ref: 37a8fc6168b3bf82df198fb20be5a8a53996187c
dir: /sys/src/cmd/kl/sched.c/
#include "l.h"
enum
{
E_ICC = 1<<0,
E_FCC = 1<<1,
E_MEM = 1<<2,
E_MEMSP = 1<<3, /* uses offset and size */
E_MEMSB = 1<<4, /* uses offset and size */
ANYMEM = E_MEM|E_MEMSP|E_MEMSB,
ALL = ~0
};
typedef struct Sch Sch;
typedef struct Dep Dep;
struct Dep
{
ulong ireg;
ulong freg;
ulong cc;
};
struct Sch
{
Prog p;
Dep set;
Dep used;
long soffset;
char size;
char nop;
char comp;
};
void regsused(Sch*, Prog*);
int depend(Sch*, Sch*);
int conflict(Sch*, Sch*);
int offoverlap(Sch*, Sch*);
void dumpbits(Sch*, Dep*);
void
sched(Prog *p0, Prog *pe)
{
Prog *p, *q;
Sch sch[NSCHED], *s, *t, *u, *se, stmp;
/*
* build side structure
*/
s = sch;
for(p=p0;; p=p->link) {
memset(s, 0, sizeof(*s));
s->p = *p;
regsused(s, p);
if(debug['X']) {
Bprint(&bso, "%P\tset", &s->p);
dumpbits(s, &s->set);
Bprint(&bso, "; used");
dumpbits(s, &s->used);
if(s->comp)
Bprint(&bso, "; compound");
if(s->p.mark & LOAD)
Bprint(&bso, "; load");
if(s->p.mark & BRANCH)
Bprint(&bso, "; branch");
if(s->p.mark & FCMP)
Bprint(&bso, "; fcmp");
Bprint(&bso, "\n");
}
s++;
if(p == pe)
break;
}
se = s;
for(s=se-1; s>=sch; s--) {
/*
* branch delay slot
*/
if(s->p.mark & BRANCH) {
/* t is the trial instruction to use */
for(t=s-1; t>=sch; t--) {
if(t->comp || (t->p.mark & FCMP))
goto no1;
for(u=t+1; u<=s; u++)
if(depend(u, t))
goto no1;
goto out1;
no1:;
}
if(debug['X'])
Bprint(&bso, "?b%P\n", &s->p);
s->nop = 1;
continue;
out1:
if(debug['X']) {
Bprint(&bso, "!b%P\n", &t->p);
Bprint(&bso, "%P\n", &s->p);
}
stmp = *t;
memmove(t, t+1, (uchar*)s - (uchar*)t);
*s = stmp;
s--;
continue;
}
/*
* load delay. interlocked.
*/
if(s->p.mark & LOAD) {
if(s >= se-1)
continue;
if(!conflict(s, (s+1)))
continue;
/*
* s is load, s+1 is immediate use of result
* t is the trial instruction to insert between s and s+1
*/
for(t=s-1; t>=sch; t--) {
if(t->p.mark & BRANCH)
goto no2;
if(t->p.mark & FCMP)
if((s+1)->p.mark & BRANCH)
goto no2;
if(t->p.mark & LOAD)
if(conflict(t, (s+1)))
goto no2;
for(u=t+1; u<=s; u++)
if(depend(u, t))
goto no2;
goto out2;
no2:;
}
if(debug['X'])
Bprint(&bso, "?l%P\n", &s->p);
continue;
out2:
if(debug['X']) {
Bprint(&bso, "!l%P\n", &t->p);
Bprint(&bso, "%P\n", &s->p);
}
stmp = *t;
memmove(t, t+1, (uchar*)s - (uchar*)t);
*s = stmp;
s--;
continue;
}
/*
* fop2 delay.
*/
if(s->p.mark & FCMP) {
if(s >= se-1) {
s->nop = 1;
continue;
}
if(!((s+1)->p.mark & BRANCH))
continue;
/* t is the trial instruction to use */
for(t=s-1; t>=sch; t--) {
for(u=t+1; u<=s; u++)
if(depend(u, t))
goto no3;
goto out3;
no3:;
}
if(debug['X'])
Bprint(&bso, "?f%P\n", &s->p);
s->nop = 1;
continue;
out3:
if(debug['X']) {
Bprint(&bso, "!f%P\n", &t->p);
Bprint(&bso, "%P\n", &s->p);
}
stmp = *t;
memmove(t, t+1, (uchar*)s - (uchar*)t);
*s = stmp;
s--;
continue;
}
}
/*
* put it all back
*/
for(s=sch, p=p0; s<se; s++, p=q) {
q = p->link;
if(q != s->p.link) {
*p = s->p;
p->link = q;
}
if(s->nop)
addnop(p);
}
if(debug['X'])
Bprint(&bso, "\n");
}
void
regsused(Sch *s, Prog *realp)
{
int c, ar, ad, ld, sz;
ulong m;
Prog *p;
p = &s->p;
s->comp = compound(p);
s->nop = 0;
if(s->comp) {
s->set.ireg |= 1<<REGTMP;
s->used.ireg |= 1<<REGTMP;
}
ar = 0; /* dest is really reference */
ad = 0; /* source/dest is really address */
ld = 0; /* opcode is load instruction */
sz = 20; /* size of load/store for overlap computation */
/*
* flags based on opcode
*/
switch(p->as) {
case ATEXT:
curtext = realp;
autosize = p->to.offset + 4;
ad = 1;
break;
case AJMPL:
c = p->reg;
if(c == NREG)
c = REGLINK;
s->set.ireg |= 1<<c;
ar = 1;
ad = 1;
break;
case AJMP:
ar = 1;
ad = 1;
break;
case ACMP:
s->set.cc |= E_ICC;
ar = 1;
break;
case AFCMPD:
case AFCMPED:
case AFCMPEF:
case AFCMPEX:
case AFCMPF:
case AFCMPX:
s->set.cc |= E_FCC;
ar = 1;
break;
case ABE:
case ABNE:
case ABLE:
case ABG:
case ABL:
case ABGE:
case ABLEU:
case ABGU:
case ABCS:
case ABCC:
case ABNEG:
case ABPOS:
case ABVC:
case ABVS:
s->used.cc |= E_ICC;
ar = 1;
break;
case AFBE:
case AFBLG:
case AFBG:
case AFBLE:
case AFBGE:
case AFBL:
s->used.cc |= E_FCC;
ar = 1;
break;
case AMOVB:
case AMOVBU:
sz = 1;
ld = 1;
break;
case AMOVH:
case AMOVHU:
sz = 2;
ld = 1;
break;
case AFMOVF:
case AMOVW:
sz = 4;
ld = 1;
break;
case AMOVD:
case AFMOVD:
sz = 8;
ld = 1;
break;
case AFMOVX: /* gok */
sz = 16;
ld = 1;
break;
case AADDCC:
case AADDXCC:
case AANDCC:
case AANDNCC:
case AORCC:
case AORNCC:
case ASUBCC:
case ASUBXCC:
case ATADDCC:
case ATADDCCTV:
case ATSUBCC:
case ATSUBCCTV:
case AXNORCC:
case AXORCC:
s->set.cc |= E_ICC;
break;
case ADIV:
case ADIVL:
case AMOD:
case AMODL:
case AMUL:
case AMULSCC:
case ATAS:
s->set.ireg = ALL;
s->set.freg = ALL;
s->set.cc = ALL;
break;
}
/*
* flags based on 'to' field
*/
c = p->to.class;
if(c == 0) {
c = aclass(&p->to) + 1;
p->to.class = c;
}
c--;
switch(c) {
default:
print("unknown class %d %D\n", c, &p->to);
case C_ZCON:
case C_SCON:
case C_UCON:
case C_LCON:
case C_NONE:
case C_SBRA:
case C_LBRA:
break;
case C_CREG:
case C_FSR:
case C_FQ:
case C_PREG:
s->set.ireg = ALL;
s->set.freg = ALL;
s->set.cc = ALL;
break;
case C_ZOREG:
case C_SOREG:
case C_LOREG:
case C_ASI:
c = p->to.reg;
s->used.ireg |= 1<<c;
if(ad)
break;
s->size = sz;
s->soffset = regoff(&p->to);
m = ANYMEM;
if(c == REGSB)
m = E_MEMSB;
if(c == REGSP)
m = E_MEMSP;
if(ar)
s->used.cc |= m;
else
s->set.cc |= m;
break;
case C_SACON:
case C_LACON:
s->used.ireg |= 1<<REGSP;
break;
case C_SECON:
case C_LECON:
s->used.ireg |= 1<<REGSB;
break;
case C_REG:
if(ar)
s->used.ireg |= 1<<p->to.reg;
else
s->set.ireg |= 1<<p->to.reg;
break;
case C_FREG:
/* do better -- determine double prec */
if(ar) {
s->used.freg |= 1<<p->to.reg;
s->used.freg |= 1<<(p->to.reg|1);
} else {
s->set.freg |= 1<<p->to.reg;
s->set.freg |= 1<<(p->to.reg|1);
}
break;
case C_SAUTO:
case C_LAUTO:
case C_ESAUTO:
case C_OSAUTO:
case C_ELAUTO:
case C_OLAUTO:
s->used.ireg |= 1<<REGSP;
if(ad)
break;
s->size = sz;
s->soffset = regoff(&p->to);
if(ar)
s->used.cc |= E_MEMSP;
else
s->set.cc |= E_MEMSP;
break;
case C_SEXT:
case C_LEXT:
case C_ESEXT:
case C_OSEXT:
case C_ELEXT:
case C_OLEXT:
s->used.ireg |= 1<<REGSB;
if(ad)
break;
s->size = sz;
s->soffset = regoff(&p->to);
if(ar)
s->used.cc |= E_MEMSB;
else
s->set.cc |= E_MEMSB;
break;
}
/*
* flags based on 'from' field
*/
c = p->from.class;
if(c == 0) {
c = aclass(&p->from) + 1;
p->from.class = c;
}
c--;
switch(c) {
default:
print("unknown class %d %D\n", c, &p->from);
case C_ZCON:
case C_SCON:
case C_UCON:
case C_LCON:
case C_NONE:
case C_SBRA:
case C_LBRA:
c = p->from.reg;
if(c != NREG)
s->used.ireg |= 1<<c;
break;
case C_CREG:
case C_FSR:
case C_FQ:
case C_PREG:
s->set.ireg = ALL;
s->set.freg = ALL;
s->set.cc = ALL;
break;
case C_ZOREG:
case C_SOREG:
case C_LOREG:
case C_ASI:
c = p->from.reg;
s->used.ireg |= 1<<c;
if(ld)
p->mark |= LOAD;
if(ad)
break;
s->size = sz;
s->soffset = regoff(&p->from);
m = ANYMEM;
if(c == REGSB)
m = E_MEMSB;
if(c == REGSP)
m = E_MEMSP;
s->used.cc |= m;
break;
case C_SACON:
case C_LACON:
s->used.ireg |= 1<<REGSP;
break;
case C_SECON:
case C_LECON:
s->used.ireg |= 1<<REGSB;
break;
case C_REG:
s->used.ireg |= 1<<p->from.reg;
break;
case C_FREG:
/* do better -- determine double prec */
s->used.freg |= 1<<p->from.reg;
s->used.freg |= 1<<(p->from.reg|1);
break;
case C_SAUTO:
case C_LAUTO:
case C_ESAUTO:
case C_ELAUTO:
case C_OSAUTO:
case C_OLAUTO:
s->used.ireg |= 1<<REGSP;
if(ld)
p->mark |= LOAD;
if(ad)
break;
s->size = sz;
s->soffset = regoff(&p->from);
s->used.cc |= E_MEMSP;
break;
case C_SEXT:
case C_LEXT:
case C_ESEXT:
case C_ELEXT:
case C_OSEXT:
case C_OLEXT:
s->used.ireg |= 1<<REGSB;
if(ld)
p->mark |= LOAD;
if(ad)
break;
s->size = sz;
s->soffset = regoff(&p->from);
s->used.cc |= E_MEMSB;
break;
}
c = p->reg;
if(c != NREG) {
if(p->from.type == D_FREG || p->to.type == D_FREG) {
s->used.freg |= 1<<c;
s->used.freg |= 1<<(c|1);
} else
s->used.ireg |= 1<<c;
}
s->set.ireg &= ~(1<<0); /* R0 cant be set */
}
/*
* test to see if 2 instrictions can be
* interchanged without changing semantics
*/
int
depend(Sch *sa, Sch *sb)
{
ulong x;
if(sa->set.ireg & (sb->set.ireg|sb->used.ireg))
return 1;
if(sb->set.ireg & sa->used.ireg)
return 1;
if(sa->set.freg & (sb->set.freg|sb->used.freg))
return 1;
if(sb->set.freg & sa->used.freg)
return 1;
x = (sa->set.cc & (sb->set.cc|sb->used.cc)) |
(sb->set.cc & sa->used.cc);
if(x) {
/*
* allow SB and SP to pass each other.
* allow SB to pass SB iff doffsets are ok
* anything else conflicts
*/
if(x != E_MEMSP && x != E_MEMSB)
return 1;
x = sa->set.cc | sb->set.cc |
sa->used.cc | sb->used.cc;
if(x & E_MEM)
return 1;
if(offoverlap(sa, sb))
return 1;
}
return 0;
}
int
offoverlap(Sch *sa, Sch *sb)
{
if(sa->soffset < sb->soffset) {
if(sa->soffset+sa->size > sb->soffset)
return 1;
return 0;
}
if(sb->soffset+sb->size > sa->soffset)
return 1;
return 0;
}
/*
* test 2 adjacent instructions
* and find out if inserted instructions
* are desired to prevent stalls.
* first instruction is a load instruction.
*/
int
conflict(Sch *sa, Sch *sb)
{
if(sa->set.ireg & sb->used.ireg)
return 1;
if(sa->set.freg & sb->used.freg)
return 1;
return 0;
}
int
compound(Prog *p)
{
Optab *o;
o = oplook(p);
if(o->size != 4)
return 1;
if(p->to.type == D_REG && p->to.reg == REGSB)
return 1;
return 0;
}
void
dumpbits(Sch *s, Dep *d)
{
int i;
for(i=0; i<32; i++)
if(d->ireg & (1<<i))
Bprint(&bso, " R%d", i);
for(i=0; i<32; i++)
if(d->freg & (1<<i))
Bprint(&bso, " F%d", i);
for(i=0; i<32; i++)
switch(d->cc & (1<<i)) {
default:
break;
case E_ICC:
Bprint(&bso, " ICC");
break;
case E_FCC:
Bprint(&bso, " FCC");
break;
case E_MEM:
Bprint(&bso, " MEM%d", s->size);
break;
case E_MEMSB:
Bprint(&bso, " SB%d", s->size);
break;
case E_MEMSP:
Bprint(&bso, " SP%d", s->size);
break;
}
}