rega(void)

#include "gc.h"

Reg*
rega(void)
{
Reg *r;

r = freer;
if(r == R) {
r = alloc(sizeof(*r));
} else
freer = r->link;

*r = zreg;
return r;
}

int
rcmp(const void *a1, const void *a2)
{
Rgn *p1, *p2;
int c1, c2;

p1 = (Rgn*)a1;
p2 = (Rgn*)a2;
c1 = p2->cost;
c2 = p1->cost;
if(c1 -= c2)
return c1;
return p2->varno - p1->varno;
}

void
regopt(Prog *p)
{
Reg *r, *r1, *r2;
Prog *p1;
int i, z;
long initpc, val, npc;
ulong vreg;
Bits bit;
struct
{
long m;
long c;
Reg* p;
} log5[6], *lp;

firstr = R;
lastr = R;
nvar = 0;
regbits = RtoB(D_SP) | RtoB(D_AX) | RtoB(D_X0);
if(REGEXT)
regbits |= RtoB(REGEXT) | RtoB(REGEXT-1);
for(z=0; z<BITS; z++) {
externs.b[z] = 0;
params.b[z] = 0;
consts.b[z] = 0;
addrs.b[z] = 0;
}

/*
* pass 1
* build aux data structure
* allocate pcs
* find use and set of variables
*/
val = 5L * 5L * 5L * 5L * 5L;
lp = log5;
for(i=0; i<5; i++) {
lp->m = val;
lp->c = 0;
lp->p = R;
val /= 5L;
lp++;
}
val = 0;
for(; p != P; p = p->link) {
switch(p->as) {
case ADATA:
case AGLOBL:
case ANAME:
case ASIGNAME:
continue;
}
r = rega();
if(firstr == R) {
firstr = r;
lastr = r;
} else {
lastr->link = r;
r->p1 = lastr;
lastr->s1 = r;
lastr = r;
}
r->prog = p;
r->pc = val;
val++;

lp = log5;
for(i=0; i<5; i++) {
lp->c--;
if(lp->c <= 0) {
lp->c = lp->m;
if(lp->p != R)
lp->p->log5 = r;
lp->p = r;
(lp+1)->c = 0;
break;
}
lp++;
}

r1 = r->p1;
if(r1 != R)
switch(r1->prog->as) {
case ARET:
case AJMP:
case AIRETL:
case AIRETQ:
r->p1 = R;
r1->s1 = R;
}

bit = mkvar(r, &p->from);
if(bany(&bit))
switch(p->as) {
/*
* funny
*/
case ALEAL:
case ALEAQ:
for(z=0; z<BITS; z++)
addrs.b[z] |= bit.b[z];
break;

/*
* left side read
*/
default:
for(z=0; z<BITS; z++)
r->use1.b[z] |= bit.b[z];
break;
}

bit = mkvar(r, &p->to);
if(bany(&bit))
switch(p->as) {
default:
diag(Z, "reg: unknown op: %A", p->as);
break;

/*
* right side read
*/
case ACMPB:
case ACMPL:
case ACMPQ:
case ACMPW:
case ACOMISS:
case ACOMISD:
case AUCOMISS:
case AUCOMISD:
for(z=0; z<BITS; z++)
r->use2.b[z] |= bit.b[z];
break;

/*
* right side write
*/
case ANOP:
case AMOVL:
case AMOVQ:
case AMOVB:
case AMOVW:
case AMOVBLSX:
case AMOVBLZX:
case AMOVBQSX:
case AMOVBQZX:
case AMOVLQSX:
case AMOVLQZX:
case AMOVWLSX:
case AMOVWLZX:
case AMOVWQSX:
case AMOVWQZX:
case AMOVQL:

case AMOVSS:
case AMOVSD:
case ACVTSD2SL:
case ACVTSD2SQ:
case ACVTSD2SS:
case ACVTSL2SD:
case ACVTSL2SS:
case ACVTSQ2SD:
case ACVTSQ2SS:
case ACVTSS2SD:
case ACVTSS2SL:
case ACVTSS2SQ:
case ACVTTSD2SL:
case ACVTTSD2SQ:
case ACVTTSS2SL:
case ACVTTSS2SQ:
for(z=0; z<BITS; z++)
r->set.b[z] |= bit.b[z];
break;

/*
* right side read+write
*/
case AADDB:
case AADDL:
case AADDQ:
case AADDW:
case AANDB:
case AANDL:
case AANDQ:
case AANDW:
case ASUBB:
case ASUBL:
case ASUBQ:
case ASUBW:
case AORB:
case AORL:
case AORQ:
case AORW:
case AXORB:
case AXORL:
case AXORQ:
case AXORW:
case ASALB:
case ASALL:
case ASALQ:
case ASALW:
case ASARB:
case ASARL:
case ASARQ:
case ASARW:
case AROLB:
case AROLL:
case AROLQ:
case AROLW:
case ARORB:
case ARORL:
case ARORQ:
case ARORW:
case ASHLB:
case ASHLL:
case ASHLQ:
case ASHLW:
case ASHRB:
case ASHRL:
case ASHRQ:
case ASHRW:
case AIMULL:
case AIMULQ:
case AIMULW:
case ANEGL:
case ANEGQ:
case ANOTL:
case ANOTQ:
case AADCL:
case AADCQ:
case ASBBL:
case ASBBQ:

case AADDSD:
case AADDSS:
case ACMPSD:
case ACMPSS:
case ADIVSD:
case ADIVSS:
case AMAXSD:
case AMAXSS:
case AMINSD:
case AMINSS:
case AMULSD:
case AMULSS:
case ARCPSS:
case ARSQRTSS:
case ASQRTSD:
case ASQRTSS:
case ASUBSD:
case ASUBSS:
case AXORPD:
for(z=0; z<BITS; z++) {
r->set.b[z] |= bit.b[z];
r->use2.b[z] |= bit.b[z];
}
break;

/*
* funny
*/
case ACALL:
for(z=0; z<BITS; z++)
addrs.b[z] |= bit.b[z];
break;
}

switch(p->as) {
case AIMULL:
case AIMULQ:
case AIMULW:
if(p->to.type != D_NONE)
break;

case AIDIVB:
case AIDIVL:
case AIDIVQ:
case AIDIVW:
case AIMULB:
case ADIVB:
case ADIVL:
case ADIVQ:
case ADIVW:
case AMULB:
case AMULL:
case AMULQ:
case AMULW:

case ACWD:
case ACDQ:
case ACQO:
r->regu |= RtoB(D_AX) | RtoB(D_DX);
break;

case AREP:
case AREPN:
case ALOOP:
case ALOOPEQ:
case ALOOPNE:
r->regu |= RtoB(D_CX);
break;

case AMOVSB:
case AMOVSL:
case AMOVSQ:
case AMOVSW:
case ACMPSB:
case ACMPSL:
case ACMPSQ:
case ACMPSW:
r->regu |= RtoB(D_SI) | RtoB(D_DI);
break;

case ASTOSB:
case ASTOSL:
case ASTOSQ:
case ASTOSW:
case ASCASB:
case ASCASL:
case ASCASQ:
case ASCASW:
r->regu |= RtoB(D_AX) | RtoB(D_DI);
break;

case AINSB:
case AINSL:
case AINSW:
case AOUTSB:
case AOUTSL:
case AOUTSW:
r->regu |= RtoB(D_DI) | RtoB(D_DX);
break;
}
}
if(firstr == R)
return;
initpc = pc - val;
npc = val;

/*
* pass 2
* turn branch references to pointers
* build back pointers
*/
for(r = firstr; r != R; r = r->link) {
p = r->prog;
if(p->to.type == D_BRANCH) {
val = p->to.offset - initpc;
r1 = firstr;
while(r1 != R) {
r2 = r1->log5;
if(r2 != R && val >= r2->pc) {
r1 = r2;
continue;
}
if(r1->pc == val)
break;
r1 = r1->link;
}
if(r1 == R) {
nearln = p->lineno;
diag(Z, "ref not found\n%P", p);
continue;
}
if(r1 == r) {
nearln = p->lineno;
diag(Z, "ref to self\n%P", p);
continue;
}
r->s2 = r1;
r->p2link = r1->p2;
r1->p2 = r;
}
}
if(debug['R']) {
p = firstr->prog;
print("\n%L %D\n", p->lineno, &p->from);
}

/*
* pass 2.5
* find looping structure
*/
for(r = firstr; r != R; r = r->link)
r->active = 0;
change = 0;
loopit(firstr, npc);
if(debug['R'] && debug['v']) {
print("\nlooping structure:\n");
for(r = firstr; r != R; r = r->link) {
print("%ld:%P", r->loop, r->prog);
for(z=0; z<BITS; z++)
bit.b[z] = r->use1.b[z] |
r->use2.b[z] |
r->set.b[z];
if(bany(&bit)) {
print("\t");
if(bany(&r->use1))
print(" u1=%B", r->use1);
if(bany(&r->use2))
print(" u2=%B", r->use2);
if(bany(&r->set))
print(" st=%B", r->set);
}
print("\n");
}
}

/*
* pass 3
* iterate propagating usage
* back until flow graph is complete
*/
loop1:
change = 0;
for(r = firstr; r != R; r = r->link)
r->active = 0;
for(r = firstr; r != R; r = r->link)
if(r->prog->as == ARET)
prop(r, zbits, zbits);
loop11:
/* pick up unreachable code */
i = 0;
for(r = firstr; r != R; r = r1) {
r1 = r->link;
if(r1 && r1->active && !r->active) {
prop(r, zbits, zbits);
i = 1;
}
}
if(i)
goto loop11;
if(change)
goto loop1;

/*
* pass 4
* iterate propagating register/variable synchrony
* forward until graph is complete
*/
loop2:
change = 0;
for(r = firstr; r != R; r = r->link)
r->active = 0;
synch(firstr, zbits);
if(change)
goto loop2;

/*
* pass 5
* isolate regions
* calculate costs (paint1)
*/
r = firstr;
if(r) {
for(z=0; z<BITS; z++)
bit.b[z] = (r->refahead.b[z] | r->calahead.b[z]) &
~(externs.b[z] | params.b[z] | addrs.b[z] | consts.b[z]);
if(bany(&bit)) {
nearln = r->prog->lineno;
warn(Z, "used and not set: %B", bit);
if(debug['R'] && !debug['w'])
print("used and not set: %B\n", bit);
}
}
if(debug['R'] && debug['v'])
print("\nprop structure:\n");
for(r = firstr; r != R; r = r->link)
r->act = zbits;
rgp = region;
nregion = 0;
for(r = firstr; r != R; r = r->link) {
if(debug['R'] && debug['v']) {
print("%P\t", r->prog);
if(bany(&r->set))
print("s:%B ", r->set);
if(bany(&r->refahead))
print("ra:%B ", r->refahead);
if(bany(&r->calahead))
print("ca:%B ", r->calahead);
print("\n");
}
for(z=0; z<BITS; z++)
bit.b[z] = r->set.b[z] &
~(r->refahead.b[z] | r->calahead.b[z] | addrs.b[z]);
if(bany(&bit)) {
nearln = r->prog->lineno;
warn(Z, "set and not used: %B", bit);
if(debug['R'])
print("set and not used: %B\n", bit);
excise(r);
}
for(z=0; z<BITS; z++)
bit.b[z] = LOAD(r) & ~(r->act.b[z] | addrs.b[z]);
while(bany(&bit)) {
i = bnum(bit);
rgp->enter = r;
rgp->varno = i;
change = 0;
if(debug['R'] && debug['v'])
print("\n");
paint1(r, i);
bit.b[i/32] &= ~(1L<<(i%32));
if(change <= 0) {
if(debug['R'])
print("%L$%d: %B\n",
r->prog->lineno, change, blsh(i));
continue;
}
rgp->cost = change;
nregion++;
if(nregion >= NRGN) {
warn(Z, "too many regions");
goto brk;
}
rgp++;
}
}
brk:
qsort(region, nregion, sizeof(region[0]), rcmp);

/*
* pass 6
* determine used registers (paint2)
* replace code (paint3)
*/
rgp = region;
for(i=0; i<nregion; i++) {
bit = blsh(rgp->varno);
vreg = paint2(rgp->enter, rgp->varno);
vreg = allreg(vreg, rgp);
if(debug['R']) {
print("%L$%d %R: %B\n",
rgp->enter->prog->lineno,
rgp->cost,
rgp->regno,
bit);
}
if(rgp->regno != 0)
paint3(rgp->enter, rgp->varno, vreg, rgp->regno);
rgp++;
}
/*
* pass 7
* peep-hole on basic block
*/
if(!debug['R'] || debug['P'])
peep();

/*
* pass 8
* recalculate pc
*/
val = initpc;
for(r = firstr; r != R; r = r1) {
r->pc = val;
p = r->prog;
p1 = P;
r1 = r->link;
if(r1 != R)
p1 = r1->prog;
for(; p != p1; p = p->link) {
switch(p->as) {
default:
val++;
break;

case ANOP:
case ADATA:
case AGLOBL:
case ANAME:
case ASIGNAME:
break;
}
}
}
pc = val;

/*
* fix up branches
*/
if(debug['R'])
if(bany(&addrs))
print("addrs: %B\n", addrs);

r1 = 0; /* set */
for(r = firstr; r != R; r = r->link) {
p = r->prog;
if(p->to.type == D_BRANCH)
p->to.offset = r->s2->pc;
r1 = r;
}

/*
* last pass
* eliminate nops
* free aux structures
*/
for(p = firstr->prog; p != P; p = p->link){
while(p->link && p->link->as == ANOP)
p->link = p->link->link;
}
if(r1 != R) {
r1->link = freer;
freer = firstr;
}
}

/*
* add mov b,rn
* just after r
*/
void
addmove(Reg *r, int bn, int rn, int f)
{
Prog *p, *p1;
Adr *a;
Var *v;

p1 = alloc(sizeof(*p1));
*p1 = zprog;
p = r->prog;

p1->link = p->link;
p->link = p1;
p1->lineno = p->lineno;

v = var + bn;

a = &p1->to;
a->sym = v->sym;
a->offset = v->offset;
a->etype = v->etype;
a->type = v->name;

p1->as = AMOVL;
if(v->etype == TCHAR || v->etype == TUCHAR)
p1->as = AMOVB;
if(v->etype == TSHORT || v->etype == TUSHORT)
p1->as = AMOVW;
if(v->etype == TVLONG || v->etype == TUVLONG || v->etype == TIND)
p1->as = AMOVQ;
if(v->etype == TFLOAT)
p1->as = AMOVSS;
if(v->etype == TDOUBLE)
p1->as = AMOVSD;

p1->from.type = rn;
if(!f) {
p1->from = *a;
*a = zprog.from;
a->type = rn;
if(v->etype == TUCHAR)
p1->as = AMOVB;
if(v->etype == TUSHORT)
p1->as = AMOVW;
}
if(debug['R'])
print("%P\t.a%P\n", p, p1);
}

ulong
doregbits(int r)
{
ulong b;

b = 0;
if(r >= D_INDIR)
r -= D_INDIR;
if(r >= D_AX && r <= D_R15)
b |= RtoB(r);
else
if(r >= D_AL && r <= D_R15B)
b |= RtoB(r-D_AL+D_AX);
else
if(r >= D_AH && r <= D_BH)
b |= RtoB(r-D_AH+D_AX);
else
if(r >= D_X0 && r <= D_X0+15)
b |= FtoB(r);
return b;
}

Bits
mkvar(Reg *r, Adr *a)
{
Var *v;
int i, t, n, et, z;
long o;
Bits bit;
Sym *s;

/*
* mark registers used
*/
t = a->type;
r->regu |= doregbits(t);
r->regu |= doregbits(a->index);

switch(t) {
default:
goto none;
case D_ADDR:
a->type = a->index;
bit = mkvar(r, a);
for(z=0; z<BITS; z++)
addrs.b[z] |= bit.b[z];
a->type = t;
goto none;
case D_EXTERN:
case D_STATIC:
case D_PARAM:
case D_AUTO:
n = t;
break;
}
s = a->sym;
if(s == S)
goto none;
if(s->name[0] == '.')
goto none;
et = a->etype;
o = a->offset;
v = var;
for(i=0; i<nvar; i++) {
if(s == v->sym)
if(n == v->name)
if(o == v->offset)
goto out;
v++;
}
if(nvar >= NVAR) {
if(debug['w'] > 1 && s)
warn(Z, "variable not optimized: %s", s->name);
goto none;
}
i = nvar;
nvar++;
v = &var[i];
v->sym = s;
v->offset = o;
v->name = n;
v->etype = et;
if(debug['R'])
print("bit=%2d et=%2d %D\n", i, et, a);

out:
bit = blsh(i);
if(n == D_EXTERN || n == D_STATIC)
for(z=0; z<BITS; z++)
externs.b[z] |= bit.b[z];
if(n == D_PARAM)
for(z=0; z<BITS; z++)
params.b[z] |= bit.b[z];
if(v->etype != et || !(typechlpfd[et] || typev[et])) /* funny punning */
for(z=0; z<BITS; z++)
addrs.b[z] |= bit.b[z];
return bit;

none:
return zbits;
}

void
prop(Reg *r, Bits ref, Bits cal)
{
Reg *r1, *r2;
int z;

for(r1 = r; r1 != R; r1 = r1->p1) {
for(z=0; z<BITS; z++) {
ref.b[z] |= r1->refahead.b[z];
if(ref.b[z] != r1->refahead.b[z]) {
r1->refahead.b[z] = ref.b[z];
change++;
}
cal.b[z] |= r1->calahead.b[z];
if(cal.b[z] != r1->calahead.b[z]) {
r1->calahead.b[z] = cal.b[z];
change++;
}
}
switch(r1->prog->as) {
case ACALL:
for(z=0; z<BITS; z++) {
cal.b[z] |= ref.b[z] | externs.b[z];
ref.b[z] = 0;
}
break;

case ATEXT:
for(z=0; z<BITS; z++) {
cal.b[z] = 0;
ref.b[z] = 0;
}
break;

case ARET:
for(z=0; z<BITS; z++) {
cal.b[z] = externs.b[z];
ref.b[z] = 0;
}
}
for(z=0; z<BITS; z++) {
ref.b[z] = (ref.b[z] & ~r1->set.b[z]) |
r1->use1.b[z] | r1->use2.b[z];
cal.b[z] &= ~(r1->set.b[z] | r1->use1.b[z] | r1->use2.b[z]);
r1->refbehind.b[z] = ref.b[z];
r1->calbehind.b[z] = cal.b[z];
}
if(r1->active)
break;
r1->active = 1;
}
for(; r != r1; r = r->p1)
for(r2 = r->p2; r2 != R; r2 = r2->p2link)
prop(r2, r->refbehind, r->calbehind);
}

/*
* find looping structure
*
* 1) find reverse postordering
* 2) find approximate dominators,
* the actual dominators if the flow graph is reducible
* otherwise, dominators plus some other non-dominators.
* See Matthew S. Hecht and Jeffrey D. Ullman,
* "Analysis of a Simple Algorithm for Global Data Flow Problems",
* Conf. Record of ACM Symp. on Principles of Prog. Langs, Boston, Massachusetts,
* Oct. 1-3, 1973, pp. 207-217.
* 3) find all nodes with a predecessor dominated by the current node.
* such a node is a loop head.
* recursively, all preds with a greater rpo number are in the loop
*/
long
postorder(Reg *r, Reg **rpo2r, long n)
{
Reg *r1;

r->rpo = 1;
r1 = r->s1;
if(r1 && !r1->rpo)
n = postorder(r1, rpo2r, n);
r1 = r->s2;
if(r1 && !r1->rpo)
n = postorder(r1, rpo2r, n);
rpo2r[n] = r;
n++;
return n;
}

long
rpolca(long *idom, long rpo1, long rpo2)
{
long t;

if(rpo1 == -1)
return rpo2;
while(rpo1 != rpo2){
if(rpo1 > rpo2){
t = rpo2;
rpo2 = rpo1;
rpo1 = t;
}
while(rpo1 < rpo2){
t = idom[rpo2];
if(t >= rpo2)
fatal(Z, "bad idom");
rpo2 = t;
}
}
return rpo1;
}

int
doms(long *idom, long r, long s)
{
while(s > r)
s = idom[s];
return s == r;
}

int
loophead(long *idom, Reg *r)
{
long src;

src = r->rpo;
if(r->p1 != R && doms(idom, src, r->p1->rpo))
return 1;
for(r = r->p2; r != R; r = r->p2link)
if(doms(idom, src, r->rpo))
return 1;
return 0;
}

void
loopmark(Reg **rpo2r, long head, Reg *r)
{
if(r->rpo < head || r->active == head)
return;
r->active = head;
r->loop += LOOP;
if(r->p1 != R)
loopmark(rpo2r, head, r->p1);
for(r = r->p2; r != R; r = r->p2link)
loopmark(rpo2r, head, r);
}

void
loopit(Reg *r, long nr)
{
Reg *r1;
long i, d, me;

if(nr > maxnr) {
rpo2r = alloc(nr * sizeof(Reg*));
idom = alloc(nr * sizeof(long));
maxnr = nr;
}

d = postorder(r, rpo2r, 0);
if(d > nr)
fatal(Z, "too many reg nodes");
nr = d;
for(i = 0; i < nr / 2; i++){
r1 = rpo2r[i];
rpo2r[i] = rpo2r[nr - 1 - i];
rpo2r[nr - 1 - i] = r1;
}
for(i = 0; i < nr; i++)
rpo2r[i]->rpo = i;

idom[0] = 0;
for(i = 0; i < nr; i++){
r1 = rpo2r[i];
me = r1->rpo;
d = -1;
if(r1->p1 != R && r1->p1->rpo < me)
d = r1->p1->rpo;
for(r1 = r1->p2; r1 != nil; r1 = r1->p2link)
if(r1->rpo < me)
d = rpolca(idom, d, r1->rpo);
idom[i] = d;
}

for(i = 0; i < nr; i++){
r1 = rpo2r[i];
r1->loop++;
if(r1->p2 != R && loophead(idom, r1))
loopmark(rpo2r, i, r1);
}
}

void
synch(Reg *r, Bits dif)
{
Reg *r1;
int z;

for(r1 = r; r1 != R; r1 = r1->s1) {
for(z=0; z<BITS; z++) {
dif.b[z] = (dif.b[z] &
~(~r1->refbehind.b[z] & r1->refahead.b[z])) |
r1->set.b[z] | r1->regdiff.b[z];
if(dif.b[z] != r1->regdiff.b[z]) {
r1->regdiff.b[z] = dif.b[z];
change++;
}
}
if(r1->active)
break;
r1->active = 1;
for(z=0; z<BITS; z++)
dif.b[z] &= ~(~r1->calbehind.b[z] & r1->calahead.b[z]);
if(r1->s2 != R)
synch(r1->s2, dif);
}
}

ulong
allreg(ulong b, Rgn *r)
{
Var *v;
int i;

v = var + r->varno;
r->regno = 0;
switch(v->etype) {

default:
diag(Z, "unknown etype %d/%d", bitno(b), v->etype);
break;

case TCHAR:
case TUCHAR:
case TSHORT:
case TUSHORT:
case TINT:
case TUINT:
case TLONG:
case TULONG:
case TVLONG:
case TUVLONG:
case TIND:
case TARRAY:
i = BtoR(~b);
if(i && r->cost > 0) {
r->regno = i;
return RtoB(i);
}
break;

case TDOUBLE:
case TFLOAT:
i = BtoF(~b);
if(i && r->cost > 0) {
r->regno = i;
return FtoB(i);
}
break;
}
return 0;
}

void
paint1(Reg *r, int bn)
{
Reg *r1;
Prog *p;
int z;
ulong bb;

z = bn/32;
bb = 1L<<(bn%32);
if(r->act.b[z] & bb)
return;
for(;;) {
if(!(r->refbehind.b[z] & bb))
break;
r1 = r->p1;
if(r1 == R)
break;
if(!(r1->refahead.b[z] & bb))
break;
if(r1->act.b[z] & bb)
break;
r = r1;
}

if(LOAD(r) & ~(r->set.b[z]&~(r->use1.b[z]|r->use2.b[z])) & bb) {
change -= CLOAD * r->loop;
if(debug['R'] && debug['v'])
print("%ld%P\tld %B $%d\n", r->loop,
r->prog, blsh(bn), change);
}
for(;;) {
r->act.b[z] |= bb;
p = r->prog;

if(r->use1.b[z] & bb) {
change += CREF * r->loop;
if(debug['R'] && debug['v'])
print("%ld%P\tu1 %B $%d\n", r->loop,
p, blsh(bn), change);
}

if((r->use2.b[z]|r->set.b[z]) & bb) {
change += CREF * r->loop;
if(debug['R'] && debug['v'])
print("%ld%P\tu2 %B $%d\n", r->loop,
p, blsh(bn), change);
}

if(STORE(r) & r->regdiff.b[z] & bb) {
change -= CLOAD * r->loop;
if(debug['R'] && debug['v'])
print("%ld%P\tst %B $%d\n", r->loop,
p, blsh(bn), change);
}

if(r->refbehind.b[z] & bb)
for(r1 = r->p2; r1 != R; r1 = r1->p2link)
if(r1->refahead.b[z] & bb)
paint1(r1, bn);

if(!(r->refahead.b[z] & bb))
break;
r1 = r->s2;
if(r1 != R)
if(r1->refbehind.b[z] & bb)
paint1(r1, bn);
r = r->s1;
if(r == R)
break;
if(r->act.b[z] & bb)
break;
if(!(r->refbehind.b[z] & bb))
break;
}
}

ulong
regset(Reg *r, ulong bb)
{
ulong b, set;
Adr v;
int c;

set = 0;
v = zprog.from;
while(b = bb & ~(bb-1)) {
v.type = b & 0xFFFF? BtoR(b): BtoF(b);
if(v.type == 0)
diag(Z, "zero v.type for %#lux", b);
c = copyu(r->prog, &v, A);
if(c == 3)
set |= b;
bb &= ~b;
}
return set;
}

ulong
reguse(Reg *r, ulong bb)
{
ulong b, set;
Adr v;
int c;

set = 0;
v = zprog.from;
while(b = bb & ~(bb-1)) {
v.type = b & 0xFFFF? BtoR(b): BtoF(b);
c = copyu(r->prog, &v, A);
if(c == 1 || c == 2 || c == 4)
set |= b;
bb &= ~b;
}
return set;
}

ulong
paint2(Reg *r, int bn)
{
Reg *r1;
int z;
ulong bb, vreg, x;

z = bn/32;
bb = 1L << (bn%32);
vreg = regbits;
if(!(r->act.b[z] & bb))
return vreg;
for(;;) {
if(!(r->refbehind.b[z] & bb))
break;
r1 = r->p1;
if(r1 == R)
break;
if(!(r1->refahead.b[z] & bb))
break;
if(!(r1->act.b[z] & bb))
break;
r = r1;
}
for(;;) {
r->act.b[z] &= ~bb;

vreg |= r->regu;

if(r->refbehind.b[z] & bb)
for(r1 = r->p2; r1 != R; r1 = r1->p2link)
if(r1->refahead.b[z] & bb)
vreg |= paint2(r1, bn);

if(!(r->refahead.b[z] & bb))
break;
r1 = r->s2;
if(r1 != R)
if(r1->refbehind.b[z] & bb)
vreg |= paint2(r1, bn);
r = r->s1;
if(r == R)
break;
if(!(r->act.b[z] & bb))
break;
if(!(r->refbehind.b[z] & bb))
break;
}

bb = vreg;
for(; r; r=r->s1) {
x = r->regu & ~bb;
if(x) {
vreg |= reguse(r, x);
bb |= regset(r, x);
}
}
return vreg;
}

void
paint3(Reg *r, int bn, long rb, int rn)
{
Reg *r1;
Prog *p;
int z;
ulong bb;

z = bn/32;
bb = 1L << (bn%32);
if(r->act.b[z] & bb)
return;
for(;;) {
if(!(r->refbehind.b[z] & bb))
break;
r1 = r->p1;
if(r1 == R)
break;
if(!(r1->refahead.b[z] & bb))
break;
if(r1->act.b[z] & bb)
break;
r = r1;
}

if(LOAD(r) & ~(r->set.b[z] & ~(r->use1.b[z]|r->use2.b[z])) & bb)
addmove(r, bn, rn, 0);
for(;;) {
r->act.b[z] |= bb;
p = r->prog;

if(r->use1.b[z] & bb) {
if(debug['R'])
print("%P", p);
addreg(&p->from, rn);
if(debug['R'])
print("\t.c%P\n", p);
}
if((r->use2.b[z]|r->set.b[z]) & bb) {
if(debug['R'])
print("%P", p);
addreg(&p->to, rn);
if(debug['R'])
print("\t.c%P\n", p);
}

if(STORE(r) & r->regdiff.b[z] & bb)
addmove(r, bn, rn, 1);
r->regu |= rb;

if(r->refbehind.b[z] & bb)
for(r1 = r->p2; r1 != R; r1 = r1->p2link)
if(r1->refahead.b[z] & bb)
paint3(r1, bn, rb, rn);

if(!(r->refahead.b[z] & bb))
break;
r1 = r->s2;
if(r1 != R)
if(r1->refbehind.b[z] & bb)
paint3(r1, bn, rb, rn);
r = r->s1;
if(r == R)
break;
if(r->act.b[z] & bb)
break;
if(!(r->refbehind.b[z] & bb))
break;
}
}

void
addreg(Adr *a, int rn)
{

a->sym = 0;
a->offset = 0;
a->type = rn;
}

long
RtoB(int r)
{

if(r < D_AX || r > D_R15)
return 0;
return 1L << (r-D_AX);
}

int
BtoR(long b)
{

b &= 0xffffL;
if(b == 0)
return 0;
return bitno(b) + D_AX;
}

/*
* bit reg
* 16 X5
* 17 X6
* 18 X7
*/
long
FtoB(int f)
{
if(f < FREGMIN || f > FREGEXT)
return 0;
return 1L << (f - FREGMIN + 16);
}

int
BtoF(long b)
{

b &= 0x70000L;
if(b == 0)
return 0;
return bitno(b) - 16 + FREGMIN;
}