void
regopt(Prog *firstp)
{
Reg *r, *r1;
Prog *p;
Graph *g;
int i, z;
uint32 vreg;
Bits bit;
ProgInfo info;
if(first) {
fmtinstall('Q', Qconv);
first = 0;
}
fixjmp(firstp);
mergetemp(firstp);
/*
* control flow is more complicated in generated go code
* than in generated c code. define pseudo-variables for
* registers, so we have complete register usage information.
*/
nvar = NREGVAR;
memset(var, 0, NREGVAR*sizeof var[0]);
for(i=0; i<NREGVAR; i++) {
if(regnodes[i] == N)
regnodes[i] = newname(lookup(regname[i]));
var[i].node = regnodes[i];
}
regbits = RtoB(REGSP)|RtoB(REGLINK)|RtoB(REGPC);
for(z=0; z<BITS; z++) {
externs.b[z] = 0;
params.b[z] = 0;
consts.b[z] = 0;
addrs.b[z] = 0;
ovar.b[z] = 0;
}
// build list of return variables
setoutvar();
/*
* pass 1
* build aux data structure
* allocate pcs
* find use and set of variables
*/
g = flowstart(firstp, sizeof(Reg));
if(g == nil)
return;
firstr = (Reg*)g->start;
for(r = firstr; r != R; r = (Reg*)r->f.link) {
p = r->f.prog;
proginfo(&info, p);
// Avoid making variables for direct-called functions.
if(p->as == ABL && p->to.type == D_EXTERN)
continue;
bit = mkvar(r, &p->from);
if(info.flags & LeftRead)
for(z=0; z<BITS; z++)
r->use1.b[z] |= bit.b[z];
if(info.flags & LeftAddr)
setaddrs(bit);
if(info.flags & RegRead) {
if(p->from.type != D_FREG)
r->use1.b[0] |= RtoB(p->reg);
else
r->use1.b[0] |= FtoB(p->reg);
}
if(info.flags & (RightAddr | RightRead | RightWrite)) {
bit = mkvar(r, &p->to);
if(info.flags & RightAddr)
setaddrs(bit);
if(info.flags & RightRead)
for(z=0; z<BITS; z++)
r->use2.b[z] |= bit.b[z];
if(info.flags & RightWrite)
for(z=0; z<BITS; z++)
r->set.b[z] |= bit.b[z];
}
}
if(firstr == R)
return;
for(i=0; i<nvar; i++) {
Var *v = var+i;
if(v->addr) {
bit = blsh(i);
for(z=0; z<BITS; z++)
addrs.b[z] |= bit.b[z];
}
if(debug['R'] && debug['v'])
print("bit=%2d addr=%d et=%-6E w=%-2d s=%N + %lld\n",
i, v->addr, v->etype, v->width, v->node, v->offset);
}
if(debug['R'] && debug['v'])
dumpit("pass1", &firstr->f, 1);
/*
* pass 2
* find looping structure
*/
flowrpo(g);
if(debug['R'] && debug['v'])
dumpit("pass2", &firstr->f, 1);
/*
* pass 3
* iterate propagating usage
* back until flow graph is complete
*/
loop1:
change = 0;
for(r = firstr; r != R; r = (Reg*)r->f.link)
r->f.active = 0;
for(r = firstr; r != R; r = (Reg*)r->f.link)
if(r->f.prog->as == ARET)
prop(r, zbits, zbits);
loop11:
/* pick up unreachable code */
i = 0;
for(r = firstr; r != R; r = r1) {
r1 = (Reg*)r->f.link;
if(r1 && r1->f.active && !r->f.active) {
prop(r, zbits, zbits);
i = 1;
}
}
if(i)
goto loop11;
if(change)
goto loop1;
if(debug['R'] && debug['v'])
dumpit("pass3", &firstr->f, 1);
/*
* pass 4
* iterate propagating register/variable synchrony
* forward until graph is complete
*/
loop2:
change = 0;
for(r = firstr; r != R; r = (Reg*)r->f.link)
r->f.active = 0;
synch(firstr, zbits);
if(change)
goto loop2;
addsplits();
if(debug['R'] && debug['v'])
dumpit("pass4", &firstr->f, 1);
if(debug['R'] > 1) {
print("\nprop structure:\n");
for(r = firstr; r != R; r = (Reg*)r->f.link) {
print("%d:%P", r->f.loop, r->f.prog);
for(z=0; z<BITS; z++) {
bit.b[z] = r->set.b[z] |
r->refahead.b[z] | r->calahead.b[z] |
r->refbehind.b[z] | r->calbehind.b[z] |
r->use1.b[z] | r->use2.b[z];
bit.b[z] &= ~addrs.b[z];
}
if(bany(&bit)) {
print("\t");
if(bany(&r->use1))
print(" u1=%Q", r->use1);
if(bany(&r->use2))
print(" u2=%Q", r->use2);
if(bany(&r->set))
print(" st=%Q", r->set);
if(bany(&r->refahead))
print(" ra=%Q", r->refahead);
if(bany(&r->calahead))
print(" ca=%Q", r->calahead);
if(bany(&r->refbehind))
print(" rb=%Q", r->refbehind);
if(bany(&r->calbehind))
print(" cb=%Q", r->calbehind);
}
print("\n");
}
}
/*
* pass 4.5
* move register pseudo-variables into regu.
*/
for(r = firstr; r != R; r = (Reg*)r->f.link) {
r->regu = (r->refbehind.b[0] | r->set.b[0]) & REGBITS;
r->set.b[0] &= ~REGBITS;
r->use1.b[0] &= ~REGBITS;
r->use2.b[0] &= ~REGBITS;
r->refbehind.b[0] &= ~REGBITS;
r->refahead.b[0] &= ~REGBITS;
r->calbehind.b[0] &= ~REGBITS;
r->calahead.b[0] &= ~REGBITS;
r->regdiff.b[0] &= ~REGBITS;
r->act.b[0] &= ~REGBITS;
}
if(debug['R'] && debug['v'])
dumpit("pass4.5", &firstr->f, 1);
/*
* 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) & !r->f.refset) {
// should never happen - all variables are preset
if(debug['w'])
print("%L: used and not set: %Q\n", r->f.prog->lineno, bit);
r->f.refset = 1;
}
}
for(r = firstr; r != R; r = (Reg*)r->f.link)
r->act = zbits;
rgp = region;
nregion = 0;
for(r = firstr; r != R; r = (Reg*)r->f.link) {
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) && !r->f.refset) {
if(debug['w'])
print("%L: set and not used: %Q\n", r->f.prog->lineno, bit);
r->f.refset = 1;
excise(&r->f);
}
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'] > 1)
print("\n");
paint1(r, i);
bit.b[i/32] &= ~(1L<<(i%32));
if(change <= 0) {
if(debug['R'])
print("%L $%d: %Q\n",
r->f.prog->lineno, change, blsh(i));
continue;
}
rgp->cost = change;
nregion++;
if(nregion >= NRGN) {
if(debug['R'] > 1)
print("too many regions\n");
goto brk;
}
rgp++;
}
}
brk:
qsort(region, nregion, sizeof(region[0]), rcmp);
if(debug['R'] && debug['v'])
dumpit("pass5", &firstr->f, 1);
/*
* 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']) {
if(rgp->regno >= NREG)
print("%L $%d F%d: %Q\n",
rgp->enter->f.prog->lineno,
rgp->cost,
rgp->regno-NREG,
bit);
else
print("%L $%d R%d: %Q\n",
rgp->enter->f.prog->lineno,
rgp->cost,
rgp->regno,
bit);
}
if(rgp->regno != 0)
paint3(rgp->enter, rgp->varno, vreg, rgp->regno);
rgp++;
}
if(debug['R'] && debug['v'])
dumpit("pass6", &firstr->f, 1);
/*
* pass 7
* peep-hole on basic block
*/
if(!debug['R'] || debug['P']) {
peep(firstp);
}
if(debug['R'] && debug['v'])
dumpit("pass7", &firstr->f, 1);
/*
* last pass
* eliminate nops
* free aux structures
* adjust the stack pointer
* MOVW.W R1,-12(R13) <<- start
* MOVW R0,R1
* MOVW R1,8(R13)
* MOVW $0,R1
* MOVW R1,4(R13)
* BL ,runtime.newproc+0(SB)
* MOVW &ft+-32(SP),R7 <<- adjust
* MOVW &j+-40(SP),R6 <<- adjust
* MOVW autotmp_0003+-24(SP),R5 <<- adjust
* MOVW $12(R13),R13 <<- finish
*/
vreg = 0;
for(p = firstp; p != P; p = p->link) {
while(p->link != P && p->link->as == ANOP)
p->link = p->link->link;
if(p->to.type == D_BRANCH)
while(p->to.u.branch != P && p->to.u.branch->as == ANOP)
p->to.u.branch = p->to.u.branch->link;
if(p->as == AMOVW && p->to.reg == 13) {
if(p->scond & C_WBIT) {
vreg = -p->to.offset; // in adjust region
// print("%P adjusting %d\n", p, vreg);
continue;
}
if(p->from.type == D_CONST && p->to.type == D_REG) {
if(p->from.offset != vreg)
print("in and out different\n");
// print("%P finish %d\n", p, vreg);
vreg = 0; // done adjust region
continue;
}
// print("%P %d %d from type\n", p, p->from.type, D_CONST);
// print("%P %d %d to type\n\n", p, p->to.type, D_REG);
}
if(p->as == AMOVW && vreg != 0) {
if(p->from.sym != S)
if(p->from.name == D_AUTO || p->from.name == D_PARAM) {
p->from.offset += vreg;
// print("%P adjusting from %d %d\n", p, vreg, p->from.type);
}
if(p->to.sym != S)
if(p->to.name == D_AUTO || p->to.name == D_PARAM) {
p->to.offset += vreg;
// print("%P adjusting to %d %d\n", p, vreg, p->from.type);
}
}
}
flowend(g);
}
Bits
mkvar(Reg *r, Adr *a)
{
Var *v;
int i, t, n, et, z, w, flag;
int32 o;
Bits bit;
Node *node;
// mark registers used
t = a->type;
flag = 0;
switch(t) {
default:
print("type %d %d %D\n", t, a->name, a);
goto none;
case D_NONE:
case D_FCONST:
case D_BRANCH:
break;
case D_REGREG:
case D_REGREG2:
bit = zbits;
if(a->offset != NREG)
bit.b[0] |= RtoB(a->offset);
if(a->reg != NREG)
bit.b[0] |= RtoB(a->reg);
return bit;
case D_CONST:
case D_REG:
case D_SHIFT:
if(a->reg != NREG) {
bit = zbits;
bit.b[0] = RtoB(a->reg);
return bit;
}
break;
case D_OREG:
if(a->reg != NREG) {
if(a == &r->f.prog->from)
r->use1.b[0] |= RtoB(a->reg);
else
r->use2.b[0] |= RtoB(a->reg);
if(r->f.prog->scond & (C_PBIT|C_WBIT))
r->set.b[0] |= RtoB(a->reg);
}
break;
case D_FREG:
if(a->reg != NREG) {
bit = zbits;
bit.b[0] = FtoB(a->reg);
return bit;
}
break;
}
switch(a->name) {
default:
goto none;
case D_EXTERN:
case D_STATIC:
case D_AUTO:
case D_PARAM:
n = a->name;
break;
}
node = a->node;
if(node == N || node->op != ONAME || node->orig == N)
goto none;
node = node->orig;
if(node->orig != node)
fatal("%D: bad node", a);
if(node->sym == S || node->sym->name[0] == '.')
goto none;
et = a->etype;
o = a->offset;
w = a->width;
if(w < 0)
fatal("bad width %d for %D", w, a);
for(i=0; i<nvar; i++) {
v = var+i;
if(v->node == node && v->name == n) {
if(v->offset == o)
if(v->etype == et)
if(v->width == w)
if(!flag)
return blsh(i);
// if they overlap, disable both
if(overlap(v->offset, v->width, o, w)) {
v->addr = 1;
flag = 1;
}
}
}
switch(et) {
case 0:
case TFUNC:
goto none;
}
if(nvar >= NVAR) {
if(debug['w'] > 1 && node)
fatal("variable not optimized: %D", a);
goto none;
}
i = nvar;
nvar++;
//print("var %d %E %D %S\n", i, et, a, s);
v = var+i;
v->offset = o;
v->name = n;
v->etype = et;
v->width = w;
v->addr = flag; // funny punning
v->node = node;
if(debug['R'])
print("bit=%2d et=%2E w=%d+%d %#N %D flag=%d\n", i, et, o, w, node, a, v->addr);
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];
return bit;
none:
return zbits;
}
void
regopt(Prog *p)
{
Reg *r, *r1, *r2;
Prog *p1;
int i, z;
int32 initpc, val, npc;
uint32 vreg;
Bits bit;
struct
{
int32 m;
int32 c;
Reg* p;
} log5[6], *lp;
firstr = R;
lastr = R;
nvar = 0;
regbits = RtoB(D_SP) | RtoB(D_AX);
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:
r->p1 = R;
r1->s1 = R;
}
bit = mkvar(r, &p->from);
if(bany(&bit))
switch(p->as) {
/*
* funny
*/
case ALEAL:
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 ACMPW:
for(z=0; z<BITS; z++)
r->use2.b[z] |= bit.b[z];
break;
/*
* right side write
*/
case ANOP:
case AMOVL:
case AMOVB:
case AMOVW:
case AMOVBLSX:
case AMOVBLZX:
case AMOVWLSX:
case AMOVWLZX:
for(z=0; z<BITS; z++)
r->set.b[z] |= bit.b[z];
break;
/*
* right side read+write
*/
case AADDB:
case AADDL:
case AADDW:
case AANDB:
case AANDL:
case AANDW:
case ASUBB:
case ASUBL:
case ASUBW:
case AORB:
case AORL:
case AORW:
case AXORB:
case AXORL:
case AXORW:
case ASALB:
case ASALL:
case ASALW:
case ASARB:
case ASARL:
case ASARW:
case AROLB:
case AROLL:
case AROLW:
case ARORB:
case ARORL:
case ARORW:
case ASHLB:
case ASHLL:
case ASHLW:
case ASHRB:
case ASHRL:
case ASHRW:
case AIMULL:
case AIMULW:
case ANEGL:
case ANOTL:
case AADCL:
case ASBBL:
for(z=0; z<BITS; z++) {
r->set.b[z] |= bit.b[z];
r->use2.b[z] |= bit.b[z];
}
break;
/*
* funny
*/
case AFMOVDP:
case AFMOVFP:
case AFMOVLP:
case AFMOVVP:
case AFMOVWP:
case ACALL:
for(z=0; z<BITS; z++)
addrs.b[z] |= bit.b[z];
break;
}
switch(p->as) {
case AIMULL:
case AIMULW:
if(p->to.type != D_NONE)
break;
case AIDIVB:
case AIDIVL:
case AIDIVW:
case AIMULB:
case ADIVB:
case ADIVL:
case ADIVW:
case AMULB:
case AMULL:
case AMULW:
case ACWD:
case ACDQ:
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 AMOVSW:
case ACMPSB:
case ACMPSL:
case ACMPSW:
r->regu |= RtoB(D_SI) | RtoB(D_DI);
break;
case ASTOSB:
case ASTOSL:
case ASTOSW:
case ASCASB:
case ASCASL:
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;
case AFSTSW:
case ASAHF:
r->regu |= RtoB(D_AX);
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;
}
}
Bits
mkvar(Reg *r, Adr *a)
{
Var *v;
int i, t, n, et, z;
int32 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]) /* funny punning */
for(z=0; z<BITS; z++)
addrs.b[z] |= bit.b[z];
return bit;
none:
return zbits;
}
Bits
mkvar(Adr *a, int docon)
{
Var *v;
int i, t, n, et, z;
long o;
Bits bit;
Sym *s;
t = a->type;
if(t == D_REG && a->reg != NREG)
regbits |= RtoB(a->reg);
if(t == D_FREG && a->reg != NREG)
regbits |= FtoB(a->reg);
s = a->sym;
o = a->offset;
et = a->etype;
if(s == S) {
if(t != D_CONST || !docon || a->reg != NREG)
goto none;
et = TLONG;
}
if(t == D_CONST) {
if(s == S && sval(o))
goto none;
}
n = a->name;
v = var;
for(i=0; i<nvar; i++) {
if(s == v->sym)
if(n == v->name)
if(o == v->offset)
goto out;
v++;
}
if(s)
if(s->name[0] == '.')
goto none;
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->etype = et;
v->name = n;
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]) /* funny punning */
for(z=0; z<BITS; z++)
addrs.b[z] |= bit.b[z];
if(t == D_CONST) {
if(s == S) {
for(z=0; z<BITS; z++)
consts.b[z] |= bit.b[z];
return bit;
}
if(et != TARRAY)
for(z=0; z<BITS; z++)
addrs.b[z] |= bit.b[z];
for(z=0; z<BITS; z++)
params.b[z] |= bit.b[z];
return bit;
}
if(t == D_OREG)
return bit;
none:
return zbits;
}
void
paint1(Reg *r, int bn)
{
Reg *r1;
Prog *p;
int z;
uint32 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(p->as == AFMOVL)
if(BtoR(bb) != D_F0)
change = -CINF;
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(p->as == AFMOVL)
if(BtoR(bb) != D_F0)
change = -CINF;
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(p->as == AFMOVL)
if(BtoR(bb) != D_F0)
change = -CINF;
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;
}
}
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 = 0;
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 ARETURN:
case ABR:
case ARFI:
r->p1 = R;
r1->s1 = R;
}
/*
* left side always read
*/
bit = mkvar(&p->from, p->as==AMOVW);
for(z=0; z<BITS; z++)
r->use1.b[z] |= bit.b[z];
/*
* right side depends on opcode
*/
bit = mkvar(&p->to, 0);
if(bany(&bit))
switch(p->as) {
default:
diag(Z, "reg: unknown asop: %A", p->as);
break;
/*
* right side write
*/
case ANOP:
case AMOVB:
case AMOVBU:
case AMOVBZ:
case AMOVBZU:
case AMOVH:
case AMOVHBR:
case AMOVHU:
case AMOVHZ:
case AMOVHZU:
case AMOVW:
case AMOVWU:
case AFMOVD:
case AFMOVDCC:
case AFMOVDU:
case AFMOVS:
case AFMOVSU:
case AFRSP:
for(z=0; z<BITS; z++)
r->set.b[z] |= bit.b[z];
break;
/*
* funny
*/
case ABL:
for(z=0; z<BITS; z++)
addrs.b[z] |= bit.b[z];
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 == ARETURN)
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\n set = %B; rah = %B; cal = %B\n",
r->prog, r->set, r->refahead, r->calahead);
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 an 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']) {
if(rgp->regno >= NREG)
print("%L$%d F%d: %B\n",
rgp->enter->prog->lineno,
rgp->cost,
rgp->regno-NREG,
bit);
else
print("%L$%d R%d: %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;
}
}
Bits
mkvar(Reg *r, Adr *a)
{
Var *v;
int i, t, n, et, z, w, flag, regu;
int32 o;
Bits bit;
Sym *s;
/*
* mark registers used
*/
t = a->type;
if(t == D_NONE)
goto none;
if(r != R)
r->use1.b[0] |= doregbits(a->index);
switch(t) {
default:
regu = doregbits(t);
if(regu == 0)
goto none;
bit = zbits;
bit.b[0] = regu;
return bit;
case D_ADDR:
a->type = a->index;
bit = mkvar(r, a);
setaddrs(bit);
a->type = t;
ostats.naddr++;
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;
w = a->width;
flag = 0;
for(i=0; i<nvar; i++) {
v = var+i;
if(v->sym == s && v->name == n) {
if(v->offset == o)
if(v->etype == et)
if(v->width == w)
return blsh(i);
// if they overlaps, disable both
if(overlap(v->offset, v->width, o, w)) {
if(debug['R'])
print("disable %s\n", v->sym->name);
v->addr = 1;
flag = 1;
}
}
}
if(a->pun)
flag = 1;
switch(et) {
case 0:
case TFUNC:
goto none;
}
if(nvar >= NVAR) {
if(debug['w'] > 1 && s)
fatal("variable not optimized: %D", a);
goto none;
}
i = nvar;
nvar++;
v = var+i;
v->sym = s;
v->offset = o;
v->name = n;
v->gotype = a->gotype;
v->etype = et;
v->width = w;
v->addr = flag; // funny punning
v->node = a->node;
if(debug['R'])
print("bit=%2d et=%2d w=%d %S %D flag=%d\n", i, et, w, s, a, v->addr);
ostats.nvar++;
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];
return bit;
none:
return zbits;
}
void
regopt(Prog *firstp)
{
Reg *r, *r1;
Prog *p;
int i, z, nr;
uint32 vreg;
Bits bit;
if(first) {
fmtinstall('Q', Qconv);
exregoffset = D_DI; // no externals
first = 0;
}
// count instructions
nr = 0;
for(p=firstp; p!=P; p=p->link)
nr++;
// if too big dont bother
if(nr >= 10000) {
// print("********** %S is too big (%d)\n", curfn->nname->sym, nr);
return;
}
r1 = R;
firstr = R;
lastr = R;
/*
* control flow is more complicated in generated go code
* than in generated c code. define pseudo-variables for
* registers, so we have complete register usage information.
*/
nvar = NREGVAR;
memset(var, 0, NREGVAR*sizeof var[0]);
for(i=0; i<NREGVAR; i++)
var[i].sym = lookup(regname[i]);
regbits = RtoB(D_SP);
for(z=0; z<BITS; z++) {
externs.b[z] = 0;
params.b[z] = 0;
consts.b[z] = 0;
addrs.b[z] = 0;
ovar.b[z] = 0;
}
// build list of return variables
setoutvar();
/*
* pass 1
* build aux data structure
* allocate pcs
* find use and set of variables
*/
nr = 0;
for(p=firstp; p!=P; p=p->link) {
switch(p->as) {
case ADATA:
case AGLOBL:
case ANAME:
case ASIGNAME:
continue;
}
r = rega();
nr++;
if(firstr == R) {
firstr = r;
lastr = r;
} else {
lastr->link = r;
r->p1 = lastr;
lastr->s1 = r;
lastr = r;
}
r->prog = p;
p->reg = r;
r1 = r->p1;
if(r1 != R) {
switch(r1->prog->as) {
case ARET:
case AJMP:
case AIRETL:
r->p1 = R;
r1->s1 = R;
}
}
bit = mkvar(r, &p->from);
if(bany(&bit))
switch(p->as) {
/*
* funny
*/
case ALEAL:
setaddrs(bit);
break;
/*
* left side read
*/
default:
for(z=0; z<BITS; z++)
r->use1.b[z] |= bit.b[z];
break;
/*
* left side read+write
*/
case AXCHGB:
case AXCHGW:
case AXCHGL:
for(z=0; z<BITS; z++) {
r->use1.b[z] |= bit.b[z];
r->set.b[z] |= bit.b[z];
}
break;
}
bit = mkvar(r, &p->to);
if(bany(&bit))
switch(p->as) {
default:
yyerror("reg: unknown op: %A", p->as);
break;
/*
* right side read
*/
case ACMPB:
case ACMPL:
case ACMPW:
case ATESTB:
case ATESTL:
case ATESTW:
for(z=0; z<BITS; z++)
r->use2.b[z] |= bit.b[z];
break;
/*
* right side write
*/
case AFSTSW:
case ALEAL:
case ANOP:
case AMOVL:
case AMOVB:
case AMOVW:
case AMOVBLSX:
case AMOVBLZX:
case AMOVBWSX:
case AMOVBWZX:
case AMOVWLSX:
case AMOVWLZX:
case APOPL:
for(z=0; z<BITS; z++)
r->set.b[z] |= bit.b[z];
break;
/*
* right side read+write
*/
case AINCB:
case AINCL:
case AINCW:
case ADECB:
case ADECL:
case ADECW:
case AADDB:
case AADDL:
case AADDW:
case AANDB:
case AANDL:
case AANDW:
case ASUBB:
case ASUBL:
case ASUBW:
case AORB:
case AORL:
case AORW:
case AXORB:
case AXORL:
case AXORW:
case ASALB:
case ASALL:
case ASALW:
case ASARB:
case ASARL:
case ASARW:
case ARCLB:
case ARCLL:
case ARCLW:
case ARCRB:
case ARCRL:
case ARCRW:
case AROLB:
case AROLL:
case AROLW:
case ARORB:
case ARORL:
case ARORW:
case ASHLB:
case ASHLL:
case ASHLW:
case ASHRB:
case ASHRL:
case ASHRW:
case AIMULL:
case AIMULW:
case ANEGB:
case ANEGL:
case ANEGW:
case ANOTB:
case ANOTL:
case ANOTW:
case AADCL:
case ASBBL:
case ASETCC:
case ASETCS:
case ASETEQ:
case ASETGE:
case ASETGT:
case ASETHI:
case ASETLE:
case ASETLS:
case ASETLT:
case ASETMI:
case ASETNE:
case ASETOC:
case ASETOS:
case ASETPC:
case ASETPL:
case ASETPS:
case AXCHGB:
case AXCHGW:
case AXCHGL:
for(z=0; z<BITS; z++) {
r->set.b[z] |= bit.b[z];
r->use2.b[z] |= bit.b[z];
}
break;
/*
* funny
*/
case AFMOVDP:
case AFMOVFP:
case AFMOVLP:
case AFMOVVP:
case AFMOVWP:
case ACALL:
setaddrs(bit);
break;
}
switch(p->as) {
case AIMULL:
case AIMULW:
if(p->to.type != D_NONE)
break;
case AIDIVL:
case AIDIVW:
case ADIVL:
case ADIVW:
case AMULL:
case AMULW:
r->set.b[0] |= RtoB(D_AX) | RtoB(D_DX);
r->use1.b[0] |= RtoB(D_AX) | RtoB(D_DX);
break;
case AIDIVB:
case AIMULB:
case ADIVB:
case AMULB:
r->set.b[0] |= RtoB(D_AX);
r->use1.b[0] |= RtoB(D_AX);
break;
case ACWD:
r->set.b[0] |= RtoB(D_AX) | RtoB(D_DX);
r->use1.b[0] |= RtoB(D_AX);
break;
case ACDQ:
r->set.b[0] |= RtoB(D_DX);
r->use1.b[0] |= RtoB(D_AX);
break;
case AREP:
case AREPN:
case ALOOP:
case ALOOPEQ:
case ALOOPNE:
r->set.b[0] |= RtoB(D_CX);
r->use1.b[0] |= RtoB(D_CX);
break;
case AMOVSB:
case AMOVSL:
case AMOVSW:
case ACMPSB:
case ACMPSL:
case ACMPSW:
r->set.b[0] |= RtoB(D_SI) | RtoB(D_DI);
r->use1.b[0] |= RtoB(D_SI) | RtoB(D_DI);
break;
case ASTOSB:
case ASTOSL:
case ASTOSW:
case ASCASB:
case ASCASL:
case ASCASW:
r->set.b[0] |= RtoB(D_DI);
r->use1.b[0] |= RtoB(D_AX) | RtoB(D_DI);
break;
case AINSB:
case AINSL:
case AINSW:
r->set.b[0] |= RtoB(D_DX) | RtoB(D_DI);
r->use1.b[0] |= RtoB(D_DI);
break;
case AOUTSB:
case AOUTSL:
case AOUTSW:
r->set.b[0] |= RtoB(D_DI);
r->use1.b[0] |= RtoB(D_DX) | RtoB(D_DI);
break;
}
}
if(firstr == R)
return;
for(i=0; i<nvar; i++) {
Var *v = var+i;
if(v->addr) {
bit = blsh(i);
for(z=0; z<BITS; z++)
addrs.b[z] |= bit.b[z];
}
// print("bit=%2d addr=%d et=%-6E w=%-2d s=%S + %lld\n",
// i, v->addr, v->etype, v->width, v->sym, v->offset);
}
if(debug['R'] && debug['v'])
dumpit("pass1", firstr);
/*
* 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) {
if(p->to.branch == P)
fatal("pnil %P", p);
r1 = p->to.branch->reg;
if(r1 == R)
fatal("rnil %P", p);
if(r1 == r) {
//fatal("ref to self %P", p);
continue;
}
r->s2 = r1;
r->p2link = r1->p2;
r1->p2 = r;
}
}
if(debug['R'] && debug['v'])
dumpit("pass2", firstr);
/*
* pass 2.5
* find looping structure
*/
for(r = firstr; r != R; r = r->link)
r->active = 0;
change = 0;
loopit(firstr, nr);
if(debug['R'] && debug['v'])
dumpit("pass2.5", firstr);
/*
* 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;
if(debug['R'] && debug['v'])
dumpit("pass3", firstr);
/*
* 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;
if(debug['R'] && debug['v'])
dumpit("pass4", firstr);
/*
* pass 4.5
* move register pseudo-variables into regu.
*/
for(r = firstr; r != R; r = r->link) {
r->regu = (r->refbehind.b[0] | r->set.b[0]) & REGBITS;
r->set.b[0] &= ~REGBITS;
r->use1.b[0] &= ~REGBITS;
r->use2.b[0] &= ~REGBITS;
r->refbehind.b[0] &= ~REGBITS;
r->refahead.b[0] &= ~REGBITS;
r->calbehind.b[0] &= ~REGBITS;
r->calahead.b[0] &= ~REGBITS;
r->regdiff.b[0] &= ~REGBITS;
r->act.b[0] &= ~REGBITS;
}
/*
* 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) && !r->refset) {
// should never happen - all variables are preset
if(debug['w'])
print("%L: used and not set: %Q\n", r->prog->lineno, bit);
r->refset = 1;
}
}
for(r = firstr; r != R; r = r->link)
r->act = zbits;
rgp = region;
nregion = 0;
for(r = firstr; r != R; r = r->link) {
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) && !r->refset) {
if(debug['w'])
print("%L: set and not used: %Q\n", r->prog->lineno, bit);
r->refset = 1;
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;
paint1(r, i);
bit.b[i/32] &= ~(1L<<(i%32));
if(change <= 0)
continue;
rgp->cost = change;
nregion++;
if(nregion >= NRGN) {
if(debug['R'] && debug['v'])
print("too many regions\n");
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(rgp->regno != 0)
paint3(rgp->enter, rgp->varno, vreg, rgp->regno);
rgp++;
}
if(debug['R'] && debug['v'])
dumpit("pass6", firstr);
/*
* pass 7
* peep-hole on basic block
*/
if(!debug['R'] || debug['P']) {
peep();
}
/*
* eliminate nops
* free aux structures
*/
for(p=firstp; p!=P; p=p->link) {
while(p->link != P && p->link->as == ANOP)
p->link = p->link->link;
if(p->to.type == D_BRANCH)
while(p->to.branch != P && p->to.branch->as == ANOP)
p->to.branch = p->to.branch->link;
}
if(r1 != R) {
r1->link = freer;
freer = firstr;
}
if(debug['R']) {
if(ostats.ncvtreg ||
ostats.nspill ||
ostats.nreload ||
ostats.ndelmov ||
ostats.nvar ||
ostats.naddr ||
0)
print("\nstats\n");
if(ostats.ncvtreg)
print(" %4d cvtreg\n", ostats.ncvtreg);
if(ostats.nspill)
print(" %4d spill\n", ostats.nspill);
if(ostats.nreload)
print(" %4d reload\n", ostats.nreload);
if(ostats.ndelmov)
print(" %4d delmov\n", ostats.ndelmov);
if(ostats.nvar)
print(" %4d delmov\n", ostats.nvar);
if(ostats.naddr)
print(" %4d delmov\n", ostats.naddr);
memset(&ostats, 0, sizeof(ostats));
}
}
Bits
mkvar(Reg *r, Adr *a)
{
Var *v;
int i, t, n, et, z, w, flag;
int32 o;
Bits bit;
Sym *s;
/*
* mark registers used
*/
t = a->type;
if(r != R) {
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;
ostats.naddr++;
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;
w = a->width;
v = var;
flag = 0;
for(i=0; i<nvar; i++) {
if(s == v->sym)
if(n == v->name) {
// if it is the same, use it
if(v->etype == et)
if(v->width == w)
if(v->offset == o)
goto out;
// if it overlaps, set max
// width and dont registerize
if(overlap(v, o, w))
flag = 1;
}
v++;
}
if(flag)
goto none;
switch(et) {
case 0:
case TFUNC:
case TARRAY:
goto none;
}
if(nvar >= NVAR) {
if(debug['w'] > 1 && s)
fatal("variable not optimized: %D", a);
goto none;
}
i = nvar;
nvar++;
v = &var[i];
v->sym = s;
v->offset = o;
v->name = n;
v->gotype = a->gotype;
v->etype = et;
v->width = w;
if(debug['R'])
print("bit=%2d et=%2d w=%d %D\n", i, et, w, a);
ostats.nvar++;
out:
bit = blsh(i);
// funny punning
if(v->etype != et) {
if(debug['R'])
print("pun et=%d/%d w=%d/%d o=%d/%d %D\n",
v->etype, et,
v->width, w,
v->offset, o, a);
for(z=0; z<BITS; z++)
addrs.b[z] |= bit.b[z];
goto none;
}
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];
return bit;
none:
return zbits;
}
Bits
mkvar(Reg *r, Adr *a)
{
Var *v;
int i, t, n, et, z, w, flag;
uint32 regu;
int32 o;
Bits bit;
Node *node;
/*
* mark registers used
*/
t = a->type;
if(t == D_NONE)
goto none;
if(r != R)
r->use1.b[0] |= doregbits(a->index);
switch(t) {
default:
regu = doregbits(t);
if(regu == 0)
goto none;
bit = zbits;
bit.b[0] = regu;
return bit;
case D_ADDR:
a->type = a->index;
bit = mkvar(r, a);
setaddrs(bit);
a->type = t;
ostats.naddr++;
goto none;
case D_EXTERN:
case D_STATIC:
case D_PARAM:
case D_AUTO:
n = t;
break;
}
node = a->node;
if(node == N || node->op != ONAME || node->orig == N)
goto none;
node = node->orig;
if(node->orig != node)
fatal("%D: bad node", a);
if(node->sym == S || node->sym->name[0] == '.')
goto none;
et = a->etype;
o = a->offset;
w = a->width;
flag = 0;
for(i=0; i<nvar; i++) {
v = var+i;
if(v->node == node && v->name == n) {
if(v->offset == o)
if(v->etype == et)
if(v->width == w)
return blsh(i);
// if they overlaps, disable both
if(overlap(v->offset, v->width, o, w)) {
// print("disable overlap %s %d %d %d %d, %E != %E\n", s->name, v->offset, v->width, o, w, v->etype, et);
v->addr = 1;
flag = 1;
}
}
}
switch(et) {
case 0:
case TFUNC:
goto none;
}
if(nvar >= NVAR) {
if(debug['w'] > 1 && node != N)
fatal("variable not optimized: %#N", node);
goto none;
}
i = nvar;
nvar++;
v = var+i;
v->offset = o;
v->name = n;
v->gotype = a->gotype;
v->etype = et;
v->width = w;
v->addr = flag; // funny punning
v->node = node;
if(debug['R'])
print("bit=%2d et=%2d w=%d %#N %D\n", i, et, w, node, a);
ostats.nvar++;
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];
return bit;
none:
return zbits;
}
