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1 /*
2  * Copyright (C) 2009 Apple Inc. All rights reserved.
3  * Copyright (C) 2010 Patrick Gansterer <paroga@paroga.com>
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
15  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
17  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
18  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
19  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
21  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
22  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include "config.h"
28 
29 #if ENABLE(JIT)
30 #if USE(JSVALUE32_64)
31 #include "JIT.h"
32 
33 #include "JITInlineMethods.h"
34 #include "JITStubCall.h"
35 #include "JSArray.h"
36 #include "JSCell.h"
37 #include "JSFunction.h"
38 #include "JSPropertyNameIterator.h"
39 #include "LinkBuffer.h"
40 
41 namespace JSC {
42 
privateCompileCTIMachineTrampolines(RefPtr<ExecutablePool> * executablePool,JSGlobalData * globalData,TrampolineStructure * trampolines)43 void JIT::privateCompileCTIMachineTrampolines(RefPtr<ExecutablePool>* executablePool, JSGlobalData* globalData, TrampolineStructure *trampolines)
44 {
45 #if ENABLE(JIT_USE_SOFT_MODULO)
46     Label softModBegin = align();
47     softModulo();
48 #endif
49 #if ENABLE(JIT_OPTIMIZE_PROPERTY_ACCESS)
50     // (1) This function provides fast property access for string length
51     Label stringLengthBegin = align();
52 
53     // regT0 holds payload, regT1 holds tag
54 
55     Jump string_failureCases1 = branch32(NotEqual, regT1, TrustedImm32(JSValue::CellTag));
56     Jump string_failureCases2 = branchPtr(NotEqual, Address(regT0), TrustedImmPtr(m_globalData->jsStringVPtr));
57 
58     // Checks out okay! - get the length from the Ustring.
59     load32(Address(regT0, OBJECT_OFFSETOF(JSString, m_length)), regT2);
60 
61     Jump string_failureCases3 = branch32(Above, regT2, TrustedImm32(INT_MAX));
62     move(regT2, regT0);
63     move(TrustedImm32(JSValue::Int32Tag), regT1);
64 
65     ret();
66 #endif
67 
68     JumpList callLinkFailures;
69     // (2) Trampolines for the slow cases of op_call / op_call_eval / op_construct.
70 #if ENABLE(JIT_OPTIMIZE_CALL)
71     // VirtualCallLink Trampoline
72     // regT0 holds callee, regT1 holds argCount.  regT2 will hold the FunctionExecutable.
73     Label virtualCallLinkBegin = align();
74     compileOpCallInitializeCallFrame();
75     preserveReturnAddressAfterCall(regT3);
76     emitPutToCallFrameHeader(regT3, RegisterFile::ReturnPC);
77     restoreArgumentReference();
78     Call callLazyLinkCall = call();
79     callLinkFailures.append(branchTestPtr(Zero, regT0));
80     restoreReturnAddressBeforeReturn(regT3);
81     emitGetFromCallFrameHeader32(RegisterFile::ArgumentCount, regT1);
82     jump(regT0);
83 
84     // VirtualConstructLink Trampoline
85     // regT0 holds callee, regT1 holds argCount.  regT2 will hold the FunctionExecutable.
86     Label virtualConstructLinkBegin = align();
87     compileOpCallInitializeCallFrame();
88     preserveReturnAddressAfterCall(regT3);
89     emitPutToCallFrameHeader(regT3, RegisterFile::ReturnPC);
90     restoreArgumentReference();
91     Call callLazyLinkConstruct = call();
92     restoreReturnAddressBeforeReturn(regT3);
93     callLinkFailures.append(branchTestPtr(Zero, regT0));
94     emitGetFromCallFrameHeader32(RegisterFile::ArgumentCount, regT1);
95     jump(regT0);
96 
97 #endif // ENABLE(JIT_OPTIMIZE_CALL)
98 
99     // VirtualCall Trampoline
100     // regT0 holds callee, regT1 holds argCount.  regT2 will hold the FunctionExecutable.
101     Label virtualCallBegin = align();
102     compileOpCallInitializeCallFrame();
103 
104     loadPtr(Address(regT0, OBJECT_OFFSETOF(JSFunction, m_executable)), regT2);
105 
106     Jump hasCodeBlock3 = branch32(GreaterThanOrEqual, Address(regT2, OBJECT_OFFSETOF(FunctionExecutable, m_numParametersForCall)), TrustedImm32(0));
107     preserveReturnAddressAfterCall(regT3);
108     restoreArgumentReference();
109     Call callCompileCall = call();
110     callLinkFailures.append(branchTestPtr(Zero, regT0));
111     emitGetFromCallFrameHeader32(RegisterFile::ArgumentCount, regT1);
112     restoreReturnAddressBeforeReturn(regT3);
113     loadPtr(Address(regT0, OBJECT_OFFSETOF(JSFunction, m_executable)), regT2);
114     hasCodeBlock3.link(this);
115 
116     loadPtr(Address(regT2, OBJECT_OFFSETOF(FunctionExecutable, m_jitCodeForCallWithArityCheck)), regT0);
117     jump(regT0);
118 
119     // VirtualConstruct Trampoline
120     // regT0 holds callee, regT1 holds argCount.  regT2 will hold the FunctionExecutable.
121     Label virtualConstructBegin = align();
122     compileOpCallInitializeCallFrame();
123 
124     loadPtr(Address(regT0, OBJECT_OFFSETOF(JSFunction, m_executable)), regT2);
125 
126     Jump hasCodeBlock4 = branch32(GreaterThanOrEqual, Address(regT2, OBJECT_OFFSETOF(FunctionExecutable, m_numParametersForConstruct)), TrustedImm32(0));
127     preserveReturnAddressAfterCall(regT3);
128     restoreArgumentReference();
129     Call callCompileCconstruct = call();
130     callLinkFailures.append(branchTestPtr(Zero, regT0));
131     emitGetFromCallFrameHeader32(RegisterFile::ArgumentCount, regT1);
132     restoreReturnAddressBeforeReturn(regT3);
133     loadPtr(Address(regT0, OBJECT_OFFSETOF(JSFunction, m_executable)), regT2);
134     hasCodeBlock4.link(this);
135 
136     loadPtr(Address(regT2, OBJECT_OFFSETOF(FunctionExecutable, m_jitCodeForConstructWithArityCheck)), regT0);
137     jump(regT0);
138 
139     // If the parser fails we want to be able to be able to keep going,
140     // So we handle this as a parse failure.
141     callLinkFailures.link(this);
142     emitGetFromCallFrameHeaderPtr(RegisterFile::ReturnPC, regT1);
143     emitGetFromCallFrameHeaderPtr(RegisterFile::CallerFrame, callFrameRegister);
144     restoreReturnAddressBeforeReturn(regT1);
145     move(TrustedImmPtr(&globalData->exceptionLocation), regT2);
146     storePtr(regT1, regT2);
147     poke(callFrameRegister, 1 + OBJECT_OFFSETOF(struct JITStackFrame, callFrame) / sizeof(void*));
148     poke(TrustedImmPtr(FunctionPtr(ctiVMThrowTrampoline).value()));
149     ret();
150 
151     // NativeCall Trampoline
152     Label nativeCallThunk = privateCompileCTINativeCall(globalData);
153     Label nativeConstructThunk = privateCompileCTINativeCall(globalData, true);
154 
155 #if ENABLE(JIT_OPTIMIZE_PROPERTY_ACCESS)
156     Call string_failureCases1Call = makeTailRecursiveCall(string_failureCases1);
157     Call string_failureCases2Call = makeTailRecursiveCall(string_failureCases2);
158     Call string_failureCases3Call = makeTailRecursiveCall(string_failureCases3);
159 #endif
160 
161     // All trampolines constructed! copy the code, link up calls, and set the pointers on the Machine object.
162     LinkBuffer patchBuffer(this, m_globalData->executableAllocator.poolForSize(m_assembler.size()), 0);
163 
164 #if ENABLE(JIT_OPTIMIZE_PROPERTY_ACCESS)
165     patchBuffer.link(string_failureCases1Call, FunctionPtr(cti_op_get_by_id_string_fail));
166     patchBuffer.link(string_failureCases2Call, FunctionPtr(cti_op_get_by_id_string_fail));
167     patchBuffer.link(string_failureCases3Call, FunctionPtr(cti_op_get_by_id_string_fail));
168 #endif
169 #if ENABLE(JIT_OPTIMIZE_CALL)
170     patchBuffer.link(callLazyLinkCall, FunctionPtr(cti_vm_lazyLinkCall));
171     patchBuffer.link(callLazyLinkConstruct, FunctionPtr(cti_vm_lazyLinkConstruct));
172 #endif
173     patchBuffer.link(callCompileCall, FunctionPtr(cti_op_call_jitCompile));
174     patchBuffer.link(callCompileCconstruct, FunctionPtr(cti_op_construct_jitCompile));
175 
176     CodeRef finalCode = patchBuffer.finalizeCode();
177     *executablePool = finalCode.m_executablePool;
178 
179     trampolines->ctiVirtualCall = patchBuffer.trampolineAt(virtualCallBegin);
180     trampolines->ctiVirtualConstruct = patchBuffer.trampolineAt(virtualConstructBegin);
181     trampolines->ctiNativeCall = patchBuffer.trampolineAt(nativeCallThunk);
182     trampolines->ctiNativeConstruct = patchBuffer.trampolineAt(nativeConstructThunk);
183 #if ENABLE(JIT_OPTIMIZE_PROPERTY_ACCESS)
184     trampolines->ctiStringLengthTrampoline = patchBuffer.trampolineAt(stringLengthBegin);
185 #endif
186 #if ENABLE(JIT_OPTIMIZE_CALL)
187     trampolines->ctiVirtualCallLink = patchBuffer.trampolineAt(virtualCallLinkBegin);
188     trampolines->ctiVirtualConstructLink = patchBuffer.trampolineAt(virtualConstructLinkBegin);
189 #endif
190 #if ENABLE(JIT_USE_SOFT_MODULO)
191     trampolines->ctiSoftModulo = patchBuffer.trampolineAt(softModBegin);
192 #endif
193 }
194 
privateCompileCTINativeCall(JSGlobalData * globalData,bool isConstruct)195 JIT::Label JIT::privateCompileCTINativeCall(JSGlobalData* globalData, bool isConstruct)
196 {
197     int executableOffsetToFunction = isConstruct ? OBJECT_OFFSETOF(NativeExecutable, m_constructor) : OBJECT_OFFSETOF(NativeExecutable, m_function);
198 
199     Label nativeCallThunk = align();
200 
201     emitPutImmediateToCallFrameHeader(0, RegisterFile::CodeBlock);
202 
203 #if CPU(X86)
204     // Load caller frame's scope chain into this callframe so that whatever we call can
205     // get to its global data.
206     emitGetFromCallFrameHeaderPtr(RegisterFile::CallerFrame, regT0);
207     emitGetFromCallFrameHeaderPtr(RegisterFile::ScopeChain, regT1, regT0);
208     emitPutCellToCallFrameHeader(regT1, RegisterFile::ScopeChain);
209 
210     peek(regT1);
211     emitPutToCallFrameHeader(regT1, RegisterFile::ReturnPC);
212 
213     // Calling convention:      f(ecx, edx, ...);
214     // Host function signature: f(ExecState*);
215     move(callFrameRegister, X86Registers::ecx);
216 
217     subPtr(TrustedImm32(16 - sizeof(void*)), stackPointerRegister); // Align stack after call.
218 
219     // call the function
220     emitGetFromCallFrameHeaderPtr(RegisterFile::Callee, regT1);
221     loadPtr(Address(regT1, OBJECT_OFFSETOF(JSFunction, m_executable)), regT1);
222     move(regT0, callFrameRegister); // Eagerly restore caller frame register to avoid loading from stack.
223     call(Address(regT1, executableOffsetToFunction));
224 
225     addPtr(TrustedImm32(16 - sizeof(void*)), stackPointerRegister);
226 
227 #elif CPU(ARM)
228     // Load caller frame's scope chain into this callframe so that whatever we call can
229     // get to its global data.
230     emitGetFromCallFrameHeaderPtr(RegisterFile::CallerFrame, regT2);
231     emitGetFromCallFrameHeaderPtr(RegisterFile::ScopeChain, regT1, regT2);
232     emitPutCellToCallFrameHeader(regT1, RegisterFile::ScopeChain);
233 
234     preserveReturnAddressAfterCall(regT3); // Callee preserved
235     emitPutToCallFrameHeader(regT3, RegisterFile::ReturnPC);
236 
237     // Calling convention:      f(r0 == regT0, r1 == regT1, ...);
238     // Host function signature: f(ExecState*);
239     move(callFrameRegister, ARMRegisters::r0);
240 
241     // call the function
242     emitGetFromCallFrameHeaderPtr(RegisterFile::Callee, ARMRegisters::r1);
243     move(regT2, callFrameRegister); // Eagerly restore caller frame register to avoid loading from stack.
244     loadPtr(Address(ARMRegisters::r1, OBJECT_OFFSETOF(JSFunction, m_executable)), regT2);
245     call(Address(regT2, executableOffsetToFunction));
246 
247     restoreReturnAddressBeforeReturn(regT3);
248 #elif CPU(SH4)
249     // Load caller frame's scope chain into this callframe so that whatever we call can
250     // get to its global data.
251     emitGetFromCallFrameHeaderPtr(RegisterFile::CallerFrame, regT2);
252     emitGetFromCallFrameHeaderPtr(RegisterFile::ScopeChain, regT1, regT2);
253     emitPutToCallFrameHeader(regT1, RegisterFile::ScopeChain);
254 
255     preserveReturnAddressAfterCall(regT3); // Callee preserved
256     emitPutToCallFrameHeader(regT3, RegisterFile::ReturnPC);
257 
258     // Calling convention: f(r0 == regT4, r1 == regT5, ...);
259     // Host function signature: f(ExecState*);
260     move(callFrameRegister, regT4);
261 
262     emitGetFromCallFrameHeaderPtr(RegisterFile::Callee, regT5);
263     move(regT2, callFrameRegister); // Eagerly restore caller frame register to avoid loading from stack.
264     loadPtr(Address(regT5, OBJECT_OFFSETOF(JSFunction, m_executable)), regT2);
265 
266     call(Address(regT2, executableOffsetToFunction), regT0);
267     restoreReturnAddressBeforeReturn(regT3);
268 #elif CPU(MIPS)
269     // Load caller frame's scope chain into this callframe so that whatever we call can
270     // get to its global data.
271     emitGetFromCallFrameHeaderPtr(RegisterFile::CallerFrame, regT0);
272     emitGetFromCallFrameHeaderPtr(RegisterFile::ScopeChain, regT1, regT0);
273     emitPutCellToCallFrameHeader(regT1, RegisterFile::ScopeChain);
274 
275     preserveReturnAddressAfterCall(regT3); // Callee preserved
276     emitPutToCallFrameHeader(regT3, RegisterFile::ReturnPC);
277 
278     // Calling convention:      f(a0, a1, a2, a3);
279     // Host function signature: f(ExecState*);
280 
281     // Allocate stack space for 16 bytes (8-byte aligned)
282     // 16 bytes (unused) for 4 arguments
283     subPtr(TrustedImm32(16), stackPointerRegister);
284 
285     // Setup arg0
286     move(callFrameRegister, MIPSRegisters::a0);
287 
288     // Call
289     emitGetFromCallFrameHeaderPtr(RegisterFile::Callee, MIPSRegisters::a2);
290     loadPtr(Address(MIPSRegisters::a2, OBJECT_OFFSETOF(JSFunction, m_executable)), regT2);
291     move(regT0, callFrameRegister); // Eagerly restore caller frame register to avoid loading from stack.
292     call(Address(regT2, executableOffsetToFunction));
293 
294     // Restore stack space
295     addPtr(TrustedImm32(16), stackPointerRegister);
296 
297     restoreReturnAddressBeforeReturn(regT3);
298 
299 #elif ENABLE(JIT_OPTIMIZE_NATIVE_CALL)
300 #error "JIT_OPTIMIZE_NATIVE_CALL not yet supported on this platform."
301 #else
302     UNUSED_PARAM(executableOffsetToFunction);
303     breakpoint();
304 #endif // CPU(X86)
305 
306     // Check for an exception
307     Jump sawException = branch32(NotEqual, AbsoluteAddress(reinterpret_cast<char*>(&globalData->exception) + OBJECT_OFFSETOF(JSValue, u.asBits.tag)), TrustedImm32(JSValue::EmptyValueTag));
308 
309     // Return.
310     ret();
311 
312     // Handle an exception
313     sawException.link(this);
314 
315     // Grab the return address.
316     preserveReturnAddressAfterCall(regT1);
317 
318     move(TrustedImmPtr(&globalData->exceptionLocation), regT2);
319     storePtr(regT1, regT2);
320     poke(callFrameRegister, OBJECT_OFFSETOF(struct JITStackFrame, callFrame) / sizeof(void*));
321 
322     // Set the return address.
323     move(TrustedImmPtr(FunctionPtr(ctiVMThrowTrampoline).value()), regT1);
324     restoreReturnAddressBeforeReturn(regT1);
325 
326     ret();
327 
328     return nativeCallThunk;
329 }
330 
privateCompileCTINativeCall(PassRefPtr<ExecutablePool> executablePool,JSGlobalData * globalData,NativeFunction func)331 JIT::CodePtr JIT::privateCompileCTINativeCall(PassRefPtr<ExecutablePool> executablePool, JSGlobalData* globalData, NativeFunction func)
332 {
333     Call nativeCall;
334     Label nativeCallThunk = align();
335 
336     emitPutImmediateToCallFrameHeader(0, RegisterFile::CodeBlock);
337 
338 #if CPU(X86)
339     // Load caller frame's scope chain into this callframe so that whatever we call can
340     // get to its global data.
341     emitGetFromCallFrameHeaderPtr(RegisterFile::CallerFrame, regT0);
342     emitGetFromCallFrameHeaderPtr(RegisterFile::ScopeChain, regT1, regT0);
343     emitPutCellToCallFrameHeader(regT1, RegisterFile::ScopeChain);
344 
345     peek(regT1);
346     emitPutToCallFrameHeader(regT1, RegisterFile::ReturnPC);
347 
348     // Calling convention:      f(ecx, edx, ...);
349     // Host function signature: f(ExecState*);
350     move(callFrameRegister, X86Registers::ecx);
351 
352     subPtr(TrustedImm32(16 - sizeof(void*)), stackPointerRegister); // Align stack after call.
353 
354     move(regT0, callFrameRegister); // Eagerly restore caller frame register to avoid loading from stack.
355 
356     // call the function
357     nativeCall = call();
358 
359     addPtr(TrustedImm32(16 - sizeof(void*)), stackPointerRegister);
360 
361 #elif CPU(ARM)
362     // Load caller frame's scope chain into this callframe so that whatever we call can
363     // get to its global data.
364     emitGetFromCallFrameHeaderPtr(RegisterFile::CallerFrame, regT2);
365     emitGetFromCallFrameHeaderPtr(RegisterFile::ScopeChain, regT1, regT2);
366     emitPutCellToCallFrameHeader(regT1, RegisterFile::ScopeChain);
367 
368     preserveReturnAddressAfterCall(regT3); // Callee preserved
369     emitPutToCallFrameHeader(regT3, RegisterFile::ReturnPC);
370 
371     // Calling convention:      f(r0 == regT0, r1 == regT1, ...);
372     // Host function signature: f(ExecState*);
373     move(callFrameRegister, ARMRegisters::r0);
374 
375     emitGetFromCallFrameHeaderPtr(RegisterFile::Callee, ARMRegisters::r1);
376     move(regT2, callFrameRegister); // Eagerly restore caller frame register to avoid loading from stack.
377     loadPtr(Address(ARMRegisters::r1, OBJECT_OFFSETOF(JSFunction, m_executable)), regT2);
378 
379     // call the function
380     nativeCall = call();
381 
382     restoreReturnAddressBeforeReturn(regT3);
383 
384 #elif CPU(MIPS)
385     // Load caller frame's scope chain into this callframe so that whatever we call can
386     // get to its global data.
387     emitGetFromCallFrameHeaderPtr(RegisterFile::CallerFrame, regT0);
388     emitGetFromCallFrameHeaderPtr(RegisterFile::ScopeChain, regT1, regT0);
389     emitPutCellToCallFrameHeader(regT1, RegisterFile::ScopeChain);
390 
391     preserveReturnAddressAfterCall(regT3); // Callee preserved
392     emitPutToCallFrameHeader(regT3, RegisterFile::ReturnPC);
393 
394     // Calling convention:      f(a0, a1, a2, a3);
395     // Host function signature: f(ExecState*);
396 
397     // Allocate stack space for 16 bytes (8-byte aligned)
398     // 16 bytes (unused) for 4 arguments
399     subPtr(TrustedImm32(16), stackPointerRegister);
400 
401     // Setup arg0
402     move(callFrameRegister, MIPSRegisters::a0);
403 
404     // Call
405     emitGetFromCallFrameHeaderPtr(RegisterFile::Callee, MIPSRegisters::a2);
406     loadPtr(Address(MIPSRegisters::a2, OBJECT_OFFSETOF(JSFunction, m_executable)), regT2);
407     move(regT0, callFrameRegister); // Eagerly restore caller frame register to avoid loading from stack.
408 
409     // call the function
410     nativeCall = call();
411 
412     // Restore stack space
413     addPtr(TrustedImm32(16), stackPointerRegister);
414 
415     restoreReturnAddressBeforeReturn(regT3);
416 #elif CPU(SH4)
417     // Load caller frame's scope chain into this callframe so that whatever we call can
418     // get to its global data.
419     emitGetFromCallFrameHeaderPtr(RegisterFile::CallerFrame, regT2);
420     emitGetFromCallFrameHeaderPtr(RegisterFile::ScopeChain, regT1, regT2);
421     emitPutToCallFrameHeader(regT1, RegisterFile::ScopeChain);
422 
423     preserveReturnAddressAfterCall(regT3); // Callee preserved
424     emitPutToCallFrameHeader(regT3, RegisterFile::ReturnPC);
425 
426     // Calling convention: f(r0 == regT4, r1 == regT5, ...);
427     // Host function signature: f(ExecState*);
428     move(callFrameRegister, regT4);
429 
430     emitGetFromCallFrameHeaderPtr(RegisterFile::Callee, regT5);
431     move(regT2, callFrameRegister); // Eagerly restore caller frame register to avoid loading from stack.
432     loadPtr(Address(regT5, OBJECT_OFFSETOF(JSFunction, m_executable)), regT2);
433 
434     // call the function
435     nativeCall = call();
436 
437     restoreReturnAddressBeforeReturn(regT3);
438 #elif ENABLE(JIT_OPTIMIZE_NATIVE_CALL)
439 #error "JIT_OPTIMIZE_NATIVE_CALL not yet supported on this platform."
440 #else
441     breakpoint();
442 #endif // CPU(X86)
443 
444     // Check for an exception
445     Jump sawException = branch32(NotEqual, AbsoluteAddress(reinterpret_cast<char*>(&globalData->exception) + OBJECT_OFFSETOF(JSValue, u.asBits.tag)), TrustedImm32(JSValue::EmptyValueTag));
446 
447     // Return.
448     ret();
449 
450     // Handle an exception
451     sawException.link(this);
452 
453     // Grab the return address.
454     preserveReturnAddressAfterCall(regT1);
455 
456     move(TrustedImmPtr(&globalData->exceptionLocation), regT2);
457     storePtr(regT1, regT2);
458     poke(callFrameRegister, OBJECT_OFFSETOF(struct JITStackFrame, callFrame) / sizeof(void*));
459 
460     // Set the return address.
461     move(TrustedImmPtr(FunctionPtr(ctiVMThrowTrampoline).value()), regT1);
462     restoreReturnAddressBeforeReturn(regT1);
463 
464     ret();
465 
466     // All trampolines constructed! copy the code, link up calls, and set the pointers on the Machine object.
467     LinkBuffer patchBuffer(this, executablePool, 0);
468 
469     patchBuffer.link(nativeCall, FunctionPtr(func));
470     patchBuffer.finalizeCode();
471 
472     return patchBuffer.trampolineAt(nativeCallThunk);
473 }
474 
emit_op_mov(Instruction * currentInstruction)475 void JIT::emit_op_mov(Instruction* currentInstruction)
476 {
477     unsigned dst = currentInstruction[1].u.operand;
478     unsigned src = currentInstruction[2].u.operand;
479 
480     if (m_codeBlock->isConstantRegisterIndex(src))
481         emitStore(dst, getConstantOperand(src));
482     else {
483         emitLoad(src, regT1, regT0);
484         emitStore(dst, regT1, regT0);
485         map(m_bytecodeOffset + OPCODE_LENGTH(op_mov), dst, regT1, regT0);
486     }
487 }
488 
emit_op_end(Instruction * currentInstruction)489 void JIT::emit_op_end(Instruction* currentInstruction)
490 {
491     ASSERT(returnValueRegister != callFrameRegister);
492     emitLoad(currentInstruction[1].u.operand, regT1, regT0);
493     restoreReturnAddressBeforeReturn(Address(callFrameRegister, RegisterFile::ReturnPC * static_cast<int>(sizeof(Register))));
494     ret();
495 }
496 
emit_op_jmp(Instruction * currentInstruction)497 void JIT::emit_op_jmp(Instruction* currentInstruction)
498 {
499     unsigned target = currentInstruction[1].u.operand;
500     addJump(jump(), target);
501 }
502 
emit_op_loop_if_lesseq(Instruction * currentInstruction)503 void JIT::emit_op_loop_if_lesseq(Instruction* currentInstruction)
504 {
505     unsigned op1 = currentInstruction[1].u.operand;
506     unsigned op2 = currentInstruction[2].u.operand;
507     unsigned target = currentInstruction[3].u.operand;
508 
509     emitTimeoutCheck();
510 
511     if (isOperandConstantImmediateInt(op1)) {
512         emitLoad(op2, regT1, regT0);
513         addSlowCase(branch32(NotEqual, regT1, TrustedImm32(JSValue::Int32Tag)));
514         addJump(branch32(GreaterThanOrEqual, regT0, Imm32(getConstantOperand(op1).asInt32())), target);
515         return;
516     }
517 
518     if (isOperandConstantImmediateInt(op2)) {
519         emitLoad(op1, regT1, regT0);
520         addSlowCase(branch32(NotEqual, regT1, TrustedImm32(JSValue::Int32Tag)));
521         addJump(branch32(LessThanOrEqual, regT0, Imm32(getConstantOperand(op2).asInt32())), target);
522         return;
523     }
524 
525     emitLoad2(op1, regT1, regT0, op2, regT3, regT2);
526     addSlowCase(branch32(NotEqual, regT1, TrustedImm32(JSValue::Int32Tag)));
527     addSlowCase(branch32(NotEqual, regT3, TrustedImm32(JSValue::Int32Tag)));
528     addJump(branch32(LessThanOrEqual, regT0, regT2), target);
529 }
530 
emitSlow_op_loop_if_lesseq(Instruction * currentInstruction,Vector<SlowCaseEntry>::iterator & iter)531 void JIT::emitSlow_op_loop_if_lesseq(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
532 {
533     unsigned op1 = currentInstruction[1].u.operand;
534     unsigned op2 = currentInstruction[2].u.operand;
535     unsigned target = currentInstruction[3].u.operand;
536 
537     if (!isOperandConstantImmediateInt(op1) && !isOperandConstantImmediateInt(op2))
538         linkSlowCase(iter); // int32 check
539     linkSlowCase(iter); // int32 check
540 
541     JITStubCall stubCall(this, cti_op_loop_if_lesseq);
542     stubCall.addArgument(op1);
543     stubCall.addArgument(op2);
544     stubCall.call();
545     emitJumpSlowToHot(branchTest32(NonZero, regT0), target);
546 }
547 
emit_op_new_object(Instruction * currentInstruction)548 void JIT::emit_op_new_object(Instruction* currentInstruction)
549 {
550     JITStubCall(this, cti_op_new_object).call(currentInstruction[1].u.operand);
551 }
552 
emit_op_check_has_instance(Instruction * currentInstruction)553 void JIT::emit_op_check_has_instance(Instruction* currentInstruction)
554 {
555     unsigned baseVal = currentInstruction[1].u.operand;
556 
557     emitLoadPayload(baseVal, regT0);
558 
559     // Check that baseVal is a cell.
560     emitJumpSlowCaseIfNotJSCell(baseVal);
561 
562     // Check that baseVal 'ImplementsHasInstance'.
563     loadPtr(Address(regT0, JSCell::structureOffset()), regT0);
564     addSlowCase(branchTest8(Zero, Address(regT0, Structure::typeInfoFlagsOffset()), TrustedImm32(ImplementsHasInstance)));
565 }
566 
emit_op_instanceof(Instruction * currentInstruction)567 void JIT::emit_op_instanceof(Instruction* currentInstruction)
568 {
569     unsigned dst = currentInstruction[1].u.operand;
570     unsigned value = currentInstruction[2].u.operand;
571     unsigned baseVal = currentInstruction[3].u.operand;
572     unsigned proto = currentInstruction[4].u.operand;
573 
574     // Load the operands into registers.
575     // We use regT0 for baseVal since we will be done with this first, and we can then use it for the result.
576     emitLoadPayload(value, regT2);
577     emitLoadPayload(baseVal, regT0);
578     emitLoadPayload(proto, regT1);
579 
580     // Check that proto are cells.  baseVal must be a cell - this is checked by op_check_has_instance.
581     emitJumpSlowCaseIfNotJSCell(value);
582     emitJumpSlowCaseIfNotJSCell(proto);
583 
584     // Check that prototype is an object
585     loadPtr(Address(regT1, JSCell::structureOffset()), regT3);
586     addSlowCase(branch8(NotEqual, Address(regT3, Structure::typeInfoTypeOffset()), TrustedImm32(ObjectType)));
587 
588     // Fixme: this check is only needed because the JSC API allows HasInstance to be overridden; we should deprecate this.
589     // Check that baseVal 'ImplementsDefaultHasInstance'.
590     loadPtr(Address(regT0, JSCell::structureOffset()), regT0);
591     addSlowCase(branchTest8(Zero, Address(regT0, Structure::typeInfoFlagsOffset()), TrustedImm32(ImplementsDefaultHasInstance)));
592 
593     // Optimistically load the result true, and start looping.
594     // Initially, regT1 still contains proto and regT2 still contains value.
595     // As we loop regT2 will be updated with its prototype, recursively walking the prototype chain.
596     move(TrustedImm32(1), regT0);
597     Label loop(this);
598 
599     // Load the prototype of the cell in regT2.  If this is equal to regT1 - WIN!
600     // Otherwise, check if we've hit null - if we have then drop out of the loop, if not go again.
601     loadPtr(Address(regT2, JSCell::structureOffset()), regT2);
602     load32(Address(regT2, Structure::prototypeOffset() + OBJECT_OFFSETOF(JSValue, u.asBits.payload)), regT2);
603     Jump isInstance = branchPtr(Equal, regT2, regT1);
604     branchTest32(NonZero, regT2).linkTo(loop, this);
605 
606     // We get here either by dropping out of the loop, or if value was not an Object.  Result is false.
607     move(TrustedImm32(0), regT0);
608 
609     // isInstance jumps right down to here, to skip setting the result to false (it has already set true).
610     isInstance.link(this);
611     emitStoreBool(dst, regT0);
612 }
613 
emitSlow_op_check_has_instance(Instruction * currentInstruction,Vector<SlowCaseEntry>::iterator & iter)614 void JIT::emitSlow_op_check_has_instance(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
615 {
616     unsigned baseVal = currentInstruction[1].u.operand;
617 
618     linkSlowCaseIfNotJSCell(iter, baseVal);
619     linkSlowCase(iter);
620 
621     JITStubCall stubCall(this, cti_op_check_has_instance);
622     stubCall.addArgument(baseVal);
623     stubCall.call();
624 }
625 
emitSlow_op_instanceof(Instruction * currentInstruction,Vector<SlowCaseEntry>::iterator & iter)626 void JIT::emitSlow_op_instanceof(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
627 {
628     unsigned dst = currentInstruction[1].u.operand;
629     unsigned value = currentInstruction[2].u.operand;
630     unsigned baseVal = currentInstruction[3].u.operand;
631     unsigned proto = currentInstruction[4].u.operand;
632 
633     linkSlowCaseIfNotJSCell(iter, value);
634     linkSlowCaseIfNotJSCell(iter, proto);
635     linkSlowCase(iter);
636     linkSlowCase(iter);
637 
638     JITStubCall stubCall(this, cti_op_instanceof);
639     stubCall.addArgument(value);
640     stubCall.addArgument(baseVal);
641     stubCall.addArgument(proto);
642     stubCall.call(dst);
643 }
644 
emit_op_get_global_var(Instruction * currentInstruction)645 void JIT::emit_op_get_global_var(Instruction* currentInstruction)
646 {
647     int dst = currentInstruction[1].u.operand;
648     JSGlobalObject* globalObject = m_codeBlock->globalObject();
649     ASSERT(globalObject->isGlobalObject());
650     int index = currentInstruction[2].u.operand;
651 
652     loadPtr(&globalObject->m_registers, regT2);
653 
654     emitLoad(index, regT1, regT0, regT2);
655     emitStore(dst, regT1, regT0);
656     map(m_bytecodeOffset + OPCODE_LENGTH(op_get_global_var), dst, regT1, regT0);
657 }
658 
emit_op_put_global_var(Instruction * currentInstruction)659 void JIT::emit_op_put_global_var(Instruction* currentInstruction)
660 {
661     JSGlobalObject* globalObject = m_codeBlock->globalObject();
662     ASSERT(globalObject->isGlobalObject());
663     int index = currentInstruction[1].u.operand;
664     int value = currentInstruction[2].u.operand;
665 
666     emitLoad(value, regT1, regT0);
667 
668     loadPtr(&globalObject->m_registers, regT2);
669     emitStore(index, regT1, regT0, regT2);
670     map(m_bytecodeOffset + OPCODE_LENGTH(op_put_global_var), value, regT1, regT0);
671 }
672 
emit_op_get_scoped_var(Instruction * currentInstruction)673 void JIT::emit_op_get_scoped_var(Instruction* currentInstruction)
674 {
675     int dst = currentInstruction[1].u.operand;
676     int index = currentInstruction[2].u.operand;
677     int skip = currentInstruction[3].u.operand;
678 
679     emitGetFromCallFrameHeaderPtr(RegisterFile::ScopeChain, regT2);
680     bool checkTopLevel = m_codeBlock->codeType() == FunctionCode && m_codeBlock->needsFullScopeChain();
681     ASSERT(skip || !checkTopLevel);
682     if (checkTopLevel && skip--) {
683         Jump activationNotCreated;
684         if (checkTopLevel)
685             activationNotCreated = branch32(Equal, tagFor(m_codeBlock->activationRegister()), TrustedImm32(JSValue::EmptyValueTag));
686         loadPtr(Address(regT2, OBJECT_OFFSETOF(ScopeChainNode, next)), regT2);
687         activationNotCreated.link(this);
688     }
689     while (skip--)
690         loadPtr(Address(regT2, OBJECT_OFFSETOF(ScopeChainNode, next)), regT2);
691 
692     loadPtr(Address(regT2, OBJECT_OFFSETOF(ScopeChainNode, object)), regT2);
693     loadPtr(Address(regT2, OBJECT_OFFSETOF(JSVariableObject, m_registers)), regT2);
694 
695     emitLoad(index, regT1, regT0, regT2);
696     emitStore(dst, regT1, regT0);
697     map(m_bytecodeOffset + OPCODE_LENGTH(op_get_scoped_var), dst, regT1, regT0);
698 }
699 
emit_op_put_scoped_var(Instruction * currentInstruction)700 void JIT::emit_op_put_scoped_var(Instruction* currentInstruction)
701 {
702     int index = currentInstruction[1].u.operand;
703     int skip = currentInstruction[2].u.operand;
704     int value = currentInstruction[3].u.operand;
705 
706     emitLoad(value, regT1, regT0);
707 
708     emitGetFromCallFrameHeaderPtr(RegisterFile::ScopeChain, regT2);
709     bool checkTopLevel = m_codeBlock->codeType() == FunctionCode && m_codeBlock->needsFullScopeChain();
710     ASSERT(skip || !checkTopLevel);
711     if (checkTopLevel && skip--) {
712         Jump activationNotCreated;
713         if (checkTopLevel)
714             activationNotCreated = branch32(Equal, tagFor(m_codeBlock->activationRegister()), TrustedImm32(JSValue::EmptyValueTag));
715         loadPtr(Address(regT2, OBJECT_OFFSETOF(ScopeChainNode, next)), regT2);
716         activationNotCreated.link(this);
717     }
718     while (skip--)
719         loadPtr(Address(regT2, OBJECT_OFFSETOF(ScopeChainNode, next)), regT2);
720 
721     loadPtr(Address(regT2, OBJECT_OFFSETOF(ScopeChainNode, object)), regT2);
722     loadPtr(Address(regT2, OBJECT_OFFSETOF(JSVariableObject, m_registers)), regT2);
723 
724     emitStore(index, regT1, regT0, regT2);
725     map(m_bytecodeOffset + OPCODE_LENGTH(op_put_scoped_var), value, regT1, regT0);
726 }
727 
emit_op_tear_off_activation(Instruction * currentInstruction)728 void JIT::emit_op_tear_off_activation(Instruction* currentInstruction)
729 {
730     unsigned activation = currentInstruction[1].u.operand;
731     unsigned arguments = currentInstruction[2].u.operand;
732     Jump activationCreated = branch32(NotEqual, tagFor(activation), TrustedImm32(JSValue::EmptyValueTag));
733     Jump argumentsNotCreated = branch32(Equal, tagFor(arguments), TrustedImm32(JSValue::EmptyValueTag));
734     activationCreated.link(this);
735     JITStubCall stubCall(this, cti_op_tear_off_activation);
736     stubCall.addArgument(currentInstruction[1].u.operand);
737     stubCall.addArgument(unmodifiedArgumentsRegister(currentInstruction[2].u.operand));
738     stubCall.call();
739     argumentsNotCreated.link(this);
740 }
741 
emit_op_tear_off_arguments(Instruction * currentInstruction)742 void JIT::emit_op_tear_off_arguments(Instruction* currentInstruction)
743 {
744     int dst = currentInstruction[1].u.operand;
745 
746     Jump argsNotCreated = branch32(Equal, tagFor(unmodifiedArgumentsRegister(dst)), TrustedImm32(JSValue::EmptyValueTag));
747     JITStubCall stubCall(this, cti_op_tear_off_arguments);
748     stubCall.addArgument(unmodifiedArgumentsRegister(dst));
749     stubCall.call();
750     argsNotCreated.link(this);
751 }
752 
emit_op_new_array(Instruction * currentInstruction)753 void JIT::emit_op_new_array(Instruction* currentInstruction)
754 {
755     JITStubCall stubCall(this, cti_op_new_array);
756     stubCall.addArgument(Imm32(currentInstruction[2].u.operand));
757     stubCall.addArgument(Imm32(currentInstruction[3].u.operand));
758     stubCall.call(currentInstruction[1].u.operand);
759 }
760 
emit_op_resolve(Instruction * currentInstruction)761 void JIT::emit_op_resolve(Instruction* currentInstruction)
762 {
763     JITStubCall stubCall(this, cti_op_resolve);
764     stubCall.addArgument(TrustedImmPtr(&m_codeBlock->identifier(currentInstruction[2].u.operand)));
765     stubCall.call(currentInstruction[1].u.operand);
766 }
767 
emit_op_to_primitive(Instruction * currentInstruction)768 void JIT::emit_op_to_primitive(Instruction* currentInstruction)
769 {
770     int dst = currentInstruction[1].u.operand;
771     int src = currentInstruction[2].u.operand;
772 
773     emitLoad(src, regT1, regT0);
774 
775     Jump isImm = branch32(NotEqual, regT1, TrustedImm32(JSValue::CellTag));
776     addSlowCase(branchPtr(NotEqual, Address(regT0), TrustedImmPtr(m_globalData->jsStringVPtr)));
777     isImm.link(this);
778 
779     if (dst != src)
780         emitStore(dst, regT1, regT0);
781     map(m_bytecodeOffset + OPCODE_LENGTH(op_to_primitive), dst, regT1, regT0);
782 }
783 
emitSlow_op_to_primitive(Instruction * currentInstruction,Vector<SlowCaseEntry>::iterator & iter)784 void JIT::emitSlow_op_to_primitive(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
785 {
786     int dst = currentInstruction[1].u.operand;
787 
788     linkSlowCase(iter);
789 
790     JITStubCall stubCall(this, cti_op_to_primitive);
791     stubCall.addArgument(regT1, regT0);
792     stubCall.call(dst);
793 }
794 
emit_op_strcat(Instruction * currentInstruction)795 void JIT::emit_op_strcat(Instruction* currentInstruction)
796 {
797     JITStubCall stubCall(this, cti_op_strcat);
798     stubCall.addArgument(Imm32(currentInstruction[2].u.operand));
799     stubCall.addArgument(Imm32(currentInstruction[3].u.operand));
800     stubCall.call(currentInstruction[1].u.operand);
801 }
802 
emit_op_resolve_base(Instruction * currentInstruction)803 void JIT::emit_op_resolve_base(Instruction* currentInstruction)
804 {
805     JITStubCall stubCall(this, currentInstruction[3].u.operand ? cti_op_resolve_base_strict_put : cti_op_resolve_base);
806     stubCall.addArgument(TrustedImmPtr(&m_codeBlock->identifier(currentInstruction[2].u.operand)));
807     stubCall.call(currentInstruction[1].u.operand);
808 }
809 
emit_op_ensure_property_exists(Instruction * currentInstruction)810 void JIT::emit_op_ensure_property_exists(Instruction* currentInstruction)
811 {
812     JITStubCall stubCall(this, cti_op_ensure_property_exists);
813     stubCall.addArgument(Imm32(currentInstruction[1].u.operand));
814     stubCall.addArgument(TrustedImmPtr(&m_codeBlock->identifier(currentInstruction[2].u.operand)));
815     stubCall.call(currentInstruction[1].u.operand);
816 }
817 
emit_op_resolve_skip(Instruction * currentInstruction)818 void JIT::emit_op_resolve_skip(Instruction* currentInstruction)
819 {
820     JITStubCall stubCall(this, cti_op_resolve_skip);
821     stubCall.addArgument(TrustedImmPtr(&m_codeBlock->identifier(currentInstruction[2].u.operand)));
822     stubCall.addArgument(Imm32(currentInstruction[3].u.operand));
823     stubCall.call(currentInstruction[1].u.operand);
824 }
825 
emit_op_resolve_global(Instruction * currentInstruction,bool dynamic)826 void JIT::emit_op_resolve_global(Instruction* currentInstruction, bool dynamic)
827 {
828     // FIXME: Optimize to use patching instead of so many memory accesses.
829 
830     unsigned dst = currentInstruction[1].u.operand;
831     void* globalObject = m_codeBlock->globalObject();
832 
833     unsigned currentIndex = m_globalResolveInfoIndex++;
834     void* structureAddress = &(m_codeBlock->globalResolveInfo(currentIndex).structure);
835     void* offsetAddr = &(m_codeBlock->globalResolveInfo(currentIndex).offset);
836 
837     // Verify structure.
838     move(TrustedImmPtr(globalObject), regT0);
839     loadPtr(structureAddress, regT1);
840     addSlowCase(branchPtr(NotEqual, regT1, Address(regT0, JSCell::structureOffset())));
841 
842     // Load property.
843     loadPtr(Address(regT0, OBJECT_OFFSETOF(JSGlobalObject, m_propertyStorage)), regT2);
844     load32(offsetAddr, regT3);
845     load32(BaseIndex(regT2, regT3, TimesEight, OBJECT_OFFSETOF(JSValue, u.asBits.payload)), regT0); // payload
846     load32(BaseIndex(regT2, regT3, TimesEight, OBJECT_OFFSETOF(JSValue, u.asBits.tag)), regT1); // tag
847     emitStore(dst, regT1, regT0);
848     map(m_bytecodeOffset + dynamic ? OPCODE_LENGTH(op_resolve_global_dynamic) : OPCODE_LENGTH(op_resolve_global), dst, regT1, regT0);
849 }
850 
emitSlow_op_resolve_global(Instruction * currentInstruction,Vector<SlowCaseEntry>::iterator & iter)851 void JIT::emitSlow_op_resolve_global(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
852 {
853     unsigned dst = currentInstruction[1].u.operand;
854     Identifier* ident = &m_codeBlock->identifier(currentInstruction[2].u.operand);
855 
856     unsigned currentIndex = m_globalResolveInfoIndex++;
857 
858     linkSlowCase(iter);
859     JITStubCall stubCall(this, cti_op_resolve_global);
860     stubCall.addArgument(TrustedImmPtr(ident));
861     stubCall.addArgument(Imm32(currentIndex));
862     stubCall.call(dst);
863 }
864 
emit_op_not(Instruction * currentInstruction)865 void JIT::emit_op_not(Instruction* currentInstruction)
866 {
867     unsigned dst = currentInstruction[1].u.operand;
868     unsigned src = currentInstruction[2].u.operand;
869 
870     emitLoadTag(src, regT0);
871 
872     emitLoad(src, regT1, regT0);
873     addSlowCase(branch32(NotEqual, regT1, TrustedImm32(JSValue::BooleanTag)));
874     xor32(TrustedImm32(1), regT0);
875 
876     emitStoreBool(dst, regT0, (dst == src));
877 }
878 
emitSlow_op_not(Instruction * currentInstruction,Vector<SlowCaseEntry>::iterator & iter)879 void JIT::emitSlow_op_not(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
880 {
881     unsigned dst = currentInstruction[1].u.operand;
882     unsigned src = currentInstruction[2].u.operand;
883 
884     linkSlowCase(iter);
885 
886     JITStubCall stubCall(this, cti_op_not);
887     stubCall.addArgument(src);
888     stubCall.call(dst);
889 }
890 
emit_op_jfalse(Instruction * currentInstruction)891 void JIT::emit_op_jfalse(Instruction* currentInstruction)
892 {
893     unsigned cond = currentInstruction[1].u.operand;
894     unsigned target = currentInstruction[2].u.operand;
895 
896     emitLoad(cond, regT1, regT0);
897 
898     ASSERT((JSValue::BooleanTag + 1 == JSValue::Int32Tag) && !(JSValue::Int32Tag + 1));
899     addSlowCase(branch32(Below, regT1, TrustedImm32(JSValue::BooleanTag)));
900     addJump(branchTest32(Zero, regT0), target);
901 }
902 
emitSlow_op_jfalse(Instruction * currentInstruction,Vector<SlowCaseEntry>::iterator & iter)903 void JIT::emitSlow_op_jfalse(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
904 {
905     unsigned cond = currentInstruction[1].u.operand;
906     unsigned target = currentInstruction[2].u.operand;
907 
908     linkSlowCase(iter);
909 
910     if (supportsFloatingPoint()) {
911         // regT1 contains the tag from the hot path.
912         Jump notNumber = branch32(Above, regT1, Imm32(JSValue::LowestTag));
913 
914         emitLoadDouble(cond, fpRegT0);
915         emitJumpSlowToHot(branchDoubleZeroOrNaN(fpRegT0, fpRegT1), target);
916         emitJumpSlowToHot(jump(), OPCODE_LENGTH(op_jfalse));
917 
918         notNumber.link(this);
919     }
920 
921     JITStubCall stubCall(this, cti_op_jtrue);
922     stubCall.addArgument(cond);
923     stubCall.call();
924     emitJumpSlowToHot(branchTest32(Zero, regT0), target); // Inverted.
925 }
926 
emit_op_jtrue(Instruction * currentInstruction)927 void JIT::emit_op_jtrue(Instruction* currentInstruction)
928 {
929     unsigned cond = currentInstruction[1].u.operand;
930     unsigned target = currentInstruction[2].u.operand;
931 
932     emitLoad(cond, regT1, regT0);
933 
934     ASSERT((JSValue::BooleanTag + 1 == JSValue::Int32Tag) && !(JSValue::Int32Tag + 1));
935     addSlowCase(branch32(Below, regT1, TrustedImm32(JSValue::BooleanTag)));
936     addJump(branchTest32(NonZero, regT0), target);
937 }
938 
emitSlow_op_jtrue(Instruction * currentInstruction,Vector<SlowCaseEntry>::iterator & iter)939 void JIT::emitSlow_op_jtrue(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
940 {
941     unsigned cond = currentInstruction[1].u.operand;
942     unsigned target = currentInstruction[2].u.operand;
943 
944     linkSlowCase(iter);
945 
946     if (supportsFloatingPoint()) {
947         // regT1 contains the tag from the hot path.
948         Jump notNumber = branch32(Above, regT1, Imm32(JSValue::LowestTag));
949 
950         emitLoadDouble(cond, fpRegT0);
951         emitJumpSlowToHot(branchDoubleNonZero(fpRegT0, fpRegT1), target);
952         emitJumpSlowToHot(jump(), OPCODE_LENGTH(op_jtrue));
953 
954         notNumber.link(this);
955     }
956 
957     JITStubCall stubCall(this, cti_op_jtrue);
958     stubCall.addArgument(cond);
959     stubCall.call();
960     emitJumpSlowToHot(branchTest32(NonZero, regT0), target);
961 }
962 
emit_op_jeq_null(Instruction * currentInstruction)963 void JIT::emit_op_jeq_null(Instruction* currentInstruction)
964 {
965     unsigned src = currentInstruction[1].u.operand;
966     unsigned target = currentInstruction[2].u.operand;
967 
968     emitLoad(src, regT1, regT0);
969 
970     Jump isImmediate = branch32(NotEqual, regT1, TrustedImm32(JSValue::CellTag));
971 
972     // First, handle JSCell cases - check MasqueradesAsUndefined bit on the structure.
973     loadPtr(Address(regT0, JSCell::structureOffset()), regT2);
974     addJump(branchTest8(NonZero, Address(regT2, Structure::typeInfoFlagsOffset()), TrustedImm32(MasqueradesAsUndefined)), target);
975 
976     Jump wasNotImmediate = jump();
977 
978     // Now handle the immediate cases - undefined & null
979     isImmediate.link(this);
980 
981     ASSERT((JSValue::UndefinedTag + 1 == JSValue::NullTag) && (JSValue::NullTag & 0x1));
982     or32(TrustedImm32(1), regT1);
983     addJump(branch32(Equal, regT1, TrustedImm32(JSValue::NullTag)), target);
984 
985     wasNotImmediate.link(this);
986 }
987 
emit_op_jneq_null(Instruction * currentInstruction)988 void JIT::emit_op_jneq_null(Instruction* currentInstruction)
989 {
990     unsigned src = currentInstruction[1].u.operand;
991     unsigned target = currentInstruction[2].u.operand;
992 
993     emitLoad(src, regT1, regT0);
994 
995     Jump isImmediate = branch32(NotEqual, regT1, TrustedImm32(JSValue::CellTag));
996 
997     // First, handle JSCell cases - check MasqueradesAsUndefined bit on the structure.
998     loadPtr(Address(regT0, JSCell::structureOffset()), regT2);
999     addJump(branchTest8(Zero, Address(regT2, Structure::typeInfoFlagsOffset()), TrustedImm32(MasqueradesAsUndefined)), target);
1000 
1001     Jump wasNotImmediate = jump();
1002 
1003     // Now handle the immediate cases - undefined & null
1004     isImmediate.link(this);
1005 
1006     ASSERT((JSValue::UndefinedTag + 1 == JSValue::NullTag) && (JSValue::NullTag & 0x1));
1007     or32(TrustedImm32(1), regT1);
1008     addJump(branch32(NotEqual, regT1, TrustedImm32(JSValue::NullTag)), target);
1009 
1010     wasNotImmediate.link(this);
1011 }
1012 
emit_op_jneq_ptr(Instruction * currentInstruction)1013 void JIT::emit_op_jneq_ptr(Instruction* currentInstruction)
1014 {
1015     unsigned src = currentInstruction[1].u.operand;
1016     JSCell* ptr = currentInstruction[2].u.jsCell.get();
1017     unsigned target = currentInstruction[3].u.operand;
1018 
1019     emitLoad(src, regT1, regT0);
1020     addJump(branch32(NotEqual, regT1, TrustedImm32(JSValue::CellTag)), target);
1021     addJump(branchPtr(NotEqual, regT0, TrustedImmPtr(ptr)), target);
1022 }
1023 
emit_op_jsr(Instruction * currentInstruction)1024 void JIT::emit_op_jsr(Instruction* currentInstruction)
1025 {
1026     int retAddrDst = currentInstruction[1].u.operand;
1027     int target = currentInstruction[2].u.operand;
1028     DataLabelPtr storeLocation = storePtrWithPatch(TrustedImmPtr(0), Address(callFrameRegister, sizeof(Register) * retAddrDst));
1029     addJump(jump(), target);
1030     m_jsrSites.append(JSRInfo(storeLocation, label()));
1031 }
1032 
emit_op_sret(Instruction * currentInstruction)1033 void JIT::emit_op_sret(Instruction* currentInstruction)
1034 {
1035     jump(Address(callFrameRegister, sizeof(Register) * currentInstruction[1].u.operand));
1036 }
1037 
emit_op_eq(Instruction * currentInstruction)1038 void JIT::emit_op_eq(Instruction* currentInstruction)
1039 {
1040     unsigned dst = currentInstruction[1].u.operand;
1041     unsigned src1 = currentInstruction[2].u.operand;
1042     unsigned src2 = currentInstruction[3].u.operand;
1043 
1044     emitLoad2(src1, regT1, regT0, src2, regT3, regT2);
1045     addSlowCase(branch32(NotEqual, regT1, regT3));
1046     addSlowCase(branch32(Equal, regT1, TrustedImm32(JSValue::CellTag)));
1047     addSlowCase(branch32(Below, regT1, TrustedImm32(JSValue::LowestTag)));
1048 
1049     set32Compare32(Equal, regT0, regT2, regT0);
1050 
1051     emitStoreBool(dst, regT0);
1052 }
1053 
emitSlow_op_eq(Instruction * currentInstruction,Vector<SlowCaseEntry>::iterator & iter)1054 void JIT::emitSlow_op_eq(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
1055 {
1056     unsigned dst = currentInstruction[1].u.operand;
1057     unsigned op1 = currentInstruction[2].u.operand;
1058     unsigned op2 = currentInstruction[3].u.operand;
1059 
1060     JumpList storeResult;
1061     JumpList genericCase;
1062 
1063     genericCase.append(getSlowCase(iter)); // tags not equal
1064 
1065     linkSlowCase(iter); // tags equal and JSCell
1066     genericCase.append(branchPtr(NotEqual, Address(regT0), TrustedImmPtr(m_globalData->jsStringVPtr)));
1067     genericCase.append(branchPtr(NotEqual, Address(regT2), TrustedImmPtr(m_globalData->jsStringVPtr)));
1068 
1069     // String case.
1070     JITStubCall stubCallEqStrings(this, cti_op_eq_strings);
1071     stubCallEqStrings.addArgument(regT0);
1072     stubCallEqStrings.addArgument(regT2);
1073     stubCallEqStrings.call();
1074     storeResult.append(jump());
1075 
1076     // Generic case.
1077     genericCase.append(getSlowCase(iter)); // doubles
1078     genericCase.link(this);
1079     JITStubCall stubCallEq(this, cti_op_eq);
1080     stubCallEq.addArgument(op1);
1081     stubCallEq.addArgument(op2);
1082     stubCallEq.call(regT0);
1083 
1084     storeResult.link(this);
1085     emitStoreBool(dst, regT0);
1086 }
1087 
emit_op_neq(Instruction * currentInstruction)1088 void JIT::emit_op_neq(Instruction* currentInstruction)
1089 {
1090     unsigned dst = currentInstruction[1].u.operand;
1091     unsigned src1 = currentInstruction[2].u.operand;
1092     unsigned src2 = currentInstruction[3].u.operand;
1093 
1094     emitLoad2(src1, regT1, regT0, src2, regT3, regT2);
1095     addSlowCase(branch32(NotEqual, regT1, regT3));
1096     addSlowCase(branch32(Equal, regT1, TrustedImm32(JSValue::CellTag)));
1097     addSlowCase(branch32(Below, regT1, TrustedImm32(JSValue::LowestTag)));
1098 
1099     set32Compare32(NotEqual, regT0, regT2, regT0);
1100 
1101     emitStoreBool(dst, regT0);
1102 }
1103 
emitSlow_op_neq(Instruction * currentInstruction,Vector<SlowCaseEntry>::iterator & iter)1104 void JIT::emitSlow_op_neq(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
1105 {
1106     unsigned dst = currentInstruction[1].u.operand;
1107 
1108     JumpList storeResult;
1109     JumpList genericCase;
1110 
1111     genericCase.append(getSlowCase(iter)); // tags not equal
1112 
1113     linkSlowCase(iter); // tags equal and JSCell
1114     genericCase.append(branchPtr(NotEqual, Address(regT0), TrustedImmPtr(m_globalData->jsStringVPtr)));
1115     genericCase.append(branchPtr(NotEqual, Address(regT2), TrustedImmPtr(m_globalData->jsStringVPtr)));
1116 
1117     // String case.
1118     JITStubCall stubCallEqStrings(this, cti_op_eq_strings);
1119     stubCallEqStrings.addArgument(regT0);
1120     stubCallEqStrings.addArgument(regT2);
1121     stubCallEqStrings.call(regT0);
1122     storeResult.append(jump());
1123 
1124     // Generic case.
1125     genericCase.append(getSlowCase(iter)); // doubles
1126     genericCase.link(this);
1127     JITStubCall stubCallEq(this, cti_op_eq);
1128     stubCallEq.addArgument(regT1, regT0);
1129     stubCallEq.addArgument(regT3, regT2);
1130     stubCallEq.call(regT0);
1131 
1132     storeResult.link(this);
1133     xor32(TrustedImm32(0x1), regT0);
1134     emitStoreBool(dst, regT0);
1135 }
1136 
compileOpStrictEq(Instruction * currentInstruction,CompileOpStrictEqType type)1137 void JIT::compileOpStrictEq(Instruction* currentInstruction, CompileOpStrictEqType type)
1138 {
1139     unsigned dst = currentInstruction[1].u.operand;
1140     unsigned src1 = currentInstruction[2].u.operand;
1141     unsigned src2 = currentInstruction[3].u.operand;
1142 
1143     emitLoadTag(src1, regT0);
1144     emitLoadTag(src2, regT1);
1145 
1146     // Jump to a slow case if either operand is double, or if both operands are
1147     // cells and/or Int32s.
1148     move(regT0, regT2);
1149     and32(regT1, regT2);
1150     addSlowCase(branch32(Below, regT2, TrustedImm32(JSValue::LowestTag)));
1151     addSlowCase(branch32(AboveOrEqual, regT2, TrustedImm32(JSValue::CellTag)));
1152 
1153     if (type == OpStrictEq)
1154         set32Compare32(Equal, regT0, regT1, regT0);
1155     else
1156         set32Compare32(NotEqual, regT0, regT1, regT0);
1157 
1158     emitStoreBool(dst, regT0);
1159 }
1160 
emit_op_stricteq(Instruction * currentInstruction)1161 void JIT::emit_op_stricteq(Instruction* currentInstruction)
1162 {
1163     compileOpStrictEq(currentInstruction, OpStrictEq);
1164 }
1165 
emitSlow_op_stricteq(Instruction * currentInstruction,Vector<SlowCaseEntry>::iterator & iter)1166 void JIT::emitSlow_op_stricteq(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
1167 {
1168     unsigned dst = currentInstruction[1].u.operand;
1169     unsigned src1 = currentInstruction[2].u.operand;
1170     unsigned src2 = currentInstruction[3].u.operand;
1171 
1172     linkSlowCase(iter);
1173     linkSlowCase(iter);
1174 
1175     JITStubCall stubCall(this, cti_op_stricteq);
1176     stubCall.addArgument(src1);
1177     stubCall.addArgument(src2);
1178     stubCall.call(dst);
1179 }
1180 
emit_op_nstricteq(Instruction * currentInstruction)1181 void JIT::emit_op_nstricteq(Instruction* currentInstruction)
1182 {
1183     compileOpStrictEq(currentInstruction, OpNStrictEq);
1184 }
1185 
emitSlow_op_nstricteq(Instruction * currentInstruction,Vector<SlowCaseEntry>::iterator & iter)1186 void JIT::emitSlow_op_nstricteq(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
1187 {
1188     unsigned dst = currentInstruction[1].u.operand;
1189     unsigned src1 = currentInstruction[2].u.operand;
1190     unsigned src2 = currentInstruction[3].u.operand;
1191 
1192     linkSlowCase(iter);
1193     linkSlowCase(iter);
1194 
1195     JITStubCall stubCall(this, cti_op_nstricteq);
1196     stubCall.addArgument(src1);
1197     stubCall.addArgument(src2);
1198     stubCall.call(dst);
1199 }
1200 
emit_op_eq_null(Instruction * currentInstruction)1201 void JIT::emit_op_eq_null(Instruction* currentInstruction)
1202 {
1203     unsigned dst = currentInstruction[1].u.operand;
1204     unsigned src = currentInstruction[2].u.operand;
1205 
1206     emitLoad(src, regT1, regT0);
1207     Jump isImmediate = branch32(NotEqual, regT1, TrustedImm32(JSValue::CellTag));
1208 
1209     loadPtr(Address(regT0, JSCell::structureOffset()), regT1);
1210     set32Test8(NonZero, Address(regT1, Structure::typeInfoFlagsOffset()), TrustedImm32(MasqueradesAsUndefined), regT1);
1211 
1212     Jump wasNotImmediate = jump();
1213 
1214     isImmediate.link(this);
1215 
1216     set32Compare32(Equal, regT1, TrustedImm32(JSValue::NullTag), regT2);
1217     set32Compare32(Equal, regT1, TrustedImm32(JSValue::UndefinedTag), regT1);
1218     or32(regT2, regT1);
1219 
1220     wasNotImmediate.link(this);
1221 
1222     emitStoreBool(dst, regT1);
1223 }
1224 
emit_op_neq_null(Instruction * currentInstruction)1225 void JIT::emit_op_neq_null(Instruction* currentInstruction)
1226 {
1227     unsigned dst = currentInstruction[1].u.operand;
1228     unsigned src = currentInstruction[2].u.operand;
1229 
1230     emitLoad(src, regT1, regT0);
1231     Jump isImmediate = branch32(NotEqual, regT1, TrustedImm32(JSValue::CellTag));
1232 
1233     loadPtr(Address(regT0, JSCell::structureOffset()), regT1);
1234     set32Test8(Zero, Address(regT1, Structure::typeInfoFlagsOffset()), TrustedImm32(MasqueradesAsUndefined), regT1);
1235 
1236     Jump wasNotImmediate = jump();
1237 
1238     isImmediate.link(this);
1239 
1240     set32Compare32(NotEqual, regT1, TrustedImm32(JSValue::NullTag), regT2);
1241     set32Compare32(NotEqual, regT1, TrustedImm32(JSValue::UndefinedTag), regT1);
1242     and32(regT2, regT1);
1243 
1244     wasNotImmediate.link(this);
1245 
1246     emitStoreBool(dst, regT1);
1247 }
1248 
emit_op_resolve_with_base(Instruction * currentInstruction)1249 void JIT::emit_op_resolve_with_base(Instruction* currentInstruction)
1250 {
1251     JITStubCall stubCall(this, cti_op_resolve_with_base);
1252     stubCall.addArgument(TrustedImmPtr(&m_codeBlock->identifier(currentInstruction[3].u.operand)));
1253     stubCall.addArgument(Imm32(currentInstruction[1].u.operand));
1254     stubCall.call(currentInstruction[2].u.operand);
1255 }
1256 
emit_op_new_func_exp(Instruction * currentInstruction)1257 void JIT::emit_op_new_func_exp(Instruction* currentInstruction)
1258 {
1259     JITStubCall stubCall(this, cti_op_new_func_exp);
1260     stubCall.addArgument(TrustedImmPtr(m_codeBlock->functionExpr(currentInstruction[2].u.operand)));
1261     stubCall.call(currentInstruction[1].u.operand);
1262 }
1263 
emit_op_throw(Instruction * currentInstruction)1264 void JIT::emit_op_throw(Instruction* currentInstruction)
1265 {
1266     unsigned exception = currentInstruction[1].u.operand;
1267     JITStubCall stubCall(this, cti_op_throw);
1268     stubCall.addArgument(exception);
1269     stubCall.call();
1270 
1271 #ifndef NDEBUG
1272     // cti_op_throw always changes it's return address,
1273     // this point in the code should never be reached.
1274     breakpoint();
1275 #endif
1276 }
1277 
emit_op_get_pnames(Instruction * currentInstruction)1278 void JIT::emit_op_get_pnames(Instruction* currentInstruction)
1279 {
1280     int dst = currentInstruction[1].u.operand;
1281     int base = currentInstruction[2].u.operand;
1282     int i = currentInstruction[3].u.operand;
1283     int size = currentInstruction[4].u.operand;
1284     int breakTarget = currentInstruction[5].u.operand;
1285 
1286     JumpList isNotObject;
1287 
1288     emitLoad(base, regT1, regT0);
1289     if (!m_codeBlock->isKnownNotImmediate(base))
1290         isNotObject.append(branch32(NotEqual, regT1, TrustedImm32(JSValue::CellTag)));
1291     if (base != m_codeBlock->thisRegister() || m_codeBlock->isStrictMode()) {
1292         loadPtr(Address(regT0, JSCell::structureOffset()), regT2);
1293         isNotObject.append(branch8(NotEqual, Address(regT2, Structure::typeInfoTypeOffset()), TrustedImm32(ObjectType)));
1294     }
1295 
1296     // We could inline the case where you have a valid cache, but
1297     // this call doesn't seem to be hot.
1298     Label isObject(this);
1299     JITStubCall getPnamesStubCall(this, cti_op_get_pnames);
1300     getPnamesStubCall.addArgument(regT0);
1301     getPnamesStubCall.call(dst);
1302     load32(Address(regT0, OBJECT_OFFSETOF(JSPropertyNameIterator, m_jsStringsSize)), regT3);
1303     store32(TrustedImm32(Int32Tag), intTagFor(i));
1304     store32(TrustedImm32(0), intPayloadFor(i));
1305     store32(TrustedImm32(Int32Tag), intTagFor(size));
1306     store32(regT3, payloadFor(size));
1307     Jump end = jump();
1308 
1309     isNotObject.link(this);
1310     addJump(branch32(Equal, regT1, TrustedImm32(JSValue::NullTag)), breakTarget);
1311     addJump(branch32(Equal, regT1, TrustedImm32(JSValue::UndefinedTag)), breakTarget);
1312     JITStubCall toObjectStubCall(this, cti_to_object);
1313     toObjectStubCall.addArgument(regT1, regT0);
1314     toObjectStubCall.call(base);
1315     jump().linkTo(isObject, this);
1316 
1317     end.link(this);
1318 }
1319 
emit_op_next_pname(Instruction * currentInstruction)1320 void JIT::emit_op_next_pname(Instruction* currentInstruction)
1321 {
1322     int dst = currentInstruction[1].u.operand;
1323     int base = currentInstruction[2].u.operand;
1324     int i = currentInstruction[3].u.operand;
1325     int size = currentInstruction[4].u.operand;
1326     int it = currentInstruction[5].u.operand;
1327     int target = currentInstruction[6].u.operand;
1328 
1329     JumpList callHasProperty;
1330 
1331     Label begin(this);
1332     load32(intPayloadFor(i), regT0);
1333     Jump end = branch32(Equal, regT0, intPayloadFor(size));
1334 
1335     // Grab key @ i
1336     loadPtr(payloadFor(it), regT1);
1337     loadPtr(Address(regT1, OBJECT_OFFSETOF(JSPropertyNameIterator, m_jsStrings)), regT2);
1338     load32(BaseIndex(regT2, regT0, TimesEight), regT2);
1339     store32(TrustedImm32(JSValue::CellTag), tagFor(dst));
1340     store32(regT2, payloadFor(dst));
1341 
1342     // Increment i
1343     add32(TrustedImm32(1), regT0);
1344     store32(regT0, intPayloadFor(i));
1345 
1346     // Verify that i is valid:
1347     loadPtr(payloadFor(base), regT0);
1348 
1349     // Test base's structure
1350     loadPtr(Address(regT0, JSCell::structureOffset()), regT2);
1351     callHasProperty.append(branchPtr(NotEqual, regT2, Address(Address(regT1, OBJECT_OFFSETOF(JSPropertyNameIterator, m_cachedStructure)))));
1352 
1353     // Test base's prototype chain
1354     loadPtr(Address(Address(regT1, OBJECT_OFFSETOF(JSPropertyNameIterator, m_cachedPrototypeChain))), regT3);
1355     loadPtr(Address(regT3, OBJECT_OFFSETOF(StructureChain, m_vector)), regT3);
1356     addJump(branchTestPtr(Zero, Address(regT3)), target);
1357 
1358     Label checkPrototype(this);
1359     callHasProperty.append(branch32(Equal, Address(regT2, Structure::prototypeOffset() + OBJECT_OFFSETOF(JSValue, u.asBits.tag)), TrustedImm32(JSValue::NullTag)));
1360     loadPtr(Address(regT2, Structure::prototypeOffset() + OBJECT_OFFSETOF(JSValue, u.asBits.payload)), regT2);
1361     loadPtr(Address(regT2, JSCell::structureOffset()), regT2);
1362     callHasProperty.append(branchPtr(NotEqual, regT2, Address(regT3)));
1363     addPtr(TrustedImm32(sizeof(Structure*)), regT3);
1364     branchTestPtr(NonZero, Address(regT3)).linkTo(checkPrototype, this);
1365 
1366     // Continue loop.
1367     addJump(jump(), target);
1368 
1369     // Slow case: Ask the object if i is valid.
1370     callHasProperty.link(this);
1371     loadPtr(addressFor(dst), regT1);
1372     JITStubCall stubCall(this, cti_has_property);
1373     stubCall.addArgument(regT0);
1374     stubCall.addArgument(regT1);
1375     stubCall.call();
1376 
1377     // Test for valid key.
1378     addJump(branchTest32(NonZero, regT0), target);
1379     jump().linkTo(begin, this);
1380 
1381     // End of loop.
1382     end.link(this);
1383 }
1384 
emit_op_push_scope(Instruction * currentInstruction)1385 void JIT::emit_op_push_scope(Instruction* currentInstruction)
1386 {
1387     JITStubCall stubCall(this, cti_op_push_scope);
1388     stubCall.addArgument(currentInstruction[1].u.operand);
1389     stubCall.call(currentInstruction[1].u.operand);
1390 }
1391 
emit_op_pop_scope(Instruction *)1392 void JIT::emit_op_pop_scope(Instruction*)
1393 {
1394     JITStubCall(this, cti_op_pop_scope).call();
1395 }
1396 
emit_op_to_jsnumber(Instruction * currentInstruction)1397 void JIT::emit_op_to_jsnumber(Instruction* currentInstruction)
1398 {
1399     int dst = currentInstruction[1].u.operand;
1400     int src = currentInstruction[2].u.operand;
1401 
1402     emitLoad(src, regT1, regT0);
1403 
1404     Jump isInt32 = branch32(Equal, regT1, TrustedImm32(JSValue::Int32Tag));
1405     addSlowCase(branch32(AboveOrEqual, regT1, TrustedImm32(JSValue::EmptyValueTag)));
1406     isInt32.link(this);
1407 
1408     if (src != dst)
1409         emitStore(dst, regT1, regT0);
1410     map(m_bytecodeOffset + OPCODE_LENGTH(op_to_jsnumber), dst, regT1, regT0);
1411 }
1412 
emitSlow_op_to_jsnumber(Instruction * currentInstruction,Vector<SlowCaseEntry>::iterator & iter)1413 void JIT::emitSlow_op_to_jsnumber(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
1414 {
1415     int dst = currentInstruction[1].u.operand;
1416 
1417     linkSlowCase(iter);
1418 
1419     JITStubCall stubCall(this, cti_op_to_jsnumber);
1420     stubCall.addArgument(regT1, regT0);
1421     stubCall.call(dst);
1422 }
1423 
emit_op_push_new_scope(Instruction * currentInstruction)1424 void JIT::emit_op_push_new_scope(Instruction* currentInstruction)
1425 {
1426     JITStubCall stubCall(this, cti_op_push_new_scope);
1427     stubCall.addArgument(TrustedImmPtr(&m_codeBlock->identifier(currentInstruction[2].u.operand)));
1428     stubCall.addArgument(currentInstruction[3].u.operand);
1429     stubCall.call(currentInstruction[1].u.operand);
1430 }
1431 
emit_op_catch(Instruction * currentInstruction)1432 void JIT::emit_op_catch(Instruction* currentInstruction)
1433 {
1434     // cti_op_throw returns the callFrame for the handler.
1435     move(regT0, callFrameRegister);
1436 
1437     // Now store the exception returned by cti_op_throw.
1438     loadPtr(Address(stackPointerRegister, OBJECT_OFFSETOF(struct JITStackFrame, globalData)), regT3);
1439     load32(Address(regT3, OBJECT_OFFSETOF(JSGlobalData, exception) + OBJECT_OFFSETOF(JSValue, u.asBits.payload)), regT0);
1440     load32(Address(regT3, OBJECT_OFFSETOF(JSGlobalData, exception) + OBJECT_OFFSETOF(JSValue, u.asBits.tag)), regT1);
1441     store32(TrustedImm32(JSValue().payload()), Address(regT3, OBJECT_OFFSETOF(JSGlobalData, exception) + OBJECT_OFFSETOF(JSValue, u.asBits.payload)));
1442     store32(TrustedImm32(JSValue().tag()), Address(regT3, OBJECT_OFFSETOF(JSGlobalData, exception) + OBJECT_OFFSETOF(JSValue, u.asBits.tag)));
1443 
1444     unsigned exception = currentInstruction[1].u.operand;
1445     emitStore(exception, regT1, regT0);
1446     map(m_bytecodeOffset + OPCODE_LENGTH(op_catch), exception, regT1, regT0);
1447 }
1448 
emit_op_jmp_scopes(Instruction * currentInstruction)1449 void JIT::emit_op_jmp_scopes(Instruction* currentInstruction)
1450 {
1451     JITStubCall stubCall(this, cti_op_jmp_scopes);
1452     stubCall.addArgument(Imm32(currentInstruction[1].u.operand));
1453     stubCall.call();
1454     addJump(jump(), currentInstruction[2].u.operand);
1455 }
1456 
emit_op_switch_imm(Instruction * currentInstruction)1457 void JIT::emit_op_switch_imm(Instruction* currentInstruction)
1458 {
1459     unsigned tableIndex = currentInstruction[1].u.operand;
1460     unsigned defaultOffset = currentInstruction[2].u.operand;
1461     unsigned scrutinee = currentInstruction[3].u.operand;
1462 
1463     // create jump table for switch destinations, track this switch statement.
1464     SimpleJumpTable* jumpTable = &m_codeBlock->immediateSwitchJumpTable(tableIndex);
1465     m_switches.append(SwitchRecord(jumpTable, m_bytecodeOffset, defaultOffset, SwitchRecord::Immediate));
1466     jumpTable->ctiOffsets.grow(jumpTable->branchOffsets.size());
1467 
1468     JITStubCall stubCall(this, cti_op_switch_imm);
1469     stubCall.addArgument(scrutinee);
1470     stubCall.addArgument(Imm32(tableIndex));
1471     stubCall.call();
1472     jump(regT0);
1473 }
1474 
emit_op_switch_char(Instruction * currentInstruction)1475 void JIT::emit_op_switch_char(Instruction* currentInstruction)
1476 {
1477     unsigned tableIndex = currentInstruction[1].u.operand;
1478     unsigned defaultOffset = currentInstruction[2].u.operand;
1479     unsigned scrutinee = currentInstruction[3].u.operand;
1480 
1481     // create jump table for switch destinations, track this switch statement.
1482     SimpleJumpTable* jumpTable = &m_codeBlock->characterSwitchJumpTable(tableIndex);
1483     m_switches.append(SwitchRecord(jumpTable, m_bytecodeOffset, defaultOffset, SwitchRecord::Character));
1484     jumpTable->ctiOffsets.grow(jumpTable->branchOffsets.size());
1485 
1486     JITStubCall stubCall(this, cti_op_switch_char);
1487     stubCall.addArgument(scrutinee);
1488     stubCall.addArgument(Imm32(tableIndex));
1489     stubCall.call();
1490     jump(regT0);
1491 }
1492 
emit_op_switch_string(Instruction * currentInstruction)1493 void JIT::emit_op_switch_string(Instruction* currentInstruction)
1494 {
1495     unsigned tableIndex = currentInstruction[1].u.operand;
1496     unsigned defaultOffset = currentInstruction[2].u.operand;
1497     unsigned scrutinee = currentInstruction[3].u.operand;
1498 
1499     // create jump table for switch destinations, track this switch statement.
1500     StringJumpTable* jumpTable = &m_codeBlock->stringSwitchJumpTable(tableIndex);
1501     m_switches.append(SwitchRecord(jumpTable, m_bytecodeOffset, defaultOffset));
1502 
1503     JITStubCall stubCall(this, cti_op_switch_string);
1504     stubCall.addArgument(scrutinee);
1505     stubCall.addArgument(Imm32(tableIndex));
1506     stubCall.call();
1507     jump(regT0);
1508 }
1509 
emit_op_throw_reference_error(Instruction * currentInstruction)1510 void JIT::emit_op_throw_reference_error(Instruction* currentInstruction)
1511 {
1512     unsigned message = currentInstruction[1].u.operand;
1513 
1514     JITStubCall stubCall(this, cti_op_throw_reference_error);
1515     stubCall.addArgument(m_codeBlock->getConstant(message));
1516     stubCall.call();
1517 }
1518 
emit_op_debug(Instruction * currentInstruction)1519 void JIT::emit_op_debug(Instruction* currentInstruction)
1520 {
1521 #if ENABLE(DEBUG_WITH_BREAKPOINT)
1522     UNUSED_PARAM(currentInstruction);
1523     breakpoint();
1524 #else
1525     JITStubCall stubCall(this, cti_op_debug);
1526     stubCall.addArgument(Imm32(currentInstruction[1].u.operand));
1527     stubCall.addArgument(Imm32(currentInstruction[2].u.operand));
1528     stubCall.addArgument(Imm32(currentInstruction[3].u.operand));
1529     stubCall.call();
1530 #endif
1531 }
1532 
1533 
emit_op_enter(Instruction *)1534 void JIT::emit_op_enter(Instruction*)
1535 {
1536     // Even though JIT code doesn't use them, we initialize our constant
1537     // registers to zap stale pointers, to avoid unnecessarily prolonging
1538     // object lifetime and increasing GC pressure.
1539     for (int i = 0; i < m_codeBlock->m_numVars; ++i)
1540         emitStore(i, jsUndefined());
1541 }
1542 
emit_op_create_activation(Instruction * currentInstruction)1543 void JIT::emit_op_create_activation(Instruction* currentInstruction)
1544 {
1545     unsigned activation = currentInstruction[1].u.operand;
1546 
1547     Jump activationCreated = branch32(NotEqual, tagFor(activation), TrustedImm32(JSValue::EmptyValueTag));
1548     JITStubCall(this, cti_op_push_activation).call(activation);
1549     activationCreated.link(this);
1550 }
1551 
emit_op_create_arguments(Instruction * currentInstruction)1552 void JIT::emit_op_create_arguments(Instruction* currentInstruction)
1553 {
1554     unsigned dst = currentInstruction[1].u.operand;
1555 
1556     Jump argsCreated = branch32(NotEqual, tagFor(dst), TrustedImm32(JSValue::EmptyValueTag));
1557 
1558     if (m_codeBlock->m_numParameters == 1)
1559         JITStubCall(this, cti_op_create_arguments_no_params).call();
1560     else
1561         JITStubCall(this, cti_op_create_arguments).call();
1562 
1563     emitStore(dst, regT1, regT0);
1564     emitStore(unmodifiedArgumentsRegister(dst), regT1, regT0);
1565 
1566     argsCreated.link(this);
1567 }
1568 
emit_op_init_lazy_reg(Instruction * currentInstruction)1569 void JIT::emit_op_init_lazy_reg(Instruction* currentInstruction)
1570 {
1571     unsigned dst = currentInstruction[1].u.operand;
1572 
1573     emitStore(dst, JSValue());
1574 }
1575 
emit_op_get_callee(Instruction * currentInstruction)1576 void JIT::emit_op_get_callee(Instruction* currentInstruction)
1577 {
1578     int dst = currentInstruction[1].u.operand;
1579     emitGetFromCallFrameHeaderPtr(RegisterFile::Callee, regT0);
1580     emitStoreCell(dst, regT0);
1581 }
1582 
emit_op_create_this(Instruction * currentInstruction)1583 void JIT::emit_op_create_this(Instruction* currentInstruction)
1584 {
1585     unsigned protoRegister = currentInstruction[2].u.operand;
1586     emitLoad(protoRegister, regT1, regT0);
1587     JITStubCall stubCall(this, cti_op_create_this);
1588     stubCall.addArgument(regT1, regT0);
1589     stubCall.call(currentInstruction[1].u.operand);
1590 }
1591 
emit_op_convert_this(Instruction * currentInstruction)1592 void JIT::emit_op_convert_this(Instruction* currentInstruction)
1593 {
1594     unsigned thisRegister = currentInstruction[1].u.operand;
1595 
1596     emitLoad(thisRegister, regT1, regT0);
1597 
1598     addSlowCase(branch32(NotEqual, regT1, TrustedImm32(JSValue::CellTag)));
1599 
1600     loadPtr(Address(regT0, JSCell::structureOffset()), regT2);
1601     addSlowCase(branchTest8(NonZero, Address(regT2, Structure::typeInfoFlagsOffset()), TrustedImm32(NeedsThisConversion)));
1602 
1603     map(m_bytecodeOffset + OPCODE_LENGTH(op_convert_this), thisRegister, regT1, regT0);
1604 }
1605 
emit_op_convert_this_strict(Instruction * currentInstruction)1606 void JIT::emit_op_convert_this_strict(Instruction* currentInstruction)
1607 {
1608     unsigned thisRegister = currentInstruction[1].u.operand;
1609 
1610     emitLoad(thisRegister, regT1, regT0);
1611 
1612     Jump notNull = branch32(NotEqual, regT1, TrustedImm32(JSValue::EmptyValueTag));
1613     emitStore(thisRegister, jsNull());
1614     Jump setThis = jump();
1615     notNull.link(this);
1616     Jump isImmediate = branch32(NotEqual, regT1, TrustedImm32(JSValue::CellTag));
1617     loadPtr(Address(regT0, JSCell::structureOffset()), regT2);
1618     Jump notAnObject = branch8(NotEqual, Address(regT2, Structure::typeInfoTypeOffset()), TrustedImm32(ObjectType));
1619     addSlowCase(branchTest8(NonZero, Address(regT2, Structure::typeInfoFlagsOffset()), TrustedImm32(NeedsThisConversion)));
1620     isImmediate.link(this);
1621     notAnObject.link(this);
1622     setThis.link(this);
1623     map(m_bytecodeOffset + OPCODE_LENGTH(op_convert_this_strict), thisRegister, regT1, regT0);
1624 }
1625 
emitSlow_op_convert_this(Instruction * currentInstruction,Vector<SlowCaseEntry>::iterator & iter)1626 void JIT::emitSlow_op_convert_this(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
1627 {
1628     unsigned thisRegister = currentInstruction[1].u.operand;
1629 
1630     linkSlowCase(iter);
1631     linkSlowCase(iter);
1632 
1633     JITStubCall stubCall(this, cti_op_convert_this);
1634     stubCall.addArgument(regT1, regT0);
1635     stubCall.call(thisRegister);
1636 }
1637 
emitSlow_op_convert_this_strict(Instruction * currentInstruction,Vector<SlowCaseEntry>::iterator & iter)1638 void JIT::emitSlow_op_convert_this_strict(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
1639 {
1640     unsigned thisRegister = currentInstruction[1].u.operand;
1641 
1642     linkSlowCase(iter);
1643 
1644     JITStubCall stubCall(this, cti_op_convert_this_strict);
1645     stubCall.addArgument(regT1, regT0);
1646     stubCall.call(thisRegister);
1647 }
1648 
emit_op_profile_will_call(Instruction * currentInstruction)1649 void JIT::emit_op_profile_will_call(Instruction* currentInstruction)
1650 {
1651     peek(regT2, OBJECT_OFFSETOF(JITStackFrame, enabledProfilerReference) / sizeof(void*));
1652     Jump noProfiler = branchTestPtr(Zero, Address(regT2));
1653 
1654     JITStubCall stubCall(this, cti_op_profile_will_call);
1655     stubCall.addArgument(currentInstruction[1].u.operand);
1656     stubCall.call();
1657     noProfiler.link(this);
1658 }
1659 
emit_op_profile_did_call(Instruction * currentInstruction)1660 void JIT::emit_op_profile_did_call(Instruction* currentInstruction)
1661 {
1662     peek(regT2, OBJECT_OFFSETOF(JITStackFrame, enabledProfilerReference) / sizeof(void*));
1663     Jump noProfiler = branchTestPtr(Zero, Address(regT2));
1664 
1665     JITStubCall stubCall(this, cti_op_profile_did_call);
1666     stubCall.addArgument(currentInstruction[1].u.operand);
1667     stubCall.call();
1668     noProfiler.link(this);
1669 }
1670 
emit_op_get_arguments_length(Instruction * currentInstruction)1671 void JIT::emit_op_get_arguments_length(Instruction* currentInstruction)
1672 {
1673     int dst = currentInstruction[1].u.operand;
1674     int argumentsRegister = currentInstruction[2].u.operand;
1675     addSlowCase(branch32(NotEqual, tagFor(argumentsRegister), TrustedImm32(JSValue::EmptyValueTag)));
1676     emitGetFromCallFrameHeader32(RegisterFile::ArgumentCount, regT0);
1677     sub32(TrustedImm32(1), regT0);
1678     emitStoreInt32(dst, regT0);
1679 }
1680 
emitSlow_op_get_arguments_length(Instruction * currentInstruction,Vector<SlowCaseEntry>::iterator & iter)1681 void JIT::emitSlow_op_get_arguments_length(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
1682 {
1683     linkSlowCase(iter);
1684     int dst = currentInstruction[1].u.operand;
1685     int base = currentInstruction[2].u.operand;
1686     int ident = currentInstruction[3].u.operand;
1687 
1688     JITStubCall stubCall(this, cti_op_get_by_id_generic);
1689     stubCall.addArgument(base);
1690     stubCall.addArgument(TrustedImmPtr(&(m_codeBlock->identifier(ident))));
1691     stubCall.call(dst);
1692 }
1693 
emit_op_get_argument_by_val(Instruction * currentInstruction)1694 void JIT::emit_op_get_argument_by_val(Instruction* currentInstruction)
1695 {
1696     int dst = currentInstruction[1].u.operand;
1697     int argumentsRegister = currentInstruction[2].u.operand;
1698     int property = currentInstruction[3].u.operand;
1699     addSlowCase(branch32(NotEqual, tagFor(argumentsRegister), TrustedImm32(JSValue::EmptyValueTag)));
1700     emitLoad(property, regT1, regT2);
1701     addSlowCase(branch32(NotEqual, regT1, TrustedImm32(JSValue::Int32Tag)));
1702     add32(TrustedImm32(1), regT2);
1703     // regT2 now contains the integer index of the argument we want, including this
1704     emitGetFromCallFrameHeader32(RegisterFile::ArgumentCount, regT3);
1705     addSlowCase(branch32(AboveOrEqual, regT2, regT3));
1706 
1707     Jump skipOutofLineParams;
1708     int numArgs = m_codeBlock->m_numParameters;
1709     if (numArgs) {
1710         Jump notInInPlaceArgs = branch32(AboveOrEqual, regT2, Imm32(numArgs));
1711         addPtr(Imm32(static_cast<unsigned>(-(RegisterFile::CallFrameHeaderSize + numArgs) * sizeof(Register))), callFrameRegister, regT1);
1712         loadPtr(BaseIndex(regT1, regT2, TimesEight, OBJECT_OFFSETOF(JSValue, u.asBits.payload)), regT0);
1713         loadPtr(BaseIndex(regT1, regT2, TimesEight, OBJECT_OFFSETOF(JSValue, u.asBits.tag)), regT1);
1714         skipOutofLineParams = jump();
1715         notInInPlaceArgs.link(this);
1716     }
1717 
1718     addPtr(Imm32(static_cast<unsigned>(-(RegisterFile::CallFrameHeaderSize + numArgs) * sizeof(Register))), callFrameRegister, regT1);
1719     mul32(TrustedImm32(sizeof(Register)), regT3, regT3);
1720     subPtr(regT3, regT1);
1721     loadPtr(BaseIndex(regT1, regT2, TimesEight, OBJECT_OFFSETOF(JSValue, u.asBits.payload)), regT0);
1722     loadPtr(BaseIndex(regT1, regT2, TimesEight, OBJECT_OFFSETOF(JSValue, u.asBits.tag)), regT1);
1723     if (numArgs)
1724         skipOutofLineParams.link(this);
1725     emitStore(dst, regT1, regT0);
1726 }
1727 
emitSlow_op_get_argument_by_val(Instruction * currentInstruction,Vector<SlowCaseEntry>::iterator & iter)1728 void JIT::emitSlow_op_get_argument_by_val(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
1729 {
1730     unsigned dst = currentInstruction[1].u.operand;
1731     unsigned arguments = currentInstruction[2].u.operand;
1732     unsigned property = currentInstruction[3].u.operand;
1733 
1734     linkSlowCase(iter);
1735     Jump skipArgumentsCreation = jump();
1736 
1737     linkSlowCase(iter);
1738     linkSlowCase(iter);
1739     if (m_codeBlock->m_numParameters == 1)
1740         JITStubCall(this, cti_op_create_arguments_no_params).call();
1741     else
1742         JITStubCall(this, cti_op_create_arguments).call();
1743 
1744     emitStore(arguments, regT1, regT0);
1745     emitStore(unmodifiedArgumentsRegister(arguments), regT1, regT0);
1746 
1747     skipArgumentsCreation.link(this);
1748     JITStubCall stubCall(this, cti_op_get_by_val);
1749     stubCall.addArgument(arguments);
1750     stubCall.addArgument(property);
1751     stubCall.call(dst);
1752 }
1753 
1754 #if ENABLE(JIT_USE_SOFT_MODULO)
softModulo()1755 void JIT::softModulo()
1756 {
1757     push(regT1);
1758     push(regT3);
1759     move(regT2, regT3);
1760     move(regT0, regT2);
1761     move(TrustedImm32(0), regT1);
1762 
1763     // Check for negative result reminder
1764     Jump positiveRegT3 = branch32(GreaterThanOrEqual, regT3, TrustedImm32(0));
1765     neg32(regT3);
1766     xor32(TrustedImm32(1), regT1);
1767     positiveRegT3.link(this);
1768 
1769     Jump positiveRegT2 = branch32(GreaterThanOrEqual, regT2, TrustedImm32(0));
1770     neg32(regT2);
1771     xor32(TrustedImm32(2), regT1);
1772     positiveRegT2.link(this);
1773 
1774     // Save the condition for negative reminder
1775     push(regT1);
1776 
1777     Jump exitBranch = branch32(LessThan, regT2, regT3);
1778 
1779     // Power of two fast case
1780     move(regT3, regT0);
1781     sub32(TrustedImm32(1), regT0);
1782     Jump powerOfTwo = branchTest32(NotEqual, regT0, regT3);
1783     and32(regT0, regT2);
1784     powerOfTwo.link(this);
1785 
1786     and32(regT3, regT0);
1787 
1788     Jump exitBranch2 = branchTest32(Zero, regT0);
1789 
1790     countLeadingZeros32(regT2, regT0);
1791     countLeadingZeros32(regT3, regT1);
1792     sub32(regT0, regT1);
1793 
1794     Jump useFullTable = branch32(Equal, regT1, TrustedImm32(31));
1795 
1796     neg32(regT1);
1797     add32(TrustedImm32(31), regT1);
1798 
1799     int elementSizeByShift = -1;
1800 #if CPU(ARM)
1801     elementSizeByShift = 3;
1802 #else
1803 #error "JIT_OPTIMIZE_MOD not yet supported on this platform."
1804 #endif
1805     relativeTableJump(regT1, elementSizeByShift);
1806 
1807     useFullTable.link(this);
1808     // Modulo table
1809     for (int i = 31; i > 0; --i) {
1810 #if CPU(ARM_TRADITIONAL)
1811         m_assembler.cmp_r(regT2, m_assembler.lsl(regT3, i));
1812         m_assembler.sub_r(regT2, regT2, m_assembler.lsl(regT3, i), ARMAssembler::CS);
1813 #elif CPU(ARM_THUMB2)
1814         ShiftTypeAndAmount shift(SRType_LSL, i);
1815         m_assembler.sub_S(regT1, regT2, regT3, shift);
1816         m_assembler.it(ARMv7Assembler::ConditionCS);
1817         m_assembler.mov(regT2, regT1);
1818 #else
1819 #error "JIT_OPTIMIZE_MOD not yet supported on this platform."
1820 #endif
1821     }
1822 
1823     Jump lower = branch32(Below, regT2, regT3);
1824     sub32(regT3, regT2);
1825     lower.link(this);
1826 
1827     exitBranch.link(this);
1828     exitBranch2.link(this);
1829 
1830     // Check for negative reminder
1831     pop(regT1);
1832     Jump positiveResult = branch32(Equal, regT1, TrustedImm32(0));
1833     neg32(regT2);
1834     positiveResult.link(this);
1835 
1836     move(regT2, regT0);
1837 
1838     pop(regT3);
1839     pop(regT1);
1840     ret();
1841 }
1842 #endif // ENABLE(JIT_USE_SOFT_MODULO)
1843 
1844 } // namespace JSC
1845 
1846 #endif // USE(JSVALUE32_64)
1847 #endif // ENABLE(JIT)
1848