diff options
Diffstat (limited to 'lisc')
| -rw-r--r-- | lisc/rega.c | 36 |
1 files changed, 29 insertions, 7 deletions
diff --git a/lisc/rega.c b/lisc/rega.c index d368977..628f7e8 100644 --- a/lisc/rega.c +++ b/lisc/rega.c @@ -360,7 +360,7 @@ doblk(Blk *b, RMap *cur) void rega(Fn *fn) { - int j, n, t, r, r1, x; + int j, n, t, r, r1, x, rl[RAX+NReg]; Blk *b, *b1, *s, ***ps, *blist; RMap *end, *beg, cur, old; Ins *i; @@ -403,15 +403,36 @@ rega(Fn *fn) doblk(b, &cur); b->in = cur.b; for (p=b->phi; p; p=p->link) - if (rtype(p->to) == RTmp) + if (rtype(p->to) == RTmp) { BCLR(b->in, p->to.val); + /* heuristic 0: + * if the phi destination has an + * argument from a frequent block + * that was already allocated to + * 'r', use 'r' as the new hint + */ + memset(rl, 0, sizeof rl); + for (u=0; u<p->narg; u++) { + t = p->arg[u].val; + b1 = p->blk[u]; + if (rtype(p->arg[u]) == RTmp) + if ((r=rfind(&end[b1->id], t)) != -1) + rl[r] += b1->loop; + } + for (x=0, j=RAX; j<RAX+NReg; j++) + if (rl[j] > rl[x]) + x = j; + if (rl[x] >= b->loop) + *hint(p->to.val) = x; + } if (b->npred > 1) { - /* attempt to satisfy hints + /* heuristic 1: + * attempt to satisfy hints * when it's simple and we have * multiple predecessors */ old = cur; - curi = insb; + curi = &insb[NIns]; for (j=0; j<old.n; j++) { t = old.t[j]; r = *hint(t); @@ -420,13 +441,14 @@ rega(Fn *fn) if (!BGET(cur.b, r)) { rfree(&cur, t); radd(&cur, t, r); - *curi++ = (Ins){OCopy, tmp[t].wide, TMP(r1), {TMP(r)}}; + x = tmp[t].wide; + emit(OCopy, x, TMP(r1), TMP(r), R); } } - if ((j = curi - insb)) { + if ((j = &insb[NIns] - curi)) { b->nins += j; i = alloc(b->nins * sizeof(Ins)); - icpy(icpy(i, insb, j), b->ins, b->nins-j); + icpy(icpy(i, curi, j), b->ins, b->nins-j); b->ins = i; } } |