| /* |
| * Copyright (C) 2012 Apple Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY |
| * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR |
| * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY |
| * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include "config.h" |
| #include "LowLevelInterpreter.h" |
| |
| #if ENABLE(LLINT) |
| |
| #include "LLIntOfflineAsmConfig.h" |
| #include <wtf/InlineASM.h> |
| |
| #if ENABLE(LLINT_C_LOOP) |
| #include "CodeBlock.h" |
| #include "LLIntCLoop.h" |
| #include "LLIntSlowPaths.h" |
| #include "VMInspector.h" |
| #include <wtf/Assertions.h> |
| #include <wtf/CheckedArithmetic.h> |
| #include <wtf/MathExtras.h> |
| |
| using namespace JSC::LLInt; |
| |
| // LLInt C Loop opcodes |
| // ==================== |
| // In the implementation of the C loop, the LLint trampoline glue functions |
| // (e.g. llint_program_prologue, llint_eval_prologue, etc) are addressed as |
| // if they are bytecode handlers. That means the names of the trampoline |
| // functions will be added to the OpcodeID list via the |
| // FOR_EACH_LLINT_OPCODE_EXTENSION() macro that FOR_EACH_OPCODE_ID() |
| // includes. |
| // |
| // In addition, some JIT trampoline functions which are needed by LLInt |
| // (e.g. getHostCallReturnValue, ctiOpThrowNotCaught) are also added as |
| // bytecodes, and the CLoop will provide bytecode handlers for them. |
| // |
| // In the CLoop, we can only dispatch indirectly to these bytecodes |
| // (including the LLInt and JIT extensions). All other dispatches |
| // (i.e. goto's) must be to a known label (i.e. local / global labels). |
| |
| |
| // How are the opcodes named? |
| // ========================== |
| // Here is a table to show examples of how each of the manifestation of the |
| // opcodes are named: |
| // |
| // Type: Opcode Trampoline Glue |
| // ====== =============== |
| // [In the llint .asm files] |
| // llint labels: llint_op_enter llint_program_prologue |
| // |
| // OpcodeID: op_enter llint_program |
| // [in Opcode.h] [in LLIntOpcode.h] |
| // |
| // When using a switch statement dispatch in the CLoop, each "opcode" is |
| // a case statement: |
| // Opcode: case op_enter: case llint_program_prologue: |
| // |
| // When using a computed goto dispatch in the CLoop, each opcode is a label: |
| // Opcode: op_enter: llint_program_prologue: |
| |
| |
| //============================================================================ |
| // Define the opcode dispatch mechanism when using the C loop: |
| // |
| |
| // These are for building a C Loop interpreter: |
| #define OFFLINE_ASM_BEGIN |
| #define OFFLINE_ASM_END |
| |
| |
| #define OFFLINE_ASM_OPCODE_LABEL(opcode) DEFINE_OPCODE(opcode) |
| #if ENABLE(COMPUTED_GOTO_OPCODES) |
| #define OFFLINE_ASM_GLUE_LABEL(label) label: |
| #else |
| #define OFFLINE_ASM_GLUE_LABEL(label) case label: label: |
| #endif |
| |
| #define OFFLINE_ASM_LOCAL_LABEL(label) label: |
| |
| |
| //============================================================================ |
| // Some utilities: |
| // |
| |
| namespace JSC { |
| namespace LLInt { |
| |
| #if USE(JSVALUE32_64) |
| static double Ints2Double(uint32_t lo, uint32_t hi) |
| { |
| union { |
| double dval; |
| uint64_t ival64; |
| } u; |
| u.ival64 = (static_cast<uint64_t>(hi) << 32) | lo; |
| return u.dval; |
| } |
| |
| static void Double2Ints(double input, intptr_t& lo, intptr_t& hi) |
| { |
| union { |
| double dval; |
| uint64_t ival64; |
| } u; |
| u.dval = input; |
| hi = static_cast<intptr_t>(u.ival64 >> 32); |
| lo = static_cast<intptr_t>(u.ival64); |
| } |
| #endif // USE(JSVALUE32_64) |
| |
| } // namespace LLint |
| |
| |
| //============================================================================ |
| // CLoopRegister is the storage for an emulated CPU register. |
| // It defines the policy of how ints smaller than intptr_t are packed into the |
| // pseudo register, as well as hides endianness differences. |
| |
| struct CLoopRegister { |
| union { |
| intptr_t i; |
| uintptr_t u; |
| #if USE(JSVALUE64) |
| #if CPU(BIG_ENDIAN) |
| struct { |
| int32_t i32padding; |
| int32_t i32; |
| }; |
| struct { |
| uint32_t u32padding; |
| uint32_t u32; |
| }; |
| struct { |
| int8_t i8padding[7]; |
| int8_t i8; |
| }; |
| struct { |
| uint8_t u8padding[7]; |
| uint8_t u8; |
| }; |
| #else // !CPU(BIG_ENDIAN) |
| struct { |
| int32_t i32; |
| int32_t i32padding; |
| }; |
| struct { |
| uint32_t u32; |
| uint32_t u32padding; |
| }; |
| struct { |
| int8_t i8; |
| int8_t i8padding[7]; |
| }; |
| struct { |
| uint8_t u8; |
| uint8_t u8padding[7]; |
| }; |
| #endif // !CPU(BIG_ENDIAN) |
| #else // !USE(JSVALUE64) |
| int32_t i32; |
| uint32_t u32; |
| |
| #if CPU(BIG_ENDIAN) |
| struct { |
| int8_t i8padding[3]; |
| int8_t i8; |
| }; |
| struct { |
| uint8_t u8padding[3]; |
| uint8_t u8; |
| }; |
| |
| #else // !CPU(BIG_ENDIAN) |
| struct { |
| int8_t i8; |
| int8_t i8padding[3]; |
| }; |
| struct { |
| uint8_t u8; |
| uint8_t u8padding[3]; |
| }; |
| #endif // !CPU(BIG_ENDIAN) |
| #endif // !USE(JSVALUE64) |
| |
| int8_t* i8p; |
| void* vp; |
| ExecState* execState; |
| void* instruction; |
| NativeFunction nativeFunc; |
| #if USE(JSVALUE64) |
| int64_t i64; |
| uint64_t u64; |
| EncodedJSValue encodedJSValue; |
| double castToDouble; |
| #endif |
| Opcode opcode; |
| }; |
| |
| #if USE(JSVALUE64) |
| inline void clearHighWord() { i32padding = 0; } |
| #else |
| inline void clearHighWord() { } |
| #endif |
| }; |
| |
| //============================================================================ |
| // The llint C++ interpreter loop: |
| // |
| |
| JSValue CLoop::execute(CallFrame* callFrame, OpcodeID bootstrapOpcodeId, |
| bool isInitializationPass) |
| { |
| #define CAST reinterpret_cast |
| #define SIGN_BIT32(x) ((x) & 0x80000000) |
| |
| // One-time initialization of our address tables. We have to put this code |
| // here because our labels are only in scope inside this function. The |
| // caller (or one of its ancestors) is responsible for ensuring that this |
| // is only called once during the initialization of the VM before threads |
| // are at play. |
| if (UNLIKELY(isInitializationPass)) { |
| #if ENABLE(COMPUTED_GOTO_OPCODES) |
| Opcode* opcodeMap = LLInt::opcodeMap(); |
| #define OPCODE_ENTRY(__opcode, length) \ |
| opcodeMap[__opcode] = bitwise_cast<void*>(&&__opcode); |
| FOR_EACH_OPCODE_ID(OPCODE_ENTRY) |
| #undef OPCODE_ENTRY |
| |
| #define LLINT_OPCODE_ENTRY(__opcode, length) \ |
| opcodeMap[__opcode] = bitwise_cast<void*>(&&__opcode); |
| |
| FOR_EACH_LLINT_NATIVE_HELPER(LLINT_OPCODE_ENTRY) |
| #undef LLINT_OPCODE_ENTRY |
| #endif |
| // Note: we can only set the exceptionInstructions after we have |
| // initialized the opcodeMap above. This is because getCodePtr() |
| // can depend on the opcodeMap. |
| Instruction* exceptionInstructions = LLInt::exceptionInstructions(); |
| for (int i = 0; i < maxOpcodeLength + 1; ++i) |
| exceptionInstructions[i].u.pointer = |
| LLInt::getCodePtr(llint_throw_from_slow_path_trampoline); |
| |
| return JSValue(); |
| } |
| |
| ASSERT(callFrame->globalData().topCallFrame == callFrame); |
| |
| // Define the pseudo registers used by the LLINT C Loop backend: |
| ASSERT(sizeof(CLoopRegister) == sizeof(intptr_t)); |
| |
| union CLoopDoubleRegister { |
| double d; |
| #if USE(JSVALUE64) |
| int64_t castToInt64; |
| #endif |
| }; |
| |
| // The CLoop llint backend is initially based on the ARMv7 backend, and |
| // then further enhanced with a few instructions from the x86 backend to |
| // support building for X64 targets. Hence, the shape of the generated |
| // code and the usage convention of registers will look a lot like the |
| // ARMv7 backend's. |
| // |
| // For example, on a 32-bit build: |
| // 1. Outgoing args will be set up as follows: |
| // arg1 in t0 (r0 on ARM) |
| // arg2 in t1 (r1 on ARM) |
| // 2. 32 bit return values will be in t0 (r0 on ARM). |
| // 3. 64 bit return values (e.g. doubles) will be in t0,t1 (r0,r1 on ARM). |
| // |
| // But instead of naming these simulator registers based on their ARM |
| // counterparts, we'll name them based on their original llint asm names. |
| // This will make it easier to correlate the generated code with the |
| // original llint asm code. |
| // |
| // On a 64-bit build, it more like x64 in that the registers are 64 bit. |
| // Hence: |
| // 1. Outgoing args are still the same: arg1 in t0, arg2 in t1, etc. |
| // 2. 32 bit result values will be in the low 32-bit of t0. |
| // 3. 64 bit result values will be in t0. |
| |
| CLoopRegister t0, t1, t2, t3; |
| #if USE(JSVALUE64) |
| CLoopRegister rBasePC, tagTypeNumber, tagMask; |
| #endif |
| CLoopRegister rRetVPC; |
| CLoopDoubleRegister d0, d1; |
| |
| #if COMPILER(MSVC) |
| // Keep the compiler happy. We don't really need this, but the compiler |
| // will complain. This makes the warning go away. |
| t0.i = 0; |
| t1.i = 0; |
| #endif |
| |
| // Instantiate the pseudo JIT stack frame used by the LLINT C Loop backend: |
| JITStackFrame jitStackFrame; |
| |
| // The llint expects the native stack pointer, sp, to be pointing to the |
| // jitStackFrame (which is the simulation of the native stack frame): |
| JITStackFrame* const sp = &jitStackFrame; |
| sp->globalData = &callFrame->globalData(); |
| |
| // Set up an alias for the globalData ptr in the JITStackFrame: |
| JSGlobalData* &globalData = sp->globalData; |
| |
| CodeBlock* codeBlock = callFrame->codeBlock(); |
| Instruction* vPC; |
| |
| // rPC is an alias for vPC. Set up the alias: |
| CLoopRegister& rPC = *CAST<CLoopRegister*>(&vPC); |
| |
| #if USE(JSVALUE32_64) |
| vPC = codeBlock->instructions().begin(); |
| #else // USE(JSVALUE64) |
| vPC = 0; |
| rBasePC.vp = codeBlock->instructions().begin(); |
| |
| // For the ASM llint, JITStubs takes care of this initialization. We do |
| // it explicitly here for the C loop: |
| tagTypeNumber.i = 0xFFFF000000000000; |
| tagMask.i = 0xFFFF000000000002; |
| #endif // USE(JSVALUE64) |
| |
| // cfr is an alias for callFrame. Set up this alias: |
| CLoopRegister& cfr = *CAST<CLoopRegister*>(&callFrame); |
| |
| // Simulate a native return PC which should never be used: |
| rRetVPC.i = 0xbbadbeef; |
| |
| // Interpreter variables for value passing between opcodes and/or helpers: |
| NativeFunction nativeFunc = 0; |
| JSValue functionReturnValue; |
| Opcode opcode; |
| |
| opcode = LLInt::getOpcode(bootstrapOpcodeId); |
| |
| #if ENABLE(OPCODE_STATS) |
| #define RECORD_OPCODE_STATS(__opcode) \ |
| OpcodeStats::recordInstruction(__opcode) |
| #else |
| #define RECORD_OPCODE_STATS(__opcode) |
| #endif |
| |
| #if USE(JSVALUE32_64) |
| #define FETCH_OPCODE() vPC->u.opcode |
| #else // USE(JSVALUE64) |
| #define FETCH_OPCODE() *bitwise_cast<Opcode*>(rBasePC.i8p + rPC.i * 8) |
| #endif // USE(JSVALUE64) |
| |
| #define NEXT_INSTRUCTION() \ |
| do { \ |
| opcode = FETCH_OPCODE(); \ |
| DISPATCH_OPCODE(); \ |
| } while (false) |
| |
| #if ENABLE(COMPUTED_GOTO_OPCODES) |
| |
| //======================================================================== |
| // Loop dispatch mechanism using computed goto statements: |
| |
| #define DISPATCH_OPCODE() goto *opcode |
| |
| #define DEFINE_OPCODE(__opcode) \ |
| __opcode: \ |
| RECORD_OPCODE_STATS(__opcode); |
| |
| // Dispatch to the current PC's bytecode: |
| DISPATCH_OPCODE(); |
| |
| #else // !ENABLE(COMPUTED_GOTO_OPCODES) |
| //======================================================================== |
| // Loop dispatch mechanism using a C switch statement: |
| |
| #define DISPATCH_OPCODE() goto dispatchOpcode |
| |
| #define DEFINE_OPCODE(__opcode) \ |
| case __opcode: \ |
| __opcode: \ |
| RECORD_OPCODE_STATS(__opcode); |
| |
| // Dispatch to the current PC's bytecode: |
| dispatchOpcode: |
| switch (opcode) |
| |
| #endif // !ENABLE(COMPUTED_GOTO_OPCODES) |
| |
| //======================================================================== |
| // Bytecode handlers: |
| { |
| // This is the file generated by offlineasm, which contains all of the |
| // bytecode handlers for the interpreter, as compiled from |
| // LowLevelInterpreter.asm and its peers. |
| #include "LLIntAssembly.h" |
| |
| // In the ASM llint, getHostCallReturnValue() is a piece of glue |
| // function provided by the JIT (see dfg/DFGOperations.cpp). |
| // We simulate it here with a pseduo-opcode handler. |
| OFFLINE_ASM_GLUE_LABEL(getHostCallReturnValue) |
| { |
| // The ASM part pops the frame: |
| callFrame = callFrame->callerFrame(); |
| |
| // The part in getHostCallReturnValueWithExecState(): |
| JSValue result = globalData->hostCallReturnValue; |
| #if USE(JSVALUE32_64) |
| t1.i = result.tag(); |
| t0.i = result.payload(); |
| #else |
| t0.encodedJSValue = JSValue::encode(result); |
| #endif |
| goto doReturnHelper; |
| } |
| |
| OFFLINE_ASM_GLUE_LABEL(ctiOpThrowNotCaught) |
| { |
| return globalData->exception; |
| } |
| |
| #if !ENABLE(COMPUTED_GOTO_OPCODES) |
| default: |
| ASSERT(false); |
| #endif |
| |
| } // END bytecode handler cases. |
| |
| //======================================================================== |
| // Bytecode helpers: |
| |
| doReturnHelper: { |
| ASSERT(!!callFrame); |
| if (callFrame->hasHostCallFrameFlag()) { |
| #if USE(JSVALUE32_64) |
| return JSValue(t1.i, t0.i); // returning JSValue(tag, payload); |
| #else |
| return JSValue::decode(t0.encodedJSValue); |
| #endif |
| } |
| |
| // The normal ASM llint call implementation returns to the caller as |
| // recorded in rRetVPC, and the caller would fetch the return address |
| // from ArgumentCount.tag() (see the dispatchAfterCall() macro used in |
| // the callTargetFunction() macro in the llint asm files). |
| // |
| // For the C loop, we don't have the JIT stub to this work for us. |
| // So, we need to implement the equivalent of dispatchAfterCall() here |
| // before dispatching to the PC. |
| |
| vPC = callFrame->currentVPC(); |
| |
| #if USE(JSVALUE64) |
| // Based on LowLevelInterpreter64.asm's dispatchAfterCall(): |
| |
| // When returning from a native trampoline call, unlike the assembly |
| // LLInt, we can't simply return to the caller. In our case, we grab |
| // the caller's VPC and resume execution there. However, the caller's |
| // VPC returned by callFrame->currentVPC() is in the form of the real |
| // address of the target bytecode, but the 64-bit llint expects the |
| // VPC to be a bytecode offset. Hence, we need to map it back to a |
| // bytecode offset before we dispatch via the usual dispatch mechanism |
| // i.e. NEXT_INSTRUCTION(): |
| |
| codeBlock = callFrame->codeBlock(); |
| ASSERT(codeBlock); |
| rPC.vp = callFrame->currentVPC(); |
| rPC.i = rPC.i8p - reinterpret_cast<int8_t*>(codeBlock->instructions().begin()); |
| rPC.i >>= 3; |
| |
| rBasePC.vp = codeBlock->instructions().begin(); |
| #endif // USE(JSVALUE64) |
| |
| NEXT_INSTRUCTION(); |
| |
| } // END doReturnHelper. |
| |
| |
| // Keep the compiler happy so that it doesn't complain about unused |
| // labels for the LLInt trampoline glue. The labels are automatically |
| // emitted by label macros above, and some of them are referenced by |
| // the llint generated code. Since we can't tell ahead of time which |
| // will be referenced and which will be not, we'll just passify the |
| // compiler on all such labels: |
| #define LLINT_OPCODE_ENTRY(__opcode, length) \ |
| UNUSED_LABEL(__opcode); |
| FOR_EACH_OPCODE_ID(LLINT_OPCODE_ENTRY); |
| #undef LLINT_OPCODE_ENTRY |
| |
| |
| #undef NEXT_INSTRUCTION |
| #undef DEFINE_OPCODE |
| #undef CHECK_FOR_TIMEOUT |
| #undef CAST |
| #undef SIGN_BIT32 |
| |
| } // Interpreter::llintCLoopExecute() |
| |
| } // namespace JSC |
| |
| #else // !ENABLE(LLINT_C_LOOP) |
| |
| //============================================================================ |
| // Define the opcode dispatch mechanism when using an ASM loop: |
| // |
| |
| // These are for building an interpreter from generated assembly code: |
| #define OFFLINE_ASM_BEGIN asm ( |
| #define OFFLINE_ASM_END ); |
| |
| #define OFFLINE_ASM_OPCODE_LABEL(__opcode) OFFLINE_ASM_GLOBAL_LABEL(llint_##__opcode) |
| #define OFFLINE_ASM_GLUE_LABEL(__opcode) OFFLINE_ASM_GLOBAL_LABEL(__opcode) |
| |
| #if CPU(ARM_THUMB2) |
| #define OFFLINE_ASM_GLOBAL_LABEL(label) \ |
| ".globl " SYMBOL_STRING(label) "\n" \ |
| HIDE_SYMBOL(label) "\n" \ |
| ".thumb\n" \ |
| ".thumb_func " THUMB_FUNC_PARAM(label) "\n" \ |
| SYMBOL_STRING(label) ":\n" |
| #else |
| #define OFFLINE_ASM_GLOBAL_LABEL(label) \ |
| ".globl " SYMBOL_STRING(label) "\n" \ |
| HIDE_SYMBOL(label) "\n" \ |
| SYMBOL_STRING(label) ":\n" |
| #endif |
| |
| #define OFFLINE_ASM_LOCAL_LABEL(label) LOCAL_LABEL_STRING(label) ":\n" |
| |
| // This is a file generated by offlineasm, which contains all of the assembly code |
| // for the interpreter, as compiled from LowLevelInterpreter.asm. |
| #include "LLIntAssembly.h" |
| |
| #endif // !ENABLE(LLINT_C_LOOP) |
| |
| #endif // ENABLE(LLINT) |
