1 // Copyright 2014 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
7 #include "src/codegen.h"
8 #include "src/deoptimizer.h"
9 #include "src/full-codegen.h"
10 #include "src/safepoint-table.h"
15 const int Deoptimizer::table_entry_size_ = 8;
18 int Deoptimizer::patch_size() {
19 #if V8_TARGET_ARCH_PPC64
20 const int kCallInstructionSizeInWords = 7;
22 const int kCallInstructionSizeInWords = 4;
24 return kCallInstructionSizeInWords * Assembler::kInstrSize;
28 void Deoptimizer::EnsureRelocSpaceForLazyDeoptimization(Handle<Code> code) {
29 // Empty because there is no need for relocation information for the code
30 // patching in Deoptimizer::PatchCodeForDeoptimization below.
34 void Deoptimizer::PatchCodeForDeoptimization(Isolate* isolate, Code* code) {
35 Address code_start_address = code->instruction_start();
37 // Invalidate the relocation information, as it will become invalid by the
38 // code patching below, and is not needed any more.
39 code->InvalidateRelocation();
41 if (FLAG_zap_code_space) {
42 // Fail hard and early if we enter this code object again.
43 byte* pointer = code->FindCodeAgeSequence();
44 if (pointer != NULL) {
45 pointer += kNoCodeAgeSequenceLength;
47 pointer = code->instruction_start();
49 CodePatcher patcher(pointer, 1);
50 patcher.masm()->bkpt(0);
52 DeoptimizationInputData* data =
53 DeoptimizationInputData::cast(code->deoptimization_data());
54 int osr_offset = data->OsrPcOffset()->value();
56 CodePatcher osr_patcher(code->instruction_start() + osr_offset, 1);
57 osr_patcher.masm()->bkpt(0);
61 DeoptimizationInputData* deopt_data =
62 DeoptimizationInputData::cast(code->deoptimization_data());
64 Address prev_call_address = NULL;
66 // For each LLazyBailout instruction insert a call to the corresponding
67 // deoptimization entry.
68 for (int i = 0; i < deopt_data->DeoptCount(); i++) {
69 if (deopt_data->Pc(i)->value() == -1) continue;
70 Address call_address = code_start_address + deopt_data->Pc(i)->value();
71 Address deopt_entry = GetDeoptimizationEntry(isolate, i, LAZY);
72 // We need calls to have a predictable size in the unoptimized code, but
73 // this is optimized code, so we don't have to have a predictable size.
74 int call_size_in_bytes = MacroAssembler::CallSizeNotPredictableCodeSize(
75 deopt_entry, kRelocInfo_NONEPTR);
76 int call_size_in_words = call_size_in_bytes / Assembler::kInstrSize;
77 DCHECK(call_size_in_bytes % Assembler::kInstrSize == 0);
78 DCHECK(call_size_in_bytes <= patch_size());
79 CodePatcher patcher(call_address, call_size_in_words);
80 patcher.masm()->Call(deopt_entry, kRelocInfo_NONEPTR);
81 DCHECK(prev_call_address == NULL ||
82 call_address >= prev_call_address + patch_size());
83 DCHECK(call_address + patch_size() <= code->instruction_end());
85 prev_call_address = call_address;
91 void Deoptimizer::FillInputFrame(Address tos, JavaScriptFrame* frame) {
92 // Set the register values. The values are not important as there are no
93 // callee saved registers in JavaScript frames, so all registers are
94 // spilled. Registers fp and sp are set to the correct values though.
95 // We ensure the values are Smis to avoid confusing the garbage
96 // collector in the event that any values are retreived and stored
99 for (int i = 0; i < Register::kNumRegisters; i++) {
100 input_->SetRegister(i, reinterpret_cast<intptr_t>(Smi::FromInt(i)));
102 input_->SetRegister(sp.code(), reinterpret_cast<intptr_t>(frame->sp()));
103 input_->SetRegister(fp.code(), reinterpret_cast<intptr_t>(frame->fp()));
104 for (int i = 0; i < DoubleRegister::NumAllocatableRegisters(); i++) {
105 input_->SetDoubleRegister(i, 0.0);
108 // Fill the frame content from the actual data on the frame.
109 for (unsigned i = 0; i < input_->GetFrameSize(); i += kPointerSize) {
110 input_->SetFrameSlot(
111 i, reinterpret_cast<intptr_t>(Memory::Address_at(tos + i)));
116 void Deoptimizer::SetPlatformCompiledStubRegisters(
117 FrameDescription* output_frame, CodeStubDescriptor* descriptor) {
118 ApiFunction function(descriptor->deoptimization_handler());
119 ExternalReference xref(&function, ExternalReference::BUILTIN_CALL, isolate_);
120 intptr_t handler = reinterpret_cast<intptr_t>(xref.address());
121 int params = descriptor->GetHandlerParameterCount();
122 output_frame->SetRegister(r3.code(), params);
123 output_frame->SetRegister(r4.code(), handler);
127 void Deoptimizer::CopyDoubleRegisters(FrameDescription* output_frame) {
128 for (int i = 0; i < DoubleRegister::kMaxNumRegisters; ++i) {
129 double double_value = input_->GetDoubleRegister(i);
130 output_frame->SetDoubleRegister(i, double_value);
135 bool Deoptimizer::HasAlignmentPadding(JSFunction* function) {
136 // There is no dynamic alignment padding on PPC in the input frame.
143 // This code tries to be close to ia32 code so that any changes can be
145 void Deoptimizer::EntryGenerator::Generate() {
148 // Unlike on ARM we don't save all the registers, just the useful ones.
149 // For the rest, there are gaps on the stack, so the offsets remain the same.
150 const int kNumberOfRegisters = Register::kNumRegisters;
152 RegList restored_regs = kJSCallerSaved | kCalleeSaved;
153 RegList saved_regs = restored_regs | sp.bit();
155 const int kDoubleRegsSize =
156 kDoubleSize * DoubleRegister::kMaxNumAllocatableRegisters;
158 // Save all FPU registers before messing with them.
159 __ subi(sp, sp, Operand(kDoubleRegsSize));
160 for (int i = 0; i < DoubleRegister::kMaxNumAllocatableRegisters; ++i) {
161 DoubleRegister fpu_reg = DoubleRegister::FromAllocationIndex(i);
162 int offset = i * kDoubleSize;
163 __ stfd(fpu_reg, MemOperand(sp, offset));
166 // Push saved_regs (needed to populate FrameDescription::registers_).
167 // Leave gaps for other registers.
168 __ subi(sp, sp, Operand(kNumberOfRegisters * kPointerSize));
169 for (int16_t i = kNumberOfRegisters - 1; i >= 0; i--) {
170 if ((saved_regs & (1 << i)) != 0) {
171 __ StoreP(ToRegister(i), MemOperand(sp, kPointerSize * i));
175 const int kSavedRegistersAreaSize =
176 (kNumberOfRegisters * kPointerSize) + kDoubleRegsSize;
178 // Get the bailout id from the stack.
179 __ LoadP(r5, MemOperand(sp, kSavedRegistersAreaSize));
181 // Get the address of the location in the code object (r6) (return
182 // address for lazy deoptimization) and compute the fp-to-sp delta in
185 // Correct one word for bailout id.
186 __ addi(r7, sp, Operand(kSavedRegistersAreaSize + (1 * kPointerSize)));
189 // Allocate a new deoptimizer object.
190 // Pass six arguments in r3 to r8.
191 __ PrepareCallCFunction(6, r8);
192 __ LoadP(r3, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
193 __ li(r4, Operand(type())); // bailout type,
194 // r5: bailout id already loaded.
195 // r6: code address or 0 already loaded.
196 // r7: Fp-to-sp delta.
197 __ mov(r8, Operand(ExternalReference::isolate_address(isolate())));
198 // Call Deoptimizer::New().
200 AllowExternalCallThatCantCauseGC scope(masm());
201 __ CallCFunction(ExternalReference::new_deoptimizer_function(isolate()), 6);
204 // Preserve "deoptimizer" object in register r3 and get the input
205 // frame descriptor pointer to r4 (deoptimizer->input_);
206 __ LoadP(r4, MemOperand(r3, Deoptimizer::input_offset()));
208 // Copy core registers into FrameDescription::registers_[kNumRegisters].
209 DCHECK(Register::kNumRegisters == kNumberOfRegisters);
210 for (int i = 0; i < kNumberOfRegisters; i++) {
211 int offset = (i * kPointerSize) + FrameDescription::registers_offset();
212 __ LoadP(r5, MemOperand(sp, i * kPointerSize));
213 __ StoreP(r5, MemOperand(r4, offset));
216 int double_regs_offset = FrameDescription::double_registers_offset();
217 // Copy VFP registers to
218 // double_registers_[DoubleRegister::kNumAllocatableRegisters]
219 for (int i = 0; i < DoubleRegister::NumAllocatableRegisters(); ++i) {
220 int dst_offset = i * kDoubleSize + double_regs_offset;
221 int src_offset = i * kDoubleSize + kNumberOfRegisters * kPointerSize;
222 __ lfd(d0, MemOperand(sp, src_offset));
223 __ stfd(d0, MemOperand(r4, dst_offset));
226 // Remove the bailout id and the saved registers from the stack.
227 __ addi(sp, sp, Operand(kSavedRegistersAreaSize + (1 * kPointerSize)));
229 // Compute a pointer to the unwinding limit in register r5; that is
230 // the first stack slot not part of the input frame.
231 __ LoadP(r5, MemOperand(r4, FrameDescription::frame_size_offset()));
234 // Unwind the stack down to - but not including - the unwinding
235 // limit and copy the contents of the activation frame to the input
236 // frame description.
237 __ addi(r6, r4, Operand(FrameDescription::frame_content_offset()));
239 Label pop_loop_header;
240 __ b(&pop_loop_header);
243 __ StoreP(r7, MemOperand(r6, 0));
244 __ addi(r6, r6, Operand(kPointerSize));
245 __ bind(&pop_loop_header);
249 // Compute the output frame in the deoptimizer.
250 __ push(r3); // Preserve deoptimizer object across call.
251 // r3: deoptimizer object; r4: scratch.
252 __ PrepareCallCFunction(1, r4);
253 // Call Deoptimizer::ComputeOutputFrames().
255 AllowExternalCallThatCantCauseGC scope(masm());
257 ExternalReference::compute_output_frames_function(isolate()), 1);
259 __ pop(r3); // Restore deoptimizer object (class Deoptimizer).
261 // Replace the current (input) frame with the output frames.
262 Label outer_push_loop, inner_push_loop, outer_loop_header, inner_loop_header;
263 // Outer loop state: r7 = current "FrameDescription** output_",
264 // r4 = one past the last FrameDescription**.
265 __ lwz(r4, MemOperand(r3, Deoptimizer::output_count_offset()));
266 __ LoadP(r7, MemOperand(r3, Deoptimizer::output_offset())); // r7 is output_.
267 __ ShiftLeftImm(r4, r4, Operand(kPointerSizeLog2));
269 __ b(&outer_loop_header);
271 __ bind(&outer_push_loop);
272 // Inner loop state: r5 = current FrameDescription*, r6 = loop index.
273 __ LoadP(r5, MemOperand(r7, 0)); // output_[ix]
274 __ LoadP(r6, MemOperand(r5, FrameDescription::frame_size_offset()));
275 __ b(&inner_loop_header);
277 __ bind(&inner_push_loop);
278 __ addi(r6, r6, Operand(-sizeof(intptr_t)));
280 __ LoadP(r9, MemOperand(r9, FrameDescription::frame_content_offset()));
283 __ bind(&inner_loop_header);
284 __ cmpi(r6, Operand::Zero());
285 __ bne(&inner_push_loop); // test for gt?
287 __ addi(r7, r7, Operand(kPointerSize));
288 __ bind(&outer_loop_header);
290 __ blt(&outer_push_loop);
292 __ LoadP(r4, MemOperand(r3, Deoptimizer::input_offset()));
293 for (int i = 0; i < DoubleRegister::kMaxNumAllocatableRegisters; ++i) {
294 const DoubleRegister dreg = DoubleRegister::FromAllocationIndex(i);
295 int src_offset = i * kDoubleSize + double_regs_offset;
296 __ lfd(dreg, MemOperand(r4, src_offset));
299 // Push state, pc, and continuation from the last output frame.
300 __ LoadP(r9, MemOperand(r5, FrameDescription::state_offset()));
302 __ LoadP(r9, MemOperand(r5, FrameDescription::pc_offset()));
304 __ LoadP(r9, MemOperand(r5, FrameDescription::continuation_offset()));
307 // Restore the registers from the last output frame.
308 DCHECK(!(ip.bit() & restored_regs));
310 for (int i = kNumberOfRegisters - 1; i >= 0; i--) {
311 int offset = (i * kPointerSize) + FrameDescription::registers_offset();
312 if ((restored_regs & (1 << i)) != 0) {
313 __ LoadP(ToRegister(i), MemOperand(ip, offset));
317 __ InitializeRootRegister();
319 __ pop(ip); // get continuation, leave pc on stack
323 __ stop("Unreachable.");
327 void Deoptimizer::TableEntryGenerator::GeneratePrologue() {
328 Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm());
330 // Create a sequence of deoptimization entries.
331 // Note that registers are still live when jumping to an entry.
333 for (int i = 0; i < count(); i++) {
334 int start = masm()->pc_offset();
336 __ li(ip, Operand(i));
338 DCHECK(masm()->pc_offset() - start == table_entry_size_);
345 void FrameDescription::SetCallerPc(unsigned offset, intptr_t value) {
346 SetFrameSlot(offset, value);
350 void FrameDescription::SetCallerFp(unsigned offset, intptr_t value) {
351 SetFrameSlot(offset, value);
355 void FrameDescription::SetCallerConstantPool(unsigned offset, intptr_t value) {
356 #if V8_OOL_CONSTANT_POOL
357 DCHECK(FLAG_enable_ool_constant_pool);
358 SetFrameSlot(offset, value);
360 // No out-of-line constant pool support.
368 } // namespace v8::internal