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#include "gc.h"

static  char    resvreg[nelem(reg)];

void
ginit(void)
{
        Type *t;

        thechar = '5';
        thestring = "arm";
        exregoffset = REGEXT;
        exfregoffset = FREGEXT;
        listinit();
        nstring = 0;
        mnstring = 0;
        nrathole = 0;
        pc = 0;
        breakpc = -1;
        continpc = -1;
        cases = C;
        firstp = P;
        lastp = P;
        tfield = types[TLONG];

        zprog.link = P;
        zprog.as = AGOK;
        zprog.reg = NREG;
        zprog.from.type = D_NONE;
        zprog.from.name = D_NONE;
        zprog.from.reg = NREG;
        zprog.to = zprog.from;
        zprog.scond = 0xE;  

        regnode.op = OREGISTER;
        regnode.class = CEXREG;
        regnode.reg = REGTMP;
        regnode.complex = 0;
        regnode.addable = 11;
        regnode.type = types[TLONG];

        constnode.op = OCONST;
        constnode.class = CXXX;
        constnode.complex = 0;
        constnode.addable = 20;
        constnode.type = types[TLONG];

        fconstnode.op = OCONST;
        fconstnode.class = CXXX;
        fconstnode.complex = 0;
        fconstnode.addable = 20;
        fconstnode.type = types[TDOUBLE];

        nodsafe = new(ONAME, Z, Z);
        nodsafe->sym = slookup(".safe");
        nodsafe->type = types[TINT];
        nodsafe->etype = types[TINT]->etype;
        nodsafe->class = CAUTO;
        complex(nodsafe);

        t = typ(TARRAY, types[TCHAR]);
        symrathole = slookup(".rathole");
        symrathole->class = CGLOBL;
        symrathole->type = t;

        nodrat = new(ONAME, Z, Z);
        nodrat->sym = symrathole;
        nodrat->type = types[TIND];
        nodrat->etype = TVOID;
        nodrat->class = CGLOBL;
        complex(nodrat);
        nodrat->type = t;

        nodret = new(ONAME, Z, Z);
        nodret->sym = slookup(".ret");
        nodret->type = types[TIND];
        nodret->etype = TIND;
        nodret->class = CPARAM;
        nodret = new(OIND, nodret, Z);
        complex(nodret);

        com64init();

        memset(reg, 0, sizeof(reg));
        /* don't allocate */
        reg[REGTMP] = 1;
        reg[REGSB] = 1;
        reg[REGSP] = 1;
        reg[REGLINK] = 1;
        reg[REGPC] = 1;
        /* keep two external registers */
        reg[REGEXT] = 1;
        reg[REGEXT-1] = 1;
        memmove(resvreg, reg, sizeof(reg));
}

void
gclean(void)
{
        int i;
        Sym *s;

        for(i=0; i<NREG; i++)
                if(reg[i] && !resvreg[i])
                        diag(Z, "reg %d left allocated", i);
        for(i=NREG; i<NREG+NFREG; i++)
                if(reg[i] && !resvreg[i])
                        diag(Z, "freg %d left allocated", i-NREG);
        while(mnstring)
                outstring("", 1L);
        symstring->type->width = nstring;
        symrathole->type->width = nrathole;
        for(i=0; i<NHASH; i++)
        for(s = hash[i]; s != S; s = s->link) {
                if(s->type == T)
                        continue;
                if(s->type->width == 0)
                        continue;
                if(s->class != CGLOBL && s->class != CSTATIC)
                        continue;
                if(s->type == types[TENUM])
                        continue;
                gpseudo(AGLOBL, s, nodconst(s->type->width));
        }
        nextpc();
        p->as = AEND;
        outcode();
}

void
nextpc(void)
{

        p = alloc(sizeof(*p));
        *p = zprog;
        p->lineno = nearln;
        pc++;
        if(firstp == P) {
                firstp = p;
                lastp = p;
                return;
        }
        lastp->link = p;
        lastp = p;
}

void
gargs(Node *n, Node *tn1, Node *tn2)
{
        long regs;
        Node fnxargs[20], *fnxp;

        regs = cursafe;

        fnxp = fnxargs;
        garg1(n, tn1, tn2, 0, &fnxp);   /* compile fns to temps */

        curarg = 0;
        fnxp = fnxargs;
        garg1(n, tn1, tn2, 1, &fnxp);   /* compile normal args and temps */

        cursafe = regs;
}

void
garg1(Node *n, Node *tn1, Node *tn2, int f, Node **fnxp)
{
        Node nod;

        if(n == Z)
                return;
        if(n->op == OLIST) {
                garg1(n->left, tn1, tn2, f, fnxp);
                garg1(n->right, tn1, tn2, f, fnxp);
                return;
        }
        if(f == 0) {
                if(n->complex >= FNX) {
                        regsalloc(*fnxp, n);
                        nod = znode;
                        nod.op = OAS;
                        nod.left = *fnxp;
                        nod.right = n;
                        nod.type = n->type;
                        cgen(&nod, Z);
                        (*fnxp)++;
                }
                return;
        }
        if(typesuv[n->type->etype]) {
                regaalloc(tn2, n);
                if(n->complex >= FNX) {
                        sugen(*fnxp, tn2, n->type->width);
                        (*fnxp)++;
                } else
                        sugen(n, tn2, n->type->width);
                return;
        }
        if(REGARG >= 0 && curarg == 0 && typechlp[n->type->etype]) {
                regaalloc1(tn1, n);
                if(n->complex >= FNX) {
                        cgen(*fnxp, tn1);
                        (*fnxp)++;
                } else
                        cgen(n, tn1);
                return;
        }
        regalloc(tn1, n, Z);
        if(n->complex >= FNX) {
                cgen(*fnxp, tn1);
                (*fnxp)++;
        } else
                cgen(n, tn1);
        regaalloc(tn2, n);
        gopcode(OAS, tn1, Z, tn2);
        regfree(tn1);
}

Node*
nodconst(long v)
{
        constnode.vconst = v;
        return &constnode;
}

Node*
nod32const(vlong v)
{
        constnode.vconst = v & MASK(32);
        return &constnode;
}

Node*
nodfconst(double d)
{
        fconstnode.fconst = d;
        return &fconstnode;
}

void
nodreg(Node *n, Node *nn, int reg)
{
        *n = regnode;
        n->reg = reg;
        n->type = nn->type;
        n->lineno = nn->lineno;
}

void
regret(Node *n, Node *nn)
{
        int r;

        r = REGRET;
        if(typefd[nn->type->etype])
                r = FREGRET+NREG;
        nodreg(n, nn, r);
        reg[r]++;
}

int
tmpreg(void)
{
        int i;

        for(i=REGRET+1; i<NREG; i++)
                if(reg[i] == 0)
                        return i;
        diag(Z, "out of fixed registers");
        return 0;
}

void
regalloc(Node *n, Node *tn, Node *o)
{
        int i, j;
        static int lasti;

        switch(tn->type->etype) {
        case TCHAR:
        case TUCHAR:
        case TSHORT:
        case TUSHORT:
        case TINT:
        case TUINT:
        case TLONG:
        case TULONG:
        case TIND:
                if(o != Z && o->op == OREGISTER) {
                        i = o->reg;
                        if(i >= 0 && i < NREG)
                                goto out;
                }
                j = lasti + REGRET+1;
                for(i=REGRET+1; i<NREG; i++) {
                        if(j >= NREG)
                                j = REGRET+1;
                        if(reg[j] == 0 && resvreg[j] == 0) {
                                i = j;
                                goto out;
                        }
                        j++;
                }
                diag(tn, "out of fixed registers");
                goto err;

        case TFLOAT:
        case TDOUBLE:
        case TVLONG:
                if(o != Z && o->op == OREGISTER) {
                        i = o->reg;
                        if(i >= NREG && i < NREG+NFREG)
                                goto out;
                }
                j = 0*2 + NREG;
                for(i=NREG; i<NREG+NFREG; i++) {
                        if(j >= NREG+NFREG)
                                j = NREG;
                        if(reg[j] == 0) {
                                i = j;
                                goto out;
                        }
                        j++;
                }
                diag(tn, "out of float registers");
                goto err;
        }
        diag(tn, "unknown type in regalloc: %T", tn->type);
err:
        nodreg(n, tn, 0);
        return;
out:
        reg[i]++;
        lasti++;
        if(lasti >= 5)
                lasti = 0;
        nodreg(n, tn, i);
}

void
regialloc(Node *n, Node *tn, Node *o)
{
        Node nod;

        nod = *tn;
        nod.type = types[TIND];
        regalloc(n, &nod, o);
}

void
regfree(Node *n)
{
        int i;

        i = 0;
        if(n->op != OREGISTER && n->op != OINDREG)
                goto err;
        i = n->reg;
        if(i < 0 || i >= sizeof(reg))
                goto err;
        if(reg[i] <= 0)
                goto err;
        reg[i]--;
        return;
err:
        diag(n, "error in regfree: %d", i);
}

void
regsalloc(Node *n, Node *nn)
{
        cursafe = align(cursafe, nn->type, Aaut3);
        maxargsafe = maxround(maxargsafe, cursafe+curarg);
        *n = *nodsafe;
        n->xoffset = -(stkoff + cursafe);
        n->type = nn->type;
        n->etype = nn->type->etype;
        n->lineno = nn->lineno;
}

void
regaalloc1(Node *n, Node *nn)
{
        nodreg(n, nn, REGARG);
        reg[REGARG]++;
        curarg = align(curarg, nn->type, Aarg1);
        curarg = align(curarg, nn->type, Aarg2);
        maxargsafe = maxround(maxargsafe, cursafe+curarg);
}

void
regaalloc(Node *n, Node *nn)
{
        curarg = align(curarg, nn->type, Aarg1);
        *n = *nn;
        n->op = OINDREG;
        n->reg = REGSP;
        n->xoffset = curarg + SZ_LONG;
        n->complex = 0;
        n->addable = 20;
        curarg = align(curarg, nn->type, Aarg2);
        maxargsafe = maxround(maxargsafe, cursafe+curarg);
}

void
regind(Node *n, Node *nn)
{

        if(n->op != OREGISTER) {
                diag(n, "regind not OREGISTER");
                return;
        }
        n->op = OINDREG;
        n->type = nn->type;
}

void
raddr(Node *n, Prog *p)
{
        Adr a;

        naddr(n, &a);
        if(R0ISZERO && a.type == D_CONST && a.offset == 0) {
                a.type = D_REG;
                a.reg = 0;
        }
        if(a.type != D_REG && a.type != D_FREG) {
                if(n)
                        diag(n, "bad in raddr: %O", n->op);
                else
                        diag(n, "bad in raddr: <null>");
                p->reg = NREG;
        } else
                p->reg = a.reg;
}

void
naddr(Node *n, Adr *a)
{
        long v;

        a->type = D_NONE;
        if(n == Z)
                return;
        switch(n->op) {
        default:
        bad:
                diag(n, "bad in naddr: %O", n->op);
                break;

        case OREGISTER:
                a->type = D_REG;
                a->sym = S;
                a->reg = n->reg;
                if(a->reg >= NREG) {
                        a->type = D_FREG;
                        a->reg -= NREG;
                }
                break;

        case OIND:
                naddr(n->left, a);
                if(a->type == D_REG) {
                        a->type = D_OREG;
                        break;
                }
                if(a->type == D_CONST) {
                        a->type = D_OREG;
                        break;
                }
                goto bad;

        case OINDREG:
                a->type = D_OREG;
                a->sym = S;
                a->offset = n->xoffset;
                a->reg = n->reg;
                break;

        case ONAME:
                a->etype = n->etype;
                a->type = D_OREG;
                a->name = D_STATIC;
                a->sym = n->sym;
                a->offset = n->xoffset;
                if(n->class == CSTATIC)
                        break;
                if(n->class == CEXTERN || n->class == CGLOBL) {
                        a->name = D_EXTERN;
                        break;
                }
                if(n->class == CAUTO) {
                        a->name = D_AUTO;
                        break;
                }
                if(n->class == CPARAM) {
                        a->name = D_PARAM;
                        break;
                }
                goto bad;

        case OCONST:
                a->sym = S;
                a->reg = NREG;
                if(typefd[n->type->etype]) {
                        a->type = D_FCONST;
                        a->dval = n->fconst;
                } else {
                        a->type = D_CONST;
                        a->offset = n->vconst;
                }
                break;

        case OADDR:
                naddr(n->left, a);
                if(a->type == D_OREG) {
                        a->type = D_CONST;
                        break;
                }
                goto bad;

        case OADD:
                if(n->left->op == OCONST) {
                        naddr(n->left, a);
                        v = a->offset;
                        naddr(n->right, a);
                } else {
                        naddr(n->right, a);
                        v = a->offset;
                        naddr(n->left, a);
                }
                a->offset += v;
                break;

        }
}

void
fop(int as, int f1, int f2, Node *t)
{
        Node nod1, nod2, nod3;

        nodreg(&nod1, t, NREG+f1);
        nodreg(&nod2, t, NREG+f2);
        regalloc(&nod3, t, t);
        gopcode(as, &nod1, &nod2, &nod3);
        gmove(&nod3, t);
        regfree(&nod3);
}

void
gmovm(Node *f, Node *t, int w)
{
        gins(AMOVM, f, t);
        p->scond |= C_UBIT;
        if(w)
                p->scond |= C_WBIT;
}

void
gmove(Node *f, Node *t)
{
        int ft, tt, a;
        Node nod, nod1;
        Prog *p1;

        ft = f->type->etype;
        tt = t->type->etype;

        if(ft == TDOUBLE && f->op == OCONST) {
        }
        if(ft == TFLOAT && f->op == OCONST) {
        }

        /*
         * a load --
         * put it into a register then
         * worry what to do with it.
         */
        if(f->op == ONAME || f->op == OINDREG || f->op == OIND) {
                switch(ft) {
                default:
                        a = AMOVW;
                        break;
                case TFLOAT:
                        a = AMOVF;
                        break;
                case TDOUBLE:
                        a = AMOVD;
                        break;
                case TCHAR:
                        a = AMOVB;
                        break;
                case TUCHAR:
                        a = AMOVBU;
                        break;
                case TSHORT:
                        a = AMOVH;
                        break;
                case TUSHORT:
                        a = AMOVHU;
                        break;
                }
                if(typechlp[ft] && typeilp[tt])
                        regalloc(&nod, t, t);
                else
                        regalloc(&nod, f, t);
                gins(a, f, &nod);
                gmove(&nod, t);
                regfree(&nod);
                return;
        }

        /*
         * a store --
         * put it into a register then
         * store it.
         */
        if(t->op == ONAME || t->op == OINDREG || t->op == OIND) {
                switch(tt) {
                default:
                        a = AMOVW;
                        break;
                case TUCHAR:
                        a = AMOVBU;
                        break;
                case TCHAR:
                        a = AMOVB;
                        break;
                case TUSHORT:
                        a = AMOVHU;
                        break;
                case TSHORT:
                        a = AMOVH;
                        break;
                case TFLOAT:
                        a = AMOVF;
                        break;
                case TVLONG:
                case TDOUBLE:
                        a = AMOVD;
                        break;
                }
                if(ft == tt)
                        regalloc(&nod, t, f);
                else
                        regalloc(&nod, t, Z);
                gmove(f, &nod);
                gins(a, &nod, t);
                regfree(&nod);
                return;
        }

        /*
         * type x type cross table
         */
        a = AGOK;
        switch(ft) {
        case TDOUBLE:
        case TVLONG:
        case TFLOAT:
                switch(tt) {
                case TDOUBLE:
                case TVLONG:
                        a = AMOVD;
                        if(ft == TFLOAT)
                                a = AMOVFD;
                        break;
                case TFLOAT:
                        a = AMOVDF;
                        if(ft == TFLOAT)
                                a = AMOVF;
                        break;
                case TINT:
                case TUINT:
                case TLONG:
                case TULONG:
                case TIND:
                        a = AMOVDW;
                        if(ft == TFLOAT)
                                a = AMOVFW;
                        break;
                case TSHORT:
                case TUSHORT:
                case TCHAR:
                case TUCHAR:
                        a = AMOVDW;
                        if(ft == TFLOAT)
                                a = AMOVFW;
                        break;
                }
                break;
        case TUINT:
        case TULONG:
                if(tt == TFLOAT || tt == TDOUBLE) {
                        // ugly and probably longer than necessary,
                        // but vfp has a single instruction for this,
                        // so hopefully it won't last long.
                        //
                        //      tmp = f
                        //      tmp1 = tmp & 0x80000000
                        //      tmp ^= tmp1
                        //      t = float(int32(tmp))
                        //      if(tmp1)
                        //              t += 2147483648.
                        //
                        regalloc(&nod, f, Z);
                        regalloc(&nod1, f, Z);
                        gins(AMOVW, f, &nod);
                        gins(AMOVW, &nod, &nod1);
                        gins(AAND, nodconst(0x80000000), &nod1);
                        gins(AEOR, &nod1, &nod);
                        if(tt == TFLOAT)
                                gins(AMOVWF, &nod, t);
                        else
                                gins(AMOVWD, &nod, t);
                        gins(ACMP, nodconst(0), Z);
                        raddr(&nod1, p);
                        gins(ABEQ, Z, Z);
                        regfree(&nod);
                        regfree(&nod1);
                        p1 = p;
                        regalloc(&nod, t, Z);
                        if(tt == TFLOAT) {
                                gins(AMOVF, nodfconst(2147483648.), &nod);
                                gins(AADDF, &nod, t);
                        } else {
                                gins(AMOVD, nodfconst(2147483648.), &nod);
                                gins(AADDD, &nod, t);
                        }
                        regfree(&nod);
                        patch(p1, pc);
                        return;
                }
                // fall through

        case TINT:
        case TLONG:
        case TIND:
                switch(tt) {
                case TDOUBLE:
                        gins(AMOVWD, f, t);
                        return;
                case TFLOAT:
                        gins(AMOVWF, f, t);
                        return;
                case TINT:
                case TUINT:
                case TLONG:
                case TULONG:
                case TIND:
                case TSHORT:
                case TUSHORT:
                case TCHAR:
                case TUCHAR:
                        a = AMOVW;
                        break;
                }
                break;
        case TSHORT:
                switch(tt) {
                case TDOUBLE:
                        regalloc(&nod, f, Z);
                        gins(AMOVH, f, &nod);
                        gins(AMOVWD, &nod, t);
                        regfree(&nod);
                        return;
                case TFLOAT:
                        regalloc(&nod, f, Z);
                        gins(AMOVH, f, &nod);
                        gins(AMOVWF, &nod, t);
                        regfree(&nod);
                        return;
                case TUINT:
                case TINT:
                case TULONG:
                case TLONG:
                case TIND:
                        a = AMOVH;
                        break;
                case TSHORT:
                case TUSHORT:
                case TCHAR:
                case TUCHAR:
                        a = AMOVW;
                        break;
                }
                break;
        case TUSHORT:
                switch(tt) {
                case TDOUBLE:
                        regalloc(&nod, f, Z);
                        gins(AMOVHU, f, &nod);
                        gins(AMOVWD, &nod, t);
                        regfree(&nod);
                        return;
                case TFLOAT:
                        regalloc(&nod, f, Z);
                        gins(AMOVHU, f, &nod);
                        gins(AMOVWF, &nod, t);
                        regfree(&nod);
                        return;
                case TINT:
                case TUINT:
                case TLONG:
                case TULONG:
                case TIND:
                        a = AMOVHU;
                        break;
                case TSHORT:
                case TUSHORT:
                case TCHAR:
                case TUCHAR:
                        a = AMOVW;
                        break;
                }
                break;
        case TCHAR:
                switch(tt) {
                case TDOUBLE:
                        regalloc(&nod, f, Z);
                        gins(AMOVB, f, &nod);
                        gins(AMOVWD, &nod, t);
                        regfree(&nod);
                        return;
                case TFLOAT:
                        regalloc(&nod, f, Z);
                        gins(AMOVB, f, &nod);
                        gins(AMOVWF, &nod, t);
                        regfree(&nod);
                        return;
                case TINT:
                case TUINT:
                case TLONG:
                case TULONG:
                case TIND:
                case TSHORT:
                case TUSHORT:
                        a = AMOVB;
                        break;
                case TCHAR:
                case TUCHAR:
                        a = AMOVW;
                        break;
                }
                break;
        case TUCHAR:
                switch(tt) {
                case TDOUBLE:
                        regalloc(&nod, f, Z);
                        gins(AMOVBU, f, &nod);
                        gins(AMOVWD, &nod, t);
                        regfree(&nod);
                        return;
                case TFLOAT:
                        regalloc(&nod, f, Z);
                        gins(AMOVBU, f, &nod);
                        gins(AMOVWF, &nod, t);
                        regfree(&nod);
                        return;
                case TINT:
                case TUINT:
                case TLONG:
                case TULONG:
                case TIND:
                case TSHORT:
                case TUSHORT:
                        a = AMOVBU;
                        break;
                case TCHAR:
                case TUCHAR:
                        a = AMOVW;
                        break;
                }
                break;
        }
        if(a == AGOK)
                diag(Z, "bad opcode in gmove %T -> %T", f->type, t->type);
        if(a == AMOVW || a == AMOVF || a == AMOVD)
        if(samaddr(f, t))
                return;
        gins(a, f, t);
}

void
gmover(Node *f, Node *t)
{
        int ft, tt, a;

        ft = f->type->etype;
        tt = t->type->etype;
        a = AGOK;
        if(typechlp[ft] && typechlp[tt] && ewidth[ft] >= ewidth[tt]){
                switch(tt){
                case TSHORT:
                        a = AMOVH;
                        break;
                case TUSHORT:
                        a = AMOVHU;
                        break;
                case TCHAR:
                        a = AMOVB;
                        break;
                case TUCHAR:
                        a = AMOVBU;
                        break;
                }
        }
        if(a == AGOK)
                gmove(f, t);
        else
                gins(a, f, t);
}

void
gins(int a, Node *f, Node *t)
{

        nextpc();
        p->as = a;
        if(f != Z)
                naddr(f, &p->from);
        if(t != Z)
                naddr(t, &p->to);
        if(debug['g'])
                print("%P\n", p);
}

void
gopcode(int o, Node *f1, Node *f2, Node *t)
{
        int a, et, true;
        Adr ta;

        et = TLONG;
        if(f1 != Z && f1->type != T)
                et = f1->type->etype;
        true = o & BTRUE;
        o &= ~BTRUE;
        a = AGOK;
        switch(o) {
        case OAS:
                gmove(f1, t);
                return;

        case OASADD:
        case OADD:
                a = AADD;
                if(et == TFLOAT)
                        a = AADDF;
                else
                if(et == TDOUBLE || et == TVLONG)
                        a = AADDD;
                break;

        case OASSUB:
        case OSUB:
                if(f2 && f2->op == OCONST) {
                        Node *t = f1;
                        f1 = f2;
                        f2 = t;
                        a = ARSB;
                } else
                        a = ASUB;
                if(et == TFLOAT)
                        a = ASUBF;
                else
                if(et == TDOUBLE || et == TVLONG)
                        a = ASUBD;
                break;

        case OASOR:
        case OOR:
                a = AORR;
                break;

        case OASAND:
        case OAND:
                a = AAND;
                break;

        case OASXOR:
        case OXOR:
                a = AEOR;
                break;

        case OASLSHR:
        case OLSHR:
                a = ASRL;
                break;

        case OASASHR:
        case OASHR:
                a = ASRA;
                break;

        case OASASHL:
        case OASHL:
                a = ASLL;
                break;

        case OFUNC:
                a = ABL;
                break;

        case OASMUL:
        case OMUL:
                a = AMUL;
                if(et == TFLOAT)
                        a = AMULF;
                else
                if(et == TDOUBLE || et == TVLONG)
                        a = AMULD;
                break;

        case OASDIV:
        case ODIV:
                a = ADIV;
                if(et == TFLOAT)
                        a = ADIVF;
                else
                if(et == TDOUBLE || et == TVLONG)
                        a = ADIVD;
                break;

        case OASMOD:
        case OMOD:
                a = AMOD;
                break;

        case OASLMUL:
        case OLMUL:
                a = AMULU;
                break;

        case OASLMOD:
        case OLMOD:
                a = AMODU;
                break;

        case OASLDIV:
        case OLDIV:
                a = ADIVU;
                break;

        case OCASE:
        case OEQ:
        case ONE:
        case OLT:
        case OLE:
        case OGE:
        case OGT:
        case OLO:
        case OLS:
        case OHS:
        case OHI:
                a = ACMP;
                if(et == TFLOAT)
                        a = ACMPF;
                else
                if(et == TDOUBLE || et == TVLONG)
                        a = ACMPD;
                nextpc();
                p->as = a;
                naddr(f1, &p->from);
                if(a == ACMP && f1->op == OCONST && p->from.offset < 0 &&
                    p->from.offset != 0x80000000) {
                        p->as = ACMN;
                        p->from.offset = -p->from.offset;
                }
                raddr(f2, p);
                switch(o) {
                case OEQ:
                        a = ABEQ;
                        break;
                case ONE:
                        a = ABNE;
                        break;
                case OLT:
                        a = ABLT;
                        /* ensure NaN comparison is always false */
                        if(typefd[et] && !true)
                                a = ABMI;
                        break;
                case OLE:
                        a = ABLE;
                        if(typefd[et] && !true)
                                a = ABLS;
                        break;
                case OGE:
                        a = ABGE;
                        if(typefd[et] && true)
                                a = ABPL;
                        break;
                case OGT:
                        a = ABGT;
                        if(typefd[et] && true)
                                a = ABHI;
                        break;
                case OLO:
                        a = ABLO;
                        break;
                case OLS:
                        a = ABLS;
                        break;
                case OHS:
                        a = ABHS;
                        break;
                case OHI:
                        a = ABHI;
                        break;
                case OCASE:
                        nextpc();
                        p->as = ACASE;
                        p->scond = 0x9;
                        naddr(f2, &p->from);
                        a = ABHI;
                        break;
                }
                f1 = Z;
                f2 = Z;
                break;
        }
        if(a == AGOK)
                diag(Z, "bad in gopcode %O", o);
        nextpc();
        p->as = a;
        if(f1 != Z)
                naddr(f1, &p->from);
        if(f2 != Z) {
                naddr(f2, &ta);
                p->reg = ta.reg;
        }
        if(t != Z)
                naddr(t, &p->to);
        if(debug['g'])
                print("%P\n", p);
}

samaddr(Node *f, Node *t)
{

        if(f->op != t->op)
                return 0;
        switch(f->op) {

        case OREGISTER:
                if(f->reg != t->reg)
                        break;
                return 1;
        }
        return 0;
}

void
gbranch(int o)
{
        int a;

        a = AGOK;
        switch(o) {
        case ORETURN:
                a = ARET;
                break;
        case OGOTO:
                a = AB;
                break;
        }
        nextpc();
        if(a == AGOK) {
                diag(Z, "bad in gbranch %O",  o);
                nextpc();
        }
        p->as = a;
}

void
patch(Prog *op, long pc)
{

        op->to.offset = pc;
        op->to.type = D_BRANCH;
}

void
gpseudo(int a, Sym *s, Node *n)
{

        nextpc();
        p->as = a;
        p->from.type = D_OREG;
        p->from.sym = s;
        p->from.name = D_EXTERN;
        if(a == ATEXT)
                p->reg = (profileflg ? 0 : NOPROF);
        if(s->class == CSTATIC)
                p->from.name = D_STATIC;
        naddr(n, &p->to);
        if(a == ADATA || a == AGLOBL)
                pc--;
}

int
sconst(Node *n)
{
        vlong vv;

        if(n->op == OCONST) {
                if(!typefd[n->type->etype]) {
                        vv = n->vconst;
                        if(vv >= (vlong)(-32766) && vv < (vlong)32766)
                                return 1;
                        /*
                         * should be specialised for constant values which will
                         * fit in different instructionsl; for now, let 5l
                         * sort it out
                         */
                        return 1;
                }
        }
        return 0;
}

int
sval(long v)
{
        int i;

        for(i=0; i<16; i++) {
                if((v & ~0xff) == 0)
                        return 1;
                if((~v & ~0xff) == 0)
                        return 1;
                v = (v<<2) | ((ulong)v>>30);
        }
        return 0;
}

long
exreg(Type *t)
{
        long o;

        if(typechlp[t->etype]) {
                if(exregoffset <= REGEXT-2)
                        return 0;
                o = exregoffset;
                if(reg[o] && !resvreg[o])
                        return 0;
                resvreg[o] = reg[o] = 1;
                exregoffset--;
                return o;
        }
        if(typefd[t->etype]) {
                if(exfregoffset <= NFREG-1)
                        return 0;
                o = exfregoffset + NREG;
                if(reg[o] && !resvreg[o])
                        return 0;
                resvreg[o] = reg[o] = 1;
                exfregoffset--;
                return o;
        }
        return 0;
}

schar   ewidth[NTYPE] =
{
        -1,             /* [TXXX] */
        SZ_CHAR,        /* [TCHAR] */
        SZ_CHAR,        /* [TUCHAR] */
        SZ_SHORT,       /* [TSHORT] */
        SZ_SHORT,       /* [TUSHORT] */
        SZ_INT,         /* [TINT] */
        SZ_INT,         /* [TUINT] */
        SZ_LONG,        /* [TLONG] */
        SZ_LONG,        /* [TULONG] */
        SZ_VLONG,       /* [TVLONG] */
        SZ_VLONG,       /* [TUVLONG] */
        SZ_FLOAT,       /* [TFLOAT] */
        SZ_DOUBLE,      /* [TDOUBLE] */
        SZ_IND,         /* [TIND] */
        0,              /* [TFUNC] */
        -1,             /* [TARRAY] */
        0,              /* [TVOID] */
        -1,             /* [TSTRUCT] */
        -1,             /* [TUNION] */
        SZ_INT,         /* [TENUM] */
};

long    ncast[NTYPE] =
{
        0,                              /* [TXXX] */
        BCHAR|BUCHAR,                   /* [TCHAR] */
        BCHAR|BUCHAR,                   /* [TUCHAR] */
        BSHORT|BUSHORT,                 /* [TSHORT] */
        BSHORT|BUSHORT,                 /* [TUSHORT] */
        BINT|BUINT|BLONG|BULONG|BIND,   /* [TINT] */
        BINT|BUINT|BLONG|BULONG|BIND,   /* [TUINT] */
        BINT|BUINT|BLONG|BULONG|BIND,   /* [TLONG] */
        BINT|BUINT|BLONG|BULONG|BIND,   /* [TULONG] */
        BVLONG|BUVLONG,                 /* [TVLONG] */
        BVLONG|BUVLONG,                 /* [TUVLONG] */
        BFLOAT,                         /* [TFLOAT] */
        BDOUBLE,                        /* [TDOUBLE] */
        BLONG|BULONG|BIND,              /* [TIND] */
        0,                              /* [TFUNC] */
        0,                              /* [TARRAY] */
        0,                              /* [TVOID] */
        BSTRUCT,                        /* [TSTRUCT] */
        BUNION,                         /* [TUNION] */
        0,                              /* [TENUM] */
};