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#include        "l.h"

void
span(void)
{
        Prog *p, *q;
        long v, c, idat;
        int m, n, again;

        xdefine("etext", STEXT, 0L);
        idat = INITDAT;
        for(p = firstp; p != P; p = p->link) {
                if(p->as == ATEXT)
                        curtext = p;
                n = 0;
                if(p->to.type == D_BRANCH)
                        if(p->pcond == P)
                                p->pcond = p;
                if((q = p->pcond) != P)
                        if(q->back != 2)
                                n = 1;
                p->back = n;
                if(p->as == AADJSP) {
                        p->to.type = D_SP;
                        v = -p->from.offset;
                        p->from.offset = v;
                        p->as = AADDL;
                        if(v < 0) {
                                p->as = ASUBL;
                                v = -v;
                                p->from.offset = v;
                        }
                        if(v == 0)
                                p->as = ANOP;
                }
        }
        n = 0;

start:
        if(debug['v'])
                Bprint(&bso, "%5.2f span\n", cputime());
        Bflush(&bso);
        c = INITTEXT;
        for(p = firstp; p != P; p = p->link) {
                if(p->as == ATEXT)
                        curtext = p;
                if(p->to.type == D_BRANCH)
                        if(p->back)
                                p->pc = c;
                asmins(p);
                p->pc = c;
                m = andptr-and;
                p->mark = m;
                c += m;
        }

loop:
        n++;
        if(debug['v'])
                Bprint(&bso, "%5.2f span %d\n", cputime(), n);
        Bflush(&bso);
        if(n > 50) {
                print("span must be looping\n");
                errorexit();
        }
        again = 0;
        c = INITTEXT;
        for(p = firstp; p != P; p = p->link) {
                if(p->as == ATEXT)
                        curtext = p;
                if(p->to.type == D_BRANCH) {
                        if(p->back)
                                p->pc = c;
                        asmins(p);
                        m = andptr-and;
                        if(m != p->mark) {
                                p->mark = m;
                                again++;
                        }
                }
                p->pc = c;
                c += p->mark;
        }
        if(again) {
                textsize = c;
                goto loop;
        }
        if(INITRND) {
                INITDAT = rnd(c, INITRND);
                if(INITDAT != idat) {
                        idat = INITDAT;
                        goto start;
                }
        }
        xdefine("etext", STEXT, c);
        if(debug['v'])
                Bprint(&bso, "etext = %lux\n", c);
        Bflush(&bso);
        for(p = textp; p != P; p = p->pcond)
                p->from.sym->value = p->pc;
        textsize = c - INITTEXT;
}

void
xdefine(char *p, int t, long v)
{
        Sym *s;

        s = lookup(p, 0);
        if(s->type == 0 || s->type == SXREF) {
                s->type = t;
                s->value = v;
        }
        if(s->type == STEXT && s->value == 0)
                s->value = v;
}

void
putsymb(char *s, int t, long v, int ver)
{
        int i, f;

        if(t == 'f')
                s++;
        lput(v);
        if(ver)
                t += 'a' - 'A';
        cput(t+0x80);                   /* 0x80 is variable length */

        if(t == 'Z' || t == 'z') {
                cput(s[0]);
                for(i=1; s[i] != 0 || s[i+1] != 0; i += 2) {
                        cput(s[i]);
                        cput(s[i+1]);
                }
                cput(0);
                cput(0);
                i++;
        }
        else {
                for(i=0; s[i]; i++)
                        cput(s[i]);
                cput(0);
        }
        symsize += 4 + 1 + i + 1;

        if(debug['n']) {
                if(t == 'z' || t == 'Z') {
                        Bprint(&bso, "%c %.8lux ", t, v);
                        for(i=1; s[i] != 0 || s[i+1] != 0; i+=2) {
                                f = ((s[i]&0xff) << 8) | (s[i+1]&0xff);
                                Bprint(&bso, "/%x", f);
                        }
                        Bprint(&bso, "\n");
                        return;
                }
                if(ver)
                        Bprint(&bso, "%c %.8lux %s<%d>\n", t, v, s, ver);
                else
                        Bprint(&bso, "%c %.8lux %s\n", t, v, s);
        }
}

void
asmsym(void)
{
        Prog *p;
        Auto *a;
        Sym *s;
        int h;

        s = lookup("etext", 0);
        if(s->type == STEXT)
                putsymb(s->name, 'T', s->value, s->version);

        for(h=0; h<NHASH; h++)
                for(s=hash[h]; s!=S; s=s->link)
                        switch(s->type) {
                        case SCONST:
                                putsymb(s->name, 'D', s->value, s->version);
                                continue;

                        case SDATA:
                                putsymb(s->name, 'D', s->value+INITDAT, s->version);
                                continue;

                        case SBSS:
                                putsymb(s->name, 'B', s->value+INITDAT, s->version);
                                continue;

                        case SFILE:
                                putsymb(s->name, 'f', s->value, s->version);
                                continue;
                        }

        for(p=textp; p!=P; p=p->pcond) {
                s = p->from.sym;
                if(s->type != STEXT)
                        continue;

                /* filenames first */
                for(a=p->to.autom; a; a=a->link)
                        if(a->type == D_FILE)
                                putsymb(a->asym->name, 'z', a->aoffset, 0);
                        else
                        if(a->type == D_FILE1)
                                putsymb(a->asym->name, 'Z', a->aoffset, 0);

                putsymb(s->name, 'T', s->value, s->version);

                /* frame, auto and param after */
                putsymb(".frame", 'm', p->to.offset+4, 0);

                for(a=p->to.autom; a; a=a->link)
                        if(a->type == D_AUTO)
                                putsymb(a->asym->name, 'a', -a->aoffset, 0);
                        else
                        if(a->type == D_PARAM)
                                putsymb(a->asym->name, 'p', a->aoffset, 0);
        }
        if(debug['v'] || debug['n'])
                Bprint(&bso, "symsize = %lud\n", symsize);
        Bflush(&bso);
}

void
asmlc(void)
{
        long oldpc, oldlc;
        Prog *p;
        long v, s;

        oldpc = INITTEXT;
        oldlc = 0;
        for(p = firstp; p != P; p = p->link) {
                if(p->line == oldlc || p->as == ATEXT || p->as == ANOP) {
                        if(p->as == ATEXT)
                                curtext = p;
                        if(debug['V'])
                                Bprint(&bso, "%6lux %P\n",
                                        p->pc, p);
                        continue;
                }
                if(debug['V'])
                        Bprint(&bso, "\t\t%6ld", lcsize);
                v = (p->pc - oldpc) / MINLC;
                while(v) {
                        s = 127;
                        if(v < 127)
                                s = v;
                        cput(s+128);    /* 129-255 +pc */
                        if(debug['V'])
                                Bprint(&bso, " pc+%ld*%d(%ld)", s, MINLC, s+128);
                        v -= s;
                        lcsize++;
                }
                s = p->line - oldlc;
                oldlc = p->line;
                oldpc = p->pc + MINLC;
                if(s > 64 || s < -64) {
                        cput(0);        /* 0 vv +lc */
                        cput(s>>24);
                        cput(s>>16);
                        cput(s>>8);
                        cput(s);
                        if(debug['V']) {
                                if(s > 0)
                                        Bprint(&bso, " lc+%ld(%d,%ld)\n",
                                                s, 0, s);
                                else
                                        Bprint(&bso, " lc%ld(%d,%ld)\n",
                                                s, 0, s);
                                Bprint(&bso, "%6lux %P\n",
                                        p->pc, p);
                        }
                        lcsize += 5;
                        continue;
                }
                if(s > 0) {
                        cput(0+s);      /* 1-64 +lc */
                        if(debug['V']) {
                                Bprint(&bso, " lc+%ld(%ld)\n", s, 0+s);
                                Bprint(&bso, "%6lux %P\n",
                                        p->pc, p);
                        }
                } else {
                        cput(64-s);     /* 65-128 -lc */
                        if(debug['V']) {
                                Bprint(&bso, " lc%ld(%ld)\n", s, 64-s);
                                Bprint(&bso, "%6lux %P\n",
                                        p->pc, p);
                        }
                }
                lcsize++;
        }
        while(lcsize & 1) {
                s = 129;
                cput(s);
                lcsize++;
        }
        if(debug['v'] || debug['V'])
                Bprint(&bso, "lcsize = %ld\n", lcsize);
        Bflush(&bso);
}

int
prefixof(Adr *a)
{
        switch(a->type) {
        case D_INDIR+D_CS:
                return 0x2e;
        case D_INDIR+D_DS:
                return 0x3e;
        case D_INDIR+D_ES:
                return 0x26;
        case D_INDIR+D_FS:
                return 0x64;
        case D_INDIR+D_GS:
                return 0x65;
        }
        return 0;
}

int
oclass(Adr *a)
{
        long v;

        if(a->type >= D_INDIR || a->index != D_NONE) {
                if(a->index != D_NONE && a->scale == 0) {
                        if(a->type == D_ADDR) {
                                switch(a->index) {
                                case D_EXTERN:
                                case D_STATIC:
                                        return Yi32;
                                case D_AUTO:
                                case D_PARAM:
                                        return Yiauto;
                                }
                                return Yxxx;
                        }
                        return Ycol;
                }
                return Ym;
        }
        switch(a->type)
        {
        case D_AL:
                return Yal;

        case D_AX:
                return Yax;

        case D_CL:
                return Ycl;

        case D_DL:
        case D_BL:
        case D_AH:
        case D_CH:
        case D_DH:
        case D_BH:
                return Yrb;

        case D_CX:
                return Ycx;

        case D_DX:
        case D_BX:
                return Yrx;

        case D_SP:
        case D_BP:
        case D_SI:
        case D_DI:
                return Yrl;

        case D_F0+0:
                return  Yf0;

        case D_F0+1:
        case D_F0+2:
        case D_F0+3:
        case D_F0+4:
        case D_F0+5:
        case D_F0+6:
        case D_F0+7:
                return  Yrf;

        case D_NONE:
                return Ynone;

        case D_CS:      return  Ycs;
        case D_SS:      return  Yss;
        case D_DS:      return  Yds;
        case D_ES:      return  Yes;
        case D_FS:      return  Yfs;
        case D_GS:      return  Ygs;

        case D_GDTR:    return  Ygdtr;
        case D_IDTR:    return  Yidtr;
        case D_LDTR:    return  Yldtr;
        case D_MSW:     return  Ymsw;
        case D_TASK:    return  Ytask;

        case D_CR+0:    return  Ycr0;
        case D_CR+1:    return  Ycr1;
        case D_CR+2:    return  Ycr2;
        case D_CR+3:    return  Ycr3;
        case D_CR+4:    return  Ycr4;
        case D_CR+5:    return  Ycr5;
        case D_CR+6:    return  Ycr6;
        case D_CR+7:    return  Ycr7;

        case D_DR+0:    return  Ydr0;
        case D_DR+1:    return  Ydr1;
        case D_DR+2:    return  Ydr2;
        case D_DR+3:    return  Ydr3;
        case D_DR+4:    return  Ydr4;
        case D_DR+5:    return  Ydr5;
        case D_DR+6:    return  Ydr6;
        case D_DR+7:    return  Ydr7;

        case D_TR+0:    return  Ytr0;
        case D_TR+1:    return  Ytr1;
        case D_TR+2:    return  Ytr2;
        case D_TR+3:    return  Ytr3;
        case D_TR+4:    return  Ytr4;
        case D_TR+5:    return  Ytr5;
        case D_TR+6:    return  Ytr6;
        case D_TR+7:    return  Ytr7;

        case D_EXTERN:
        case D_STATIC:
        case D_AUTO:
        case D_PARAM:
                return Ym;

        case D_CONST:
        case D_ADDR:
                if(a->sym == S) {
                        v = a->offset;
                        if(v == 0)
                                return Yi0;
                        if(v == 1)
                                return Yi1;
                        if(v >= -128 && v <= 127)
                                return Yi8;
                }
                return Yi32;

        case D_BRANCH:
                return Ybr;
        }
        return Yxxx;
}

void
asmidx(Adr *a, int base)
{
        int i;

        switch(a->index) {
        default:
                goto bad;

        case D_NONE:
                i = 4 << 3;
                goto bas;

        case D_AX:
        case D_CX:
        case D_DX:
        case D_BX:
        case D_BP:
        case D_SI:
        case D_DI:
                i = reg[a->index] << 3;
                break;
        }
        switch(a->scale) {
        default:
                goto bad;
        case 1:
                break;
        case 2:
                i |= (1<<6);
                break;
        case 4:
                i |= (2<<6);
                break;
        case 8:
                i |= (3<<6);
                break;
        }
bas:
        switch(base) {
        default:
                goto bad;
        case D_NONE:    /* must be mod=00 */
                i |= 5;
                break;
        case D_AX:
        case D_CX:
        case D_DX:
        case D_BX:
        case D_SP:
        case D_BP:
        case D_SI:
        case D_DI:
                i |= reg[base];
                break;
        }
        *andptr++ = i;
        return;
bad:
        diag("asmidx: bad address %D", a);
        *andptr++ = 0;
        return;
}

static void
put4(long v)
{
        if(dlm && curp != P && reloca != nil){
                dynreloc(reloca->sym, curp->pc + andptr - &and[0], 1);
                reloca = nil;
        }
        andptr[0] = v;
        andptr[1] = v>>8;
        andptr[2] = v>>16;
        andptr[3] = v>>24;
        andptr += 4;
}

long
vaddr(Adr *a)
{
        int t;
        long v;
        Sym *s;

        t = a->type;
        v = a->offset;
        if(t == D_ADDR)
                t = a->index;
        switch(t) {
        case D_STATIC:
        case D_EXTERN:
                s = a->sym;
                if(s != nil) {
                        if(dlm && curp != P)
                                reloca = a;
                        switch(s->type) {
                        case SUNDEF:
                                ckoff(s, v);
                        case STEXT:
                        case SCONST:
                                v += s->value;
                                break;
                        default:
                                v += INITDAT + s->value;
                        }
                }
        }
        return v;
}

void
asmand(Adr *a, int r)
{
        long v;
        int t;
        Adr aa;

        v = a->offset;
        t = a->type;
        if(a->index != D_NONE) {
                if(t >= D_INDIR) {
                        t -= D_INDIR;
                        if(t == D_NONE) {
                                *andptr++ = (0 << 6) | (4 << 0) | (r << 3);
                                asmidx(a, t);
                                put4(v);
                                return;
                        }
                        if(v == 0 && t != D_BP) {
                                *andptr++ = (0 << 6) | (4 << 0) | (r << 3);
                                asmidx(a, t);
                                return;
                        }
                        if(v >= -128 && v < 128) {
                                *andptr++ = (1 << 6) | (4 << 0) | (r << 3);
                                asmidx(a, t);
                                *andptr++ = v;
                                return;
                        }
                        *andptr++ = (2 << 6) | (4 << 0) | (r << 3);
                        asmidx(a, t);
                        put4(v);
                        return;
                }
                switch(t) {
                default:
                        goto bad;
                case D_STATIC:
                case D_EXTERN:
                        aa.type = D_NONE+D_INDIR;
                        break;
                case D_AUTO:
                case D_PARAM:
                        aa.type = D_SP+D_INDIR;
                        break;
                }
                aa.offset = vaddr(a);
                aa.index = a->index;
                aa.scale = a->scale;
                asmand(&aa, r);
                return;
        }
        if(t >= D_AL && t <= D_F0+7) {
                if(v)
                        goto bad;
                *andptr++ = (3 << 6) | (reg[t] << 0) | (r << 3);
                return;
        }
        if(t >= D_INDIR) {
                t -= D_INDIR;
                if(t == D_NONE || D_CS <= t && t <= D_GS) {
                        *andptr++ = (0 << 6) | (5 << 0) | (r << 3);
                        put4(v);
                        return;
                }
                if(t == D_SP) {
                        if(v == 0) {
                                *andptr++ = (0 << 6) | (4 << 0) | (r << 3);
                                asmidx(a, D_SP);
                                return;
                        }
                        if(v >= -128 && v < 128) {
                                *andptr++ = (1 << 6) | (4 << 0) | (r << 3);
                                asmidx(a, D_SP);
                                *andptr++ = v;
                                return;
                        }
                        *andptr++ = (2 << 6) | (4 << 0) | (r << 3);
                        asmidx(a, D_SP);
                        put4(v);
                        return;
                }
                if(t >= D_AX && t <= D_DI) {
                        if(v == 0 && t != D_BP) {
                                *andptr++ = (0 << 6) | (reg[t] << 0) | (r << 3);
                                return;
                        }
                        if(v >= -128 && v < 128) {
                                andptr[0] = (1 << 6) | (reg[t] << 0) | (r << 3);
                                andptr[1] = v;
                                andptr += 2;
                                return;
                        }
                        *andptr++ = (2 << 6) | (reg[t] << 0) | (r << 3);
                        put4(v);
                        return;
                }
                goto bad;
        }
        switch(a->type) {
        default:
                goto bad;
        case D_STATIC:
        case D_EXTERN:
                aa.type = D_NONE+D_INDIR;
                break;
        case D_AUTO:
        case D_PARAM:
                aa.type = D_SP+D_INDIR;
                break;
        }
        aa.index = D_NONE;
        aa.scale = 1;
        aa.offset = vaddr(a);
        asmand(&aa, r);
        return;
bad:
        diag("asmand: bad address %D", a);
        return;
}

#define E       0xff
uchar   ymovtab[] =
{
/* push */
        APUSHL, Ycs,    Ynone,  0,      0x0e,E,0,0,
        APUSHL, Yss,    Ynone,  0,      0x16,E,0,0,
        APUSHL, Yds,    Ynone,  0,      0x1e,E,0,0,
        APUSHL, Yes,    Ynone,  0,      0x06,E,0,0,
        APUSHL, Yfs,    Ynone,  0,      0x0f,0xa0,E,0,
        APUSHL, Ygs,    Ynone,  0,      0x0f,0xa8,E,0,

        APUSHW, Ycs,    Ynone,  0,      Pe,0x0e,E,0,
        APUSHW, Yss,    Ynone,  0,      Pe,0x16,E,0,
        APUSHW, Yds,    Ynone,  0,      Pe,0x1e,E,0,
        APUSHW, Yes,    Ynone,  0,      Pe,0x06,E,0,
        APUSHW, Yfs,    Ynone,  0,      Pe,0x0f,0xa0,E,
        APUSHW, Ygs,    Ynone,  0,      Pe,0x0f,0xa8,E,

/* pop */
        APOPL,  Ynone,  Yds,    0,      0x1f,E,0,0,
        APOPL,  Ynone,  Yes,    0,      0x07,E,0,0,
        APOPL,  Ynone,  Yss,    0,      0x17,E,0,0,
        APOPL,  Ynone,  Yfs,    0,      0x0f,0xa1,E,0,
        APOPL,  Ynone,  Ygs,    0,      0x0f,0xa9,E,0,

        APOPW,  Ynone,  Yds,    0,      Pe,0x1f,E,0,
        APOPW,  Ynone,  Yes,    0,      Pe,0x07,E,0,
        APOPW,  Ynone,  Yss,    0,      Pe,0x17,E,0,
        APOPW,  Ynone,  Yfs,    0,      Pe,0x0f,0xa1,E,
        APOPW,  Ynone,  Ygs,    0,      Pe,0x0f,0xa9,E,

/* mov seg */
        AMOVW,  Yes,    Yml,    1,      0x8c,0,0,0,
        AMOVW,  Ycs,    Yml,    1,      0x8c,1,0,0,
        AMOVW,  Yss,    Yml,    1,      0x8c,2,0,0,
        AMOVW,  Yds,    Yml,    1,      0x8c,3,0,0,
        AMOVW,  Yfs,    Yml,    1,      0x8c,4,0,0,
        AMOVW,  Ygs,    Yml,    1,      0x8c,5,0,0,

        AMOVW,  Yml,    Yes,    2,      0x8e,0,0,0,
        AMOVW,  Yml,    Ycs,    2,      0x8e,1,0,0,
        AMOVW,  Yml,    Yss,    2,      0x8e,2,0,0,
        AMOVW,  Yml,    Yds,    2,      0x8e,3,0,0,
        AMOVW,  Yml,    Yfs,    2,      0x8e,4,0,0,
        AMOVW,  Yml,    Ygs,    2,      0x8e,5,0,0,

/* mov cr */
        AMOVL,  Ycr0,   Yml,    3,      0x0f,0x20,0,0,
        AMOVL,  Ycr2,   Yml,    3,      0x0f,0x20,2,0,
        AMOVL,  Ycr3,   Yml,    3,      0x0f,0x20,3,0,
        AMOVL,  Ycr4,   Yml,    3,      0x0f,0x20,4,0,

        AMOVL,  Yml,    Ycr0,   4,      0x0f,0x22,0,0,
        AMOVL,  Yml,    Ycr2,   4,      0x0f,0x22,2,0,
        AMOVL,  Yml,    Ycr3,   4,      0x0f,0x22,3,0,
        AMOVL,  Yml,    Ycr4,   4,      0x0f,0x22,4,0,

/* mov dr */
        AMOVL,  Ydr0,   Yml,    3,      0x0f,0x21,0,0,
        AMOVL,  Ydr6,   Yml,    3,      0x0f,0x21,6,0,
        AMOVL,  Ydr7,   Yml,    3,      0x0f,0x21,7,0,

        AMOVL,  Yml,    Ydr0,   4,      0x0f,0x23,0,0,
        AMOVL,  Yml,    Ydr6,   4,      0x0f,0x23,6,0,
        AMOVL,  Yml,    Ydr7,   4,      0x0f,0x23,7,0,

/* mov tr */
        AMOVL,  Ytr6,   Yml,    3,      0x0f,0x24,6,0,
        AMOVL,  Ytr7,   Yml,    3,      0x0f,0x24,7,0,

        AMOVL,  Yml,    Ytr6,   4,      0x0f,0x26,6,E,
        AMOVL,  Yml,    Ytr7,   4,      0x0f,0x26,7,E,

/* lgdt, sgdt, lidt, sidt */
        AMOVL,  Ym,     Ygdtr,  4,      0x0f,0x01,2,0,
        AMOVL,  Ygdtr,  Ym,     3,      0x0f,0x01,0,0,
        AMOVL,  Ym,     Yidtr,  4,      0x0f,0x01,3,0,
        AMOVL,  Yidtr,  Ym,     3,      0x0f,0x01,1,0,

/* lldt, sldt */
        AMOVW,  Yml,    Yldtr,  4,      0x0f,0x00,2,0,
        AMOVW,  Yldtr,  Yml,    3,      0x0f,0x00,0,0,

/* lmsw, smsw */
        AMOVW,  Yml,    Ymsw,   4,      0x0f,0x01,6,0,
        AMOVW,  Ymsw,   Yml,    3,      0x0f,0x01,4,0,

/* ltr, str */
        AMOVW,  Yml,    Ytask,  4,      0x0f,0x00,3,0,
        AMOVW,  Ytask,  Yml,    3,      0x0f,0x00,1,0,

/* load full pointer */
        AMOVL,  Yml,    Ycol,   5,      0,0,0,0,
        AMOVW,  Yml,    Ycol,   5,      Pe,0,0,0,

/* double shift */
        ASHLL,  Ycol,   Yml,    6,      0xa4,0xa5,0,0,
        ASHRL,  Ycol,   Yml,    6,      0xac,0xad,0,0,

/* extra imul */
        AIMULW, Yml,    Yrl,    7,      Pq,0xaf,0,0,
        AIMULL, Yml,    Yrl,    7,      Pm,0xaf,0,0,
        0
};

int
isax(Adr *a)
{

        switch(a->type) {
        case D_AX:
        case D_AL:
        case D_AH:
        case D_INDIR+D_AX:
                return 1;
        }
        if(a->index == D_AX)
                return 1;
        return 0;
}

void
subreg(Prog *p, int from, int to)
{

        if(debug['Q'])
                print("\n%P     s/%R/%R/\n", p, from, to);

        if(p->from.type == from)
                p->from.type = to;
        if(p->to.type == from)
                p->to.type = to;

        if(p->from.index == from)
                p->from.index = to;
        if(p->to.index == from)
                p->to.index = to;

        from += D_INDIR;
        if(p->from.type == from)
                p->from.type = to+D_INDIR;
        if(p->to.type == from)
                p->to.type = to+D_INDIR;

        if(debug['Q'])
                print("%P\n", p);
}

void
doasm(Prog *p)
{
        Optab *o;
        Prog *q, pp;
        uchar *t;
        int z, op, ft, tt;
        long v, pre;

        pre = prefixof(&p->from);
        if(pre)
                *andptr++ = pre;
        pre = prefixof(&p->to);
        if(pre)
                *andptr++ = pre;

        o = &optab[p->as];
        ft = oclass(&p->from) * Ymax;
        tt = oclass(&p->to) * Ymax;
        t = o->ytab;
        if(t == 0) {
                diag("asmins: noproto %P", p);
                return;
        }
        for(z=0; *t; z+=t[3],t+=4)
                if(ycover[ft+t[0]])
                if(ycover[tt+t[1]])
                        goto found;
        goto domov;

found:
        switch(o->prefix) {
        case Pq:        /* 16 bit escape and opcode escape */
                *andptr++ = Pe;
                *andptr++ = Pm;
                break;

        case Pm:        /* opcode escape */
                *andptr++ = Pm;
                break;

        case Pe:        /* 16 bit escape */
                *andptr++ = Pe;
                break;

        case Pb:        /* botch */
                break;
        }
        v = vaddr(&p->from);
        op = o->op[z];
        switch(t[2]) {
        default:
                diag("asmins: unknown z %d %P", t[2], p);
                return;

        case Zpseudo:
                break;

        case Zlit:
                for(; op = o->op[z]; z++)
                        *andptr++ = op;
                break;

        case Zm_r:
                *andptr++ = op;
                asmand(&p->from, reg[p->to.type]);
                break;

        case Zaut_r:
                *andptr++ = 0x8d;       /* leal */
                if(p->from.type != D_ADDR)
                        diag("asmins: Zaut sb type ADDR");
                p->from.type = p->from.index;
                p->from.index = D_NONE;
                asmand(&p->from, reg[p->to.type]);
                p->from.index = p->from.type;
                p->from.type = D_ADDR;
                break;

        case Zm_o:
                *andptr++ = op;
                asmand(&p->from, o->op[z+1]);
                break;

        case Zr_m:
                *andptr++ = op;
                asmand(&p->to, reg[p->from.type]);
                break;

        case Zo_m:
                *andptr++ = op;
                asmand(&p->to, o->op[z+1]);
                break;

        case Zm_ibo:
                v = vaddr(&p->to);
                *andptr++ = op;
                asmand(&p->from, o->op[z+1]);
                *andptr++ = v;
                break;

        case Zibo_m:
                *andptr++ = op;
                asmand(&p->to, o->op[z+1]);
                *andptr++ = v;
                break;

        case Z_ib:
                v = vaddr(&p->to);
        case Zib_:
                *andptr++ = op;
                *andptr++ = v;
                break;

        case Zib_rp:
                *andptr++ = op + reg[p->to.type];
                *andptr++ = v;
                break;

        case Zil_rp:
                *andptr++ = op + reg[p->to.type];
                if(o->prefix == Pe) {
                        *andptr++ = v;
                        *andptr++ = v>>8;
                }
                else
                        put4(v);
                break;

        case Zib_rr:
                *andptr++ = op;
                asmand(&p->to, reg[p->to.type]);
                *andptr++ = v;
                break;

        case Z_il:
                v = vaddr(&p->to);
        case Zil_:
                *andptr++ = op;
                if(o->prefix == Pe) {
                        *andptr++ = v;
                        *andptr++ = v>>8;
                }
                else
                        put4(v);
                break;

        case Zm_ilo:
                v = vaddr(&p->to);
                *andptr++ = op;
                asmand(&p->from, o->op[z+1]);
                if(o->prefix == Pe) {
                        *andptr++ = v;
                        *andptr++ = v>>8;
                }
                else
                        put4(v);
                break;

        case Zilo_m:
                *andptr++ = op;
                asmand(&p->to, o->op[z+1]);
                if(o->prefix == Pe) {
                        *andptr++ = v;
                        *andptr++ = v>>8;
                }
                else
                        put4(v);
                break;

        case Zil_rr:
                *andptr++ = op;
                asmand(&p->to, reg[p->to.type]);
                if(o->prefix == Pe) {
                        *andptr++ = v;
                        *andptr++ = v>>8;
                }
                else
                        put4(v);
                break;

        case Z_rp:
                *andptr++ = op + reg[p->to.type];
                break;

        case Zrp_:
                *andptr++ = op + reg[p->from.type];
                break;

        case Zclr:
                *andptr++ = op;
                asmand(&p->to, reg[p->to.type]);
                break;

        case Zbr:
                q = p->pcond;
                if(q) {
                        v = q->pc - p->pc - 2;
                        if(v >= -128 && v <= 127) {
                                *andptr++ = op;
                                *andptr++ = v;
                        } else {
                                v -= 6-2;
                                *andptr++ = 0x0f;
                                *andptr++ = o->op[z+1];
                                *andptr++ = v;
                                *andptr++ = v>>8;
                                *andptr++ = v>>16;
                                *andptr++ = v>>24;
                        }
                }
                break;

        case Zcall:
                q = p->pcond;
                if(q) {
                        v = q->pc - p->pc - 5;
                        if(dlm && curp != P && p->to.sym->type == SUNDEF){
                                /* v = 0 - p->pc - 5; */
                                v = 0;
                                ckoff(p->to.sym, v);
                                v += p->to.sym->value;
                                dynreloc(p->to.sym, p->pc+1, 0);
                        }
                        *andptr++ = op;
                        *andptr++ = v;
                        *andptr++ = v>>8;
                        *andptr++ = v>>16;
                        *andptr++ = v>>24;
                }
                break;

        case Zjmp:
                q = p->pcond;
                if(q) {
                        v = q->pc - p->pc - 2;
                        if(v >= -128 && v <= 127) {
                                *andptr++ = op;
                                *andptr++ = v;
                        } else {
                                v -= 5-2;
                                *andptr++ = o->op[z+1];
                                *andptr++ = v;
                                *andptr++ = v>>8;
                                *andptr++ = v>>16;
                                *andptr++ = v>>24;
                        }
                }
                break;

        case Zloop:
                q = p->pcond;
                if(q) {
                        v = q->pc - p->pc - 2;
                        if(v < -128 || v > 127)
                                diag("loop too far: %P", p);
                        *andptr++ = op;
                        *andptr++ = v;
                }
                break;

        case Zbyte:
                *andptr++ = v;
                if(op > 1) {
                        *andptr++ = v>>8;
                        if(op > 2) {
                                *andptr++ = v>>16;
                                *andptr++ = v>>24;
                        }
                }
                break;

        case Zmov:
                goto domov;
        }
        return;

domov:
        for(t=ymovtab; *t; t+=8)
                if(p->as == t[0])
                if(ycover[ft+t[1]])
                if(ycover[tt+t[2]])
                        goto mfound;
bad:
        /*
         * here, the assembly has failed.
         * if its a byte instruction that has
         * unaddressable registers, try to
         * exchange registers and reissue the
         * instruction with the operands renamed.
         */
        pp = *p;
        z = p->from.type;
        if(z >= D_BP && z <= D_DI) {
                if(isax(&p->to)) {
                        *andptr++ = 0x87;                       /* xchg lhs,bx */
                        asmand(&p->from, reg[D_BX]);
                        subreg(&pp, z, D_BX);
                        doasm(&pp);
                        *andptr++ = 0x87;                       /* xchg lhs,bx */
                        asmand(&p->from, reg[D_BX]);
                } else {
                        *andptr++ = 0x90 + reg[z];              /* xchg lsh,ax */
                        subreg(&pp, z, D_AX);
                        doasm(&pp);
                        *andptr++ = 0x90 + reg[z];              /* xchg lsh,ax */
                }
                return;
        }
        z = p->to.type;
        if(z >= D_BP && z <= D_DI) {
                if(isax(&p->from)) {
                        *andptr++ = 0x87;                       /* xchg rhs,bx */
                        asmand(&p->to, reg[D_BX]);
                        subreg(&pp, z, D_BX);
                        doasm(&pp);
                        *andptr++ = 0x87;                       /* xchg rhs,bx */
                        asmand(&p->to, reg[D_BX]);
                } else {
                        *andptr++ = 0x90 + reg[z];              /* xchg rsh,ax */
                        subreg(&pp, z, D_AX);
                        doasm(&pp);
                        *andptr++ = 0x90 + reg[z];              /* xchg rsh,ax */
                }
                return;
        }
        diag("doasm: notfound t2=%ux from=%ux to=%ux %P", t[2], p->from.type, p->to.type, p);
        return;

mfound:
        switch(t[3]) {
        default:
                diag("asmins: unknown mov %d %P", t[3], p);
                break;

        case 0:  /* lit */
                for(z=4; t[z]!=E; z++)
                        *andptr++ = t[z];
                break;

        case 1: /* r,m */
                *andptr++ = t[4];
                asmand(&p->to, t[5]);
                break;

        case 2: /* m,r */
                *andptr++ = t[4];
                asmand(&p->from, t[5]);
                break;

        case 3: /* r,m - 2op */
                *andptr++ = t[4];
                *andptr++ = t[5];
                asmand(&p->to, t[6]);
                break;

        case 4: /* m,r - 2op */
                *andptr++ = t[4];
                *andptr++ = t[5];
                asmand(&p->from, t[6]);
                break;

        case 5: /* load full pointer, trash heap */
                if(t[4])
                        *andptr++ = t[4];
                switch(p->to.index) {
                default:
                        goto bad;
                case D_DS:
                        *andptr++ = 0xc5;
                        break;
                case D_SS:
                        *andptr++ = 0x0f;
                        *andptr++ = 0xb2;
                        break;
                case D_ES:
                        *andptr++ = 0xc4;
                        break;
                case D_FS:
                        *andptr++ = 0x0f;
                        *andptr++ = 0xb4;
                        break;
                case D_GS:
                        *andptr++ = 0x0f;
                        *andptr++ = 0xb5;
                        break;
                }
                asmand(&p->from, reg[p->to.type]);
                break;

        case 6: /* double shift */
                z = p->from.type;
                switch(z) {
                default:
                        goto bad;
                case D_CONST:
                        *andptr++ = 0x0f;
                        *andptr++ = t[4];
                        asmand(&p->to, reg[p->from.index]);
                        *andptr++ = p->from.offset;
                        break;
                case D_CL:
                case D_CX:
                        *andptr++ = 0x0f;
                        *andptr++ = t[5];
                        asmand(&p->to, reg[p->from.index]);
                        break;
                }
                break;

        case 7: /* imul rm,r */
                *andptr++ = t[4];
                *andptr++ = t[5];
                asmand(&p->from, reg[p->to.type]);
                break;
        }
}

void
asmins(Prog *p)
{

        andptr = and;
        doasm(p);
}

enum{
        ABSD = 0,
        ABSU = 1,
        RELD = 2,
        RELU = 3,
};

int modemap[4] = { 0, 1, -1, 2, };

typedef struct Reloc Reloc;

struct Reloc
{
        int n;
        int t;
        uchar *m;
        ulong *a;
};

Reloc rels;

static void
grow(Reloc *r)
{
        int t;
        uchar *m, *nm;
        ulong *a, *na;

        t = r->t;
        r->t += 64;
        m = r->m;
        a = r->a;
        r->m = nm = malloc(r->t*sizeof(uchar));
        r->a = na = malloc(r->t*sizeof(ulong));
        memmove(nm, m, t*sizeof(uchar));
        memmove(na, a, t*sizeof(ulong));
        free(m);
        free(a);
}

void
dynreloc(Sym *s, ulong v, int abs)
{
        int i, k, n;
        uchar *m;
        ulong *a;
        Reloc *r;

        if(s->type == SUNDEF)
                k = abs ? ABSU : RELU;
        else
                k = abs ? ABSD : RELD;
        /* Bprint(&bso, "R %s a=%ld(%lx) %d\n", s->name, v, v, k); */
        k = modemap[k];
        r = &rels;
        n = r->n;
        if(n >= r->t)
                grow(r);
        m = r->m;
        a = r->a;
        for(i = n; i > 0; i--){
                if(v < a[i-1]){ /* happens occasionally for data */
                        m[i] = m[i-1];
                        a[i] = a[i-1];
                }
                else
                        break;
        }
        m[i] = k;
        a[i] = v;
        r->n++;
}

static int
sput(char *s)
{
        char *p;

        p = s;
        while(*s)
                cput(*s++);
        cput(0);
        return s-p+1;
}

void
asmdyn()
{
        int i, n, t, c;
        Sym *s;
        ulong la, ra, *a;
        vlong off;
        uchar *m;
        Reloc *r;

        cflush();
        off = seek(cout, 0, 1);
        lput(0);
        t = 0;
        lput(imports);
        t += 4;
        for(i = 0; i < NHASH; i++)
                for(s = hash[i]; s != S; s = s->link)
                        if(s->type == SUNDEF){
                                lput(s->sig);
                                t += 4;
                                t += sput(s->name);
                        }

        la = 0;
        r = &rels;
        n = r->n;
        m = r->m;
        a = r->a;
        lput(n);
        t += 4;
        for(i = 0; i < n; i++){
                ra = *a-la;
                if(*a < la)
                        diag("bad relocation order");
                if(ra < 256)
                        c = 0;
                else if(ra < 65536)
                        c = 1;
                else
                        c = 2;
                cput((c<<6)|*m++);
                t++;
                if(c == 0){
                        cput(ra);
                        t++;
                }
                else if(c == 1){
                        wput(ra);
                        t += 2;
                }
                else{
                        lput(ra);
                        t += 4;
                }
                la = *a++;
        }

        cflush();
        seek(cout, off, 0);
        lput(t);

        if(debug['v']){
                Bprint(&bso, "import table entries = %d\n", imports);
                Bprint(&bso, "export table entries = %d\n", exports);
        }
}