// Copyright 2010 the V8 project authors. All rights reserved. // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are // met: // // * Redistributions of source code must retain the above copyright // notice, this list of conditions and the following disclaimer. // * 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. // * Neither the name of Google Inc. nor the names of its // contributors may be used to endorse or promote products derived // from this software without specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS // "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 THE COPYRIGHT // OWNER 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. // A Disassembler object is used to disassemble a block of code instruction by // instruction. The default implementation of the NameConverter object can be // overriden to modify register names or to do symbol lookup on addresses. // // The example below will disassemble a block of code and print it to stdout. // // NameConverter converter; // Disassembler d(converter); // for (byte* pc = begin; pc < end;) { // v8::internal::EmbeddedVector buffer; // byte* prev_pc = pc; // pc += d.InstructionDecode(buffer, pc); // printf("%p %08x %s\n", // prev_pc, *reinterpret_cast(prev_pc), buffer); // } // // The Disassembler class also has a convenience method to disassemble a block // of code into a FILE*, meaning that the above functionality could also be // achieved by just calling Disassembler::Disassemble(stdout, begin, end); #include #include #include #include #ifndef WIN32 #include #endif #include "v8.h" #include "constants-arm.h" #include "disasm.h" #include "macro-assembler.h" #include "platform.h" namespace assembler { namespace arm { namespace v8i = v8::internal; //------------------------------------------------------------------------------ // Decoder decodes and disassembles instructions into an output buffer. // It uses the converter to convert register names and call destinations into // more informative description. class Decoder { public: Decoder(const disasm::NameConverter& converter, v8::internal::Vector out_buffer) : converter_(converter), out_buffer_(out_buffer), out_buffer_pos_(0) { out_buffer_[out_buffer_pos_] = '\0'; } ~Decoder() {} // Writes one disassembled instruction into 'buffer' (0-terminated). // Returns the length of the disassembled machine instruction in bytes. int InstructionDecode(byte* instruction); private: // Bottleneck functions to print into the out_buffer. void PrintChar(const char ch); void Print(const char* str); // Printing of common values. void PrintRegister(int reg); void PrintSRegister(int reg); void PrintDRegister(int reg); int FormatVFPRegister(Instr* instr, const char* format); int FormatVFPinstruction(Instr* instr, const char* format); void PrintCondition(Instr* instr); void PrintShiftRm(Instr* instr); void PrintShiftImm(Instr* instr); void PrintPU(Instr* instr); void PrintSoftwareInterrupt(SoftwareInterruptCodes swi); // Handle formatting of instructions and their options. int FormatRegister(Instr* instr, const char* option); int FormatOption(Instr* instr, const char* option); void Format(Instr* instr, const char* format); void Unknown(Instr* instr); // Each of these functions decodes one particular instruction type, a 3-bit // field in the instruction encoding. // Types 0 and 1 are combined as they are largely the same except for the way // they interpret the shifter operand. void DecodeType01(Instr* instr); void DecodeType2(Instr* instr); void DecodeType3(Instr* instr); void DecodeType4(Instr* instr); void DecodeType5(Instr* instr); void DecodeType6(Instr* instr); void DecodeType7(Instr* instr); void DecodeUnconditional(Instr* instr); // For VFP support. void DecodeTypeVFP(Instr* instr); void DecodeType6CoprocessorIns(Instr* instr); void DecodeVMOVBetweenCoreAndSinglePrecisionRegisters(Instr* instr); void DecodeVCMP(Instr* instr); void DecodeVCVTBetweenDoubleAndSingle(Instr* instr); void DecodeVCVTBetweenFloatingPointAndInteger(Instr* instr); const disasm::NameConverter& converter_; v8::internal::Vector out_buffer_; int out_buffer_pos_; DISALLOW_COPY_AND_ASSIGN(Decoder); }; // Support for assertions in the Decoder formatting functions. #define STRING_STARTS_WITH(string, compare_string) \ (strncmp(string, compare_string, strlen(compare_string)) == 0) // Append the ch to the output buffer. void Decoder::PrintChar(const char ch) { out_buffer_[out_buffer_pos_++] = ch; } // Append the str to the output buffer. void Decoder::Print(const char* str) { char cur = *str++; while (cur != '\0' && (out_buffer_pos_ < (out_buffer_.length() - 1))) { PrintChar(cur); cur = *str++; } out_buffer_[out_buffer_pos_] = 0; } // These condition names are defined in a way to match the native disassembler // formatting. See for example the command "objdump -d ". static const char* cond_names[max_condition] = { "eq", "ne", "cs" , "cc" , "mi" , "pl" , "vs" , "vc" , "hi", "ls", "ge", "lt", "gt", "le", "", "invalid", }; // Print the condition guarding the instruction. void Decoder::PrintCondition(Instr* instr) { Print(cond_names[instr->ConditionField()]); } // Print the register name according to the active name converter. void Decoder::PrintRegister(int reg) { Print(converter_.NameOfCPURegister(reg)); } // Print the VFP S register name according to the active name converter. void Decoder::PrintSRegister(int reg) { Print(assembler::arm::VFPRegisters::Name(reg, false)); } // Print the VFP D register name according to the active name converter. void Decoder::PrintDRegister(int reg) { Print(assembler::arm::VFPRegisters::Name(reg, true)); } // These shift names are defined in a way to match the native disassembler // formatting. See for example the command "objdump -d ". static const char* shift_names[max_shift] = { "lsl", "lsr", "asr", "ror" }; // Print the register shift operands for the instruction. Generally used for // data processing instructions. void Decoder::PrintShiftRm(Instr* instr) { Shift shift = instr->ShiftField(); int shift_amount = instr->ShiftAmountField(); int rm = instr->RmField(); PrintRegister(rm); if ((instr->RegShiftField() == 0) && (shift == LSL) && (shift_amount == 0)) { // Special case for using rm only. return; } if (instr->RegShiftField() == 0) { // by immediate if ((shift == ROR) && (shift_amount == 0)) { Print(", RRX"); return; } else if (((shift == LSR) || (shift == ASR)) && (shift_amount == 0)) { shift_amount = 32; } out_buffer_pos_ += v8i::OS::SNPrintF(out_buffer_ + out_buffer_pos_, ", %s #%d", shift_names[shift], shift_amount); } else { // by register int rs = instr->RsField(); out_buffer_pos_ += v8i::OS::SNPrintF(out_buffer_ + out_buffer_pos_, ", %s ", shift_names[shift]); PrintRegister(rs); } } // Print the immediate operand for the instruction. Generally used for data // processing instructions. void Decoder::PrintShiftImm(Instr* instr) { int rotate = instr->RotateField() * 2; int immed8 = instr->Immed8Field(); int imm = (immed8 >> rotate) | (immed8 << (32 - rotate)); out_buffer_pos_ += v8i::OS::SNPrintF(out_buffer_ + out_buffer_pos_, "#%d", imm); } // Print PU formatting to reduce complexity of FormatOption. void Decoder::PrintPU(Instr* instr) { switch (instr->PUField()) { case 0: { Print("da"); break; } case 1: { Print("ia"); break; } case 2: { Print("db"); break; } case 3: { Print("ib"); break; } default: { UNREACHABLE(); break; } } } // Print SoftwareInterrupt codes. Factoring this out reduces the complexity of // the FormatOption method. void Decoder::PrintSoftwareInterrupt(SoftwareInterruptCodes swi) { switch (swi) { case call_rt_redirected: Print("call_rt_redirected"); return; case break_point: Print("break_point"); return; default: out_buffer_pos_ += v8i::OS::SNPrintF(out_buffer_ + out_buffer_pos_, "%d", swi); return; } } // Handle all register based formatting in this function to reduce the // complexity of FormatOption. int Decoder::FormatRegister(Instr* instr, const char* format) { ASSERT(format[0] == 'r'); if (format[1] == 'n') { // 'rn: Rn register int reg = instr->RnField(); PrintRegister(reg); return 2; } else if (format[1] == 'd') { // 'rd: Rd register int reg = instr->RdField(); PrintRegister(reg); return 2; } else if (format[1] == 's') { // 'rs: Rs register int reg = instr->RsField(); PrintRegister(reg); return 2; } else if (format[1] == 'm') { // 'rm: Rm register int reg = instr->RmField(); PrintRegister(reg); return 2; } else if (format[1] == 't') { // 'rt: Rt register int reg = instr->RtField(); PrintRegister(reg); return 2; } else if (format[1] == 'l') { // 'rlist: register list for load and store multiple instructions ASSERT(STRING_STARTS_WITH(format, "rlist")); int rlist = instr->RlistField(); int reg = 0; Print("{"); // Print register list in ascending order, by scanning the bit mask. while (rlist != 0) { if ((rlist & 1) != 0) { PrintRegister(reg); if ((rlist >> 1) != 0) { Print(", "); } } reg++; rlist >>= 1; } Print("}"); return 5; } UNREACHABLE(); return -1; } // Handle all VFP register based formatting in this function to reduce the // complexity of FormatOption. int Decoder::FormatVFPRegister(Instr* instr, const char* format) { ASSERT((format[0] == 'S') || (format[0] == 'D')); if (format[1] == 'n') { int reg = instr->VnField(); if (format[0] == 'S') PrintSRegister(((reg << 1) | instr->NField())); if (format[0] == 'D') PrintDRegister(reg); return 2; } else if (format[1] == 'm') { int reg = instr->VmField(); if (format[0] == 'S') PrintSRegister(((reg << 1) | instr->MField())); if (format[0] == 'D') PrintDRegister(reg); return 2; } else if (format[1] == 'd') { int reg = instr->VdField(); if (format[0] == 'S') PrintSRegister(((reg << 1) | instr->DField())); if (format[0] == 'D') PrintDRegister(reg); return 2; } UNREACHABLE(); return -1; } int Decoder::FormatVFPinstruction(Instr* instr, const char* format) { Print(format); return 0; } // FormatOption takes a formatting string and interprets it based on // the current instructions. The format string points to the first // character of the option string (the option escape has already been // consumed by the caller.) FormatOption returns the number of // characters that were consumed from the formatting string. int Decoder::FormatOption(Instr* instr, const char* format) { switch (format[0]) { case 'a': { // 'a: accumulate multiplies if (instr->Bit(21) == 0) { Print("ul"); } else { Print("la"); } return 1; } case 'b': { // 'b: byte loads or stores if (instr->HasB()) { Print("b"); } return 1; } case 'c': { // 'cond: conditional execution ASSERT(STRING_STARTS_WITH(format, "cond")); PrintCondition(instr); return 4; } case 'h': { // 'h: halfword operation for extra loads and stores if (instr->HasH()) { Print("h"); } else { Print("b"); } return 1; } case 'l': { // 'l: branch and link if (instr->HasLink()) { Print("l"); } return 1; } case 'm': { if (format[1] == 'e') { // 'memop: load/store instructions ASSERT(STRING_STARTS_WITH(format, "memop")); if (instr->HasL()) { Print("ldr"); } else if ((instr->Bits(27, 25) == 0) && (instr->Bit(20) == 0)) { if (instr->Bits(7, 4) == 0xf) { Print("strd"); } else { Print("ldrd"); } } else { Print("str"); } return 5; } // 'msg: for simulator break instructions ASSERT(STRING_STARTS_WITH(format, "msg")); byte* str = reinterpret_cast(instr->InstructionBits() & 0x0fffffff); out_buffer_pos_ += v8i::OS::SNPrintF(out_buffer_ + out_buffer_pos_, "%s", converter_.NameInCode(str)); return 3; } case 'o': { if ((format[3] == '1') && (format[4] == '2')) { // 'off12: 12-bit offset for load and store instructions ASSERT(STRING_STARTS_WITH(format, "off12")); out_buffer_pos_ += v8i::OS::SNPrintF(out_buffer_ + out_buffer_pos_, "%d", instr->Offset12Field()); return 5; } else if ((format[3] == '1') && (format[4] == '6')) { ASSERT(STRING_STARTS_WITH(format, "off16to20")); out_buffer_pos_ += v8i::OS::SNPrintF(out_buffer_ + out_buffer_pos_, "%d", instr->Bits(20, 16) +1); return 9; } else if (format[3] == '7') { ASSERT(STRING_STARTS_WITH(format, "off7to11")); out_buffer_pos_ += v8i::OS::SNPrintF(out_buffer_ + out_buffer_pos_, "%d", instr->ShiftAmountField()); return 8; } else if (format[3] == '0') { // 'off0to3and8to19 16-bit immediate encoded in bits 19-8 and 3-0. ASSERT(STRING_STARTS_WITH(format, "off0to3and8to19")); out_buffer_pos_ += v8i::OS::SNPrintF(out_buffer_ + out_buffer_pos_, "%d", (instr->Bits(19, 8) << 4) + instr->Bits(3, 0)); return 15; } // 'off8: 8-bit offset for extra load and store instructions ASSERT(STRING_STARTS_WITH(format, "off8")); int offs8 = (instr->ImmedHField() << 4) | instr->ImmedLField(); out_buffer_pos_ += v8i::OS::SNPrintF(out_buffer_ + out_buffer_pos_, "%d", offs8); return 4; } case 'p': { // 'pu: P and U bits for load and store instructions ASSERT(STRING_STARTS_WITH(format, "pu")); PrintPU(instr); return 2; } case 'r': { return FormatRegister(instr, format); } case 's': { if (format[1] == 'h') { // 'shift_op or 'shift_rm if (format[6] == 'o') { // 'shift_op ASSERT(STRING_STARTS_WITH(format, "shift_op")); if (instr->TypeField() == 0) { PrintShiftRm(instr); } else { ASSERT(instr->TypeField() == 1); PrintShiftImm(instr); } return 8; } else { // 'shift_rm ASSERT(STRING_STARTS_WITH(format, "shift_rm")); PrintShiftRm(instr); return 8; } } else if (format[1] == 'w') { // 'swi ASSERT(STRING_STARTS_WITH(format, "swi")); PrintSoftwareInterrupt(instr->SwiField()); return 3; } else if (format[1] == 'i') { // 'sign: signed extra loads and stores ASSERT(STRING_STARTS_WITH(format, "sign")); if (instr->HasSign()) { Print("s"); } return 4; } // 's: S field of data processing instructions if (instr->HasS()) { Print("s"); } return 1; } case 't': { // 'target: target of branch instructions ASSERT(STRING_STARTS_WITH(format, "target")); int off = (instr->SImmed24Field() << 2) + 8; out_buffer_pos_ += v8i::OS::SNPrintF( out_buffer_ + out_buffer_pos_, "%+d -> %s", off, converter_.NameOfAddress(reinterpret_cast(instr) + off)); return 6; } case 'u': { // 'u: signed or unsigned multiplies // The manual gets the meaning of bit 22 backwards in the multiply // instruction overview on page A3.16.2. The instructions that // exist in u and s variants are the following: // smull A4.1.87 // umull A4.1.129 // umlal A4.1.128 // smlal A4.1.76 // For these 0 means u and 1 means s. As can be seen on their individual // pages. The other 18 mul instructions have the bit set or unset in // arbitrary ways that are unrelated to the signedness of the instruction. // None of these 18 instructions exist in both a 'u' and an 's' variant. if (instr->Bit(22) == 0) { Print("u"); } else { Print("s"); } return 1; } case 'v': { return FormatVFPinstruction(instr, format); } case 'S': case 'D': { return FormatVFPRegister(instr, format); } case 'w': { // 'w: W field of load and store instructions if (instr->HasW()) { Print("!"); } return 1; } default: { UNREACHABLE(); break; } } UNREACHABLE(); return -1; } // Format takes a formatting string for a whole instruction and prints it into // the output buffer. All escaped options are handed to FormatOption to be // parsed further. void Decoder::Format(Instr* instr, const char* format) { char cur = *format++; while ((cur != 0) && (out_buffer_pos_ < (out_buffer_.length() - 1))) { if (cur == '\'') { // Single quote is used as the formatting escape. format += FormatOption(instr, format); } else { out_buffer_[out_buffer_pos_++] = cur; } cur = *format++; } out_buffer_[out_buffer_pos_] = '\0'; } // For currently unimplemented decodings the disassembler calls Unknown(instr) // which will just print "unknown" of the instruction bits. void Decoder::Unknown(Instr* instr) { Format(instr, "unknown"); } void Decoder::DecodeType01(Instr* instr) { int type = instr->TypeField(); if ((type == 0) && instr->IsSpecialType0()) { // multiply instruction or extra loads and stores if (instr->Bits(7, 4) == 9) { if (instr->Bit(24) == 0) { // multiply instructions if (instr->Bit(23) == 0) { if (instr->Bit(21) == 0) { // The MUL instruction description (A 4.1.33) refers to Rd as being // the destination for the operation, but it confusingly uses the // Rn field to encode it. Format(instr, "mul'cond's 'rn, 'rm, 'rs"); } else { // The MLA instruction description (A 4.1.28) refers to the order // of registers as "Rd, Rm, Rs, Rn". But confusingly it uses the // Rn field to encode the Rd register and the Rd field to encode // the Rn register. Format(instr, "mla'cond's 'rn, 'rm, 'rs, 'rd"); } } else { // The signed/long multiply instructions use the terms RdHi and RdLo // when referring to the target registers. They are mapped to the Rn // and Rd fields as follows: // RdLo == Rd field // RdHi == Rn field // The order of registers is: , , , Format(instr, "'um'al'cond's 'rd, 'rn, 'rm, 'rs"); } } else { Unknown(instr); // not used by V8 } } else if ((instr->Bit(20) == 0) && ((instr->Bits(7, 4) & 0xd) == 0xd)) { // ldrd, strd switch (instr->PUField()) { case 0: { if (instr->Bit(22) == 0) { Format(instr, "'memop'cond's 'rd, ['rn], -'rm"); } else { Format(instr, "'memop'cond's 'rd, ['rn], #-'off8"); } break; } case 1: { if (instr->Bit(22) == 0) { Format(instr, "'memop'cond's 'rd, ['rn], +'rm"); } else { Format(instr, "'memop'cond's 'rd, ['rn], #+'off8"); } break; } case 2: { if (instr->Bit(22) == 0) { Format(instr, "'memop'cond's 'rd, ['rn, -'rm]'w"); } else { Format(instr, "'memop'cond's 'rd, ['rn, #-'off8]'w"); } break; } case 3: { if (instr->Bit(22) == 0) { Format(instr, "'memop'cond's 'rd, ['rn, +'rm]'w"); } else { Format(instr, "'memop'cond's 'rd, ['rn, #+'off8]'w"); } break; } default: { // The PU field is a 2-bit field. UNREACHABLE(); break; } } } else { // extra load/store instructions switch (instr->PUField()) { case 0: { if (instr->Bit(22) == 0) { Format(instr, "'memop'cond'sign'h 'rd, ['rn], -'rm"); } else { Format(instr, "'memop'cond'sign'h 'rd, ['rn], #-'off8"); } break; } case 1: { if (instr->Bit(22) == 0) { Format(instr, "'memop'cond'sign'h 'rd, ['rn], +'rm"); } else { Format(instr, "'memop'cond'sign'h 'rd, ['rn], #+'off8"); } break; } case 2: { if (instr->Bit(22) == 0) { Format(instr, "'memop'cond'sign'h 'rd, ['rn, -'rm]'w"); } else { Format(instr, "'memop'cond'sign'h 'rd, ['rn, #-'off8]'w"); } break; } case 3: { if (instr->Bit(22) == 0) { Format(instr, "'memop'cond'sign'h 'rd, ['rn, +'rm]'w"); } else { Format(instr, "'memop'cond'sign'h 'rd, ['rn, #+'off8]'w"); } break; } default: { // The PU field is a 2-bit field. UNREACHABLE(); break; } } return; } } else if ((type == 0) && instr->IsMiscType0()) { if (instr->Bits(22, 21) == 1) { switch (instr->Bits(7, 4)) { case BX: Format(instr, "bx'cond 'rm"); break; case BLX: Format(instr, "blx'cond 'rm"); break; case BKPT: Format(instr, "bkpt 'off0to3and8to19"); break; default: Unknown(instr); // not used by V8 break; } } else if (instr->Bits(22, 21) == 3) { switch (instr->Bits(7, 4)) { case CLZ: Format(instr, "clz'cond 'rd, 'rm"); break; default: Unknown(instr); // not used by V8 break; } } else { Unknown(instr); // not used by V8 } } else { switch (instr->OpcodeField()) { case AND: { Format(instr, "and'cond's 'rd, 'rn, 'shift_op"); break; } case EOR: { Format(instr, "eor'cond's 'rd, 'rn, 'shift_op"); break; } case SUB: { Format(instr, "sub'cond's 'rd, 'rn, 'shift_op"); break; } case RSB: { Format(instr, "rsb'cond's 'rd, 'rn, 'shift_op"); break; } case ADD: { Format(instr, "add'cond's 'rd, 'rn, 'shift_op"); break; } case ADC: { Format(instr, "adc'cond's 'rd, 'rn, 'shift_op"); break; } case SBC: { Format(instr, "sbc'cond's 'rd, 'rn, 'shift_op"); break; } case RSC: { Format(instr, "rsc'cond's 'rd, 'rn, 'shift_op"); break; } case TST: { if (instr->HasS()) { Format(instr, "tst'cond 'rn, 'shift_op"); } else { Unknown(instr); // not used by V8 } break; } case TEQ: { if (instr->HasS()) { Format(instr, "teq'cond 'rn, 'shift_op"); } else { // Other instructions matching this pattern are handled in the // miscellaneous instructions part above. UNREACHABLE(); } break; } case CMP: { if (instr->HasS()) { Format(instr, "cmp'cond 'rn, 'shift_op"); } else { Unknown(instr); // not used by V8 } break; } case CMN: { if (instr->HasS()) { Format(instr, "cmn'cond 'rn, 'shift_op"); } else { // Other instructions matching this pattern are handled in the // miscellaneous instructions part above. UNREACHABLE(); } break; } case ORR: { Format(instr, "orr'cond's 'rd, 'rn, 'shift_op"); break; } case MOV: { Format(instr, "mov'cond's 'rd, 'shift_op"); break; } case BIC: { Format(instr, "bic'cond's 'rd, 'rn, 'shift_op"); break; } case MVN: { Format(instr, "mvn'cond's 'rd, 'shift_op"); break; } default: { // The Opcode field is a 4-bit field. UNREACHABLE(); break; } } } } void Decoder::DecodeType2(Instr* instr) { switch (instr->PUField()) { case 0: { if (instr->HasW()) { Unknown(instr); // not used in V8 } Format(instr, "'memop'cond'b 'rd, ['rn], #-'off12"); break; } case 1: { if (instr->HasW()) { Unknown(instr); // not used in V8 } Format(instr, "'memop'cond'b 'rd, ['rn], #+'off12"); break; } case 2: { Format(instr, "'memop'cond'b 'rd, ['rn, #-'off12]'w"); break; } case 3: { Format(instr, "'memop'cond'b 'rd, ['rn, #+'off12]'w"); break; } default: { // The PU field is a 2-bit field. UNREACHABLE(); break; } } } void Decoder::DecodeType3(Instr* instr) { switch (instr->PUField()) { case 0: { ASSERT(!instr->HasW()); Format(instr, "'memop'cond'b 'rd, ['rn], -'shift_rm"); break; } case 1: { ASSERT(!instr->HasW()); Format(instr, "'memop'cond'b 'rd, ['rn], +'shift_rm"); break; } case 2: { Format(instr, "'memop'cond'b 'rd, ['rn, -'shift_rm]'w"); break; } case 3: { if (instr->HasW() && (instr->Bits(6, 4) == 0x5)) { uint32_t widthminus1 = static_cast(instr->Bits(20, 16)); uint32_t lsbit = static_cast(instr->ShiftAmountField()); uint32_t msbit = widthminus1 + lsbit; if (msbit <= 31) { Format(instr, "ubfx'cond 'rd, 'rm, #'off7to11, #'off16to20"); } else { UNREACHABLE(); } } else { Format(instr, "'memop'cond'b 'rd, ['rn, +'shift_rm]'w"); } break; } default: { // The PU field is a 2-bit field. UNREACHABLE(); break; } } } void Decoder::DecodeType4(Instr* instr) { ASSERT(instr->Bit(22) == 0); // Privileged mode currently not supported. if (instr->HasL()) { Format(instr, "ldm'cond'pu 'rn'w, 'rlist"); } else { Format(instr, "stm'cond'pu 'rn'w, 'rlist"); } } void Decoder::DecodeType5(Instr* instr) { Format(instr, "b'l'cond 'target"); } void Decoder::DecodeType6(Instr* instr) { DecodeType6CoprocessorIns(instr); } void Decoder::DecodeType7(Instr* instr) { if (instr->Bit(24) == 1) { Format(instr, "swi'cond 'swi"); } else { DecodeTypeVFP(instr); } } void Decoder::DecodeUnconditional(Instr* instr) { if (instr->Bits(7, 4) == 0xB && instr->Bits(27, 25) == 0 && instr->HasL()) { Format(instr, "'memop'h'pu 'rd, "); bool immediate = instr->HasB(); switch (instr->PUField()) { case 0: { // Post index, negative. if (instr->HasW()) { Unknown(instr); break; } if (immediate) { Format(instr, "['rn], #-'imm12"); } else { Format(instr, "['rn], -'rm"); } break; } case 1: { // Post index, positive. if (instr->HasW()) { Unknown(instr); break; } if (immediate) { Format(instr, "['rn], #+'imm12"); } else { Format(instr, "['rn], +'rm"); } break; } case 2: { // Pre index or offset, negative. if (immediate) { Format(instr, "['rn, #-'imm12]'w"); } else { Format(instr, "['rn, -'rm]'w"); } break; } case 3: { // Pre index or offset, positive. if (immediate) { Format(instr, "['rn, #+'imm12]'w"); } else { Format(instr, "['rn, +'rm]'w"); } break; } default: { // The PU field is a 2-bit field. UNREACHABLE(); break; } } return; } Format(instr, "break 'msg"); } // void Decoder::DecodeTypeVFP(Instr* instr) // vmov: Sn = Rt // vmov: Rt = Sn // vcvt: Dd = Sm // vcvt: Sd = Dm // Dd = vadd(Dn, Dm) // Dd = vsub(Dn, Dm) // Dd = vmul(Dn, Dm) // Dd = vdiv(Dn, Dm) // vcmp(Dd, Dm) // VMRS void Decoder::DecodeTypeVFP(Instr* instr) { ASSERT((instr->TypeField() == 7) && (instr->Bit(24) == 0x0) ); ASSERT(instr->Bits(11, 9) == 0x5); if (instr->Bit(4) == 0) { if (instr->Opc1Field() == 0x7) { // Other data processing instructions if ((instr->Opc2Field() == 0x7) && (instr->Opc3Field() == 0x3)) { DecodeVCVTBetweenDoubleAndSingle(instr); } else if ((instr->Opc2Field() == 0x8) && (instr->Opc3Field() & 0x1)) { DecodeVCVTBetweenFloatingPointAndInteger(instr); } else if (((instr->Opc2Field() >> 1) == 0x6) && (instr->Opc3Field() & 0x1)) { DecodeVCVTBetweenFloatingPointAndInteger(instr); } else if (((instr->Opc2Field() == 0x4) || (instr->Opc2Field() == 0x5)) && (instr->Opc3Field() & 0x1)) { DecodeVCMP(instr); } else { Unknown(instr); // Not used by V8. } } else if (instr->Opc1Field() == 0x3) { if (instr->SzField() == 0x1) { if (instr->Opc3Field() & 0x1) { Format(instr, "vsub.f64'cond 'Dd, 'Dn, 'Dm"); } else { Format(instr, "vadd.f64'cond 'Dd, 'Dn, 'Dm"); } } else { Unknown(instr); // Not used by V8. } } else if ((instr->Opc1Field() == 0x2) && !(instr->Opc3Field() & 0x1)) { if (instr->SzField() == 0x1) { Format(instr, "vmul.f64'cond 'Dd, 'Dn, 'Dm"); } else { Unknown(instr); // Not used by V8. } } else if ((instr->Opc1Field() == 0x4) && !(instr->Opc3Field() & 0x1)) { if (instr->SzField() == 0x1) { Format(instr, "vdiv.f64'cond 'Dd, 'Dn, 'Dm"); } else { Unknown(instr); // Not used by V8. } } else { Unknown(instr); // Not used by V8. } } else { if ((instr->VCField() == 0x0) && (instr->VAField() == 0x0)) { DecodeVMOVBetweenCoreAndSinglePrecisionRegisters(instr); } else if ((instr->VLField() == 0x1) && (instr->VCField() == 0x0) && (instr->VAField() == 0x7) && (instr->Bits(19, 16) == 0x1)) { if (instr->Bits(15, 12) == 0xF) Format(instr, "vmrs'cond APSR, FPSCR"); else Unknown(instr); // Not used by V8. } else { Unknown(instr); // Not used by V8. } } } void Decoder::DecodeVMOVBetweenCoreAndSinglePrecisionRegisters(Instr* instr) { ASSERT((instr->Bit(4) == 1) && (instr->VCField() == 0x0) && (instr->VAField() == 0x0)); bool to_arm_register = (instr->VLField() == 0x1); if (to_arm_register) { Format(instr, "vmov'cond 'rt, 'Sn"); } else { Format(instr, "vmov'cond 'Sn, 'rt"); } } void Decoder::DecodeVCMP(Instr* instr) { ASSERT((instr->Bit(4) == 0) && (instr->Opc1Field() == 0x7)); ASSERT(((instr->Opc2Field() == 0x4) || (instr->Opc2Field() == 0x5)) && (instr->Opc3Field() & 0x1)); // Comparison. bool dp_operation = (instr->SzField() == 1); bool raise_exception_for_qnan = (instr->Bit(7) == 0x1); if (dp_operation && !raise_exception_for_qnan) { Format(instr, "vcmp.f64'cond 'Dd, 'Dm"); } else { Unknown(instr); // Not used by V8. } } void Decoder::DecodeVCVTBetweenDoubleAndSingle(Instr* instr) { ASSERT((instr->Bit(4) == 0) && (instr->Opc1Field() == 0x7)); ASSERT((instr->Opc2Field() == 0x7) && (instr->Opc3Field() == 0x3)); bool double_to_single = (instr->SzField() == 1); if (double_to_single) { Format(instr, "vcvt.f32.f64'cond 'Sd, 'Dm"); } else { Format(instr, "vcvt.f64.f32'cond 'Dd, 'Sm"); } } void Decoder::DecodeVCVTBetweenFloatingPointAndInteger(Instr* instr) { ASSERT((instr->Bit(4) == 0) && (instr->Opc1Field() == 0x7)); ASSERT(((instr->Opc2Field() == 0x8) && (instr->Opc3Field() & 0x1)) || (((instr->Opc2Field() >> 1) == 0x6) && (instr->Opc3Field() & 0x1))); bool to_integer = (instr->Bit(18) == 1); bool dp_operation = (instr->SzField() == 1); if (to_integer) { bool unsigned_integer = (instr->Bit(16) == 0); if (dp_operation) { if (unsigned_integer) { Format(instr, "vcvt.u32.f64'cond 'Sd, 'Dm"); } else { Format(instr, "vcvt.s32.f64'cond 'Sd, 'Dm"); } } else { if (unsigned_integer) { Format(instr, "vcvt.u32.f32'cond 'Sd, 'Sm"); } else { Format(instr, "vcvt.s32.f32'cond 'Sd, 'Sm"); } } } else { bool unsigned_integer = (instr->Bit(7) == 0); if (dp_operation) { if (unsigned_integer) { Format(instr, "vcvt.f64.u32'cond 'Dd, 'Sm"); } else { Format(instr, "vcvt.f64.s32'cond 'Dd, 'Sm"); } } else { if (unsigned_integer) { Format(instr, "vcvt.f32.u32'cond 'Sd, 'Sm"); } else { Format(instr, "vcvt.f32.s32'cond 'Sd, 'Sm"); } } } } // Decode Type 6 coprocessor instructions. // Dm = vmov(Rt, Rt2) // = vmov(Dm) // Ddst = MEM(Rbase + 4*offset). // MEM(Rbase + 4*offset) = Dsrc. void Decoder::DecodeType6CoprocessorIns(Instr* instr) { ASSERT((instr->TypeField() == 6)); if (instr->CoprocessorField() == 0xA) { switch (instr->OpcodeField()) { case 0x8: if (instr->HasL()) { Format(instr, "vldr'cond 'Sd, ['rn - 4*'off8]"); } else { Format(instr, "vstr'cond 'Sd, ['rn - 4*'off8]"); } break; case 0xC: if (instr->HasL()) { Format(instr, "vldr'cond 'Sd, ['rn + 4*'off8]"); } else { Format(instr, "vstr'cond 'Sd, ['rn + 4*'off8]"); } break; default: Unknown(instr); // Not used by V8. break; } } else if (instr->CoprocessorField() == 0xB) { switch (instr->OpcodeField()) { case 0x2: // Load and store double to two GP registers if (instr->Bits(7, 4) != 0x1) { Unknown(instr); // Not used by V8. } else if (instr->HasL()) { Format(instr, "vmov'cond 'rt, 'rn, 'Dm"); } else { Format(instr, "vmov'cond 'Dm, 'rt, 'rn"); } break; case 0x8: if (instr->HasL()) { Format(instr, "vldr'cond 'Dd, ['rn - 4*'off8]"); } else { Format(instr, "vstr'cond 'Dd, ['rn - 4*'off8]"); } break; case 0xC: if (instr->HasL()) { Format(instr, "vldr'cond 'Dd, ['rn + 4*'off8]"); } else { Format(instr, "vstr'cond 'Dd, ['rn + 4*'off8]"); } break; default: Unknown(instr); // Not used by V8. break; } } else { UNIMPLEMENTED(); // Not used by V8. } } // Disassemble the instruction at *instr_ptr into the output buffer. int Decoder::InstructionDecode(byte* instr_ptr) { Instr* instr = Instr::At(instr_ptr); // Print raw instruction bytes. out_buffer_pos_ += v8i::OS::SNPrintF(out_buffer_ + out_buffer_pos_, "%08x ", instr->InstructionBits()); if (instr->ConditionField() == special_condition) { DecodeUnconditional(instr); return Instr::kInstrSize; } switch (instr->TypeField()) { case 0: case 1: { DecodeType01(instr); break; } case 2: { DecodeType2(instr); break; } case 3: { DecodeType3(instr); break; } case 4: { DecodeType4(instr); break; } case 5: { DecodeType5(instr); break; } case 6: { DecodeType6(instr); break; } case 7: { DecodeType7(instr); break; } default: { // The type field is 3-bits in the ARM encoding. UNREACHABLE(); break; } } return Instr::kInstrSize; } } } // namespace assembler::arm //------------------------------------------------------------------------------ namespace disasm { namespace v8i = v8::internal; const char* NameConverter::NameOfAddress(byte* addr) const { static v8::internal::EmbeddedVector tmp_buffer; v8::internal::OS::SNPrintF(tmp_buffer, "%p", addr); return tmp_buffer.start(); } const char* NameConverter::NameOfConstant(byte* addr) const { return NameOfAddress(addr); } const char* NameConverter::NameOfCPURegister(int reg) const { return assembler::arm::Registers::Name(reg); } const char* NameConverter::NameOfByteCPURegister(int reg) const { UNREACHABLE(); // ARM does not have the concept of a byte register return "nobytereg"; } const char* NameConverter::NameOfXMMRegister(int reg) const { UNREACHABLE(); // ARM does not have any XMM registers return "noxmmreg"; } const char* NameConverter::NameInCode(byte* addr) const { // The default name converter is called for unknown code. So we will not try // to access any memory. return ""; } //------------------------------------------------------------------------------ Disassembler::Disassembler(const NameConverter& converter) : converter_(converter) {} Disassembler::~Disassembler() {} int Disassembler::InstructionDecode(v8::internal::Vector buffer, byte* instruction) { assembler::arm::Decoder d(converter_, buffer); return d.InstructionDecode(instruction); } int Disassembler::ConstantPoolSizeAt(byte* instruction) { int instruction_bits = *(reinterpret_cast(instruction)); if ((instruction_bits & 0xfff00000) == 0x03000000) { return instruction_bits & 0x0000ffff; } else { return -1; } } void Disassembler::Disassemble(FILE* f, byte* begin, byte* end) { NameConverter converter; Disassembler d(converter); for (byte* pc = begin; pc < end;) { v8::internal::EmbeddedVector buffer; buffer[0] = '\0'; byte* prev_pc = pc; pc += d.InstructionDecode(buffer, pc); fprintf(f, "%p %08x %s\n", prev_pc, *reinterpret_cast(prev_pc), buffer.start()); } } } // namespace disasm