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1 // Copyright 2013 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.h" | |
31 #include "deoptimizer.h" | |
32 #include "full-codegen.h" | |
33 #include "safepoint-table.h" | |
34 | |
35 | |
36 namespace v8 { | |
37 namespace internal { | |
38 | |
39 | |
40 int Deoptimizer::patch_size() { | |
41 // Size of the code used to patch lazy bailout points. | |
42 // Patching is done by Deoptimizer::DeoptimizeFunction. | |
43 return 4 * kInstructionSize; | |
44 } | |
45 | |
46 | |
47 | |
48 void Deoptimizer::PatchCodeForDeoptimization(Isolate* isolate, Code* code) { | |
49 // Invalidate the relocation information, as it will become invalid by the | |
50 // code patching below, and is not needed any more. | |
51 code->InvalidateRelocation(); | |
52 | |
53 // TODO(jkummerow): if (FLAG_zap_code_space), make the code object's | |
54 // entry sequence unusable (see other architectures). | |
55 | |
56 DeoptimizationInputData* deopt_data = | |
57 DeoptimizationInputData::cast(code->deoptimization_data()); | |
58 SharedFunctionInfo* shared = | |
59 SharedFunctionInfo::cast(deopt_data->SharedFunctionInfo()); | |
60 shared->EvictFromOptimizedCodeMap(code, "deoptimized code"); | |
61 Address code_start_address = code->instruction_start(); | |
62 #ifdef DEBUG | |
63 Address prev_call_address = NULL; | |
64 #endif | |
65 // For each LLazyBailout instruction insert a call to the corresponding | |
66 // deoptimization entry. | |
67 for (int i = 0; i < deopt_data->DeoptCount(); i++) { | |
68 if (deopt_data->Pc(i)->value() == -1) continue; | |
69 | |
70 Address call_address = code_start_address + deopt_data->Pc(i)->value(); | |
71 Address deopt_entry = GetDeoptimizationEntry(isolate, i, LAZY); | |
72 | |
73 PatchingAssembler patcher(call_address, patch_size() / kInstructionSize); | |
74 patcher.LoadLiteral(ip0, 2 * kInstructionSize); | |
75 patcher.blr(ip0); | |
76 patcher.dc64(reinterpret_cast<intptr_t>(deopt_entry)); | |
77 | |
78 ASSERT((prev_call_address == NULL) || | |
79 (call_address >= prev_call_address + patch_size())); | |
80 ASSERT(call_address + patch_size() <= code->instruction_end()); | |
81 #ifdef DEBUG | |
82 prev_call_address = call_address; | |
83 #endif | |
84 } | |
85 } | |
86 | |
87 | |
88 void Deoptimizer::FillInputFrame(Address tos, JavaScriptFrame* frame) { | |
89 // Set the register values. The values are not important as there are no | |
90 // callee saved registers in JavaScript frames, so all registers are | |
91 // spilled. Registers fp and sp are set to the correct values though. | |
92 for (int i = 0; i < Register::NumRegisters(); i++) { | |
93 input_->SetRegister(i, 0); | |
94 } | |
95 | |
96 // TODO(all): Do we also need to set a value to csp? | |
97 input_->SetRegister(jssp.code(), reinterpret_cast<intptr_t>(frame->sp())); | |
98 input_->SetRegister(fp.code(), reinterpret_cast<intptr_t>(frame->fp())); | |
99 | |
100 for (int i = 0; i < DoubleRegister::NumAllocatableRegisters(); i++) { | |
101 input_->SetDoubleRegister(i, 0.0); | |
102 } | |
103 | |
104 // Fill the frame content from the actual data on the frame. | |
105 for (unsigned i = 0; i < input_->GetFrameSize(); i += kPointerSize) { | |
106 input_->SetFrameSlot(i, Memory::uint64_at(tos + i)); | |
107 } | |
108 } | |
109 | |
110 | |
111 bool Deoptimizer::HasAlignmentPadding(JSFunction* function) { | |
112 // There is no dynamic alignment padding on A64 in the input frame. | |
113 return false; | |
114 } | |
115 | |
116 | |
117 void Deoptimizer::SetPlatformCompiledStubRegisters( | |
118 FrameDescription* output_frame, CodeStubInterfaceDescriptor* descriptor) { | |
119 ApiFunction function(descriptor->deoptimization_handler_); | |
120 ExternalReference xref(&function, ExternalReference::BUILTIN_CALL, isolate_); | |
121 intptr_t handler = reinterpret_cast<intptr_t>(xref.address()); | |
122 int params = descriptor->GetHandlerParameterCount(); | |
123 output_frame->SetRegister(x0.code(), params); | |
124 output_frame->SetRegister(x1.code(), handler); | |
125 } | |
126 | |
127 | |
128 void Deoptimizer::CopyDoubleRegisters(FrameDescription* output_frame) { | |
129 for (int i = 0; i < DoubleRegister::kMaxNumRegisters; ++i) { | |
130 double double_value = input_->GetDoubleRegister(i); | |
131 output_frame->SetDoubleRegister(i, double_value); | |
132 } | |
133 } | |
134 | |
135 | |
136 Code* Deoptimizer::NotifyStubFailureBuiltin() { | |
137 return isolate_->builtins()->builtin(Builtins::kNotifyStubFailureSaveDoubles); | |
138 } | |
139 | |
140 | |
141 #define __ masm()-> | |
142 | |
143 void Deoptimizer::EntryGenerator::Generate() { | |
144 GeneratePrologue(); | |
145 | |
146 // TODO(all): This code needs to be revisited. We probably only need to save | |
147 // caller-saved registers here. Callee-saved registers can be stored directly | |
148 // in the input frame. | |
149 | |
150 // Save all allocatable floating point registers. | |
151 CPURegList saved_fp_registers(CPURegister::kFPRegister, kDRegSizeInBits, | |
152 FPRegister::kAllocatableFPRegisters); | |
153 __ PushCPURegList(saved_fp_registers); | |
154 | |
155 // We save all the registers expcept jssp, sp and lr. | |
156 CPURegList saved_registers(CPURegister::kRegister, kXRegSizeInBits, 0, 27); | |
157 saved_registers.Combine(fp); | |
158 __ PushCPURegList(saved_registers); | |
159 | |
160 const int kSavedRegistersAreaSize = | |
161 (saved_registers.Count() * kXRegSize) + | |
162 (saved_fp_registers.Count() * kDRegSize); | |
163 | |
164 // Floating point registers are saved on the stack above core registers. | |
165 const int kFPRegistersOffset = saved_registers.Count() * kXRegSize; | |
166 | |
167 // Get the bailout id from the stack. | |
168 Register bailout_id = x2; | |
169 __ Peek(bailout_id, kSavedRegistersAreaSize); | |
170 | |
171 Register code_object = x3; | |
172 Register fp_to_sp = x4; | |
173 // Get the address of the location in the code object. This is the return | |
174 // address for lazy deoptimization. | |
175 __ Mov(code_object, lr); | |
176 // Compute the fp-to-sp delta, and correct one word for bailout id. | |
177 __ Add(fp_to_sp, masm()->StackPointer(), | |
178 kSavedRegistersAreaSize + (1 * kPointerSize)); | |
179 __ Sub(fp_to_sp, fp, fp_to_sp); | |
180 | |
181 // Allocate a new deoptimizer object. | |
182 __ Ldr(x0, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset)); | |
183 __ Mov(x1, type()); | |
184 // Following arguments are already loaded: | |
185 // - x2: bailout id | |
186 // - x3: code object address | |
187 // - x4: fp-to-sp delta | |
188 __ Mov(x5, ExternalReference::isolate_address(isolate())); | |
189 | |
190 { | |
191 // Call Deoptimizer::New(). | |
192 AllowExternalCallThatCantCauseGC scope(masm()); | |
193 __ CallCFunction(ExternalReference::new_deoptimizer_function(isolate()), 6); | |
194 } | |
195 | |
196 // Preserve "deoptimizer" object in register x0. | |
197 Register deoptimizer = x0; | |
198 | |
199 // Get the input frame descriptor pointer. | |
200 __ Ldr(x1, MemOperand(deoptimizer, Deoptimizer::input_offset())); | |
201 | |
202 // Copy core registers into the input frame. | |
203 CPURegList copy_to_input = saved_registers; | |
204 for (int i = 0; i < saved_registers.Count(); i++) { | |
205 // TODO(all): Look for opportunities to optimize this by using ldp/stp. | |
206 __ Peek(x2, i * kPointerSize); | |
207 CPURegister current_reg = copy_to_input.PopLowestIndex(); | |
208 int offset = (current_reg.code() * kPointerSize) + | |
209 FrameDescription::registers_offset(); | |
210 __ Str(x2, MemOperand(x1, offset)); | |
211 } | |
212 | |
213 // Copy FP registers to the input frame. | |
214 for (int i = 0; i < saved_fp_registers.Count(); i++) { | |
215 // TODO(all): Look for opportunities to optimize this by using ldp/stp. | |
216 int dst_offset = FrameDescription::double_registers_offset() + | |
217 (i * kDoubleSize); | |
218 int src_offset = kFPRegistersOffset + (i * kDoubleSize); | |
219 __ Peek(x2, src_offset); | |
220 __ Str(x2, MemOperand(x1, dst_offset)); | |
221 } | |
222 | |
223 // Remove the bailout id and the saved registers from the stack. | |
224 __ Drop(1 + (kSavedRegistersAreaSize / kXRegSize)); | |
225 | |
226 // Compute a pointer to the unwinding limit in register x2; that is | |
227 // the first stack slot not part of the input frame. | |
228 Register unwind_limit = x2; | |
229 __ Ldr(unwind_limit, MemOperand(x1, FrameDescription::frame_size_offset())); | |
230 __ Add(unwind_limit, unwind_limit, __ StackPointer()); | |
231 | |
232 // Unwind the stack down to - but not including - the unwinding | |
233 // limit and copy the contents of the activation frame to the input | |
234 // frame description. | |
235 __ Add(x3, x1, FrameDescription::frame_content_offset()); | |
236 Label pop_loop; | |
237 Label pop_loop_header; | |
238 __ B(&pop_loop_header); | |
239 __ Bind(&pop_loop); | |
240 __ Pop(x4); | |
241 __ Str(x4, MemOperand(x3, kPointerSize, PostIndex)); | |
242 __ Bind(&pop_loop_header); | |
243 __ Cmp(unwind_limit, __ StackPointer()); | |
244 __ B(ne, &pop_loop); | |
245 | |
246 // Compute the output frame in the deoptimizer. | |
247 __ Push(x0); // Preserve deoptimizer object across call. | |
248 | |
249 { | |
250 // Call Deoptimizer::ComputeOutputFrames(). | |
251 AllowExternalCallThatCantCauseGC scope(masm()); | |
252 __ CallCFunction( | |
253 ExternalReference::compute_output_frames_function(isolate()), 1); | |
254 } | |
255 __ Pop(x4); // Restore deoptimizer object (class Deoptimizer). | |
256 | |
257 // Replace the current (input) frame with the output frames. | |
258 Label outer_push_loop, inner_push_loop, | |
259 outer_loop_header, inner_loop_header; | |
260 __ Ldrsw(x1, MemOperand(x4, Deoptimizer::output_count_offset())); | |
261 __ Ldr(x0, MemOperand(x4, Deoptimizer::output_offset())); | |
262 __ Add(x1, x0, Operand(x1, LSL, kPointerSizeLog2)); | |
263 __ B(&outer_loop_header); | |
264 | |
265 __ Bind(&outer_push_loop); | |
266 Register current_frame = x2; | |
267 __ Ldr(current_frame, MemOperand(x0, 0)); | |
268 __ Ldr(x3, MemOperand(current_frame, FrameDescription::frame_size_offset())); | |
269 __ B(&inner_loop_header); | |
270 | |
271 __ Bind(&inner_push_loop); | |
272 __ Sub(x3, x3, kPointerSize); | |
273 __ Add(x6, current_frame, x3); | |
274 __ Ldr(x7, MemOperand(x6, FrameDescription::frame_content_offset())); | |
275 __ Push(x7); | |
276 __ Bind(&inner_loop_header); | |
277 __ Cbnz(x3, &inner_push_loop); | |
278 | |
279 __ Add(x0, x0, kPointerSize); | |
280 __ Bind(&outer_loop_header); | |
281 __ Cmp(x0, x1); | |
282 __ B(lt, &outer_push_loop); | |
283 | |
284 __ Ldr(x1, MemOperand(x4, Deoptimizer::input_offset())); | |
285 ASSERT(!saved_fp_registers.IncludesAliasOf(crankshaft_fp_scratch) && | |
286 !saved_fp_registers.IncludesAliasOf(fp_zero) && | |
287 !saved_fp_registers.IncludesAliasOf(fp_scratch)); | |
288 int src_offset = FrameDescription::double_registers_offset(); | |
289 while (!saved_fp_registers.IsEmpty()) { | |
290 const CPURegister reg = saved_fp_registers.PopLowestIndex(); | |
291 __ Ldr(reg, MemOperand(x1, src_offset)); | |
292 src_offset += kDoubleSize; | |
293 } | |
294 | |
295 // Push state from the last output frame. | |
296 __ Ldr(x6, MemOperand(current_frame, FrameDescription::state_offset())); | |
297 __ Push(x6); | |
298 | |
299 // TODO(all): ARM copies a lot (if not all) of the last output frame onto the | |
300 // stack, then pops it all into registers. Here, we try to load it directly | |
301 // into the relevant registers. Is this correct? If so, we should improve the | |
302 // ARM code. | |
303 | |
304 // TODO(all): This code needs to be revisited, We probably don't need to | |
305 // restore all the registers as fullcodegen does not keep live values in | |
306 // registers (note that at least fp must be restored though). | |
307 | |
308 // Restore registers from the last output frame. | |
309 // Note that lr is not in the list of saved_registers and will be restored | |
310 // later. We can use it to hold the address of last output frame while | |
311 // reloading the other registers. | |
312 ASSERT(!saved_registers.IncludesAliasOf(lr)); | |
313 Register last_output_frame = lr; | |
314 __ Mov(last_output_frame, current_frame); | |
315 | |
316 // We don't need to restore x7 as it will be clobbered later to hold the | |
317 // continuation address. | |
318 Register continuation = x7; | |
319 saved_registers.Remove(continuation); | |
320 | |
321 while (!saved_registers.IsEmpty()) { | |
322 // TODO(all): Look for opportunities to optimize this by using ldp. | |
323 CPURegister current_reg = saved_registers.PopLowestIndex(); | |
324 int offset = (current_reg.code() * kPointerSize) + | |
325 FrameDescription::registers_offset(); | |
326 __ Ldr(current_reg, MemOperand(last_output_frame, offset)); | |
327 } | |
328 | |
329 __ Ldr(continuation, MemOperand(last_output_frame, | |
330 FrameDescription::continuation_offset())); | |
331 __ Ldr(lr, MemOperand(last_output_frame, FrameDescription::pc_offset())); | |
332 __ InitializeRootRegister(); | |
333 __ Br(continuation); | |
334 } | |
335 | |
336 | |
337 // Size of an entry of the second level deopt table. | |
338 // This is the code size generated by GeneratePrologue for one entry. | |
339 const int Deoptimizer::table_entry_size_ = 2 * kInstructionSize; | |
340 | |
341 | |
342 void Deoptimizer::TableEntryGenerator::GeneratePrologue() { | |
343 UseScratchRegisterScope temps(masm()); | |
344 Register entry_id = temps.AcquireX(); | |
345 | |
346 // Create a sequence of deoptimization entries. | |
347 // Note that registers are still live when jumping to an entry. | |
348 Label done; | |
349 { | |
350 InstructionAccurateScope scope(masm()); | |
351 | |
352 // The number of entry will never exceed kMaxNumberOfEntries. | |
353 // As long as kMaxNumberOfEntries is a valid 16 bits immediate you can use | |
354 // a movz instruction to load the entry id. | |
355 ASSERT(is_uint16(Deoptimizer::kMaxNumberOfEntries)); | |
356 | |
357 for (int i = 0; i < count(); i++) { | |
358 int start = masm()->pc_offset(); | |
359 USE(start); | |
360 __ movz(entry_id, i); | |
361 __ b(&done); | |
362 ASSERT(masm()->pc_offset() - start == table_entry_size_); | |
363 } | |
364 } | |
365 __ Bind(&done); | |
366 __ Push(entry_id); | |
367 } | |
368 | |
369 | |
370 void FrameDescription::SetCallerPc(unsigned offset, intptr_t value) { | |
371 SetFrameSlot(offset, value); | |
372 } | |
373 | |
374 | |
375 void FrameDescription::SetCallerFp(unsigned offset, intptr_t value) { | |
376 SetFrameSlot(offset, value); | |
377 } | |
378 | |
379 | |
380 void FrameDescription::SetCallerConstantPool(unsigned offset, intptr_t value) { | |
381 // No out-of-line constant pool support. | |
382 UNREACHABLE(); | |
383 } | |
384 | |
385 | |
386 #undef __ | |
387 | |
388 } } // namespace v8::internal | |
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