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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 "lithium-codegen.h"
31 
32 #if V8_TARGET_ARCH_IA32
33 #include "ia32/lithium-ia32.h"
34 #include "ia32/lithium-codegen-ia32.h"
35 #elif V8_TARGET_ARCH_X64
36 #include "x64/lithium-x64.h"
37 #include "x64/lithium-codegen-x64.h"
38 #elif V8_TARGET_ARCH_ARM
39 #include "arm/lithium-arm.h"
40 #include "arm/lithium-codegen-arm.h"
41 #elif V8_TARGET_ARCH_MIPS
42 #include "mips/lithium-mips.h"
43 #include "mips/lithium-codegen-mips.h"
44 #else
45 #error Unsupported target architecture.
46 #endif
47 
48 namespace v8 {
49 namespace internal {
50 
51 
graph() const52 HGraph* LCodeGenBase::graph() const {
53   return chunk()->graph();
54 }
55 
56 
LCodeGenBase(LChunk * chunk,MacroAssembler * assembler,CompilationInfo * info)57 LCodeGenBase::LCodeGenBase(LChunk* chunk,
58                            MacroAssembler* assembler,
59                            CompilationInfo* info)
60     : chunk_(static_cast<LPlatformChunk*>(chunk)),
61       masm_(assembler),
62       info_(info),
63       zone_(info->zone()),
64       status_(UNUSED),
65       current_block_(-1),
66       current_instruction_(-1),
67       instructions_(chunk->instructions()),
68       last_lazy_deopt_pc_(0) {
69 }
70 
71 
GenerateBody()72 bool LCodeGenBase::GenerateBody() {
73   ASSERT(is_generating());
74   bool emit_instructions = true;
75   LCodeGen* codegen = static_cast<LCodeGen*>(this);
76   for (current_instruction_ = 0;
77        !is_aborted() && current_instruction_ < instructions_->length();
78        current_instruction_++) {
79     LInstruction* instr = instructions_->at(current_instruction_);
80 
81     // Don't emit code for basic blocks with a replacement.
82     if (instr->IsLabel()) {
83       emit_instructions = !LLabel::cast(instr)->HasReplacement() &&
84           (!FLAG_unreachable_code_elimination ||
85            instr->hydrogen_value()->block()->IsReachable());
86       if (FLAG_code_comments && !emit_instructions) {
87         Comment(
88             ";;; <@%d,#%d> -------------------- B%d (unreachable/replaced) "
89             "--------------------",
90             current_instruction_,
91             instr->hydrogen_value()->id(),
92             instr->hydrogen_value()->block()->block_id());
93       }
94     }
95     if (!emit_instructions) continue;
96 
97     if (FLAG_code_comments && instr->HasInterestingComment(codegen)) {
98       Comment(";;; <@%d,#%d> %s",
99               current_instruction_,
100               instr->hydrogen_value()->id(),
101               instr->Mnemonic());
102     }
103 
104     GenerateBodyInstructionPre(instr);
105 
106     HValue* value = instr->hydrogen_value();
107     if (value->position() != RelocInfo::kNoPosition) {
108       ASSERT(!graph()->info()->IsOptimizing() ||
109              !FLAG_emit_opt_code_positions ||
110              value->position() != RelocInfo::kNoPosition);
111       RecordAndWritePosition(value->position());
112     }
113 
114     instr->CompileToNative(codegen);
115 
116     GenerateBodyInstructionPost(instr);
117   }
118   EnsureSpaceForLazyDeopt(Deoptimizer::patch_size());
119   last_lazy_deopt_pc_ = masm()->pc_offset();
120   return !is_aborted();
121 }
122 
123 
Comment(const char * format,...)124 void LCodeGenBase::Comment(const char* format, ...) {
125   if (!FLAG_code_comments) return;
126   char buffer[4 * KB];
127   StringBuilder builder(buffer, ARRAY_SIZE(buffer));
128   va_list arguments;
129   va_start(arguments, format);
130   builder.AddFormattedList(format, arguments);
131   va_end(arguments);
132 
133   // Copy the string before recording it in the assembler to avoid
134   // issues when the stack allocated buffer goes out of scope.
135   size_t length = builder.position();
136   Vector<char> copy = Vector<char>::New(static_cast<int>(length) + 1);
137   OS::MemCopy(copy.start(), builder.Finalize(), copy.length());
138   masm()->RecordComment(copy.start());
139 }
140 
141 
GetNextEmittedBlock() const142 int LCodeGenBase::GetNextEmittedBlock() const {
143   for (int i = current_block_ + 1; i < graph()->blocks()->length(); ++i) {
144     if (!chunk_->GetLabel(i)->HasReplacement()) return i;
145   }
146   return -1;
147 }
148 
149 
RegisterDependentCodeForEmbeddedMaps(Handle<Code> code)150 void LCodeGenBase::RegisterDependentCodeForEmbeddedMaps(Handle<Code> code) {
151   ZoneList<Handle<Map> > maps(1, zone());
152   ZoneList<Handle<JSObject> > objects(1, zone());
153   int mode_mask = RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT);
154   for (RelocIterator it(*code, mode_mask); !it.done(); it.next()) {
155     if (Code::IsWeakEmbeddedObject(code->kind(), it.rinfo()->target_object())) {
156       if (it.rinfo()->target_object()->IsMap()) {
157         Handle<Map> map(Map::cast(it.rinfo()->target_object()));
158         maps.Add(map, zone());
159       } else if (it.rinfo()->target_object()->IsJSObject()) {
160         Handle<JSObject> object(JSObject::cast(it.rinfo()->target_object()));
161         objects.Add(object, zone());
162       }
163     }
164   }
165 #ifdef VERIFY_HEAP
166   // This disables verification of weak embedded objects after full GC.
167   // AddDependentCode can cause a GC, which would observe the state where
168   // this code is not yet in the depended code lists of the embedded maps.
169   NoWeakObjectVerificationScope disable_verification_of_embedded_objects;
170 #endif
171   for (int i = 0; i < maps.length(); i++) {
172     maps.at(i)->AddDependentCode(DependentCode::kWeaklyEmbeddedGroup, code);
173   }
174   for (int i = 0; i < objects.length(); i++) {
175     AddWeakObjectToCodeDependency(isolate()->heap(), objects.at(i), code);
176   }
177 }
178 
179 
180 } }  // namespace v8::internal
181