pcsx2/common/include/x86emitter/implement/jmpcall.h

/*  PCSX2 - PS2 Emulator for PCs
 *  Copyright (C) 2002-2010  PCSX2 Dev Team
 *
 *  PCSX2 is free software: you can redistribute it and/or modify it under the terms
 *  of the GNU Lesser General Public License as published by the Free Software Found-
 *  ation, either version 3 of the License, or (at your option) any later version.
 *
 *  PCSX2 is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 *  PURPOSE.  See the GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along with PCSX2.
 *  If not, see <http://www.gnu.org/licenses/>.
 */

#pragma once

// Implementations found here: CALL and JMP!  (unconditional only)

namespace x86Emitter
{

extern void xJccKnownTarget(JccComparisonType comparison, const void *target, bool slideForward);

// ------------------------------------------------------------------------
struct xImpl_JmpCall
{
    bool isJmp;

    void operator()(const xRegisterInt &absreg) const;
    void operator()(const xIndirect64orLess &src) const;

    // Special form for calling functions.  This form automatically resolves the
    // correct displacement based on the size of the instruction being generated.
    void operator()(void *func) const
    {
        if (isJmp)
            xJccKnownTarget(Jcc_Unconditional, (void *)(uptr)func, false); // double cast to/from (uptr) needed to appease GCC
        else {
            // calls are relative to the instruction after this one, and length is
            // always 5 bytes (16 bit calls are bad mojo, so no bother to do special logic).

            sptr dest = (sptr)func - ((sptr)xGetPtr() + 5);
            xWrite8(0xe8);
            xWrite32(dest);
        }
    }
};

// yes it is awful. Due to template code is in a header with a nice circular dep.
extern const xImpl_Mov xMOV;
extern const xImpl_JmpCall xCALL;

struct xImpl_FastCall
{
// FIXME: current 64 bits is mostly a copy/past potentially it would require to push/pop
// some registers. But I think it is enough to handle the first call.


// Type unsafety is nice
#ifdef __x86_64__

#define XFASTCALL \
    xCALL(f);

#define XFASTCALL1 \
    xMOV(rdi, a1); \
    xCALL(f);

#define XFASTCALL2 \
    xMOV(rdi, a1); \
    xMOV(rsi, a2); \
    xCALL(f);

#else

#define XFASTCALL \
    xCALL(f);

#define XFASTCALL1 \
    xMOV(ecx, a1); \
    xCALL(f);

#define XFASTCALL2 \
    xMOV(ecx, a1); \
    xMOV(edx, a2); \
    xCALL(f);

#endif

    void operator()(void *f, const xRegisterLong &a1 = xEmptyReg, const xRegisterLong &a2 = xEmptyReg) const
    {
#ifdef __x86_64__
        if (a1.IsEmpty()) {
            XFASTCALL;
        } else if (a2.IsEmpty()) {
            XFASTCALL1;
        } else {
            XFASTCALL2;
        }
#else
        if (a1.IsEmpty()) {
            XFASTCALL;
        } else if (a2.IsEmpty()) {
            XFASTCALL1;
        } else {
            XFASTCALL2;
        }
#endif
    }

    template <typename T>
    __fi void operator()(T *func, u32 a1, const xRegisterLong &a2) const
    {
        void *f = (void *)func;

#ifdef __x86_64__
        XFASTCALL2;
#else
        XFASTCALL2;
#endif
    }

    template <typename T>
    __fi void operator()(T *func, const xIndirectVoid &a1) const
    {
        void *f = (void *)func;

#ifdef __x86_64__
        XFASTCALL1;
#else
        XFASTCALL1;
#endif
    }

    template <typename T>
    __fi void operator()(T *func, u32 a1, u32 a2) const
    {
        void *f = (void *)func;

#ifdef __x86_64__
        XFASTCALL2;
#else
        XFASTCALL2;
#endif
    }

    template <typename T>
    __fi void operator()(T *func, u32 a1) const
    {
        void *f = (void *)func;

#ifdef __x86_64__
        XFASTCALL1;
#else
        XFASTCALL1;
#endif
    }

    void operator()(const xIndirect32 &f, const xRegisterLong &a1 = xEmptyReg, const xRegisterLong &a2 = xEmptyReg) const
    {
#ifdef __x86_64__
        if (a1.IsEmpty()) {
            XFASTCALL;
        } else if (a2.IsEmpty()) {
            XFASTCALL1;
        } else {
            XFASTCALL2;
        }
#else
        if (a1.IsEmpty()) {
            XFASTCALL;
        } else if (a2.IsEmpty()) {
            XFASTCALL1;
        } else {
            XFASTCALL2;
        }
#endif
    }

#undef XFASTCALL
#undef XFASTCALL1
#undef XFASTCALL2
};

} // End namespace x86Emitter