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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 #ifndef V8_X64_ASSEMBLER_X64_INL_H_
29 #define V8_X64_ASSEMBLER_X64_INL_H_
30 
31 #include "cpu.h"
32 #include "memory.h"
33 
34 namespace v8 {
35 namespace internal {
36 
NegateCondition(Condition cc)37 Condition NegateCondition(Condition cc) {
38   return static_cast<Condition>(cc ^ 1);
39 }
40 
41 
42 // -----------------------------------------------------------------------------
43 // Implementation of Assembler
44 
45 
46 
emitl(uint32_t x)47 void Assembler::emitl(uint32_t x) {
48   Memory::uint32_at(pc_) = x;
49   pc_ += sizeof(uint32_t);
50 }
51 
52 
emitq(uint64_t x,RelocInfo::Mode rmode)53 void Assembler::emitq(uint64_t x, RelocInfo::Mode rmode) {
54   Memory::uint64_at(pc_) = x;
55   if (rmode != RelocInfo::NONE) {
56     RecordRelocInfo(rmode, x);
57   }
58   pc_ += sizeof(uint64_t);
59 }
60 
61 
emitw(uint16_t x)62 void Assembler::emitw(uint16_t x) {
63   Memory::uint16_at(pc_) = x;
64   pc_ += sizeof(uint16_t);
65 }
66 
67 
emit_code_target(Handle<Code> target,RelocInfo::Mode rmode)68 void Assembler::emit_code_target(Handle<Code> target, RelocInfo::Mode rmode) {
69   ASSERT(RelocInfo::IsCodeTarget(rmode));
70   RecordRelocInfo(rmode);
71   int current = code_targets_.length();
72   if (current > 0 && code_targets_.last().is_identical_to(target)) {
73     // Optimization if we keep jumping to the same code target.
74     emitl(current - 1);
75   } else {
76     code_targets_.Add(target);
77     emitl(current);
78   }
79 }
80 
81 
emit_rex_64(Register reg,Register rm_reg)82 void Assembler::emit_rex_64(Register reg, Register rm_reg) {
83   emit(0x48 | reg.high_bit() << 2 | rm_reg.high_bit());
84 }
85 
86 
emit_rex_64(XMMRegister reg,Register rm_reg)87 void Assembler::emit_rex_64(XMMRegister reg, Register rm_reg) {
88   emit(0x48 | (reg.code() & 0x8) >> 1 | rm_reg.code() >> 3);
89 }
90 
91 
emit_rex_64(Register reg,const Operand & op)92 void Assembler::emit_rex_64(Register reg, const Operand& op) {
93   emit(0x48 | reg.high_bit() << 2 | op.rex_);
94 }
95 
96 
emit_rex_64(XMMRegister reg,const Operand & op)97 void Assembler::emit_rex_64(XMMRegister reg, const Operand& op) {
98   emit(0x48 | (reg.code() & 0x8) >> 1 | op.rex_);
99 }
100 
101 
emit_rex_64(Register rm_reg)102 void Assembler::emit_rex_64(Register rm_reg) {
103   ASSERT_EQ(rm_reg.code() & 0xf, rm_reg.code());
104   emit(0x48 | rm_reg.high_bit());
105 }
106 
107 
emit_rex_64(const Operand & op)108 void Assembler::emit_rex_64(const Operand& op) {
109   emit(0x48 | op.rex_);
110 }
111 
112 
emit_rex_32(Register reg,Register rm_reg)113 void Assembler::emit_rex_32(Register reg, Register rm_reg) {
114   emit(0x40 | reg.high_bit() << 2 | rm_reg.high_bit());
115 }
116 
117 
emit_rex_32(Register reg,const Operand & op)118 void Assembler::emit_rex_32(Register reg, const Operand& op) {
119   emit(0x40 | reg.high_bit() << 2  | op.rex_);
120 }
121 
122 
emit_rex_32(Register rm_reg)123 void Assembler::emit_rex_32(Register rm_reg) {
124   emit(0x40 | rm_reg.high_bit());
125 }
126 
127 
emit_rex_32(const Operand & op)128 void Assembler::emit_rex_32(const Operand& op) {
129   emit(0x40 | op.rex_);
130 }
131 
132 
emit_optional_rex_32(Register reg,Register rm_reg)133 void Assembler::emit_optional_rex_32(Register reg, Register rm_reg) {
134   byte rex_bits = reg.high_bit() << 2 | rm_reg.high_bit();
135   if (rex_bits != 0) emit(0x40 | rex_bits);
136 }
137 
138 
emit_optional_rex_32(Register reg,const Operand & op)139 void Assembler::emit_optional_rex_32(Register reg, const Operand& op) {
140   byte rex_bits =  reg.high_bit() << 2 | op.rex_;
141   if (rex_bits != 0) emit(0x40 | rex_bits);
142 }
143 
144 
emit_optional_rex_32(XMMRegister reg,const Operand & op)145 void Assembler::emit_optional_rex_32(XMMRegister reg, const Operand& op) {
146   byte rex_bits =  (reg.code() & 0x8) >> 1 | op.rex_;
147   if (rex_bits != 0) emit(0x40 | rex_bits);
148 }
149 
150 
emit_optional_rex_32(XMMRegister reg,XMMRegister base)151 void Assembler::emit_optional_rex_32(XMMRegister reg, XMMRegister base) {
152   byte rex_bits =  (reg.code() & 0x8) >> 1 | (base.code() & 0x8) >> 3;
153   if (rex_bits != 0) emit(0x40 | rex_bits);
154 }
155 
156 
emit_optional_rex_32(XMMRegister reg,Register base)157 void Assembler::emit_optional_rex_32(XMMRegister reg, Register base) {
158   byte rex_bits =  (reg.code() & 0x8) >> 1 | (base.code() & 0x8) >> 3;
159   if (rex_bits != 0) emit(0x40 | rex_bits);
160 }
161 
162 
emit_optional_rex_32(Register rm_reg)163 void Assembler::emit_optional_rex_32(Register rm_reg) {
164   if (rm_reg.high_bit()) emit(0x41);
165 }
166 
167 
emit_optional_rex_32(const Operand & op)168 void Assembler::emit_optional_rex_32(const Operand& op) {
169   if (op.rex_ != 0) emit(0x40 | op.rex_);
170 }
171 
172 
target_address_at(Address pc)173 Address Assembler::target_address_at(Address pc) {
174   return Memory::int32_at(pc) + pc + 4;
175 }
176 
177 
set_target_address_at(Address pc,Address target)178 void Assembler::set_target_address_at(Address pc, Address target) {
179   Memory::int32_at(pc) = static_cast<int32_t>(target - pc - 4);
180   CPU::FlushICache(pc, sizeof(int32_t));
181 }
182 
code_target_object_handle_at(Address pc)183 Handle<Object> Assembler::code_target_object_handle_at(Address pc) {
184   return code_targets_[Memory::int32_at(pc)];
185 }
186 
187 // -----------------------------------------------------------------------------
188 // Implementation of RelocInfo
189 
190 // The modes possibly affected by apply must be in kApplyMask.
apply(intptr_t delta)191 void RelocInfo::apply(intptr_t delta) {
192   if (IsInternalReference(rmode_)) {
193     // absolute code pointer inside code object moves with the code object.
194     Memory::Address_at(pc_) += static_cast<int32_t>(delta);
195   } else if (IsCodeTarget(rmode_)) {
196     Memory::int32_at(pc_) -= static_cast<int32_t>(delta);
197   } else if (rmode_ == JS_RETURN && IsPatchedReturnSequence()) {
198     // Special handling of js_return when a break point is set (call
199     // instruction has been inserted).
200     Memory::int32_at(pc_ + 1) -= static_cast<int32_t>(delta);  // relocate entry
201   }
202 }
203 
204 
target_address()205 Address RelocInfo::target_address() {
206   ASSERT(IsCodeTarget(rmode_) || rmode_ == RUNTIME_ENTRY);
207   if (IsCodeTarget(rmode_)) {
208     return Assembler::target_address_at(pc_);
209   } else {
210     return Memory::Address_at(pc_);
211   }
212 }
213 
214 
target_address_address()215 Address RelocInfo::target_address_address() {
216   ASSERT(IsCodeTarget(rmode_) || rmode_ == RUNTIME_ENTRY);
217   return reinterpret_cast<Address>(pc_);
218 }
219 
220 
set_target_address(Address target)221 void RelocInfo::set_target_address(Address target) {
222   ASSERT(IsCodeTarget(rmode_) || rmode_ == RUNTIME_ENTRY);
223   if (IsCodeTarget(rmode_)) {
224     Assembler::set_target_address_at(pc_, target);
225   } else {
226     Memory::Address_at(pc_) = target;
227   }
228 }
229 
230 
target_object()231 Object* RelocInfo::target_object() {
232   ASSERT(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
233   return Memory::Object_at(pc_);
234 }
235 
236 
target_object_handle(Assembler * origin)237 Handle<Object> RelocInfo::target_object_handle(Assembler *origin) {
238   ASSERT(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
239   if (rmode_ == EMBEDDED_OBJECT) {
240     return Memory::Object_Handle_at(pc_);
241   } else {
242     return origin->code_target_object_handle_at(pc_);
243   }
244 }
245 
246 
target_object_address()247 Object** RelocInfo::target_object_address() {
248   ASSERT(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
249   return reinterpret_cast<Object**>(pc_);
250 }
251 
252 
target_reference_address()253 Address* RelocInfo::target_reference_address() {
254   ASSERT(rmode_ == RelocInfo::EXTERNAL_REFERENCE);
255   return reinterpret_cast<Address*>(pc_);
256 }
257 
258 
set_target_object(Object * target)259 void RelocInfo::set_target_object(Object* target) {
260   ASSERT(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
261   *reinterpret_cast<Object**>(pc_) = target;
262 }
263 
264 
IsPatchedReturnSequence()265 bool RelocInfo::IsPatchedReturnSequence() {
266   // The recognized call sequence is:
267   //  movq(kScratchRegister, immediate64); call(kScratchRegister);
268   // It only needs to be distinguished from a return sequence
269   //  movq(rsp, rbp); pop(rbp); ret(n); int3 *6
270   // The 11th byte is int3 (0xCC) in the return sequence and
271   // REX.WB (0x48+register bit) for the call sequence.
272 #ifdef ENABLE_DEBUGGER_SUPPORT
273   return pc_[10] != 0xCC;
274 #else
275   return false;
276 #endif
277 }
278 
279 
call_address()280 Address RelocInfo::call_address() {
281   ASSERT(IsPatchedReturnSequence());
282   return Memory::Address_at(
283       pc_ + Assembler::kRealPatchReturnSequenceAddressOffset);
284 }
285 
286 
set_call_address(Address target)287 void RelocInfo::set_call_address(Address target) {
288   ASSERT(IsPatchedReturnSequence());
289   Memory::Address_at(pc_ + Assembler::kRealPatchReturnSequenceAddressOffset) =
290       target;
291 }
292 
293 
call_object()294 Object* RelocInfo::call_object() {
295   ASSERT(IsPatchedReturnSequence());
296   return *call_object_address();
297 }
298 
299 
set_call_object(Object * target)300 void RelocInfo::set_call_object(Object* target) {
301   ASSERT(IsPatchedReturnSequence());
302   *call_object_address() = target;
303 }
304 
305 
call_object_address()306 Object** RelocInfo::call_object_address() {
307   ASSERT(IsPatchedReturnSequence());
308   return reinterpret_cast<Object**>(
309       pc_ + Assembler::kPatchReturnSequenceAddressOffset);
310 }
311 
312 // -----------------------------------------------------------------------------
313 // Implementation of Operand
314 
set_modrm(int mod,Register rm_reg)315 void Operand::set_modrm(int mod, Register rm_reg) {
316   ASSERT(is_uint2(mod));
317   buf_[0] = mod << 6 | rm_reg.low_bits();
318   // Set REX.B to the high bit of rm.code().
319   rex_ |= rm_reg.high_bit();
320 }
321 
322 
set_sib(ScaleFactor scale,Register index,Register base)323 void Operand::set_sib(ScaleFactor scale, Register index, Register base) {
324   ASSERT(len_ == 1);
325   ASSERT(is_uint2(scale));
326   // Use SIB with no index register only for base rsp or r12. Otherwise we
327   // would skip the SIB byte entirely.
328   ASSERT(!index.is(rsp) || base.is(rsp) || base.is(r12));
329   buf_[1] = scale << 6 | index.low_bits() << 3 | base.low_bits();
330   rex_ |= index.high_bit() << 1 | base.high_bit();
331   len_ = 2;
332 }
333 
set_disp8(int disp)334 void Operand::set_disp8(int disp) {
335   ASSERT(is_int8(disp));
336   ASSERT(len_ == 1 || len_ == 2);
337   int8_t* p = reinterpret_cast<int8_t*>(&buf_[len_]);
338   *p = disp;
339   len_ += sizeof(int8_t);
340 }
341 
set_disp32(int disp)342 void Operand::set_disp32(int disp) {
343   ASSERT(len_ == 1 || len_ == 2);
344   int32_t* p = reinterpret_cast<int32_t*>(&buf_[len_]);
345   *p = disp;
346   len_ += sizeof(int32_t);
347 }
348 
349 
350 } }  // namespace v8::internal
351 
352 #endif  // V8_X64_ASSEMBLER_X64_INL_H_
353