diff options
Diffstat (limited to 'lisc/spill.c')
| -rw-r--r-- | lisc/spill.c | 46 |
1 files changed, 36 insertions, 10 deletions
diff --git a/lisc/spill.c b/lisc/spill.c index 36b08cd..d78136e 100644 --- a/lisc/spill.c +++ b/lisc/spill.c @@ -143,7 +143,9 @@ extern Ins insb[NIns], *curi; /* shared work buffer */ 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 int *svec; /* free slots vector */ +static int locs; /* stack size used by locals */ +static int slot4; /* next slot of 4 bytes */ +static int slot8; /* ditto, 8 bytes */ static int tcmp0(const void *pa, const void *pb) @@ -168,11 +170,28 @@ slot(int t) if (t < Tmp0) diag("spill: cannot spill register"); s = tmp[t].spill; - if (!s) { - if (tmp[t].wide) - s = slota(2, 1, svec); - else - s = slota(1, 0, svec); + if (s == -1) { + assert(NAlign == 3); + /* nice logic to pack stack slots + * on demand, there can be only + * one hole and slot4 points to it + * + * invariant: slot4 <= slot8 + */ + if (tmp[t].wide) { + s = slot8; + if (slot4 == slot8) + slot4 += 2; + slot8 += 2; + } else { + s = slot4; + if (slot4 == slot8) { + slot8 += 2; + slot4 += 1; + } else + slot4 = slot8; + } + s += locs; tmp[t].spill = s; } return SLOT(s); @@ -312,9 +331,11 @@ spill(Fn *fn) int j, s; Phi *p; - svec = fn->svec; tmp = fn->tmp; ntmp = fn->ntmp; + locs = fn->slot; + slot4 = 0; + slot8 = 0; assert(ntmp < NBit*BITS); for (b=fn->start; b; b=b->link) { @@ -382,7 +403,7 @@ spill(Fn *fn) i = dopm(b, i, &v); continue; } - s = 0; + s = -1; w = (Bits){{0}}; if (!req(i->to, R)) { assert(rtype(i->to) == RTmp); @@ -400,7 +421,7 @@ spill(Fn *fn) if (!j && rtype(i->arg[1]) == RTmp) BSET(w, i->arg[1].val); j -= setloc(&i->arg[1], &v, &w); - if (s) + if (s != -1) store(i->to, s); emit(*i); } @@ -411,7 +432,7 @@ spill(Fn *fn) if (BGET(v, t)) { BCLR(v, t); s = tmp[t].spill; - if (s) + if (s != -1) store(p->to, s); } else p->to = slot(p->to.val); @@ -422,4 +443,9 @@ spill(Fn *fn) b->ins = alloc(b->nins * sizeof(Ins)); memcpy(b->ins, curi, b->nins * sizeof(Ins)); } + + /* align the locals to a 16 byte boundary */ + assert(NAlign == 3); + slot8 += slot8 & 3; + fn->slot += slot8; } |