Exemple #1
0
code *nteh_monitor_prolog(Symbol *shandle)
{
    /*
     *  PUSH    handle
     *  PUSH    offset _d_monitor_handler
     *  PUSH    FS:__except_list
     *  MOV     FS:__except_list,ESP
     *  CALL    _d_monitor_prolog
     */
    CodeBuilder cdb1;
    CodeBuilder cdb;

    assert(config.exe == EX_WIN32);    // BUG: figure out how to implement for other EX's

    if (shandle->Sclass == SCfastpar)
    {   assert(shandle->Spreg != DX);
        assert(shandle->Spreg2 == NOREG);
        cdb.gen1(0x50 + shandle->Spreg);   // PUSH shandle
    }
    else
    {
        // PUSH shandle
        useregs(mCX);
        cdb.genc1(0x8B,modregrm(2,CX,4),FLconst,4 * (1 + needframe) + shandle->Soffset + localsize);
        cdb.last()->Isib = modregrm(0,4,SP);
        cdb.gen1(0x50 + CX);                      // PUSH ECX
    }

    Symbol *smh = getRtlsym(RTLSYM_MONITOR_HANDLER);
    cdb.gencs(0x68,0,FLextern,smh);             // PUSH offset _d_monitor_handler
    makeitextern(smh);

    code cs;
    useregs(mDX);
    cs.Iop = 0x8B;
    cs.Irm = modregrm(0,DX,BPRM);
    cs.Iflags = CFfs;
    cs.Irex = 0;
    cs.IFL1 = FLextern;
    cs.IEVsym1 = getRtlsym(RTLSYM_EXCEPT_LIST);
    cs.IEVoffset1 = 0;
    cdb1.gen(&cs);                   // MOV EDX,FS:__except_list

    cdb.gen1(0x50 + DX);                  // PUSH EDX

    Symbol *s = getRtlsym(RTLSYM_MONITOR_PROLOG);
    regm_t desregs = ~s->Sregsaved & ALLREGS;
    cdb.append(getregs(desregs));
    cdb.gencs(0xE8,0,FLfunc,s);       // CALL _d_monitor_prolog

    cs.Iop = 0x89;
    NEWREG(cs.Irm,SP);
    cdb.gen(&cs);                         // MOV FS:__except_list,ESP

    cdb1.append(cdb);
    return cdb1.finish();
}
Exemple #2
0
Fichier : nteh.c Projet : spott/dmd
code *nteh_unwind(regm_t retregs,unsigned index)
{   code *c;
    code cs;
    code *cs1;
    code *cs2;
    regm_t desregs;
    int reg;
    int local_unwind;

    // Shouldn't this always be CX?
#if SCPP
    reg = AX;
#else
    reg = CX;
#endif

#if MARS
    local_unwind = RTLSYM_D_LOCAL_UNWIND2;
#else
    local_unwind = RTLSYM_LOCAL_UNWIND2;
#endif
    desregs = (~rtlsym[local_unwind]->Sregsaved & (ALLREGS)) | mask[reg];
    gensaverestore(retregs & desregs,&cs1,&cs2);

    c = getregs(desregs);

    cs.Iop = 0x8D;
    cs.Irm = modregrm(2,reg,BPRM);
    cs.Iflags = 0;
    cs.Irex = 0;
    cs.IFL1 = FLconst;
    // EBP offset of __context.prev
    cs.IEV1.Vint = nteh_EBPoffset_prev();
    c = gen(c,&cs);                             // LEA  ECX,contextsym

    genc2(c,0x68,0,index);                      // PUSH index
    gen1(c,0x50 + reg);                         // PUSH ECX

#if MARS
    //gencs(c,0xB8+AX,0,FLextern,nteh_scopetable());    // MOV EAX,&scope_table
    gencs(c,0x68,0,FLextern,nteh_scopetable());         // PUSH &scope_table

    gencs(c,0xE8,0,FLfunc,rtlsym[local_unwind]);        // CALL __d_local_unwind2()
    genc2(c,0x81,modregrm(3,0,SP),12);                  // ADD ESP,12
#else
    gencs(c,0xE8,0,FLfunc,rtlsym[local_unwind]);        // CALL __local_unwind2()
    genc2(c,0x81,modregrm(3,0,SP),8);                   // ADD ESP,8
#endif

    c = cat4(cs1,c,cs2,NULL);
    return c;
}
Exemple #3
0
code *nteh_monitor_epilog(regm_t retregs)
{
    /*
     *  CALL    _d_monitor_epilog
     *  POP     FS:__except_list
     */

    assert(config.exe == EX_WIN32);    // BUG: figure out how to implement for other EX's

    Symbol *s = getRtlsym(RTLSYM_MONITOR_EPILOG);
    //desregs = ~s->Sregsaved & ALLREGS;
    regm_t desregs = 0;
    code *cs1;
    code *cs2;
    gensaverestore(retregs& desregs,&cs1,&cs2);

    CodeBuilder cdb(getregs(desregs));
    cdb.gencs(0xE8,0,FLfunc,s);               // CALL __d_monitor_epilog

    CodeBuilder cdb1(cs1);
    CodeBuilder cdb2(cs2);
    cdb1.append(cdb, cdb2);

    code cs;
    cs.Iop = 0x8F;
    cs.Irm = modregrm(0,0,BPRM);
    cs.Iflags = CFfs;
    cs.Irex = 0;
    cs.IFL1 = FLextern;
    cs.IEVsym1 = getRtlsym(RTLSYM_EXCEPT_LIST);
    cs.IEVoffset1 = 0;
    cdb1.gen(&cs);                       // POP FS:__except_list

    return cdb1.finish();
}
Exemple #4
0
code *nteh_unwind(regm_t retregs,unsigned index)
{
    code cs;
    regm_t desregs;
    int reg;
    int local_unwind;

    // Shouldn't this always be CX?
#if SCPP
    reg = AX;
#else
    reg = CX;
#endif

#if MARS
    local_unwind = RTLSYM_D_LOCAL_UNWIND2;
#else
    local_unwind = RTLSYM_LOCAL_UNWIND2;
#endif
    desregs = (~getRtlsym(local_unwind)->Sregsaved & (ALLREGS)) | mask[reg];
    code *cs1;
    code *cs2;
    gensaverestore(retregs & desregs,&cs1,&cs2);

    CodeBuilder cdb(getregs(desregs));

    cs.Iop = 0x8D;
    cs.Irm = modregrm(2,reg,BPRM);
    cs.Iflags = 0;
    cs.Irex = 0;
    cs.IFL1 = FLconst;
    // EBP offset of __context.prev
    cs.IEV1.Vint = nteh_EBPoffset_prev();
    cdb.gen(&cs);                             // LEA  ECX,contextsym

    cdb.genc2(0x68,0,index);                      // PUSH index
    cdb.gen1(0x50 + reg);                         // PUSH ECX

#if MARS
    //cdb.gencs(0xB8+AX,0,FLextern,nteh_scopetable());    // MOV EAX,&scope_table
    cdb.gencs(0x68,0,FLextern,nteh_scopetable());         // PUSH &scope_table

    cdb.gencs(0xE8,0,FLfunc,getRtlsym(local_unwind));        // CALL __d_local_unwind2()
    cdb.append(cod3_stackadj(NULL, -12));
#else
    cdb.gencs(0xE8,0,FLfunc,getRtlsym(local_unwind));        // CALL __local_unwind2()
    cdb.append(cod3_stackadj(NULL, -8));
#endif

    CodeBuilder cdb1(cs1);
    CodeBuilder cdb2(cs2);
    cdb1.append(cdb, cdb2);
    return cdb1.finish();
}
Exemple #5
0
Fichier : nteh.c Projet : spott/dmd
code *nteh_setsp(int op)
{   code cs;

    cs.Iop = op;
    cs.Irm = modregrm(2,SP,BPRM);
    cs.Iflags = 0;
    cs.Irex = 0;
    cs.IFL1 = FLconst;
    // EBP offset of __context.esp
    cs.IEV1.Vint = nteh_EBPoffset_esp();
    return gen(CNIL,&cs);               // MOV ESP,__context[EBP].esp
}
Exemple #6
0
Fichier : nteh.c Projet : spott/dmd
code *linux_unwind(regm_t retregs,unsigned index)
{   code *c;
    code *cs1;
    code *cs2;
    int i;
    regm_t desregs;
    int reg;
    int local_unwind;

    // Shouldn't this always be CX?
#if SCPP
    reg = AX;
#else
    reg = CX;
#endif

#if MARS
    local_unwind = RTLSYM_D_LOCAL_UNWIND2;
#else
    local_unwind = RTLSYM_LOCAL_UNWIND2;
#endif
    desregs = (~rtlsym[local_unwind]->Sregsaved & (ALLREGS)) | mask[reg];
    gensaverestore(retregs & desregs,&cs1,&cs2);

    c = getregs(desregs);
    c = genc2(c,0x68,0,index);                  // PUSH index

#if MARS
//    gencs(c,0x68,0,FLextern,nteh_scopetable());               // PUSH &scope_table

    gencs(c,0xE8,0,FLfunc,rtlsym[local_unwind]);        // CALL __d_local_unwind2()
    genc2(c,0x81,modregrm(3,0,SP),4);                   // ADD ESP,12
#else
    gencs(c,0xE8,0,FLfunc,rtlsym[local_unwind]);        // CALL __local_unwind2()
    genc2(c,0x81,modregrm(3,0,SP),8);                   // ADD ESP,8
#endif

    c = cat4(cs1,c,cs2,NULL);
    return c;
}
Exemple #7
0
code *nteh_filter(block *b)
{
    code cs;
    CodeBuilder cdb;

    assert(b->BC == BC_filter);
    if (b->Bflags & BFLehcode)          // if referenced __ecode
    {
        /* Generate:
                mov     EAX,__context[EBP].info
                mov     EAX,[EAX]
                mov     EAX,[EAX]
                mov     __ecode[EBP],EAX
         */

        cdb.append(getregs(mAX));

        cs.Iop = 0x8B;
        cs.Irm = modregrm(2,AX,BPRM);
        cs.Iflags = 0;
        cs.Irex = 0;
        cs.IFL1 = FLconst;
        // EBP offset of __context.info
        cs.IEV1.Vint = nteh_EBPoffset_info();
        cdb.gen(&cs);                 // MOV EAX,__context[EBP].info

        cs.Irm = modregrm(0,AX,0);
        cdb.gen(&cs);                     // MOV EAX,[EAX]
        cdb.gen(&cs);                     // MOV EAX,[EAX]

        cs.Iop = 0x89;
        cs.Irm = modregrm(2,AX,BPRM);
        cs.IFL1 = FLauto;
        cs.IEVsym1 = nteh_ecodesym();
        cs.IEVoffset1 = 0;
        cdb.gen(&cs);                     // MOV __ecode[EBP],EAX
    }
    return cdb.finish();
}
Exemple #8
0
code *nteh_epilog()
{
    if (config.exe != EX_WIN32)
        return NULL;

    /* Generate:
        mov     ECX,__context[EBP].prev
        mov     FS:__except_list,ECX
     */
    code cs;
    CodeBuilder cdb;
    unsigned reg;

#if MARS
    reg = CX;
#else
    reg = (tybasic(funcsym_p->Stype->Tnext->Tty) == TYvoid) ? AX : CX;
#endif
    useregs(mask[reg]);

    cs.Iop = 0x8B;
    cs.Irm = modregrm(2,reg,BPRM);
    cs.Iflags = 0;
    cs.Irex = 0;
    cs.IFL1 = FLconst;
    // EBP offset of __context.prev
    cs.IEV1.Vint = nteh_EBPoffset_prev();
    cdb.gen(&cs);

    cs.Iop = 0x89;
    cs.Irm = modregrm(0,reg,BPRM);
    cs.Iflags |= CFfs;
    cs.IFL1 = FLextern;
    cs.IEVsym1 = getRtlsym(RTLSYM_EXCEPT_LIST);
    cs.IEVoffset1 = 0;
    cdb.gen(&cs);
    return cdb.finish();
}
Exemple #9
0
code *nteh_setsp(int op)
{
    code cs;
    cs.Iop = op;
    cs.Irm = modregrm(2,SP,BPRM);
    cs.Iflags = 0;
    cs.Irex = 0;
    cs.IFL1 = FLconst;
    // EBP offset of __context.esp
    cs.IEV1.Vint = nteh_EBPoffset_esp();
    CodeBuilder cdb;
    cdb.gen(&cs);               // MOV ESP,__context[EBP].esp
    return cdb.finish();
}
Exemple #10
0
Fichier : nteh.c Projet : spott/dmd
code *nteh_epilog()
{
    if (!(config.flags2 & CFG2seh))
        return NULL;

    /* Generate:
        mov     ECX,__context[EBP].prev
        mov     FS:__except_list,ECX
     */
    code cs;
    code *c;
    unsigned reg;

#if MARS
    reg = CX;
#else
    reg = (tybasic(funcsym_p->Stype->Tnext->Tty) == TYvoid) ? AX : CX;
#endif
    useregs(mask[reg]);

    cs.Iop = 0x8B;
    cs.Irm = modregrm(2,reg,BPRM);
    cs.Iflags = 0;
    cs.Irex = 0;
    cs.IFL1 = FLconst;
    // EBP offset of __context.prev
    cs.IEV1.Vint = nteh_EBPoffset_prev();
    c = gen(CNIL,&cs);

    cs.Iop = 0x89;
    cs.Irm = modregrm(0,reg,BPRM);
    cs.Iflags |= CFfs;
    cs.IFL1 = FLextern;
    cs.IEVsym1 = rtlsym[RTLSYM_EXCEPT_LIST];
    cs.IEVoffset1 = 0;
    return gen(c,&cs);
}
Exemple #11
0
Fichier : nteh.c Projet : spott/dmd
code *nteh_gensindex(int sindex)
{   code *c;

    if (!(config.flags2 & CFG2seh))
        return NULL;

    // Generate:
    //  MOV     -4[EBP],sindex

    c = genc(NULL,0xC7,modregrm(1,0,BP),FLconst,(targ_uns)nteh_EBPoffset_sindex(),FLconst,sindex);      // 7 bytes long
    c->Iflags |= CFvolatile;
#ifdef DEBUG
    //assert(GENSINDEXSIZE == calccodsize(c));
#endif
    return c;
}
Exemple #12
0
code *nteh_gensindex(int sindex)
{
    if (config.exe != EX_WIN32)
        return NULL;

    // Generate:
    //  MOV     -4[EBP],sindex

    CodeBuilder cdb;
    cdb.genc(0xC7,modregrm(1,0,BP),FLconst,(targ_uns)nteh_EBPoffset_sindex(),FLconst,sindex);      // 7 bytes long
    code *c = cdb.finish();
    c->Iflags |= CFvolatile;
#ifdef DEBUG
    //assert(GENSINDEXSIZE == calccodsize(c));
#endif
    return c;
}
Exemple #13
0
Fichier : nteh.c Projet : spott/dmd
code *nteh_monitor_epilog(regm_t retregs)
{
    /*
     *  CALL    _d_monitor_epilog
     *  POP     FS:__except_list
     */
    code cs;
    code *c;
    code *cs1;
    code *cs2;
    code *cpop;
    regm_t desregs;
    Symbol *s;

    assert(config.flags2 & CFG2seh);    // BUG: figure out how to implement for other EX's

    s = rtlsym[RTLSYM_MONITOR_EPILOG];
    //desregs = ~s->Sregsaved & ALLREGS;
    desregs = 0;
    gensaverestore(retregs & desregs,&cs1,&cs2);

    c = getregs(desregs);
    c = gencs(c,0xE8,0,FLfunc,s);               // CALL __d_monitor_epilog

    cs.Iop = 0x8F;
    cs.Irm = modregrm(0,0,BPRM);
    cs.Iflags = CFfs;
    cs.Irex = 0;
    cs.IFL1 = FLextern;
    cs.IEVsym1 = rtlsym[RTLSYM_EXCEPT_LIST];
    cs.IEVoffset1 = 0;
    cpop = gen(NULL,&cs);                       // POP FS:__except_list

    c = cat4(cs1,c,cs2,cpop);
    return c;
}
Exemple #14
0
Fichier : nteh.c Projet : spott/dmd
code *nteh_monitor_prolog(Symbol *shandle)
{
    /*
     *  PUSH    handle
     *  PUSH    offset _d_monitor_handler
     *  PUSH    FS:__except_list
     *  MOV     FS:__except_list,ESP
     *  CALL    _d_monitor_prolog
     */
    code *c1 = NULL;
    code *c;
    code cs;
    Symbol *s;
    regm_t desregs;

    assert(config.flags2 & CFG2seh);    // BUG: figure out how to implement for other EX's

    if (shandle->Sclass == SCfastpar)
    {   assert(shandle->Spreg != DX);
        c = gen1(NULL,0x50 + shandle->Spreg);   // PUSH shandle
    }
    else
    {
        // PUSH shandle
#if 0
        c = genc1(NULL,0xFF,modregrm(2,6,4),FLconst,4 * (1 + needframe) + shandle->Soffset + localsize);
        c->Isib = modregrm(0,4,SP);
#else
        useregs(mCX);
        c = genc1(NULL,0x8B,modregrm(2,CX,4),FLconst,4 * (1 + needframe) + shandle->Soffset + localsize);
        c->Isib = modregrm(0,4,SP);
        gen1(c,0x50 + CX);                      // PUSH ECX
#endif
    }

    s = rtlsym[RTLSYM_MONITOR_HANDLER];
    c = gencs(c,0x68,0,FLextern,s);             // PUSH offset _d_monitor_handler
    makeitextern(s);

#if 0
    cs.Iop = 0xFF;
    cs.Irm = modregrm(0,6,BPRM);
    cs.Iflags = CFfs;
    cs.Irex = 0;
    cs.IFL1 = FLextern;
    cs.IEVsym1 = rtlsym[RTLSYM_EXCEPT_LIST];
    cs.IEVoffset1 = 0;
    gen(c,&cs);                         // PUSH FS:__except_list
#else
    useregs(mDX);
    cs.Iop = 0x8B;
    cs.Irm = modregrm(0,DX,BPRM);
    cs.Iflags = CFfs;
    cs.Irex = 0;
    cs.IFL1 = FLextern;
    cs.IEVsym1 = rtlsym[RTLSYM_EXCEPT_LIST];
    cs.IEVoffset1 = 0;
    c1 = gen(c1,&cs);                   // MOV EDX,FS:__except_list

    gen1(c,0x50 + DX);                  // PUSH EDX
#endif

    s = rtlsym[RTLSYM_MONITOR_PROLOG];
    desregs = ~s->Sregsaved & ALLREGS;
    c = cat(c,getregs(desregs));
    c = gencs(c,0xE8,0,FLfunc,s);       // CALL _d_monitor_prolog

    cs.Iop = 0x89;
    NEWREG(cs.Irm,SP);
    gen(c,&cs);                         // MOV FS:__except_list,ESP

    return cat(c1,c);
}
Exemple #15
0
code *cdvector(elem *e, regm_t *pretregs)
{
    /* e should look like one of:
     *    vector
     *      |
     *    param
     *    /   \
     *  param op2
     *  /   \
     * op   op1
     */

    if (!config.fpxmmregs)
    {   printf("SIMD operations not supported on this platform\n");
        exit(1);
    }

    unsigned n = el_nparams(e->E1);
    elem **params = (elem **)malloc(n * sizeof(elem *));
    assert(params);
    elem **tmp = params;
    el_paramArray(&tmp, e->E1);

#if 0
    printf("cdvector()\n");
    for (int i = 0; i < n; i++)
    {
        printf("[%d]: ", i);
        elem_print(params[i]);
    }
#endif

    if (*pretregs == 0)
    {   /* Evaluate for side effects only
         */
        CodeBuilder cdb;
        for (int i = 0; i < n; i++)
        {
            cdb.append(codelem(params[i], pretregs, FALSE));
            *pretregs = 0;      // in case they got set
        }
        return cdb.finish();
    }

    assert(n >= 2 && n <= 4);

    elem *eop = params[0];
    elem *op1 = params[1];
    elem *op2 = NULL;
    tym_t ty2 = 0;
    if (n >= 3)
    {   op2 = params[2];
        ty2 = tybasic(op2->Ety);
    }

    unsigned op = el_tolong(eop);
#ifdef DEBUG
    assert(!isXMMstore(op));
#endif
    tym_t ty1 = tybasic(op1->Ety);
    unsigned sz1 = _tysize[ty1];
//    assert(sz1 == 16);       // float or double

    regm_t retregs;
    CodeBuilder cdb;
    if (n == 3 && ty2 == TYuchar && op2->Eoper == OPconst)
    {   // Handle: op xmm,imm8

        retregs = *pretregs & XMMREGS;
        if (!retregs)
            retregs = XMMREGS;
        cdb.append(codelem(op1,&retregs,FALSE)); // eval left leaf
        unsigned reg = findreg(retregs);
        int r;
        switch (op)
        {
            case PSLLD:  r = 6; op = 0x660F72;  break;
            case PSLLQ:  r = 6; op = 0x660F73;  break;
            case PSLLW:  r = 6; op = 0x660F71;  break;
            case PSRAD:  r = 4; op = 0x660F72;  break;
            case PSRAW:  r = 4; op = 0x660F71;  break;
            case PSRLD:  r = 2; op = 0x660F72;  break;
            case PSRLQ:  r = 2; op = 0x660F73;  break;
            case PSRLW:  r = 2; op = 0x660F71;  break;
            case PSRLDQ: r = 3; op = 0x660F73;  break;
            case PSLLDQ: r = 7; op = 0x660F73;  break;

            default:
                printf("op = x%x\n", op);
                assert(0);
                break;
        }
        cdb.append(getregs(retregs));
        cdb.genc2(op,modregrmx(3,r,reg-XMM0), el_tolong(op2));
    }
    else if (n == 2)
    {   /* Handle: op xmm,mem
         * where xmm is written only, not read
         */
        code cs;

        if ((op1->Eoper == OPind && !op1->Ecount) || op1->Eoper == OPvar)
        {
            cdb.append(getlvalue(&cs, op1, RMload));     // get addressing mode
        }
        else
        {
            regm_t rretregs = XMMREGS;
            cdb.append(codelem(op1, &rretregs, FALSE));
            unsigned rreg = findreg(rretregs) - XMM0;
            cs.Irm = modregrm(3,0,rreg & 7);
            cs.Iflags = 0;
            cs.Irex = 0;
            if (rreg & 8)
                cs.Irex |= REX_B;
        }

        retregs = *pretregs & XMMREGS;
        if (!retregs)
            retregs = XMMREGS;
        unsigned reg;
        cdb.append(allocreg(&retregs, &reg, e->Ety));
        code_newreg(&cs, reg - XMM0);
        cs.Iop = op;
        cdb.gen(&cs);
    }
    else if (n == 3 || n == 4)
    {   /* Handle:
         *      op xmm,mem        // n = 3
         *      op xmm,mem,imm8   // n = 4
         * Both xmm and mem are operands, evaluate xmm first.
         */

        code cs;

        retregs = *pretregs & XMMREGS;
        if (!retregs)
            retregs = XMMREGS;
        cdb.append(codelem(op1,&retregs,FALSE)); // eval left leaf
        unsigned reg = findreg(retregs);

        if ((op2->Eoper == OPind && !op2->Ecount) || op2->Eoper == OPvar)
        {
            cdb.append(getlvalue(&cs, op2, RMload | retregs));     // get addressing mode
        }
        else
        {
            unsigned rretregs = XMMREGS & ~retregs;
            cdb.append(scodelem(op2, &rretregs, retregs, TRUE));
            unsigned rreg = findreg(rretregs) - XMM0;
            cs.Irm = modregrm(3,0,rreg & 7);
            cs.Iflags = 0;
            cs.Irex = 0;
            if (rreg & 8)
                cs.Irex |= REX_B;
        }

        cdb.append(getregs(retregs));
        if (n == 4)
        {
            switch (op)
            {
                case CMPPD:   case CMPSS:   case CMPSD:   case CMPPS:
                case PSHUFD:  case PSHUFHW: case PSHUFLW:
                case BLENDPD: case BLENDPS: case DPPD:    case DPPS:
                case MPSADBW: case PBLENDW:
                case ROUNDPD: case ROUNDPS: case ROUNDSD: case ROUNDSS:
                case SHUFPD:  case SHUFPS:
                    break;
                default:
                    printf("op = x%x\n", op);
                    assert(0);
                    break;
            }
            elem *imm8 = params[3];
            cs.IFL2 = FLconst;
            cs.IEV2.Vsize_t = el_tolong(imm8);
        }
        code_newreg(&cs, reg - XMM0);
        cs.Iop = op;
        cdb.gen(&cs);
    }
    else
        assert(0);
    cdb.append(fixresult(e,retregs,pretregs));
    free(params);
    freenode(e);
    return cdb.finish();
}
Exemple #16
0
code *xmmeq(elem *e, unsigned op, elem *e1, elem *e2,regm_t *pretregs)
{
    tym_t tymll;
    unsigned reg;
    int i;
    code cs;
    elem *e11;
    bool regvar;                  /* TRUE means evaluate into register variable */
    regm_t varregm;
    unsigned varreg;
    targ_int postinc;

    //printf("xmmeq(e1 = %p, e2 = %p, *pretregs = %s)\n", e1, e2, regm_str(*pretregs));
    int e2oper = e2->Eoper;
    tym_t tyml = tybasic(e1->Ety);              /* type of lvalue               */
    regm_t retregs = *pretregs;

    if (!(retregs & XMMREGS))
        retregs = XMMREGS;              // pick any XMM reg

    bool aligned = xmmIsAligned(e1);
    cs.Iop = (op == OPeq) ? xmmstore(tyml, aligned) : op;
    regvar = FALSE;
    varregm = 0;
    if (config.flags4 & CFG4optimized)
    {
        // Be careful of cases like (x = x+x+x). We cannot evaluate in
        // x if x is in a register.
        if (isregvar(e1,&varregm,&varreg) &&    // if lvalue is register variable
            doinreg(e1->EV.sp.Vsym,e2) &&       // and we can compute directly into it
            varregm & XMMREGS
           )
        {   regvar = TRUE;
            retregs = varregm;
            reg = varreg;       /* evaluate directly in target register */
        }
    }
    if (*pretregs & mPSW && !EOP(e1))     // if evaluating e1 couldn't change flags
    {   // Be careful that this lines up with jmpopcode()
        retregs |= mPSW;
        *pretregs &= ~mPSW;
    }
    CodeBuilder cdb;
    cdb.append(scodelem(e2,&retregs,0,TRUE));    // get rvalue

    // Look for special case of (*p++ = ...), where p is a register variable
    if (e1->Eoper == OPind &&
        ((e11 = e1->E1)->Eoper == OPpostinc || e11->Eoper == OPpostdec) &&
        e11->E1->Eoper == OPvar &&
        e11->E1->EV.sp.Vsym->Sfl == FLreg
       )
    {
        postinc = e11->E2->EV.Vint;
        if (e11->Eoper == OPpostdec)
            postinc = -postinc;
        cdb.append(getlvalue(&cs,e11,RMstore | retregs));
        freenode(e11->E2);
    }
    else
    {   postinc = 0;
        cdb.append(getlvalue(&cs,e1,RMstore | retregs));       // get lvalue (cl == CNIL if regvar)
    }

    cdb.append(getregs_imm(regvar ? varregm : 0));

    reg = findreg(retregs & XMMREGS);
    cs.Irm |= modregrm(0,(reg - XMM0) & 7,0);
    if ((reg - XMM0) & 8)
        cs.Irex |= REX_R;

    // Do not generate mov from register onto itself
    if (!(regvar && reg == XMM0 + ((cs.Irm & 7) | (cs.Irex & REX_B ? 8 : 0))))
    {
        cdb.gen(&cs);         // MOV EA+offset,reg
        if (op == OPeq)
            checkSetVex(cdb.last(), tyml);
    }

    if (e1->Ecount ||                     // if lvalue is a CSE or
        regvar)                           // rvalue can't be a CSE
    {
        cdb.append(getregs_imm(retregs));        // necessary if both lvalue and
                                        //  rvalue are CSEs (since a reg
                                        //  can hold only one e at a time)
        cssave(e1,retregs,EOP(e1));     // if lvalue is a CSE
    }

    cdb.append(fixresult(e,retregs,pretregs));
Lp:
    if (postinc)
    {
        int reg = findreg(idxregm(&cs));
        if (*pretregs & mPSW)
        {   // Use LEA to avoid touching the flags
            unsigned rm = cs.Irm & 7;
            if (cs.Irex & REX_B)
                rm |= 8;
            cdb.genc1(0x8D,buildModregrm(2,reg,rm),FLconst,postinc);
            if (tysize(e11->E1->Ety) == 8)
                code_orrex(cdb.last(), REX_W);
        }
        else if (I64)
        {
            cdb.genc2(0x81,modregrmx(3,0,reg),postinc);
            if (tysize(e11->E1->Ety) == 8)
                code_orrex(cdb.last(), REX_W);
        }
        else
        {
            if (postinc == 1)
                cdb.gen1(0x40 + reg);         // INC reg
            else if (postinc == -(targ_int)1)
                cdb.gen1(0x48 + reg);         // DEC reg
            else
            {
                cdb.genc2(0x81,modregrm(3,0,reg),postinc);
            }
        }
    }
    freenode(e1);
    return cdb.finish();
}
Exemple #17
0
code *nteh_prolog()
{
    code cs;

    if (usednteh & NTEHpassthru)
    {
        /* An sindex value of -2 is a magic value that tells the
         * stack unwinder to skip this frame.
         */
        assert(config.exe & (EX_LINUX | EX_LINUX64 | EX_OSX | EX_OSX64 | EX_FREEBSD | EX_FREEBSD64 | EX_SOLARIS | EX_SOLARIS64 | EX_OPENBSD | EX_OPENBSD64));
        cs.Iop = 0x68;
        cs.Iflags = 0;
        cs.Irex = 0;
        cs.IFL2 = FLconst;
        cs.IEV2.Vint = -2;
        return gen(CNIL,&cs);                   // PUSH -2
    }

    /* Generate instance of struct __nt_context on stack frame:
        [  ]                                    // previous ebp already there
        push    -1                              // sindex
        mov     EDX,FS:__except_list
        push    offset FLAT:scope_table         // stable (not for MARS or C++)
        push    offset FLAT:__except_handler3   // handler
        push    EDX                             // prev
        mov     FS:__except_list,ESP
        sub     ESP,8                           // info, esp for __except support
     */

//    useregs(mAX);                     // What is this for?

    CodeBuilder cdb1;

    cs.Iop = 0x68;
    cs.Iflags = 0;
    cs.Irex = 0;
    cs.IFL2 = FLconst;
    cs.IEV2.Vint = -1;
    cdb1.gen(&cs);                 // PUSH -1

    if (MARS || (usednteh & NTEHcpp))
    {
        // PUSH &framehandler
        cs.IFL2 = FLframehandler;
#if MARS
        nteh_scopetable();
#endif
    }
    else
    {
        // Do stable
        cs.Iflags |= CFoff;
        cs.IFL2 = FLextern;
        cs.IEVsym2 = nteh_scopetable();
        cs.IEVoffset2 = 0;
        cdb1.gen(&cs);                       // PUSH &scope_table

        cs.IFL2 = FLextern;
        cs.IEVsym2 = getRtlsym(RTLSYM_EXCEPT_HANDLER3);
        makeitextern(getRtlsym(RTLSYM_EXCEPT_HANDLER3));
    }
    CodeBuilder cdb2;
    cdb2.gen(&cs);                          // PUSH &__except_handler3

    if (config.exe == EX_WIN32)
    {
        makeitextern(getRtlsym(RTLSYM_EXCEPT_LIST));
    #if 0
        cs.Iop = 0xFF;
        cs.Irm = modregrm(0,6,BPRM);
        cs.Iflags = CFfs;
        cs.Irex = 0;
        cs.IFL1 = FLextern;
        cs.IEVsym1 = getRtlsym(RTLSYM_EXCEPT_LIST);
        cs.IEVoffset1 = 0;
        cdb2.gen(&cs);                             // PUSH FS:__except_list
    #else
        useregs(mDX);
        cs.Iop = 0x8B;
        cs.Irm = modregrm(0,DX,BPRM);
        cs.Iflags = CFfs;
        cs.Irex = 0;
        cs.IFL1 = FLextern;
        cs.IEVsym1 = getRtlsym(RTLSYM_EXCEPT_LIST);
        cs.IEVoffset1 = 0;
        cdb1.gen(&cs);                            // MOV EDX,FS:__except_list

        cdb2.gen1(0x50 + DX);                      // PUSH EDX
    #endif
        cs.Iop = 0x89;
        NEWREG(cs.Irm,SP);
        cdb2.gen(&cs);                             // MOV FS:__except_list,ESP
    }

    CodeBuilder cdb3(cod3_stackadj(NULL, 8));

    cdb1.append(cdb2, cdb3);
    return cdb1.finish();
}
Exemple #18
0
Fichier : nteh.c Projet : spott/dmd
code *cdsetjmp(elem *e,regm_t *pretregs)
{   code cs;
    code *c;
    regm_t retregs;
    unsigned stackpushsave;
    unsigned flag;

    c = NULL;
    stackpushsave = stackpush;
#if SCPP
    if (CPP && (funcsym_p->Sfunc->Fflags3 & Fcppeh || usednteh & NTEHcpp))
    {
        /*  If in C++ try block
            If the frame that is calling setjmp has a try,catch block then
            the call to setjmp3 is as follows:
              __setjmp3(environment,3,__cpp_longjmp_unwind,trylevel,funcdata);

            __cpp_longjmp_unwind is a routine in the RTL. This is a
            stdcall routine that will deal with unwinding for CPP Frames.
            trylevel is the value that gets incremented at each catch,
            constructor invocation.
            funcdata is the same value that you put into EAX prior to
            cppframehandler getting called.
         */
        symbol *s;

        s = except_gensym();
        if (!s)
            goto L1;

        c = gencs(c,0x68,0,FLextern,s);                 // PUSH &scope_table
        stackpush += 4;
        genadjesp(c,4);

        c = genc1(c,0xFF,modregrm(1,6,BP),FLconst,(targ_uns)-4);
        // PUSH trylevel
        stackpush += 4;
        genadjesp(c,4);

        cs.Iop = 0x68;
        cs.Iflags = CFoff;
        cs.Irex = 0;
        cs.IFL2 = FLextern;
        cs.IEVsym2 = rtlsym[RTLSYM_CPP_LONGJMP];
        cs.IEVoffset2 = 0;
        c = gen(c,&cs);                         // PUSH &_cpp_longjmp_unwind
        stackpush += 4;
        genadjesp(c,4);

        flag = 3;
    }
    else
#endif
        if (funcsym_p->Sfunc->Fflags3 & Fnteh)
        {
            /*  If in NT SEH try block
                If the frame that is calling setjmp has a try, except block
                then the call to setjmp3 is as follows:
                  __setjmp3(environment,2,__seh_longjmp_unwind,trylevel);
                __seth_longjmp_unwind is supplied by the RTL and is a stdcall
                function. It is the name that MSOFT uses, we should
                probably use the same one.
                trylevel is the value that you increment at each try and
                decrement at the close of the try.  This corresponds to the
                index field of the ehrec.
             */
            int sindex_off;

            sindex_off = 20;                // offset of __context.sindex
            cs.Iop = 0xFF;
            cs.Irm = modregrm(2,6,BPRM);
            cs.Iflags = 0;
            cs.Irex = 0;
            cs.IFL1 = FLbprel;
            cs.IEVsym1 = nteh_contextsym();
            cs.IEVoffset1 = sindex_off;
            c = gen(c,&cs);                 // PUSH scope_index
            stackpush += 4;
            genadjesp(c,4);

            cs.Iop = 0x68;
            cs.Iflags = CFoff;
            cs.Irex = 0;
            cs.IFL2 = FLextern;
            cs.IEVsym2 = rtlsym[RTLSYM_LONGJMP];
            cs.IEVoffset2 = 0;
            c = gen(c,&cs);                 // PUSH &_seh_longjmp_unwind
            stackpush += 4;
            genadjesp(c,4);

            flag = 2;
        }
        else
        {
            /*  If the frame calling setjmp has neither a try..except, nor a
                try..catch, then call setjmp3 as follows:
                _setjmp3(environment,0)
             */
L1:
            flag = 0;
        }

    cs.Iop = 0x68;
    cs.Iflags = 0;
    cs.Irex = 0;
    cs.IFL2 = FLconst;
    cs.IEV2.Vint = flag;
    c = gen(c,&cs);                     // PUSH flag
    stackpush += 4;
    genadjesp(c,4);

    c = cat(c,params(e->E1,REGSIZE));

    c = cat(c,getregs(~rtlsym[RTLSYM_SETJMP3]->Sregsaved & (ALLREGS | mES)));
    gencs(c,0xE8,0,FLfunc,rtlsym[RTLSYM_SETJMP3]);      // CALL __setjmp3

    c = genc2(c,0x81,modregrm(3,0,SP),stackpush - stackpushsave);       // ADD ESP,8
    genadjesp(c,-(stackpush - stackpushsave));

    stackpush = stackpushsave;
    retregs = regmask(e->Ety, TYnfunc);
    return cat(c,fixresult(e,retregs,pretregs));
}
Exemple #19
0
/***************
 * Generate code for OPvecfill (broadcast).
 * OPvecfill takes the single value in e1 and
 * fills the vector type with it.
 */
code *cdvecfill(elem *e, regm_t *pretregs)
{
    //printf("cdvecfill(e = %p, *pretregs = %s)\n",e,regm_str(*pretregs));

    regm_t retregs = *pretregs & XMMREGS;
    if (!retregs)
        retregs = XMMREGS;

    CodeBuilder cdb;
    code *c;
    code cs;

    elem *e1 = e->E1;
#if 0
    if ((e1->Eoper == OPind && !e1->Ecount) || e1->Eoper == OPvar)
    {
        cr = getlvalue(&cs, e1, RMload | retregs);     // get addressing mode
    }
    else
    {
        unsigned rretregs = XMMREGS & ~retregs;
        cr = scodelem(op2, &rretregs, retregs, TRUE);
        unsigned rreg = findreg(rretregs) - XMM0;
        cs.Irm = modregrm(3,0,rreg & 7);
        cs.Iflags = 0;
        cs.Irex = 0;
        if (rreg & 8)
            cs.Irex |= REX_B;
    }
#endif

    unsigned reg;
    unsigned rreg;
    unsigned varreg;
    regm_t varregm;
    tym_t ty = tybasic(e->Ety);
    switch (ty)
    {
        case TYfloat4:
        case TYfloat8:
            if (config.avx &&
                ((e1->Eoper == OPind && !e1->Ecount) || e1->Eoper == OPvar && !isregvar(e1,&varregm,&varreg)) ||
                tysize(ty) == 32 && !isregvar(e1,&varregm,&varreg)
               )
            {
              Lint:
                if (e1->Eoper == OPvar)
                    e1->EV.sp.Vsym->Sflags &= ~GTregcand;

                // VBROADCASTSS XMM,MEM
                cdb.append(getlvalue(&cs, e1, 0));         // get addressing mode
                assert((cs.Irm & 0xC0) != 0xC0);           // AVX1 doesn't have register source operands
                cdb.append(allocreg(&retregs,&reg,ty));
                cs.Iop = VBROADCASTSS;
                cs.Irex &= ~REX_W;
                code_newreg(&cs,reg - XMM0);
                checkSetVex(&cs,ty);
                cdb.gen(&cs);
            }
            else
            {
                // SHUFPS XMM0,XMM0,0    0F C6 /r ib
                c = codelem(e1,&retregs,FALSE); // eval left leaf
                cdb.append(c);
                reg = findreg(retregs) - XMM0;
                cdb.append(getregs(retregs));
                cs.Iop = SHUFPS;
                cs.Irm = modregxrmx(3,reg,reg);
                cs.Iflags = 0;
                cs.IFL2 = FLconst;
                cs.IEV2.Vsize_t = 0;
                if (config.avx >= 2 || tysize(ty) == 32)
                {
                    // VBROADCASTSS XMM,XMM
                    cs.Iop = VBROADCASTSS;
                    checkSetVex(&cs, ty);
                }
                cdb.gen(&cs);
            }
            break;

        case TYdouble2:
        case TYdouble4:
            if (config.avx &&
                ((e1->Eoper == OPind && !e1->Ecount) || e1->Eoper == OPvar && !isregvar(e1,&varregm,&varreg)) ||
                tysize(ty) == 32 && !isregvar(e1,&varregm,&varreg)
               )
            {
                if (e1->Eoper == OPvar)
                    e1->EV.sp.Vsym->Sflags &= ~GTregcand;

                // VBROADCASTSD XMM,MEM
                cdb.append(getlvalue(&cs, e1, 0));         // get addressing mode
                assert((cs.Irm & 0xC0) != 0xC0);           // AVX1 doesn't have register source operands
                cdb.append(allocreg(&retregs,&reg,ty));
                cs.Iop = VBROADCASTSD;
                cs.Irex &= ~REX_W;
                code_newreg(&cs,reg - XMM0);
                checkSetVex(&cs,ty);
                cdb.gen(&cs);
            }
            else
            {
                // UNPCKLPD XMM0,XMM0     66 0F 14 /r
                c = codelem(e1,&retregs,FALSE); // eval left leaf
                cdb.append(c);
                reg = findreg(retregs) - XMM0;
                cdb.append(getregs(retregs));
                cs.Iop = UNPCKLPD;
                cs.Irm = modregxrmx(3,reg,reg);
                cs.Iflags = 0;
                if (config.avx >= 2 || tysize(ty) == 32)
                {
                    // VBROADCASTSD XMM,XMM
                    cs.Iop = VBROADCASTSD;
                    checkSetVex(&cs, ty);
                }
                cdb.gen(&cs);
            }
            break;

        case TYschar16:
        case TYuchar16:
        case TYschar32:
        case TYuchar32:
        {
            /* MOVD      XMM0,r
             * PUNPCKLBW XMM0,XMM0
             * PUNPCKLWD XMM0,XMM0
             * PSHUFD    XMM0,XMM0,0
             */
            regm_t regm = ALLREGS;
            c = codelem(e1,&regm,FALSE); // eval left leaf
            cdb.append(c);
            unsigned r = findreg(regm);

            c = allocreg(&retregs,&reg, e->Ety);
            cdb.append(c);
            reg -= XMM0;
            cdb.gen2(LODD,modregxrmx(3,reg,r));     // MOVD reg,r
            checkSetVex(cdb.last(),TYschar16);

            cs.Iop = PUNPCKLBW;
            cs.Irm = modregxrmx(3,reg,reg);
            cs.Iflags = 0;
            cdb.gen(&cs);
            cs.Iop = PUNPCKLWD;
            cdb.gen(&cs);

            cs.Iop = PSHUFD;
            cs.IFL2 = FLconst;
            cs.IEV2.Vsize_t = 0;
            checkSetVex(&cs,TYschar16);
            cdb.gen(&cs);
            if (tysize(ty) == 32)
            {
                // VINSERTF128 YMM0,YMM0,XMM0,1
                cs.Iop = VINSERTF128;
                cs.Irm = modregxrmx(3,reg,reg);
                cs.Iflags = 0;
                cs.IFL2 = FLconst;
                cs.IEV2.Vsize_t = 1;
                checkSetVex(&cs,ty);
                cdb.gen(&cs);
            }
            break;
        }

        case TYshort8:
        case TYushort8:
        case TYshort16:
        case TYushort16:
        {
            regm_t regm = ALLREGS;
            c = codelem(e1,&regm,FALSE); // eval left leaf
            cdb.append(c);
            unsigned r = findreg(regm);

            if (config.avx || tysize(ty) == 32)
            {
                /*
                 * VPXOR XMM0,XMM0,XMM0
                 * VPINSRW XMM0,XMM0,r,0
                 * VPINSRW XMM0,XMM0,r,1
                 * VPINSRW XMM0,XMM0,r,2
                 * VPINSRW XMM0,XMM0,r,3
                 */
                cdb.append(allocreg(&retregs,&reg, ty));
                cdb.gen2(PXOR,modregxrmx(3,reg-XMM0,reg-XMM0));
                checkSetVex(cdb.last(), TYshort8);
                for (int i = 0; i < tysize(ty) / 4; ++i)
                {
                    cdb.genc2(PINSRW,modregxrmx(3,reg-XMM0,r),i);
                    checkSetVex(cdb.last(), TYshort8);
                }
                if (tysize(ty) == 32)
                {
                    // VINSERTF128 YMM0,YMM0,XMM0,1
                    cs.Iop = VINSERTF128;
                    cs.Irm = modregxrmx(3,reg-XMM0,reg-XMM0);
                    cs.Iflags = 0;
                    cs.IFL2 = FLconst;
                    cs.IEV2.Vsize_t = 1;
                    checkSetVex(&cs,ty);
                    cdb.gen(&cs);
                }
                else
                {
                    // VPSHUFD XMM0,XMM0,0
                    cs.Iop = PSHUFD;
                    cs.Irm = modregxrmx(3,reg-XMM0,reg-XMM0);
                    cs.Iflags = 0;
                    cs.IFL2 = FLconst;
                    cs.IEV2.Vsize_t = 0;
                    checkSetVex(&cs,ty);
                    cdb.gen(&cs);
                }
            }
            else
            {
                /* MOVD      XMM0,r
                 * PUNPCKLWD XMM0,XMM0
                 * PSHUFD    XMM0,XMM0,0
                 */
                c = allocreg(&retregs,&reg, e->Ety);
                cdb.append(c);
                reg -= XMM0;
                cdb.gen2(LODD,modregxrmx(3,reg,r));     // MOVD reg,r
                checkSetVex(cdb.last(),e->Ety);

                cs.Iop = PUNPCKLWD;
                cs.Irm = modregxrmx(3,reg,reg);
                cs.Iflags = 0;
                cdb.gen(&cs);

                cs.Iop = PSHUFD;
                cs.IFL2 = FLconst;
                cs.IEV2.Vsize_t = 0;
                cdb.gen(&cs);
            }
            break;
        }

        case TYlong8:
        case TYulong8:
        case TYlong4:
        case TYulong4:
        {
            if (config.avx &&
                ((e1->Eoper == OPind && !e1->Ecount) || e1->Eoper == OPvar && !isregvar(e1,&varregm,&varreg)) ||
                tysize(ty) == 32 && !isregvar(e1,&varregm,&varreg))
            {
                goto Lint;
            }
            /* MOVD      XMM1,r
             * PSHUFD    XMM0,XMM1,0
             */
            regm_t regm = ALLREGS;
            c = codelem(e1,&regm,FALSE); // eval left leaf
            cdb.append(c);
            unsigned r = findreg(regm);

            c = allocreg(&retregs,&reg, e->Ety);
            cdb.append(c);
            reg -= XMM0;
            cdb.gen2(LODD,modregxrmx(3,reg,r));     // MOVD reg,r

            cs.Iop = PSHUFD;
            cs.Irm = modregxrmx(3,reg,reg);
            cs.Iflags = 0;
            cs.IFL2 = FLconst;
            cs.IEV2.Vsize_t = 0;
            if (config.avx >= 2 || tysize(ty) == 32)
            {
                // VBROADCASTSS XMM,XMM
                cs.Iop = VBROADCASTSS;
                checkSetVex(&cs, ty);
            }
            cdb.gen(&cs);
            break;
        }

        case TYllong2:
        case TYullong2:
        case TYllong4:
        case TYullong4:
            if (config.avx || tysize(ty) >= 32)
            {
                if (e1->Eoper == OPvar)
                    e1->EV.sp.Vsym->Sflags &= ~GTregcand;

                // VMOVDDUP XMM,MEM
                cdb.append(getlvalue(&cs, e1, 0));         // get addressing mode
                if ((cs.Irm & 0xC0) == 0xC0)
                {
                    unsigned sreg = ((cs.Irm & 7) | (cs.Irex & REX_B ? 8 : 0));
                    regm_t sregm = XMMREGS;
                    cdb.append(fixresult(e1, mask[sreg], &sregm));
                    unsigned rmreg = findreg(sregm);
                    cs.Irm = (cs.Irm & ~7) | ((rmreg - XMM0) & 7);
                    if ((rmreg - XMM0) & 8)
                        cs.Irex |= REX_B;
                    else
                        cs.Irex &= ~REX_B;
                }
                cdb.append(allocreg(&retregs,&reg,ty));
                if (config.avx >= 2 ||  tysize(ty) >= 32)
                {
                    cs.Iop = VBROADCASTSD;
                    cs.Irex &= ~REX_W;
                }
                else
                    cs.Iop = MOVDDUP;
                code_newreg(&cs,reg - XMM0);
                checkSetVex(&cs,ty);
                cdb.gen(&cs);
            }
            else
            {
                /* MOVQ XMM0,mem128
                 * PUNPCKLQDQ XMM0,XMM0
                 */
                c = codelem(e1,&retregs,FALSE); // eval left leaf
                cdb.append(c);
                unsigned reg = findreg(retregs);
                reg -= XMM0;
                //cdb.gen2(LODD,modregxrmx(3,reg,r));     // MOVQ reg,r

                cs.Iop = PUNPCKLQDQ;
                cs.Irm = modregxrmx(3,reg,reg);
                cs.Iflags = 0;
                cdb.gen(&cs);
            }
            break;

        default:
            assert(0);
    }

    c = fixresult(e,retregs,pretregs);
    cdb.append(c);
    return cdb.finish();
}
Exemple #20
0
Fichier : nteh.c Projet : spott/dmd
code *nteh_prolog()
{
    code cs;
    code *c1;
    code *c;

    if (usednteh & NTEHpassthru)
    {
        /* An sindex value of -2 is a magic value that tells the
         * stack unwinder to skip this frame.
         */
        assert(config.exe & (EX_LINUX | EX_LINUX64 | EX_OSX | EX_OSX64 | EX_FREEBSD | EX_FREEBSD64 | EX_SOLARIS | EX_SOLARIS64));
        cs.Iop = 0x68;
        cs.Iflags = 0;
        cs.Irex = 0;
        cs.IFL2 = FLconst;
        cs.IEV2.Vint = -2;
        return gen(CNIL,&cs);                   // PUSH -2
    }

    /* Generate instance of struct __nt_context on stack frame:
        [  ]                                    // previous ebp already there
        push    -1                              // sindex
        mov     EDX,FS:__except_list
        push    offset FLAT:scope_table         // stable (not for MARS or C++)
        push    offset FLAT:__except_handler3   // handler
        push    EDX                             // prev
        mov     FS:__except_list,ESP
        sub     ESP,8                           // info, esp for __except support
     */

//    useregs(mAX);                     // What is this for?

    cs.Iop = 0x68;
    cs.Iflags = 0;
    cs.Irex = 0;
    cs.IFL2 = FLconst;
    cs.IEV2.Vint = -1;
    c1 = gen(CNIL,&cs);                 // PUSH -1

    if (usednteh & NTEHcpp || MARS)
    {
        // PUSH &framehandler
        cs.IFL2 = FLframehandler;
#if MARS
        nteh_scopetable();
#endif
    }
    else
    {
        // Do stable
        cs.Iflags |= CFoff;
        cs.IFL2 = FLextern;
        cs.IEVsym2 = nteh_scopetable();
        cs.IEVoffset2 = 0;
        c1 = gen(c1,&cs);                       // PUSH &scope_table

        cs.IFL2 = FLextern;
        cs.IEVsym2 = rtlsym[RTLSYM_EXCEPT_HANDLER3];
        makeitextern(rtlsym[RTLSYM_EXCEPT_HANDLER3]);
    }
    c = gen(NULL,&cs);                          // PUSH &__except_handler3

    if (config.exe == EX_NT)
    {
        makeitextern(rtlsym[RTLSYM_EXCEPT_LIST]);
#if 0
        cs.Iop = 0xFF;
        cs.Irm = modregrm(0,6,BPRM);
        cs.Iflags = CFfs;
        cs.Irex = 0;
        cs.IFL1 = FLextern;
        cs.IEVsym1 = rtlsym[RTLSYM_EXCEPT_LIST];
        cs.IEVoffset1 = 0;
        gen(c,&cs);                             // PUSH FS:__except_list
#else
        useregs(mDX);
        cs.Iop = 0x8B;
        cs.Irm = modregrm(0,DX,BPRM);
        cs.Iflags = CFfs;
        cs.Irex = 0;
        cs.IFL1 = FLextern;
        cs.IEVsym1 = rtlsym[RTLSYM_EXCEPT_LIST];
        cs.IEVoffset1 = 0;
        gen(c1,&cs);                            // MOV EDX,FS:__except_list

        gen1(c,0x50 + DX);                      // PUSH EDX
#endif
        cs.Iop = 0x89;
        NEWREG(cs.Irm,SP);
        gen(c,&cs);                             // MOV FS:__except_list,ESP
    }

    c = genc2(c,0x81,modregrm(3,5,SP),8);       // SUB ESP,8

    return cat(c1,c);
}