| /* | 
 |  * Copyright (C) 2009-2017 Apple Inc. All rights reserved. | 
 |  * Copyright (C) 2009 University of Szeged | 
 |  * All rights reserved. | 
 |  * Copyright (C) 2010 MIPS Technologies, 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 MIPS TECHNOLOGIES, 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 MIPS TECHNOLOGIES, 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. | 
 |  */ | 
 |  | 
 | #pragma once | 
 |  | 
 | #if ENABLE(ASSEMBLER) && CPU(MIPS) | 
 |  | 
 | #include "AssemblerBuffer.h" | 
 | #include "JITCompilationEffort.h" | 
 | #include "MIPSRegisters.h" | 
 | #include <limits.h> | 
 | #include <wtf/Assertions.h> | 
 | #include <wtf/SegmentedVector.h> | 
 |  | 
 | namespace JSC { | 
 |  | 
 | typedef uint32_t MIPSWord; | 
 |  | 
 | namespace RegisterNames { | 
 | typedef enum : int8_t { | 
 | #define REGISTER_ID(id, name, r, cs) id, | 
 |     FOR_EACH_GP_REGISTER(REGISTER_ID) | 
 | #undef REGISTER_ID | 
 | #define REGISTER_ALIAS(id, alias) id = alias, | 
 |     FOR_EACH_REGISTER_ALIAS(REGISTER_ALIAS) | 
 | #undef REGISTER_ALIAS | 
 |     InvalidGPRReg = -1, | 
 | } RegisterID; | 
 |  | 
 | typedef enum : int8_t { | 
 | #define REGISTER_ID(id, name, idx) id = idx, | 
 |     FOR_EACH_SP_REGISTER(REGISTER_ID) | 
 | #undef REGISTER_ID | 
 | } SPRegisterID; | 
 |  | 
 | typedef enum : int8_t { | 
 | #define REGISTER_ID(id, name, r, cs) id, | 
 |     FOR_EACH_FP_REGISTER(REGISTER_ID) | 
 | #undef REGISTER_ID | 
 |     InvalidFPRReg = -1, | 
 | } FPRegisterID; | 
 |  | 
 | } // namespace MIPSRegisters | 
 |  | 
 | class MIPSAssembler { | 
 | public: | 
 |     typedef MIPSRegisters::RegisterID RegisterID; | 
 |     typedef MIPSRegisters::SPRegisterID SPRegisterID; | 
 |     typedef MIPSRegisters::FPRegisterID FPRegisterID; | 
 |     typedef SegmentedVector<AssemblerLabel, 64> Jumps; | 
 |  | 
 |     static constexpr RegisterID firstRegister() { return MIPSRegisters::r0; } | 
 |     static constexpr RegisterID lastRegister() { return MIPSRegisters::r31; } | 
 |     static constexpr unsigned numberOfRegisters() { return lastRegister() - firstRegister() + 1; } | 
 |  | 
 |     static constexpr SPRegisterID firstSPRegister() { return MIPSRegisters::fir; } | 
 |     static constexpr SPRegisterID lastSPRegister() { return MIPSRegisters::pc; } | 
 |     static constexpr unsigned numberOfSPRegisters() { return lastSPRegister() - firstSPRegister() + 1; } | 
 |  | 
 |     static constexpr FPRegisterID firstFPRegister() { return MIPSRegisters::f0; } | 
 |     static constexpr FPRegisterID lastFPRegister() { return MIPSRegisters::f31; } | 
 |     static constexpr unsigned numberOfFPRegisters() { return lastFPRegister() - firstFPRegister() + 1; } | 
 |      | 
 |     static const char* gprName(RegisterID id) | 
 |     { | 
 |         ASSERT(id >= firstRegister() && id <= lastRegister()); | 
 |         static const char* const nameForRegister[numberOfRegisters()] = { | 
 | #define REGISTER_NAME(id, name, r, c) name, | 
 |         FOR_EACH_GP_REGISTER(REGISTER_NAME) | 
 | #undef REGISTER_NAME | 
 |         }; | 
 |         return nameForRegister[id]; | 
 |     } | 
 |  | 
 |     static const char* sprName(SPRegisterID id) | 
 |     { | 
 |         ASSERT(id >= firstSPRegister() && id <= lastSPRegister()); | 
 |         static const char* const nameForRegister[numberOfSPRegisters()] = { | 
 | #define REGISTER_NAME(id, name, idx) name, | 
 |         FOR_EACH_SP_REGISTER(REGISTER_NAME) | 
 | #undef REGISTER_NAME | 
 |         }; | 
 |         return nameForRegister[id]; | 
 |     } | 
 |  | 
 |     static const char* fprName(FPRegisterID id) | 
 |     { | 
 |         ASSERT(id >= firstFPRegister() && id <= lastFPRegister()); | 
 |         static const char* const nameForRegister[numberOfFPRegisters()] = { | 
 | #define REGISTER_NAME(id, name, r, cs) name, | 
 |         FOR_EACH_FP_REGISTER(REGISTER_NAME) | 
 | #undef REGISTER_NAME | 
 |         }; | 
 |         return nameForRegister[id]; | 
 |     } | 
 |  | 
 |     MIPSAssembler() | 
 |         : m_indexOfLastWatchpoint(INT_MIN) | 
 |         , m_indexOfTailOfLastWatchpoint(INT_MIN) | 
 |     { | 
 |     } | 
 |  | 
 |     AssemblerBuffer& buffer() { return m_buffer; } | 
 |  | 
 |     // MIPS instruction opcode field position | 
 |     enum { | 
 |         OP_SH_RD = 11, | 
 |         OP_SH_RT = 16, | 
 |         OP_SH_RS = 21, | 
 |         OP_SH_SHAMT = 6, | 
 |         OP_SH_CODE = 16, | 
 |         OP_SH_FD = 6, | 
 |         OP_SH_FS = 11, | 
 |         OP_SH_FT = 16, | 
 |         OP_SH_MSB = 11, | 
 |         OP_SH_LSB = 6 | 
 |     }; | 
 |  | 
 |     // FCSR Bits | 
 |     enum { | 
 |         FP_CAUSE_INVALID_OPERATION = 1 << 16 | 
 |     }; | 
 |  | 
 |     void emitInst(MIPSWord op) | 
 |     { | 
 |         void* oldBase = m_buffer.data(); | 
 |  | 
 |         m_buffer.putInt(op); | 
 |  | 
 |         void* newBase = m_buffer.data(); | 
 |         if (oldBase != newBase) | 
 |             relocateJumps(oldBase, newBase); | 
 |     } | 
 |  | 
 |     void nop() | 
 |     { | 
 |         emitInst(0x00000000); | 
 |     } | 
 |      | 
 |     using CopyFunction = void*(&)(void*, const void*, size_t); | 
 |  | 
 |     template <CopyFunction copy> | 
 |     ALWAYS_INLINE static void fillNops(void* base, size_t size) | 
 |     { | 
 |         UNUSED_PARAM(copy); | 
 |         RELEASE_ASSERT(!(size % sizeof(int32_t))); | 
 |  | 
 |         int32_t* ptr = static_cast<int32_t*>(base); | 
 |         const size_t num32s = size / sizeof(int32_t); | 
 |         const int32_t insn = 0x00000000; | 
 |         for (size_t i = 0; i < num32s; i++) | 
 |             *ptr++ = insn; | 
 |     } | 
 |      | 
 |     void sync() | 
 |     { | 
 |         // FIXME: https://bugs.webkit.org/show_bug.cgi?id=169984 | 
 |         // We might get a performance improvements by using SYNC_MB in some or | 
 |         // all cases. | 
 |         emitInst(0x0000000f); | 
 |     } | 
 |  | 
 |     /* Need to insert one load data delay nop for mips1.  */ | 
 |     void loadDelayNop() | 
 |     { | 
 | #if WTF_MIPS_ISA(1) | 
 |         nop(); | 
 | #endif | 
 |     } | 
 |  | 
 |     /* Need to insert one coprocessor access delay nop for mips1.  */ | 
 |     void copDelayNop() | 
 |     { | 
 | #if WTF_MIPS_ISA(1) | 
 |         nop(); | 
 | #endif | 
 |     } | 
 |  | 
 |     void move(RegisterID rd, RegisterID rs) | 
 |     { | 
 |         /* addu */ | 
 |         emitInst(0x00000021 | (rd << OP_SH_RD) | (rs << OP_SH_RS)); | 
 |     } | 
 |  | 
 |     /* Set an immediate value to a register.  This may generate 1 or 2 | 
 |        instructions.  */ | 
 |     void li(RegisterID dest, int imm) | 
 |     { | 
 |         if (imm >= -32768 && imm <= 32767) | 
 |             addiu(dest, MIPSRegisters::zero, imm); | 
 |         else if (imm >= 0 && imm < 65536) | 
 |             ori(dest, MIPSRegisters::zero, imm); | 
 |         else { | 
 |             lui(dest, imm >> 16); | 
 |             if (imm & 0xffff) | 
 |                 ori(dest, dest, imm); | 
 |         } | 
 |     } | 
 |  | 
 |     void ext(RegisterID rt, RegisterID rs, int pos, int size) | 
 |     { | 
 |         int msb = size - 1; | 
 |         emitInst(0x7c000000 | (rt << OP_SH_RT) | (rs << OP_SH_RS) | (pos << OP_SH_LSB) | (msb << OP_SH_MSB)); | 
 |     } | 
 |  | 
 |     void mfhc1(RegisterID rt, FPRegisterID fs) | 
 |     { | 
 |         emitInst(0x4460000 | (rt << OP_SH_RT) | (fs << OP_SH_FS)); | 
 |     } | 
 |  | 
 |     void lui(RegisterID rt, int imm) | 
 |     { | 
 |         emitInst(0x3c000000 | (rt << OP_SH_RT) | (imm & 0xffff)); | 
 |     } | 
 |  | 
 |     void clz(RegisterID rd, RegisterID rs) | 
 |     { | 
 |         emitInst(0x70000020 | (rd << OP_SH_RD) | (rs << OP_SH_RS) | (rd << OP_SH_RT)); | 
 |     } | 
 |  | 
 |     void addiu(RegisterID rt, RegisterID rs, int imm) | 
 |     { | 
 |         emitInst(0x24000000 | (rt << OP_SH_RT) | (rs << OP_SH_RS) | (imm & 0xffff)); | 
 |     } | 
 |  | 
 |     void addu(RegisterID rd, RegisterID rs, RegisterID rt) | 
 |     { | 
 |         emitInst(0x00000021 | (rd << OP_SH_RD) | (rs << OP_SH_RS) | (rt << OP_SH_RT)); | 
 |     } | 
 |  | 
 |     void subu(RegisterID rd, RegisterID rs, RegisterID rt) | 
 |     { | 
 |         emitInst(0x00000023 | (rd << OP_SH_RD) | (rs << OP_SH_RS) | (rt << OP_SH_RT)); | 
 |     } | 
 |  | 
 |     void mult(RegisterID rs, RegisterID rt) | 
 |     { | 
 |         emitInst(0x00000018 | (rs << OP_SH_RS) | (rt << OP_SH_RT)); | 
 |     } | 
 |  | 
 |     void div(RegisterID rs, RegisterID rt) | 
 |     { | 
 |         emitInst(0x0000001a | (rs << OP_SH_RS) | (rt << OP_SH_RT)); | 
 |     } | 
 |  | 
 |     void mfhi(RegisterID rd) | 
 |     { | 
 |         emitInst(0x00000010 | (rd << OP_SH_RD)); | 
 |     } | 
 |  | 
 |     void mflo(RegisterID rd) | 
 |     { | 
 |         emitInst(0x00000012 | (rd << OP_SH_RD)); | 
 |     } | 
 |  | 
 |     void mul(RegisterID rd, RegisterID rs, RegisterID rt) | 
 |     { | 
 | #if WTF_MIPS_ISA_AT_LEAST(32)  | 
 |         emitInst(0x70000002 | (rd << OP_SH_RD) | (rs << OP_SH_RS) | (rt << OP_SH_RT)); | 
 | #else | 
 |         mult(rs, rt); | 
 |         mflo(rd); | 
 | #endif | 
 |     } | 
 |  | 
 |     void andInsn(RegisterID rd, RegisterID rs, RegisterID rt) | 
 |     { | 
 |         emitInst(0x00000024 | (rd << OP_SH_RD) | (rs << OP_SH_RS) | (rt << OP_SH_RT)); | 
 |     } | 
 |  | 
 |     void andi(RegisterID rt, RegisterID rs, int imm) | 
 |     { | 
 |         emitInst(0x30000000 | (rt << OP_SH_RT) | (rs << OP_SH_RS) | (imm & 0xffff)); | 
 |     } | 
 |  | 
 |     void nor(RegisterID rd, RegisterID rs, RegisterID rt) | 
 |     { | 
 |         emitInst(0x00000027 | (rd << OP_SH_RD) | (rs << OP_SH_RS) | (rt << OP_SH_RT)); | 
 |     } | 
 |  | 
 |     void orInsn(RegisterID rd, RegisterID rs, RegisterID rt) | 
 |     { | 
 |         emitInst(0x00000025 | (rd << OP_SH_RD) | (rs << OP_SH_RS) | (rt << OP_SH_RT)); | 
 |     } | 
 |  | 
 |     void ori(RegisterID rt, RegisterID rs, int imm) | 
 |     { | 
 |         emitInst(0x34000000 | (rt << OP_SH_RT) | (rs << OP_SH_RS) | (imm & 0xffff)); | 
 |     } | 
 |  | 
 |     void xorInsn(RegisterID rd, RegisterID rs, RegisterID rt) | 
 |     { | 
 |         emitInst(0x00000026 | (rd << OP_SH_RD) | (rs << OP_SH_RS) | (rt << OP_SH_RT)); | 
 |     } | 
 |  | 
 |     void xori(RegisterID rt, RegisterID rs, int imm) | 
 |     { | 
 |         emitInst(0x38000000 | (rt << OP_SH_RT) | (rs << OP_SH_RS) | (imm & 0xffff)); | 
 |     } | 
 |  | 
 |     void slt(RegisterID rd, RegisterID rs, RegisterID rt) | 
 |     { | 
 |         emitInst(0x0000002a | (rd << OP_SH_RD) | (rs << OP_SH_RS) | (rt << OP_SH_RT)); | 
 |     } | 
 |  | 
 |     void sltu(RegisterID rd, RegisterID rs, RegisterID rt) | 
 |     { | 
 |         emitInst(0x0000002b | (rd << OP_SH_RD) | (rs << OP_SH_RS) | (rt << OP_SH_RT)); | 
 |     } | 
 |  | 
 |     void slti(RegisterID rt, RegisterID rs, int imm) | 
 |     { | 
 |         emitInst(0x28000000 | (rt << OP_SH_RT) | (rs << OP_SH_RS) | (imm & 0xffff)); | 
 |     } | 
 |  | 
 |     void sltiu(RegisterID rt, RegisterID rs, int imm) | 
 |     { | 
 |         emitInst(0x2c000000 | (rt << OP_SH_RT) | (rs << OP_SH_RS) | (imm & 0xffff)); | 
 |     } | 
 |  | 
 |     void sll(RegisterID rd, RegisterID rt, int shamt) | 
 |     { | 
 |         emitInst(0x00000000 | (rd << OP_SH_RD) | (rt << OP_SH_RT) | ((shamt & 0x1f) << OP_SH_SHAMT)); | 
 |     } | 
 |  | 
 |     void sllv(RegisterID rd, RegisterID rt, RegisterID rs) | 
 |     { | 
 |         emitInst(0x00000004 | (rd << OP_SH_RD) | (rt << OP_SH_RT) | (rs << OP_SH_RS)); | 
 |     } | 
 |  | 
 |     void sra(RegisterID rd, RegisterID rt, int shamt) | 
 |     { | 
 |         emitInst(0x00000003 | (rd << OP_SH_RD) | (rt << OP_SH_RT) | ((shamt & 0x1f) << OP_SH_SHAMT)); | 
 |     } | 
 |  | 
 |     void srav(RegisterID rd, RegisterID rt, RegisterID rs) | 
 |     { | 
 |         emitInst(0x00000007 | (rd << OP_SH_RD) | (rt << OP_SH_RT) | (rs << OP_SH_RS)); | 
 |     } | 
 |  | 
 |     void srl(RegisterID rd, RegisterID rt, int shamt) | 
 |     { | 
 |         emitInst(0x00000002 | (rd << OP_SH_RD) | (rt << OP_SH_RT) | ((shamt & 0x1f) << OP_SH_SHAMT)); | 
 |     } | 
 |  | 
 |     void srlv(RegisterID rd, RegisterID rt, RegisterID rs) | 
 |     { | 
 |         emitInst(0x00000006 | (rd << OP_SH_RD) | (rt << OP_SH_RT) | (rs << OP_SH_RS)); | 
 |     } | 
 |  | 
 |     void lb(RegisterID rt, RegisterID rs, int offset) | 
 |     { | 
 |         emitInst(0x80000000 | (rt << OP_SH_RT) | (rs << OP_SH_RS) | (offset & 0xffff)); | 
 |         loadDelayNop(); | 
 |     } | 
 |  | 
 |     void lbu(RegisterID rt, RegisterID rs, int offset) | 
 |     { | 
 |         emitInst(0x90000000 | (rt << OP_SH_RT) | (rs << OP_SH_RS) | (offset & 0xffff)); | 
 |         loadDelayNop(); | 
 |     } | 
 |  | 
 |     void lw(RegisterID rt, RegisterID rs, int offset) | 
 |     { | 
 |         emitInst(0x8c000000 | (rt << OP_SH_RT) | (rs << OP_SH_RS) | (offset & 0xffff)); | 
 |         loadDelayNop(); | 
 |     } | 
 |  | 
 |     void lwl(RegisterID rt, RegisterID rs, int offset) | 
 |     { | 
 |         emitInst(0x88000000 | (rt << OP_SH_RT) | (rs << OP_SH_RS) | (offset & 0xffff)); | 
 |         loadDelayNop(); | 
 |     } | 
 |  | 
 |     void lwr(RegisterID rt, RegisterID rs, int offset) | 
 |     { | 
 |         emitInst(0x98000000 | (rt << OP_SH_RT) | (rs << OP_SH_RS) | (offset & 0xffff)); | 
 |         loadDelayNop(); | 
 |     } | 
 |  | 
 |     void lh(RegisterID rt, RegisterID rs, int offset) | 
 |     { | 
 |         emitInst(0x84000000 | (rt << OP_SH_RT) | (rs << OP_SH_RS) | (offset & 0xffff)); | 
 |         loadDelayNop(); | 
 |     } | 
 |  | 
 |     void lhu(RegisterID rt, RegisterID rs, int offset) | 
 |     { | 
 |         emitInst(0x94000000 | (rt << OP_SH_RT) | (rs << OP_SH_RS) | (offset & 0xffff)); | 
 |         loadDelayNop(); | 
 |     } | 
 |  | 
 |     void sb(RegisterID rt, RegisterID rs, int offset) | 
 |     { | 
 |         emitInst(0xa0000000 | (rt << OP_SH_RT) | (rs << OP_SH_RS) | (offset & 0xffff)); | 
 |     } | 
 |  | 
 |     void sh(RegisterID rt, RegisterID rs, int offset) | 
 |     { | 
 |         emitInst(0xa4000000 | (rt << OP_SH_RT) | (rs << OP_SH_RS) | (offset & 0xffff)); | 
 |     } | 
 |  | 
 |     void sw(RegisterID rt, RegisterID rs, int offset) | 
 |     { | 
 |         emitInst(0xac000000 | (rt << OP_SH_RT) | (rs << OP_SH_RS) | (offset & 0xffff)); | 
 |     } | 
 |  | 
 |     void jr(RegisterID rs) | 
 |     { | 
 |         emitInst(0x00000008 | (rs << OP_SH_RS)); | 
 |     } | 
 |  | 
 |     void jalr(RegisterID rs) | 
 |     { | 
 |         emitInst(0x0000f809 | (rs << OP_SH_RS)); | 
 |     } | 
 |  | 
 |     void jal() | 
 |     { | 
 |         emitInst(0x0c000000); | 
 |     } | 
 |  | 
 |     void bkpt() | 
 |     { | 
 |         int value = 512; /* BRK_BUG */ | 
 |         emitInst(0x0000000d | ((value & 0x3ff) << OP_SH_CODE)); | 
 |     } | 
 |  | 
 |     static bool isBkpt(void* address) | 
 |     { | 
 |         int value = 512; /* BRK_BUG */ | 
 |         MIPSWord expected = (0x0000000d | ((value & 0x3ff) << OP_SH_CODE)); | 
 |         MIPSWord candidateInstruction = *reinterpret_cast<MIPSWord*>(address); | 
 |         return candidateInstruction == expected; | 
 |     } | 
 |  | 
 |     void bgez(RegisterID rs, int imm) | 
 |     { | 
 |         emitInst(0x04010000 | (rs << OP_SH_RS) | (imm & 0xffff)); | 
 |     } | 
 |  | 
 |     void bltz(RegisterID rs, int imm) | 
 |     { | 
 |         emitInst(0x04000000 | (rs << OP_SH_RS) | (imm & 0xffff)); | 
 |     } | 
 |  | 
 |     void beq(RegisterID rs, RegisterID rt, int imm) | 
 |     { | 
 |         emitInst(0x10000000 | (rs << OP_SH_RS) | (rt << OP_SH_RT) | (imm & 0xffff)); | 
 |     } | 
 |  | 
 |     void bne(RegisterID rs, RegisterID rt, int imm) | 
 |     { | 
 |         emitInst(0x14000000 | (rs << OP_SH_RS) | (rt << OP_SH_RT) | (imm & 0xffff)); | 
 |     } | 
 |  | 
 |     void bc1t() | 
 |     { | 
 |         emitInst(0x45010000); | 
 |     } | 
 |  | 
 |     void bc1f() | 
 |     { | 
 |         emitInst(0x45000000); | 
 |     } | 
 |  | 
 |     void appendJump() | 
 |     { | 
 |         m_jumps.append(m_buffer.label()); | 
 |     } | 
 |  | 
 |     void addd(FPRegisterID fd, FPRegisterID fs, FPRegisterID ft) | 
 |     { | 
 |         emitInst(0x46200000 | (fd << OP_SH_FD) | (fs << OP_SH_FS) | (ft << OP_SH_FT)); | 
 |     } | 
 |  | 
 |     void subd(FPRegisterID fd, FPRegisterID fs, FPRegisterID ft) | 
 |     { | 
 |         emitInst(0x46200001 | (fd << OP_SH_FD) | (fs << OP_SH_FS) | (ft << OP_SH_FT)); | 
 |     } | 
 |  | 
 |     void muld(FPRegisterID fd, FPRegisterID fs, FPRegisterID ft) | 
 |     { | 
 |         emitInst(0x46200002 | (fd << OP_SH_FD) | (fs << OP_SH_FS) | (ft << OP_SH_FT)); | 
 |     } | 
 |  | 
 |     void divd(FPRegisterID fd, FPRegisterID fs, FPRegisterID ft) | 
 |     { | 
 |         emitInst(0x46200003 | (fd << OP_SH_FD) | (fs << OP_SH_FS) | (ft << OP_SH_FT)); | 
 |     } | 
 |  | 
 |     void lwc1(FPRegisterID ft, RegisterID rs, int offset) | 
 |     { | 
 |         emitInst(0xc4000000 | (ft << OP_SH_FT) | (rs << OP_SH_RS) | (offset & 0xffff)); | 
 |         copDelayNop(); | 
 |     } | 
 |  | 
 |     void ldc1(FPRegisterID ft, RegisterID rs, int offset) | 
 |     { | 
 |         emitInst(0xd4000000 | (ft << OP_SH_FT) | (rs << OP_SH_RS) | (offset & 0xffff)); | 
 |     } | 
 |  | 
 |     void swc1(FPRegisterID ft, RegisterID rs, int offset) | 
 |     { | 
 |         emitInst(0xe4000000 | (ft << OP_SH_FT) | (rs << OP_SH_RS) | (offset & 0xffff)); | 
 |     } | 
 |  | 
 |     void sdc1(FPRegisterID ft, RegisterID rs, int offset) | 
 |     { | 
 |         emitInst(0xf4000000 | (ft << OP_SH_FT) | (rs << OP_SH_RS) | (offset & 0xffff)); | 
 |     } | 
 |  | 
 |     void mtc1(RegisterID rt, FPRegisterID fs) | 
 |     { | 
 |         emitInst(0x44800000 | (fs << OP_SH_FS) | (rt << OP_SH_RT)); | 
 |         copDelayNop(); | 
 |     } | 
 |  | 
 |     void mthc1(RegisterID rt, FPRegisterID fs) | 
 |     { | 
 |         emitInst(0x44e00000 | (fs << OP_SH_FS) | (rt << OP_SH_RT)); | 
 |         copDelayNop(); | 
 |     } | 
 |  | 
 |     void mfc1(RegisterID rt, FPRegisterID fs) | 
 |     { | 
 |         emitInst(0x44000000 | (fs << OP_SH_FS) | (rt << OP_SH_RT)); | 
 |         copDelayNop(); | 
 |     } | 
 |  | 
 |     void sqrtd(FPRegisterID fd, FPRegisterID fs) | 
 |     { | 
 |         emitInst(0x46200004 | (fd << OP_SH_FD) | (fs << OP_SH_FS)); | 
 |     } | 
 |  | 
 |     void absd(FPRegisterID fd, FPRegisterID fs) | 
 |     { | 
 |         emitInst(0x46200005 | (fd << OP_SH_FD) | (fs << OP_SH_FS)); | 
 |     } | 
 |  | 
 |     void movd(FPRegisterID fd, FPRegisterID fs) | 
 |     { | 
 |         emitInst(0x46200006 | (fd << OP_SH_FD) | (fs << OP_SH_FS)); | 
 |     } | 
 |  | 
 |     void negd(FPRegisterID fd, FPRegisterID fs) | 
 |     { | 
 |         emitInst(0x46200007 | (fd << OP_SH_FD) | (fs << OP_SH_FS)); | 
 |     } | 
 |  | 
 |     void truncwd(FPRegisterID fd, FPRegisterID fs) | 
 |     { | 
 |         emitInst(0x4620000d | (fd << OP_SH_FD) | (fs << OP_SH_FS)); | 
 |     } | 
 |  | 
 |     void cvtdw(FPRegisterID fd, FPRegisterID fs) | 
 |     { | 
 |         emitInst(0x46800021 | (fd << OP_SH_FD) | (fs << OP_SH_FS)); | 
 |     } | 
 |  | 
 |     void cvtds(FPRegisterID fd, FPRegisterID fs) | 
 |     { | 
 |         emitInst(0x46000021 | (fd << OP_SH_FD) | (fs << OP_SH_FS)); | 
 |     } | 
 |  | 
 |     void cvtwd(FPRegisterID fd, FPRegisterID fs) | 
 |     { | 
 |         emitInst(0x46200024 | (fd << OP_SH_FD) | (fs << OP_SH_FS)); | 
 |     } | 
 |  | 
 |     void cvtsd(FPRegisterID fd, FPRegisterID fs) | 
 |     { | 
 |         emitInst(0x46200020 | (fd << OP_SH_FD) | (fs << OP_SH_FS)); | 
 |     } | 
 |  | 
 |     void ceqd(FPRegisterID fs, FPRegisterID ft) | 
 |     { | 
 |         emitInst(0x46200032 | (fs << OP_SH_FS) | (ft << OP_SH_FT)); | 
 |         copDelayNop(); | 
 |     } | 
 |  | 
 |     void cngtd(FPRegisterID fs, FPRegisterID ft) | 
 |     { | 
 |         emitInst(0x4620003f | (fs << OP_SH_FS) | (ft << OP_SH_FT)); | 
 |         copDelayNop(); | 
 |     } | 
 |  | 
 |     void cnged(FPRegisterID fs, FPRegisterID ft) | 
 |     { | 
 |         emitInst(0x4620003d | (fs << OP_SH_FS) | (ft << OP_SH_FT)); | 
 |         copDelayNop(); | 
 |     } | 
 |  | 
 |     void cltd(FPRegisterID fs, FPRegisterID ft) | 
 |     { | 
 |         emitInst(0x4620003c | (fs << OP_SH_FS) | (ft << OP_SH_FT)); | 
 |         copDelayNop(); | 
 |     } | 
 |  | 
 |     void cled(FPRegisterID fs, FPRegisterID ft) | 
 |     { | 
 |         emitInst(0x4620003e | (fs << OP_SH_FS) | (ft << OP_SH_FT)); | 
 |         copDelayNop(); | 
 |     } | 
 |  | 
 |     void cueqd(FPRegisterID fs, FPRegisterID ft) | 
 |     { | 
 |         emitInst(0x46200033 | (fs << OP_SH_FS) | (ft << OP_SH_FT)); | 
 |         copDelayNop(); | 
 |     } | 
 |  | 
 |     void coled(FPRegisterID fs, FPRegisterID ft) | 
 |     { | 
 |         emitInst(0x46200036 | (fs << OP_SH_FS) | (ft << OP_SH_FT)); | 
 |         copDelayNop(); | 
 |     } | 
 |  | 
 |     void coltd(FPRegisterID fs, FPRegisterID ft) | 
 |     { | 
 |         emitInst(0x46200034 | (fs << OP_SH_FS) | (ft << OP_SH_FT)); | 
 |         copDelayNop(); | 
 |     } | 
 |  | 
 |     void culed(FPRegisterID fs, FPRegisterID ft) | 
 |     { | 
 |         emitInst(0x46200037 | (fs << OP_SH_FS) | (ft << OP_SH_FT)); | 
 |         copDelayNop(); | 
 |     } | 
 |  | 
 |     void cultd(FPRegisterID fs, FPRegisterID ft) | 
 |     { | 
 |         emitInst(0x46200035 | (fs << OP_SH_FS) | (ft << OP_SH_FT)); | 
 |         copDelayNop(); | 
 |     } | 
 |  | 
 |     void cfc1(RegisterID rt, SPRegisterID fs) | 
 |     { | 
 |         emitInst(0x44400000 | (rt << OP_SH_RT) | (fs << OP_SH_FS)); | 
 |         copDelayNop(); | 
 |     } | 
 |  | 
 |     // General helpers | 
 |  | 
 |     AssemblerLabel labelIgnoringWatchpoints() | 
 |     { | 
 |         return m_buffer.label(); | 
 |     } | 
 |  | 
 |     AssemblerLabel labelForWatchpoint() | 
 |     { | 
 |         AssemblerLabel result = m_buffer.label(); | 
 |         if (static_cast<int>(result.m_offset) != m_indexOfLastWatchpoint) | 
 |             result = label(); | 
 |         m_indexOfLastWatchpoint = result.m_offset; | 
 |         m_indexOfTailOfLastWatchpoint = result.m_offset + maxJumpReplacementSize(); | 
 |         return result; | 
 |     } | 
 |  | 
 |     AssemblerLabel label() | 
 |     { | 
 |         AssemblerLabel result = m_buffer.label(); | 
 |         while (UNLIKELY(static_cast<int>(result.m_offset) < m_indexOfTailOfLastWatchpoint)) { | 
 |             nop(); | 
 |             result = m_buffer.label(); | 
 |         } | 
 |         return result; | 
 |     } | 
 |  | 
 |     AssemblerLabel align(int alignment) | 
 |     { | 
 |         while (!m_buffer.isAligned(alignment)) | 
 |             bkpt(); | 
 |  | 
 |         return label(); | 
 |     } | 
 |  | 
 |     static void* getRelocatedAddress(void* code, AssemblerLabel label) | 
 |     { | 
 |         return reinterpret_cast<void*>(reinterpret_cast<char*>(code) + label.m_offset); | 
 |     } | 
 |  | 
 |     static int getDifferenceBetweenLabels(AssemblerLabel a, AssemblerLabel b) | 
 |     { | 
 |         return b.m_offset - a.m_offset; | 
 |     } | 
 |  | 
 |     // Assembler admin methods: | 
 |  | 
 |     size_t codeSize() const | 
 |     { | 
 |         return m_buffer.codeSize(); | 
 |     } | 
 |  | 
 |     unsigned debugOffset() { return m_buffer.debugOffset(); } | 
 |  | 
 |     // Assembly helpers for moving data between fp and registers. | 
 |     void vmov(RegisterID rd1, RegisterID rd2, FPRegisterID rn) | 
 |     { | 
 | #if WTF_MIPS_ISA_REV(2) && WTF_MIPS_FP64 | 
 |         mfc1(rd1, rn); | 
 |         mfhc1(rd2, rn); | 
 | #else | 
 |         mfc1(rd1, rn); | 
 |         mfc1(rd2, FPRegisterID(rn + 1)); | 
 | #endif | 
 |     } | 
 |  | 
 |     void vmov(FPRegisterID rd, RegisterID rn1, RegisterID rn2) | 
 |     { | 
 | #if WTF_MIPS_ISA_REV(2) && WTF_MIPS_FP64 | 
 |         mtc1(rn1, rd); | 
 |         mthc1(rn2, rd); | 
 | #else | 
 |         mtc1(rn1, rd); | 
 |         mtc1(rn2, FPRegisterID(rd + 1)); | 
 | #endif | 
 |     } | 
 |  | 
 |     static unsigned getCallReturnOffset(AssemblerLabel call) | 
 |     { | 
 |         // The return address is after a call and a delay slot instruction | 
 |         return call.m_offset; | 
 |     } | 
 |  | 
 |     // Linking & patching: | 
 |     // | 
 |     // 'link' and 'patch' methods are for use on unprotected code - such as the code | 
 |     // within the AssemblerBuffer, and code being patched by the patch buffer. Once | 
 |     // code has been finalized it is (platform support permitting) within a non- | 
 |     // writable region of memory; to modify the code in an execute-only execuable | 
 |     // pool the 'repatch' and 'relink' methods should be used. | 
 |  | 
 |     static size_t linkDirectJump(void* code, void* to) | 
 |     { | 
 |         MIPSWord* insn = reinterpret_cast<MIPSWord*>(reinterpret_cast<intptr_t>(code)); | 
 |         size_t ops = 0; | 
 |         int32_t slotAddr = reinterpret_cast<int>(insn) + 4; | 
 |         int32_t toAddr = reinterpret_cast<int>(to); | 
 |  | 
 |         if ((slotAddr & 0xf0000000) != (toAddr & 0xf0000000)) { | 
 |             // lui | 
 |             *insn = 0x3c000000 | (MIPSRegisters::t9 << OP_SH_RT) | ((toAddr >> 16) & 0xffff); | 
 |             ++insn; | 
 |             // ori | 
 |             *insn = 0x34000000 | (MIPSRegisters::t9 << OP_SH_RT) | (MIPSRegisters::t9 << OP_SH_RS) | (toAddr & 0xffff); | 
 |             ++insn; | 
 |             // jr | 
 |             *insn = 0x00000008 | (MIPSRegisters::t9 << OP_SH_RS); | 
 |             ++insn; | 
 |             ops = 4 * sizeof(MIPSWord); | 
 |         } else { | 
 |             // j | 
 |             *insn = 0x08000000 | ((toAddr & 0x0fffffff) >> 2); | 
 |             ++insn; | 
 |             ops = 2 * sizeof(MIPSWord); | 
 |         } | 
 |         // nop | 
 |         *insn = 0x00000000; | 
 |         return ops; | 
 |     } | 
 |  | 
 |     void linkJump(AssemblerLabel from, AssemblerLabel to) | 
 |     { | 
 |         ASSERT(to.isSet()); | 
 |         ASSERT(from.isSet()); | 
 |         MIPSWord* insn = reinterpret_cast<MIPSWord*>(reinterpret_cast<intptr_t>(m_buffer.data()) + from.m_offset); | 
 |         MIPSWord* toPos = reinterpret_cast<MIPSWord*>(reinterpret_cast<intptr_t>(m_buffer.data()) + to.m_offset); | 
 |  | 
 |         ASSERT(!(*(insn - 1)) && !(*(insn - 2)) && !(*(insn - 3)) && !(*(insn - 5))); | 
 |         insn = insn - 6; | 
 |         linkWithOffset(insn, toPos); | 
 |     } | 
 |  | 
 |     static void linkJump(void* code, AssemblerLabel from, void* to) | 
 |     { | 
 |         ASSERT(from.isSet()); | 
 |         MIPSWord* insn = reinterpret_cast<MIPSWord*>(reinterpret_cast<intptr_t>(code) + from.m_offset); | 
 |  | 
 |         ASSERT(!(*(insn - 1)) && !(*(insn - 2)) && !(*(insn - 3)) && !(*(insn - 5))); | 
 |         insn = insn - 6; | 
 |         linkWithOffset(insn, to); | 
 |     } | 
 |  | 
 |     static void linkCall(void* code, AssemblerLabel from, void* to) | 
 |     { | 
 |         MIPSWord* insn = reinterpret_cast<MIPSWord*>(reinterpret_cast<intptr_t>(code) + from.m_offset); | 
 |         linkCallInternal(insn, to); | 
 |     } | 
 |  | 
 |     static void linkPointer(void* code, AssemblerLabel from, void* to) | 
 |     { | 
 |         MIPSWord* insn = reinterpret_cast<MIPSWord*>(reinterpret_cast<intptr_t>(code) + from.m_offset); | 
 |         ASSERT((*insn & 0xffe00000) == 0x3c000000); // lui | 
 |         *insn = (*insn & 0xffff0000) | ((reinterpret_cast<intptr_t>(to) >> 16) & 0xffff); | 
 |         insn++; | 
 |         ASSERT((*insn & 0xfc000000) == 0x34000000); // ori | 
 |         *insn = (*insn & 0xffff0000) | (reinterpret_cast<intptr_t>(to) & 0xffff); | 
 |     } | 
 |  | 
 |     static void relinkJump(void* from, void* to) | 
 |     { | 
 |         MIPSWord* insn = reinterpret_cast<MIPSWord*>(from); | 
 |  | 
 |         ASSERT(!(*(insn - 1)) && !(*(insn - 5))); | 
 |         insn = insn - 6; | 
 |         int flushSize = linkWithOffset(insn, to); | 
 |  | 
 |         cacheFlush(insn, flushSize); | 
 |     } | 
 |  | 
 |     static void relinkJumpToNop(void* from) | 
 |     { | 
 |         relinkJump(from, from); | 
 |     } | 
 |  | 
 |     static void relinkCall(void* from, void* to) | 
 |     { | 
 |         void* start; | 
 |         int size = linkCallInternal(from, to); | 
 |         if (size == sizeof(MIPSWord)) | 
 |             start = reinterpret_cast<void*>(reinterpret_cast<intptr_t>(from) - 2 * sizeof(MIPSWord)); | 
 |         else | 
 |             start = reinterpret_cast<void*>(reinterpret_cast<intptr_t>(from) - 4 * sizeof(MIPSWord)); | 
 |  | 
 |         cacheFlush(start, size); | 
 |     } | 
 |  | 
 |     static void repatchInt32(void* from, int32_t to) | 
 |     { | 
 |         MIPSWord* insn = reinterpret_cast<MIPSWord*>(from); | 
 |         ASSERT((*insn & 0xffe00000) == 0x3c000000); // lui | 
 |         *insn = (*insn & 0xffff0000) | ((to >> 16) & 0xffff); | 
 |         insn++; | 
 |         ASSERT((*insn & 0xfc000000) == 0x34000000); // ori | 
 |         *insn = (*insn & 0xffff0000) | (to & 0xffff); | 
 |         cacheFlush(from, 2 * sizeof(MIPSWord)); | 
 |     } | 
 |  | 
 |     static int32_t readInt32(void* from) | 
 |     { | 
 |         MIPSWord* insn = reinterpret_cast<MIPSWord*>(from); | 
 |         ASSERT((*insn & 0xffe00000) == 0x3c000000); // lui | 
 |         int32_t result = (*insn & 0x0000ffff) << 16; | 
 |         insn++; | 
 |         ASSERT((*insn & 0xfc000000) == 0x34000000); // ori | 
 |         result |= *insn & 0x0000ffff; | 
 |         return result; | 
 |     } | 
 |      | 
 |     static void repatchCompact(void* where, int32_t value) | 
 |     { | 
 |         repatchInt32(where, value); | 
 |     } | 
 |  | 
 |     static void repatchPointer(void* from, void* to) | 
 |     { | 
 |         repatchInt32(from, reinterpret_cast<int32_t>(to)); | 
 |     } | 
 |  | 
 |     static void* readPointer(void* from) | 
 |     { | 
 |         return reinterpret_cast<void*>(readInt32(from)); | 
 |     } | 
 |  | 
 |     static void* readCallTarget(void* from) | 
 |     { | 
 |         MIPSWord* insn = reinterpret_cast<MIPSWord*>(from); | 
 |         insn -= 4; | 
 |         ASSERT((*insn & 0xffe00000) == 0x3c000000); // lui | 
 |         int32_t result = (*insn & 0x0000ffff) << 16; | 
 |         insn++; | 
 |         ASSERT((*insn & 0xfc000000) == 0x34000000); // ori | 
 |         result |= *insn & 0x0000ffff; | 
 |         return reinterpret_cast<void*>(result); | 
 |     } | 
 |  | 
 |     static void cacheFlush(void* code, size_t size) | 
 |     { | 
 |         intptr_t end = reinterpret_cast<intptr_t>(code) + size; | 
 |         __builtin___clear_cache(reinterpret_cast<char*>(code), reinterpret_cast<char*>(end)); | 
 |     } | 
 |  | 
 |     static ptrdiff_t maxJumpReplacementSize() | 
 |     { | 
 |         return sizeof(MIPSWord) * 4; | 
 |     } | 
 |  | 
 |     static constexpr ptrdiff_t patchableJumpSize() | 
 |     { | 
 |         return sizeof(MIPSWord) * 8; | 
 |     } | 
 |  | 
 |     static void revertJumpToMove(void* instructionStart, RegisterID rt, int imm) | 
 |     { | 
 |         MIPSWord* insn = static_cast<MIPSWord*>(instructionStart); | 
 |         size_t codeSize = 2 * sizeof(MIPSWord); | 
 |  | 
 |         // lui | 
 |         *insn = 0x3c000000 | (rt << OP_SH_RT) | ((imm >> 16) & 0xffff); | 
 |         ++insn; | 
 |         // ori | 
 |         *insn = 0x34000000 | (rt << OP_SH_RS) | (rt << OP_SH_RT) | (imm & 0xffff); | 
 |         ++insn; | 
 |         // if jr $t9 | 
 |         if (*insn == 0x03200008) { | 
 |             *insn = 0x00000000; | 
 |             codeSize += sizeof(MIPSWord); | 
 |         } | 
 |         cacheFlush(instructionStart, codeSize); | 
 |     } | 
 |  | 
 |     static void replaceWithJump(void* instructionStart, void* to) | 
 |     { | 
 |         ASSERT(!(bitwise_cast<uintptr_t>(instructionStart) & 3)); | 
 |         ASSERT(!(bitwise_cast<uintptr_t>(to) & 3)); | 
 |         size_t ops = linkDirectJump(instructionStart, to); | 
 |         cacheFlush(instructionStart, ops); | 
 |     } | 
 |  | 
 |     static void replaceWithLoad(void* instructionStart) | 
 |     { | 
 |         MIPSWord* insn = reinterpret_cast<MIPSWord*>(instructionStart); | 
 |         ASSERT((*insn & 0xffe00000) == 0x3c000000); // lui | 
 |         insn++; | 
 |         ASSERT((*insn & 0xfc0007ff) == 0x00000021); // addu | 
 |         insn++; | 
 |         *insn = 0x8c000000 | ((*insn) & 0x3ffffff); // lw | 
 |         cacheFlush(insn, 4); | 
 |     } | 
 |  | 
 |     static void replaceWithAddressComputation(void* instructionStart) | 
 |     { | 
 |         MIPSWord* insn = reinterpret_cast<MIPSWord*>(instructionStart); | 
 |         ASSERT((*insn & 0xffe00000) == 0x3c000000); // lui | 
 |         insn++; | 
 |         ASSERT((*insn & 0xfc0007ff) == 0x00000021); // addu | 
 |         insn++; | 
 |         *insn = 0x24000000 | ((*insn) & 0x3ffffff); // addiu | 
 |         cacheFlush(insn, 4); | 
 |     } | 
 |  | 
 |     /* Update each jump in the buffer of newBase.  */ | 
 |     void relocateJumps(void* oldBase, void* newBase) | 
 |     { | 
 |         // Check each jump | 
 |         for (Jumps::Iterator iter = m_jumps.begin(); iter != m_jumps.end(); ++iter) { | 
 |             int pos = iter->m_offset; | 
 |             MIPSWord* insn = reinterpret_cast<MIPSWord*>(reinterpret_cast<intptr_t>(newBase) + pos); | 
 |             insn = insn + 2; | 
 |             // Need to make sure we have 5 valid instructions after pos | 
 |             if ((unsigned)pos >= m_buffer.codeSize() - 5 * sizeof(MIPSWord)) | 
 |                 continue; | 
 |  | 
 |             if ((*insn & 0xfc000000) == 0x08000000) { // j | 
 |                 int offset = *insn & 0x03ffffff; | 
 |                 int oldInsnAddress = (int)insn - (int)newBase + (int)oldBase; | 
 |                 int topFourBits = (oldInsnAddress + 4) >> 28; | 
 |                 int oldTargetAddress = (topFourBits << 28) | (offset << 2); | 
 |                 int newTargetAddress = oldTargetAddress - (int)oldBase + (int)newBase; | 
 |                 int newInsnAddress = (int)insn; | 
 |                 if (((newInsnAddress + 4) >> 28) == (newTargetAddress >> 28)) | 
 |                     *insn = 0x08000000 | ((newTargetAddress >> 2) & 0x3ffffff); | 
 |                 else { | 
 |                     /* lui */ | 
 |                     *insn = 0x3c000000 | (MIPSRegisters::t9 << OP_SH_RT) | ((newTargetAddress >> 16) & 0xffff); | 
 |                     /* ori */ | 
 |                     *(insn + 1) = 0x34000000 | (MIPSRegisters::t9 << OP_SH_RT) | (MIPSRegisters::t9 << OP_SH_RS) | (newTargetAddress & 0xffff); | 
 |                     /* jr */ | 
 |                     *(insn + 2) = 0x00000008 | (MIPSRegisters::t9 << OP_SH_RS); | 
 |                 } | 
 |             } else if ((*insn & 0xffe00000) == 0x3c000000) { // lui | 
 |                 int high = (*insn & 0xffff) << 16; | 
 |                 int low = *(insn + 1) & 0xffff; | 
 |                 int oldTargetAddress = high | low; | 
 |                 int newTargetAddress = oldTargetAddress - (int)oldBase + (int)newBase; | 
 |                 /* lui */ | 
 |                 *insn = 0x3c000000 | (MIPSRegisters::t9 << OP_SH_RT) | ((newTargetAddress >> 16) & 0xffff); | 
 |                 /* ori */ | 
 |                 *(insn + 1) = 0x34000000 | (MIPSRegisters::t9 << OP_SH_RT) | (MIPSRegisters::t9 << OP_SH_RS) | (newTargetAddress & 0xffff); | 
 |             } | 
 |         } | 
 |     } | 
 |  | 
 | private: | 
 |     static int linkWithOffset(MIPSWord* insn, void* to) | 
 |     { | 
 |         ASSERT((*insn & 0xfc000000) == 0x10000000 // beq | 
 |             || (*insn & 0xfc000000) == 0x14000000 // bne | 
 |             || (*insn & 0xffff0000) == 0x45010000 // bc1t | 
 |             || (*insn & 0xffff0000) == 0x45000000); // bc1f | 
 |         intptr_t diff = (reinterpret_cast<intptr_t>(to) - reinterpret_cast<intptr_t>(insn) - 4) >> 2; | 
 |  | 
 |         if (diff < -32768 || diff > 32767 || *(insn + 2) != 0x10000003) { | 
 |             /* | 
 |                 Convert the sequence: | 
 |                   beq $2, $3, target | 
 |                   nop | 
 |                   b 1f | 
 |                   nop | 
 |                   nop | 
 |                   nop | 
 |                 1: | 
 |  | 
 |                 to the new sequence if possible: | 
 |                   bne $2, $3, 1f | 
 |                   nop | 
 |                   j    target | 
 |                   nop | 
 |                   nop | 
 |                   nop | 
 |                 1: | 
 |  | 
 |                 OR to the new sequence: | 
 |                   bne $2, $3, 1f | 
 |                   nop | 
 |                   lui $25, target >> 16 | 
 |                   ori $25, $25, target & 0xffff | 
 |                   jr $25 | 
 |                   nop | 
 |                 1: | 
 |  | 
 |                 Note: beq/bne/bc1t/bc1f are converted to bne/beq/bc1f/bc1t. | 
 |             */ | 
 |  | 
 |             if (*(insn + 2) == 0x10000003) { | 
 |                 if ((*insn & 0xfc000000) == 0x10000000) // beq | 
 |                     *insn = (*insn & 0x03ff0000) | 0x14000005; // bne | 
 |                 else if ((*insn & 0xfc000000) == 0x14000000) // bne | 
 |                     *insn = (*insn & 0x03ff0000) | 0x10000005; // beq | 
 |                 else if ((*insn & 0xffff0000) == 0x45010000) // bc1t | 
 |                     *insn = 0x45000005; // bc1f | 
 |                 else if ((*insn & 0xffff0000) == 0x45000000) // bc1f | 
 |                     *insn = 0x45010005; // bc1t | 
 |                 else | 
 |                     ASSERT(0); | 
 |             } | 
 |  | 
 |             insn = insn + 2; | 
 |             if ((reinterpret_cast<intptr_t>(insn) + 4) >> 28 | 
 |                 == reinterpret_cast<intptr_t>(to) >> 28) { | 
 |                 *insn = 0x08000000 | ((reinterpret_cast<intptr_t>(to) >> 2) & 0x3ffffff); | 
 |                 *(insn + 1) = 0; | 
 |                 return 4 * sizeof(MIPSWord); | 
 |             } | 
 |  | 
 |             intptr_t newTargetAddress = reinterpret_cast<intptr_t>(to); | 
 |             /* lui */ | 
 |             *insn = 0x3c000000 | (MIPSRegisters::t9 << OP_SH_RT) | ((newTargetAddress >> 16) & 0xffff); | 
 |             /* ori */ | 
 |             *(insn + 1) = 0x34000000 | (MIPSRegisters::t9 << OP_SH_RT) | (MIPSRegisters::t9 << OP_SH_RS) | (newTargetAddress & 0xffff); | 
 |             /* jr */ | 
 |             *(insn + 2) = 0x00000008 | (MIPSRegisters::t9 << OP_SH_RS); | 
 |             return 5 * sizeof(MIPSWord); | 
 |         } | 
 |  | 
 |         *insn = (*insn & 0xffff0000) | (diff & 0xffff); | 
 |         return sizeof(MIPSWord); | 
 |     } | 
 |  | 
 |     static int linkCallInternal(void* from, void* to) | 
 |     { | 
 |         MIPSWord* insn = reinterpret_cast<MIPSWord*>(from); | 
 |         insn = insn - 4; | 
 |  | 
 |         if ((*(insn + 2) & 0xfc000000) == 0x0c000000) { // jal | 
 |             if ((reinterpret_cast<intptr_t>(from) - 4) >> 28 | 
 |                 == reinterpret_cast<intptr_t>(to) >> 28) { | 
 |                 *(insn + 2) = 0x0c000000 | ((reinterpret_cast<intptr_t>(to) >> 2) & 0x3ffffff); | 
 |                 return sizeof(MIPSWord); | 
 |             } | 
 |  | 
 |             /* lui $25, (to >> 16) & 0xffff */ | 
 |             *insn = 0x3c000000 | (MIPSRegisters::t9 << OP_SH_RT) | ((reinterpret_cast<intptr_t>(to) >> 16) & 0xffff); | 
 |             /* ori $25, $25, to & 0xffff */ | 
 |             *(insn + 1) = 0x34000000 | (MIPSRegisters::t9 << OP_SH_RT) | (MIPSRegisters::t9 << OP_SH_RS) | (reinterpret_cast<intptr_t>(to) & 0xffff); | 
 |             /* jalr $25 */ | 
 |             *(insn + 2) = 0x0000f809 | (MIPSRegisters::t9 << OP_SH_RS); | 
 |             return 3 * sizeof(MIPSWord); | 
 |         } | 
 |  | 
 |         ASSERT((*insn & 0xffe00000) == 0x3c000000); // lui | 
 |         ASSERT((*(insn + 1) & 0xfc000000) == 0x34000000); // ori | 
 |  | 
 |         /* lui */ | 
 |         *insn = (*insn & 0xffff0000) | ((reinterpret_cast<intptr_t>(to) >> 16) & 0xffff); | 
 |         /* ori */ | 
 |         *(insn + 1) = (*(insn + 1) & 0xffff0000) | (reinterpret_cast<intptr_t>(to) & 0xffff); | 
 |         return 2 * sizeof(MIPSWord); | 
 |     } | 
 |  | 
 |     AssemblerBuffer m_buffer; | 
 |     Jumps m_jumps; | 
 |     int m_indexOfLastWatchpoint; | 
 |     int m_indexOfTailOfLastWatchpoint; | 
 | }; | 
 |  | 
 | } // namespace JSC | 
 |  | 
 | #endif // ENABLE(ASSEMBLER) && CPU(MIPS) |