(counter)), Immediate(value)); |
| 965 } |
| 966 } |
| 967 |
| 968 |
| 969 void MacroAssembler::IncrementCounter(StatsCounter* counter, int value) { |
| 970 ASSERT(value > 0); |
| 971 if (FLAG_native_code_counters && counter->Enabled()) { |
| 972 Operand operand = Operand::StaticVariable(ExternalReference(counter)); |
| 973 if (value == 1) { |
| 974 inc(operand); |
| 975 } else { |
| 976 add(operand, Immediate(value)); |
| 977 } |
| 978 } |
| 979 } |
| 980 |
| 981 |
| 982 void MacroAssembler::DecrementCounter(StatsCounter* counter, int value) { |
| 983 ASSERT(value > 0); |
| 984 if (FLAG_native_code_counters && counter->Enabled()) { |
| 985 Operand operand = Operand::StaticVariable(ExternalReference(counter)); |
| 986 if (value == 1) { |
| 987 dec(operand); |
| 988 } else { |
| 989 sub(operand, Immediate(value)); |
| 990 } |
| 991 } |
| 992 } |
| 993 |
| 994 |
| 995 void MacroAssembler::Assert(Condition cc, const char* msg) { |
| 996 if (FLAG_debug_code) Check(cc, msg); |
| 997 } |
| 998 |
| 999 |
| 1000 void MacroAssembler::Check(Condition cc, const char* msg) { |
| 1001 Label L; |
| 1002 j(cc, &L, taken); |
| 1003 Abort(msg); |
| 1004 // will not return here |
| 1005 bind(&L); |
| 1006 } |
| 1007 |
| 1008 |
| 1009 void MacroAssembler::Abort(const char* msg) { |
| 1010 // We want to pass the msg string like a smi to avoid GC |
| 1011 // problems, however msg is not guaranteed to be aligned |
| 1012 // properly. Instead, we pass an aligned pointer that is |
| 1013 // a proper v8 smi, but also pass the alignment difference |
| 1014 // from the real pointer as a smi. |
| 1015 intptr_t p1 = reinterpret_cast<intptr_t>(msg); |
| 1016 intptr_t p0 = (p1 & ~kSmiTagMask) + kSmiTag; |
| 1017 ASSERT(reinterpret_cast<Object*>(p0)->IsSmi()); |
| 1018 #ifdef DEBUG |
| 1019 if (msg != NULL) { |
| 1020 RecordComment("Abort message: "); |
| 1021 RecordComment(msg); |
| 1022 } |
| 1023 #endif |
| 1024 push(eax); |
| 1025 push(Immediate(p0)); |
| 1026 push(Immediate(reinterpret_cast<intptr_t>(Smi::FromInt(p1 - p0)))); |
| 1027 CallRuntime(Runtime::kAbort, 2); |
| 1028 // will not return here |
| 1029 } |
| 1030 |
| 1031 |
| 1032 CodePatcher::CodePatcher(byte* address, int size) |
| 1033 : address_(address), size_(size), masm_(address, size + Assembler::kGap) { |
| 1034 // Create a new macro assembler pointing to the address of the code to patch. |
| 1035 // The size is adjusted with kGap on order for the assembler to generate size |
| 1036 // bytes of instructions without failing with buffer size constraints. |
| 1037 ASSERT(masm_.reloc_info_writer.pos() == address_ + size_ + Assembler::kGap); |
| 1038 } |
| 1039 |
| 1040 |
| 1041 CodePatcher::~CodePatcher() { |
| 1042 // Indicate that code has changed. |
| 1043 CPU::FlushICache(address_, size_); |
| 1044 |
| 1045 // Check that the code was patched as expected. |
| 1046 ASSERT(masm_.pc_ == address_ + size_); |
| 1047 ASSERT(masm_.reloc_info_writer.pos() == address_ + size_ + Assembler::kGap); |
| 1048 } |
| 1049 |
| 1050 |
| 1051 } } // namespace v8::internal |
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