JavaScriptCore/assembler/MIPSAssembler.h
changeset 0 4f2f89ce4247
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/JavaScriptCore/assembler/MIPSAssembler.h	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,961 @@
+/*
+ * Copyright (C) 2009 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.
+ */
+
+#ifndef MIPSAssembler_h
+#define MIPSAssembler_h
+
+#if ENABLE(ASSEMBLER) && CPU(MIPS)
+
+#include "AssemblerBuffer.h"
+#include <wtf/Assertions.h>
+#include <wtf/SegmentedVector.h>
+
+namespace JSC {
+
+typedef uint32_t MIPSWord;
+
+namespace MIPSRegisters {
+typedef enum {
+    r0 = 0,
+    r1,
+    r2,
+    r3,
+    r4,
+    r5,
+    r6,
+    r7,
+    r8,
+    r9,
+    r10,
+    r11,
+    r12,
+    r13,
+    r14,
+    r15,
+    r16,
+    r17,
+    r18,
+    r19,
+    r20,
+    r21,
+    r22,
+    r23,
+    r24,
+    r25,
+    r26,
+    r27,
+    r28,
+    r29,
+    r30,
+    r31,
+    zero = r0,
+    at = r1,
+    v0 = r2,
+    v1 = r3,
+    a0 = r4,
+    a1 = r5,
+    a2 = r6,
+    a3 = r7,
+    t0 = r8,
+    t1 = r9,
+    t2 = r10,
+    t3 = r11,
+    t4 = r12,
+    t5 = r13,
+    t6 = r14,
+    t7 = r15,
+    s0 = r16,
+    s1 = r17,
+    s2 = r18,
+    s3 = r19,
+    s4 = r20,
+    s5 = r21,
+    s6 = r22,
+    s7 = r23,
+    t8 = r24,
+    t9 = r25,
+    k0 = r26,
+    k1 = r27,
+    gp = r28,
+    sp = r29,
+    fp = r30,
+    ra = r31
+} RegisterID;
+
+typedef enum {
+    f0,
+    f1,
+    f2,
+    f3,
+    f4,
+    f5,
+    f6,
+    f7,
+    f8,
+    f9,
+    f10,
+    f11,
+    f12,
+    f13,
+    f14,
+    f15,
+    f16,
+    f17,
+    f18,
+    f19,
+    f20,
+    f21,
+    f22,
+    f23,
+    f24,
+    f25,
+    f26,
+    f27,
+    f28,
+    f29,
+    f30,
+    f31
+} FPRegisterID;
+
+} // namespace MIPSRegisters
+
+class MIPSAssembler {
+public:
+    typedef MIPSRegisters::RegisterID RegisterID;
+    typedef MIPSRegisters::FPRegisterID FPRegisterID;
+    typedef SegmentedVector<int, 64> Jumps;
+
+    MIPSAssembler()
+    {
+    }
+
+    // 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
+    };
+
+    class JmpSrc {
+        friend class MIPSAssembler;
+    public:
+        JmpSrc()
+            : m_offset(-1)
+        {
+        }
+
+    private:
+        JmpSrc(int offset)
+            : m_offset(offset)
+        {
+        }
+
+        int m_offset;
+    };
+
+    class JmpDst {
+        friend class MIPSAssembler;
+    public:
+        JmpDst()
+            : m_offset(-1)
+            , m_used(false)
+        {
+        }
+
+        bool isUsed() const { return m_used; }
+        void used() { m_used = true; }
+    private:
+        JmpDst(int offset)
+            : m_offset(offset)
+            , m_used(false)
+        {
+            ASSERT(m_offset == offset);
+        }
+
+        int m_offset : 31;
+        int m_used : 1;
+    };
+
+    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);
+    }
+
+    /* 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 lui(RegisterID rt, int imm)
+    {
+        emitInst(0x3c000000 | (rt << OP_SH_RT) | (imm & 0xffff));
+    }
+
+    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 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 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, int 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 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 lhu(RegisterID rt, RegisterID rs, int offset)
+    {
+        emitInst(0x94000000 | (rt << OP_SH_RT) | (rs << OP_SH_RS)
+                 | (offset & 0xffff));
+        loadDelayNop();
+    }
+
+    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));
+    }
+
+    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);
+    }
+
+    JmpSrc newJmpSrc()
+    {
+        return JmpSrc(m_buffer.size());
+    }
+
+    void appendJump()
+    {
+        m_jumps.append(m_buffer.size());
+    }
+
+    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 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 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 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 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();
+    }
+
+    // General helpers
+
+    JmpDst label()
+    {
+        return JmpDst(m_buffer.size());
+    }
+
+    JmpDst align(int alignment)
+    {
+        while (!m_buffer.isAligned(alignment))
+            bkpt();
+
+        return label();
+    }
+
+    static void* getRelocatedAddress(void* code, JmpSrc jump)
+    {
+        ASSERT(jump.m_offset != -1);
+        void* b = reinterpret_cast<void*>((reinterpret_cast<intptr_t>(code)) + jump.m_offset);
+        return b;
+    }
+
+    static void* getRelocatedAddress(void* code, JmpDst label)
+    {
+        void* b = reinterpret_cast<void*>((reinterpret_cast<intptr_t>(code)) + label.m_offset);
+        return b;
+    }
+
+    static int getDifferenceBetweenLabels(JmpDst from, JmpDst to)
+    {
+        return to.m_offset - from.m_offset;
+    }
+
+    static int getDifferenceBetweenLabels(JmpDst from, JmpSrc to)
+    {
+        return to.m_offset - from.m_offset;
+    }
+
+    static int getDifferenceBetweenLabels(JmpSrc from, JmpDst to)
+    {
+        return to.m_offset - from.m_offset;
+    }
+
+    // Assembler admin methods:
+
+    size_t size() const
+    {
+        return m_buffer.size();
+    }
+
+    void* executableCopy(ExecutablePool* allocator)
+    {
+        void *result = m_buffer.executableCopy(allocator);
+        if (!result)
+            return 0;
+
+        relocateJumps(m_buffer.data(), result);
+        return result;
+    }
+
+    static unsigned getCallReturnOffset(JmpSrc 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.
+
+    void linkJump(JmpSrc from, JmpDst to)
+    {
+        ASSERT(to.m_offset != -1);
+        ASSERT(from.m_offset != -1);
+        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, JmpSrc from, void* to)
+    {
+        ASSERT(from.m_offset != -1);
+        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, JmpSrc from, void* to)
+    {
+        MIPSWord* insn = reinterpret_cast<MIPSWord*>(reinterpret_cast<intptr_t>(code) + from.m_offset);
+        linkCallInternal(insn, to);
+    }
+
+    static void linkPointer(void* code, JmpDst 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);
+
+        ExecutableAllocator::cacheFlush(insn, flushSize);
+    }
+
+    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));
+
+        ExecutableAllocator::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);
+        insn--;
+        ExecutableAllocator::cacheFlush(insn, 2 * sizeof(MIPSWord));
+    }
+
+    static void repatchPointer(void* from, void* to)
+    {
+        repatchInt32(from, reinterpret_cast<int32_t>(to));
+    }
+
+    static void repatchLoadPtrToLEA(void* from)
+    {
+        MIPSWord* insn = reinterpret_cast<MIPSWord*>(from);
+        insn = insn + 3;
+        ASSERT((*insn & 0xfc000000) == 0x8c000000); // lw
+        /* lw -> addiu */
+        *insn = 0x24000000 | (*insn & 0x03ffffff);
+
+        ExecutableAllocator::cacheFlush(insn, sizeof(MIPSWord));
+    }
+
+private:
+
+    /* 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;
+            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 int)pos >= m_buffer.size() - 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);
+            }
+        }
+    }
+
+    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;
+};
+
+} // namespace JSC
+
+#endif // ENABLE(ASSEMBLER) && CPU(MIPS)
+
+#endif // MIPSAssembler_h