From b75cb8388fb9b5f2393443d008bb46c522c5ec9b Mon Sep 17 00:00:00 2001 From: Quentin Carbonneaux Date: Mon, 28 Mar 2016 12:53:53 -0400 Subject: new layout, put LICENSE in root --- mem.c | 81 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 81 insertions(+) create mode 100644 mem.c (limited to 'mem.c') diff --git a/mem.c b/mem.c new file mode 100644 index 0000000..bda43d7 --- /dev/null +++ b/mem.c @@ -0,0 +1,81 @@ +#include "all.h" + +/* Memory optimization: + * + * - replace alloced slots used only in + * load/store operations + * Assumption: all the accesses have the + * same size (this could be wrong...) + */ + +/* require use, maintains use counts */ +void +memopt(Fn *fn) +{ + Blk *b; + Ins *i, *l; + Tmp *t; + Use *u, *ue; + int a; + + b = fn->start; + for (i=b->ins; i-b->ins < b->nins; i++) { + if (OAlloc > i->op || i->op > OAlloc1) + continue; + assert(NAlign == 3); + assert(rtype(i->to) == RTmp); + t = &fn->tmp[i->to.val]; + for (u=t->use; u != &t->use[t->nuse]; u++) { + if (u->type != UIns) + goto NextIns; + l = u->u.ins; + if (!isload(l->op) + && (!isstore(l->op) || req(i->to, l->arg[0]))) + goto NextIns; + } + /* get rid of the alloc and replace uses */ + *i = (Ins){.op = ONop}; + t->ndef--; + ue = &t->use[t->nuse]; + for (u=t->use; u!=ue; u++) { + l = u->u.ins; + if (isstore(l->op)) { + if (l->op == OStores) + l->cls = Kd; + else if (l->op == OStored) + l->cls = Kd; + else if (l->op == OStorel) + l->cls = Kl; + else + l->cls = Kw; + l->op = OCopy; + l->to = l->arg[1]; + l->arg[1] = R; + t->nuse--; + t->ndef++; + } else + /* try to turn loads into copies so we + * can eliminate them later */ + switch(l->op) { + case OLoad: + l->op = OCopy; + break; + case OLoadsw: + case OLoaduw: + l->cls = Kw; + l->op = OCopy; + break; + default: + /* keep l->cls */ + a = l->op - OLoadsw; + l->op = OExtsw + a; + break; + } + } + NextIns:; + } + if (debug['M']) { + fprintf(stderr, "\n> After memory optimization:\n"); + printfn(fn, stderr); + } +} -- cgit 1.4.1