694 lines
10 KiB
C
694 lines
10 KiB
C
#include "gc.h"
|
|
|
|
void
|
|
peep(void)
|
|
{
|
|
Reg *r, *r1, *r2;
|
|
Prog *p, *p1;
|
|
int t;
|
|
/*
|
|
* complete R structure
|
|
*/
|
|
t = 0;
|
|
for(r=firstr; r!=R; r=r1) {
|
|
r1 = r->link;
|
|
if(r1 == R)
|
|
break;
|
|
p = r->prog->link;
|
|
while(p != r1->prog)
|
|
switch(p->as) {
|
|
default:
|
|
r2 = rega();
|
|
r->link = r2;
|
|
r2->link = r1;
|
|
|
|
r2->prog = p;
|
|
r2->p1 = r;
|
|
r->s1 = r2;
|
|
r2->s1 = r1;
|
|
r1->p1 = r2;
|
|
|
|
r = r2;
|
|
t++;
|
|
|
|
case ADATA:
|
|
case AGLOBL:
|
|
case ANAME:
|
|
case ASIGNAME:
|
|
p = p->link;
|
|
}
|
|
}
|
|
|
|
loop1:
|
|
t = 0;
|
|
for(r=firstr; r!=R; r=r->link) {
|
|
p = r->prog;
|
|
if(p->as == AMOVW || p->as == AMOVF || p->as == AMOVD)
|
|
if(regtyp(&p->to)) {
|
|
if(regtyp(&p->from))
|
|
if(p->from.type == p->to.type) {
|
|
if(copyprop(r)) {
|
|
excise(r);
|
|
t++;
|
|
} else
|
|
if(subprop(r) && copyprop(r)) {
|
|
excise(r);
|
|
t++;
|
|
}
|
|
}
|
|
if(regzer(&p->from))
|
|
if(p->to.type == D_REG) {
|
|
p->from.type = D_REG;
|
|
p->from.reg = 0;
|
|
if(copyprop(r)) {
|
|
excise(r);
|
|
t++;
|
|
} else
|
|
if(subprop(r) && copyprop(r)) {
|
|
excise(r);
|
|
t++;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
if(t)
|
|
goto loop1;
|
|
/*
|
|
* look for MOVB x,R; MOVB R,R
|
|
*/
|
|
for(r=firstr; r!=R; r=r->link) {
|
|
p = r->prog;
|
|
switch(p->as) {
|
|
default:
|
|
continue;
|
|
case AMOVH:
|
|
case AMOVHU:
|
|
case AMOVB:
|
|
case AMOVBU:
|
|
if(p->to.type != D_REG)
|
|
continue;
|
|
break;
|
|
}
|
|
r1 = r->link;
|
|
if(r1 == R)
|
|
continue;
|
|
p1 = r1->prog;
|
|
if(p1->as != p->as)
|
|
continue;
|
|
if(p1->from.type != D_REG || p1->from.reg != p->to.reg)
|
|
continue;
|
|
if(p1->to.type != D_REG || p1->to.reg != p->to.reg)
|
|
continue;
|
|
excise(r1);
|
|
}
|
|
}
|
|
|
|
void
|
|
excise(Reg *r)
|
|
{
|
|
Prog *p;
|
|
|
|
p = r->prog;
|
|
p->as = ANOP;
|
|
p->from = zprog.from;
|
|
p->to = zprog.to;
|
|
p->reg = zprog.reg; /**/
|
|
}
|
|
|
|
Reg*
|
|
uniqp(Reg *r)
|
|
{
|
|
Reg *r1;
|
|
|
|
r1 = r->p1;
|
|
if(r1 == R) {
|
|
r1 = r->p2;
|
|
if(r1 == R || r1->p2link != R)
|
|
return R;
|
|
} else
|
|
if(r->p2 != R)
|
|
return R;
|
|
return r1;
|
|
}
|
|
|
|
Reg*
|
|
uniqs(Reg *r)
|
|
{
|
|
Reg *r1;
|
|
|
|
r1 = r->s1;
|
|
if(r1 == R) {
|
|
r1 = r->s2;
|
|
if(r1 == R)
|
|
return R;
|
|
} else
|
|
if(r->s2 != R)
|
|
return R;
|
|
return r1;
|
|
}
|
|
|
|
int
|
|
regzer(Adr *a)
|
|
{
|
|
|
|
if(a->type == D_CONST)
|
|
if(a->sym == S)
|
|
if(a->offset == 0)
|
|
return 1;
|
|
if(a->type == D_REG)
|
|
if(a->reg == 0)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
regtyp(Adr *a)
|
|
{
|
|
|
|
if(a->type == D_REG) {
|
|
if(a->reg != 0)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
if(a->type == D_FREG)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* the idea is to substitute
|
|
* one register for another
|
|
* from one MOV to another
|
|
* MOV a, R0
|
|
* ADD b, R0 / no use of R1
|
|
* MOV R0, R1
|
|
* would be converted to
|
|
* MOV a, R1
|
|
* ADD b, R1
|
|
* MOV R1, R0
|
|
* hopefully, then the former or latter MOV
|
|
* will be eliminated by copy propagation.
|
|
*/
|
|
int
|
|
subprop(Reg *r0)
|
|
{
|
|
Prog *p;
|
|
Adr *v1, *v2;
|
|
Reg *r;
|
|
int t;
|
|
|
|
p = r0->prog;
|
|
v1 = &p->from;
|
|
if(!regtyp(v1))
|
|
return 0;
|
|
v2 = &p->to;
|
|
if(!regtyp(v2))
|
|
return 0;
|
|
for(r=uniqp(r0); r!=R; r=uniqp(r)) {
|
|
if(uniqs(r) == R)
|
|
break;
|
|
p = r->prog;
|
|
switch(p->as) {
|
|
case AJAL:
|
|
return 0;
|
|
|
|
case ASGT:
|
|
case ASGTU:
|
|
|
|
case AADD:
|
|
case AADDU:
|
|
case ASUB:
|
|
case ASUBU:
|
|
case ASLL:
|
|
case ASRL:
|
|
case ASRA:
|
|
case AOR:
|
|
case AAND:
|
|
case AXOR:
|
|
case AMUL:
|
|
case AMULU:
|
|
case ADIV:
|
|
case ADIVU:
|
|
|
|
case AADDD:
|
|
case AADDF:
|
|
case ASUBD:
|
|
case ASUBF:
|
|
case AMULD:
|
|
case AMULF:
|
|
case ADIVD:
|
|
case ADIVF:
|
|
if(p->to.type == v1->type)
|
|
if(p->to.reg == v1->reg) {
|
|
if(p->reg == NREG)
|
|
p->reg = p->to.reg;
|
|
goto gotit;
|
|
}
|
|
break;
|
|
|
|
case AMOVF:
|
|
case AMOVD:
|
|
case AMOVW:
|
|
if(p->to.type == v1->type)
|
|
if(p->to.reg == v1->reg)
|
|
goto gotit;
|
|
break;
|
|
}
|
|
if(copyau(&p->from, v2) ||
|
|
copyau1(p, v2) ||
|
|
copyau(&p->to, v2))
|
|
break;
|
|
if(copysub(&p->from, v1, v2, 0) ||
|
|
copysub1(p, v1, v2, 0) ||
|
|
copysub(&p->to, v1, v2, 0))
|
|
break;
|
|
}
|
|
return 0;
|
|
|
|
gotit:
|
|
copysub(&p->to, v1, v2, 1);
|
|
if(debug['P']) {
|
|
print("gotit: %D->%D\n%P", v1, v2, r->prog);
|
|
if(p->from.type == v2->type)
|
|
print(" excise");
|
|
print("\n");
|
|
}
|
|
for(r=uniqs(r); r!=r0; r=uniqs(r)) {
|
|
p = r->prog;
|
|
copysub(&p->from, v1, v2, 1);
|
|
copysub1(p, v1, v2, 1);
|
|
copysub(&p->to, v1, v2, 1);
|
|
if(debug['P'])
|
|
print("%P\n", r->prog);
|
|
}
|
|
t = v1->reg;
|
|
v1->reg = v2->reg;
|
|
v2->reg = t;
|
|
if(debug['P'])
|
|
print("%P last\n", r->prog);
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* The idea is to remove redundant copies.
|
|
* v1->v2 F=0
|
|
* (use v2 s/v2/v1/)*
|
|
* set v1 F=1
|
|
* use v2 return fail
|
|
* -----------------
|
|
* v1->v2 F=0
|
|
* (use v2 s/v2/v1/)*
|
|
* set v1 F=1
|
|
* set v2 return success
|
|
*/
|
|
int
|
|
copyprop(Reg *r0)
|
|
{
|
|
Prog *p;
|
|
Adr *v1, *v2;
|
|
Reg *r;
|
|
|
|
p = r0->prog;
|
|
v1 = &p->from;
|
|
v2 = &p->to;
|
|
if(copyas(v1, v2))
|
|
return 1;
|
|
for(r=firstr; r!=R; r=r->link)
|
|
r->active = 0;
|
|
return copy1(v1, v2, r0->s1, 0);
|
|
}
|
|
|
|
int
|
|
copy1(Adr *v1, Adr *v2, Reg *r, int f)
|
|
{
|
|
int t;
|
|
Prog *p;
|
|
|
|
if(r->active) {
|
|
if(debug['P'])
|
|
print("act set; return 1\n");
|
|
return 1;
|
|
}
|
|
r->active = 1;
|
|
if(debug['P'])
|
|
print("copy %D->%D f=%d\n", v1, v2, f);
|
|
for(; r != R; r = r->s1) {
|
|
p = r->prog;
|
|
if(debug['P'])
|
|
print("%P", p);
|
|
if(!f && uniqp(r) == R) {
|
|
f = 1;
|
|
if(debug['P'])
|
|
print("; merge; f=%d", f);
|
|
}
|
|
t = copyu(p, v2, A);
|
|
switch(t) {
|
|
case 2: /* rar, cant split */
|
|
if(debug['P'])
|
|
print("; %Drar; return 0\n", v2);
|
|
return 0;
|
|
|
|
case 3: /* set */
|
|
if(debug['P'])
|
|
print("; %Dset; return 1\n", v2);
|
|
return 1;
|
|
|
|
case 1: /* used, substitute */
|
|
case 4: /* use and set */
|
|
if(f) {
|
|
if(!debug['P'])
|
|
return 0;
|
|
if(t == 4)
|
|
print("; %Dused+set and f=%d; return 0\n", v2, f);
|
|
else
|
|
print("; %Dused and f=%d; return 0\n", v2, f);
|
|
return 0;
|
|
}
|
|
if(copyu(p, v2, v1)) {
|
|
if(debug['P'])
|
|
print("; sub fail; return 0\n");
|
|
return 0;
|
|
}
|
|
if(debug['P'])
|
|
print("; sub%D/%D", v2, v1);
|
|
if(t == 4) {
|
|
if(debug['P'])
|
|
print("; %Dused+set; return 1\n", v2);
|
|
return 1;
|
|
}
|
|
break;
|
|
}
|
|
if(!f) {
|
|
t = copyu(p, v1, A);
|
|
if(!f && (t == 2 || t == 3 || t == 4)) {
|
|
f = 1;
|
|
if(debug['P'])
|
|
print("; %Dset and !f; f=%d", v1, f);
|
|
}
|
|
}
|
|
if(debug['P'])
|
|
print("\n");
|
|
if(r->s2)
|
|
if(!copy1(v1, v2, r->s2, f))
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* return
|
|
* 1 if v only used (and substitute),
|
|
* 2 if read-alter-rewrite
|
|
* 3 if set
|
|
* 4 if set and used
|
|
* 0 otherwise (not touched)
|
|
*/
|
|
copyu(Prog *p, Adr *v, Adr *s)
|
|
{
|
|
|
|
switch(p->as) {
|
|
|
|
default:
|
|
if(debug['P'])
|
|
print(" (???)");
|
|
return 2;
|
|
|
|
|
|
case ANOP: /* read, write */
|
|
case AMOVW:
|
|
case AMOVF:
|
|
case AMOVD:
|
|
case AMOVH:
|
|
case AMOVHU:
|
|
case AMOVB:
|
|
case AMOVBU:
|
|
case AMOVDW:
|
|
case AMOVWD:
|
|
case AMOVFD:
|
|
case AMOVDF:
|
|
if(s != A) {
|
|
if(copysub(&p->from, v, s, 1))
|
|
return 1;
|
|
if(!copyas(&p->to, v))
|
|
if(copysub(&p->to, v, s, 1))
|
|
return 1;
|
|
return 0;
|
|
}
|
|
if(copyas(&p->to, v)) {
|
|
if(copyau(&p->from, v))
|
|
return 4;
|
|
return 3;
|
|
}
|
|
if(copyau(&p->from, v))
|
|
return 1;
|
|
if(copyau(&p->to, v))
|
|
return 1;
|
|
return 0;
|
|
|
|
case ASGT: /* read, read, write */
|
|
case ASGTU:
|
|
|
|
case AADD:
|
|
case AADDU:
|
|
case ASUB:
|
|
case ASUBU:
|
|
case ASLL:
|
|
case ASRL:
|
|
case ASRA:
|
|
case AOR:
|
|
case ANOR:
|
|
case AAND:
|
|
case AXOR:
|
|
case AMUL:
|
|
case AMULU:
|
|
case ADIV:
|
|
case ADIVU:
|
|
|
|
case AADDF:
|
|
case AADDD:
|
|
case ASUBF:
|
|
case ASUBD:
|
|
case AMULF:
|
|
case AMULD:
|
|
case ADIVF:
|
|
case ADIVD:
|
|
if(s != A) {
|
|
if(copysub(&p->from, v, s, 1))
|
|
return 1;
|
|
if(copysub1(p, v, s, 1))
|
|
return 1;
|
|
if(!copyas(&p->to, v))
|
|
if(copysub(&p->to, v, s, 1))
|
|
return 1;
|
|
return 0;
|
|
}
|
|
if(copyas(&p->to, v)) {
|
|
if(p->reg == NREG)
|
|
p->reg = p->to.reg;
|
|
if(copyau(&p->from, v))
|
|
return 4;
|
|
if(copyau1(p, v))
|
|
return 4;
|
|
return 3;
|
|
}
|
|
if(copyau(&p->from, v))
|
|
return 1;
|
|
if(copyau1(p, v))
|
|
return 1;
|
|
if(copyau(&p->to, v))
|
|
return 1;
|
|
return 0;
|
|
|
|
case ABEQ: /* read, read */
|
|
case ABNE:
|
|
case ABGTZ:
|
|
case ABGEZ:
|
|
case ABLTZ:
|
|
case ABLEZ:
|
|
|
|
case ACMPEQD:
|
|
case ACMPEQF:
|
|
case ACMPGED:
|
|
case ACMPGEF:
|
|
case ACMPGTD:
|
|
case ACMPGTF:
|
|
case ABFPF:
|
|
case ABFPT:
|
|
if(s != A) {
|
|
if(copysub(&p->from, v, s, 1))
|
|
return 1;
|
|
return copysub1(p, v, s, 1);
|
|
}
|
|
if(copyau(&p->from, v))
|
|
return 1;
|
|
if(copyau1(p, v))
|
|
return 1;
|
|
return 0;
|
|
|
|
case AJMP: /* funny */
|
|
if(s != A) {
|
|
if(copysub(&p->to, v, s, 1))
|
|
return 1;
|
|
return 0;
|
|
}
|
|
if(copyau(&p->to, v))
|
|
return 1;
|
|
return 0;
|
|
|
|
case ARET: /* funny */
|
|
if(v->type == D_REG)
|
|
if(v->reg == REGRET)
|
|
return 2;
|
|
if(v->type == D_FREG)
|
|
if(v->reg == FREGRET)
|
|
return 2;
|
|
|
|
case AJAL: /* funny */
|
|
if(v->type == D_REG) {
|
|
if(v->reg <= REGEXT && v->reg > exregoffset)
|
|
return 2;
|
|
if(REGARG && v->reg == REGARG)
|
|
return 2;
|
|
}
|
|
if(v->type == D_FREG)
|
|
if(v->reg <= FREGEXT && v->reg > exfregoffset)
|
|
return 2;
|
|
|
|
if(s != A) {
|
|
if(copysub(&p->to, v, s, 1))
|
|
return 1;
|
|
return 0;
|
|
}
|
|
if(copyau(&p->to, v))
|
|
return 4;
|
|
return 3;
|
|
|
|
case ATEXT: /* funny */
|
|
if(v->type == D_REG)
|
|
if(v->reg == REGARG)
|
|
return 3;
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
int
|
|
a2type(Prog *p)
|
|
{
|
|
|
|
switch(p->as) {
|
|
case ABEQ:
|
|
case ABNE:
|
|
case ABGTZ:
|
|
case ABGEZ:
|
|
case ABLTZ:
|
|
case ABLEZ:
|
|
|
|
case ASGT:
|
|
case ASGTU:
|
|
|
|
case AADD:
|
|
case AADDU:
|
|
case ASUB:
|
|
case ASUBU:
|
|
case ASLL:
|
|
case ASRL:
|
|
case ASRA:
|
|
case AOR:
|
|
case AAND:
|
|
case AXOR:
|
|
case AMUL:
|
|
case AMULU:
|
|
case ADIV:
|
|
case ADIVU:
|
|
return D_REG;
|
|
|
|
case ACMPEQD:
|
|
case ACMPEQF:
|
|
case ACMPGED:
|
|
case ACMPGEF:
|
|
case ACMPGTD:
|
|
case ACMPGTF:
|
|
|
|
case AADDF:
|
|
case AADDD:
|
|
case ASUBF:
|
|
case ASUBD:
|
|
case AMULF:
|
|
case AMULD:
|
|
case ADIVF:
|
|
case ADIVD:
|
|
return D_FREG;
|
|
}
|
|
return D_NONE;
|
|
}
|
|
|
|
/*
|
|
* direct reference,
|
|
* could be set/use depending on
|
|
* semantics
|
|
*/
|
|
int
|
|
copyas(Adr *a, Adr *v)
|
|
{
|
|
|
|
if(regtyp(v))
|
|
if(a->type == v->type)
|
|
if(a->reg == v->reg)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* either direct or indirect
|
|
*/
|
|
int
|
|
copyau(Adr *a, Adr *v)
|
|
{
|
|
|
|
if(copyas(a, v))
|
|
return 1;
|
|
if(v->type == D_REG)
|
|
if(a->type == D_OREG)
|
|
if(v->reg == a->reg)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
copyau1(Prog *p, Adr *v)
|
|
{
|
|
|
|
if(regtyp(v))
|
|
if(p->from.type == v->type || p->to.type == v->type)
|
|
if(p->reg == v->reg) {
|
|
if(a2type(p) != v->type)
|
|
print("botch a2type %P\n", p);
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* substitute s for v in a
|
|
* return failure to substitute
|
|
*/
|
|
int
|
|
copysub(Adr *a, Adr *v, Adr *s, int f)
|
|
{
|
|
|
|
if(f)
|
|
if(copyau(a, v))
|
|
a->reg = s->reg;
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
copysub1(Prog *p1, Adr *v, Adr *s, int f)
|
|
{
|
|
|
|
if(f)
|
|
if(copyau1(p1, v))
|
|
p1->reg = s->reg;
|
|
return 0;
|
|
}
|