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major lifting: get rid of RReg

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I've been septic since I introduced it, this commit
proves that it costs more than it helps.  I've also fixed
a bad bug in rega() where I alloc'ed the wrong size for
internal arrays.  Enums now have names so I can use them
to cast in gdb to get the name corresponding to a constant.
This commit is contained in:
Quentin Carbonneaux 2015-08-13 16:10:54 -04:00
parent 78bf28f56e
commit 5fc8104e00
8 changed files with 97 additions and 142 deletions
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47
lisc/spill.c
View file

@ -34,7 +34,7 @@ tmpuse(Ref r, int use, int loop, Fn *fn)
{
Tmp *t;
if (rtype(r) != RTmp)
if (rtype(r) != RTmp || r.val < Tmp0)
return;
t = &fn->tmp[r.val];
t->nuse += use;
@ -77,7 +77,7 @@ fillcost(Fn *fn)
}
}
for (t=fn->tmp; t-fn->tmp < fn->ntmp; t++) {
t->cost = 0;
t->cost = t-fn->tmp < Tmp0 ? 1e6 : 0;
t->nuse = 0;
t->ndef = 0;
}
@ -104,7 +104,7 @@ fillcost(Fn *fn)
}
if (debug['S']) {
fprintf(stderr, "\n> Spill costs:\n");
for (n=0; n<fn->ntmp; n++)
for (n=Tmp0; n<fn->ntmp; n++)
fprintf(stderr, "\t%-10s %d\n",
fn->tmp[n].name,
fn->tmp[n].cost);
@ -145,8 +145,6 @@ static Bits *f; /* temps to prioritize in registers (for tcmp1) */
static Tmp *tmp; /* current temporaries (for tcmpX) */
static int ntmp; /* current # of temps (for limit) */
static uint ns; /* current # of spill slots */
static int nreg; /* # of registers available */
static Bits br; /* live registers */
static int
tcmp0(const void *pa, const void *pb)
@ -168,6 +166,8 @@ slot(int t)
{
int s;
if (t < Tmp0)
diag("spill: cannot spill register");
s = tmp[t].spill;
if (!s) {
s = ++ns;
@ -237,24 +237,11 @@ setloc(Ref *pr, Bits *v, Bits *w)
{
int t;
/* <arch>
* here we assume that the
* machine can always support
* instructions of the kind
* reg = op slot, slot
* if not, we need to add
* 't' to 'w' before calling
* limit
*/
if (rtype(*pr) == RReg) {
nreg -= !BGET(br, pr->val);
BSET(br, pr->val);
}
if (rtype(*pr) != RTmp)
return 0;
t = pr->val;
BSET(*v, t);
if (limit(v, nreg, w) == t)
if (limit(v, NReg, w) == t)
/* if t was spilled by limit,
* it was not live so we don't
* have to reload it */
@ -300,7 +287,6 @@ spill(Fn *fn)
for (n=fn->nblk-1; n>=0; n--) {
/* invariant: m>n => in,out of m updated */
b = fn->rpo[n];
assert(bcnt(&br) == 0);
/* 1. find temporaries in registers at
* the end of the block (put them in v) */
@ -345,32 +331,19 @@ spill(Fn *fn)
assert(bcnt(&v) <= NReg);
/* 2. process the block instructions */
nreg = NReg;
curi = &insb[NIns];
for (i=&b->ins[b->nins]; i!=b->ins;) {
assert(bcnt(&v) <= nreg);
assert(bcnt(&v) <= NReg);
i--;
s = 0;
switch (rtype(i->to)) {
default:
diag("spill: unhandled destination");
case RTmp:
if (!req(i->to, R)) {
assert(rtype(i->to) == RTmp);
j = i->to.val;
if (BGET(v, j))
BCLR(v, j);
else
limit(&v, nreg-1, &w);
limit(&v, NReg-1, &w);
s = tmp[j].spill;
break;
case RReg:
j = i->to.val;
if (BGET(br, j)) {
BCLR(br, j);
nreg++;
} else
limit(&v, nreg-1, &w);
break;
case -1:;
}
w = (Bits){{0}};
j = opdesc[i->op].nmem;