diff options
| -rw-r--r-- | spill.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/spill.c b/spill.c index 42f0c05..f0b593a 100644 --- a/spill.c +++ b/spill.c @@ -309,7 +309,7 @@ void spill(Fn *fn) { Blk *b, *s1, *s2, *hd, **bp; - int j, l, t, k, lvarg[2]; + int j, l, t, k, s, lvarg[2]; uint n; BSet u[1], v[1], w[1]; Ins *i; @@ -407,6 +407,7 @@ spill(Fn *fn) if (!req(i->to, R)) { assert(rtype(i->to) == RTmp); t = i->to.val; + s = tmp[t].slot; if (bshas(v, t)) bsclr(v, t); else { @@ -440,6 +441,13 @@ spill(Fn *fn) bsset(v, t); if (j-- <= 0) bsset(w, t); + else if (!lvarg[n]) { + /* recycle the slot of + * i->to when possible + */ + if (tmp[t].slot == -1) + tmp[t].slot = s; + } break; } bscopy(u, v); @@ -447,9 +455,12 @@ spill(Fn *fn) for (n=0; n<2; n++) if (rtype(i->arg[n]) == RTmp) { t = i->arg[n].val; - if (!bshas(v, t)) { + if (bshas(v, t)) { + if (tmp[t].slot == s) + tmp[t].slot = -1; + } else { /* do not reload if the - * the temporary was dead + * argument is dead */ if (!lvarg[n]) bsclr(u, t); |