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#include "ir.h"
void
copyopt(struct function *fn)
{
struct block *blk = fn->entry;
FREQUIRE(FNUSE);
do {
if (blk->npred == 1) for (int i = 0; i < blk->phi.n; ++i) {
/* simplify 1-arg phi */
int phi = blk->phi.p[i];
union ref *arg = phitab.p[instrtab[phi].l.i];
/* being conservative here because phis could have circular dependencies? */
if (arg->t != RTMP || instrtab[arg->i].op != Ophi) {
replcuses(mkref(RTMP, phi), *arg);
delphi(blk, i--);
}
}
for (int i = 0; i < blk->ins.n; ++i) {
union ref var = mkref(RTMP, blk->ins.p[i]);
struct instr *ins = &instrtab[var.i];
enum irclass k;
if (ins->op == Ocopy) {
union ref arg = ins->l;
if (arg.t == RTMP) k = insrescls(instrtab[arg.i]);
else if (arg.t == RICON) k = cls2siz[ins->cls] == 4 ? KI32 : KI64;
else if (arg.t == RXCON) k = isnumcon(arg) ? conht[arg.i].cls : KPTR;
else continue;
if (ins->cls != k) continue;
replcuses(var, arg);
*ins = mkinstr(Onop,0,);
deluses(var.i);
}
}
delnops(blk);
} while ((blk = blk->lnext) != fn->entry);
}
void
filluses(struct function *fn)
{
extern int ninstr;
struct block *blk = fn->entry;
for (int i = 0; i < ninstr; ++i)
deluses(i);
do {
for (int i = 0; i < blk->phi.n; ++i) {
int ins = blk->phi.p[i];
union ref *phi = phitab.p[instrtab[ins].l.i];
for (int i = 0; i < blk->npred; ++i)
adduse(blk, ins, phi[i]);
}
for (int i = 0; i < blk->ins.n; ++i) {
int ins = blk->ins.p[i];
adduse(blk, ins, instrtab[ins].l);
adduse(blk, ins, instrtab[ins].r);
}
adduse(blk, USERJUMP, blk->jmp.arg[0]);
adduse(blk, USERJUMP, blk->jmp.arg[1]);
} while ((blk = blk->lnext) != fn->entry);
fn->prop |= FNUSE;
}
/* vim:set ts=3 sw=3 expandtab: */
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