bool simplify_impl(Env& env, Vlabel b, size_t i, Simplify simplify) {
auto& unit = env.unit;
return vmodify(unit, b, i, [&] (Vout& v) {
auto& blocks = unit.blocks;
auto const nremove = simplify(v);
// Update use counts for to-be-removed instructions.
for (auto j = i; j < i + nremove; ++j) {
visitUses(unit, blocks[b].code[j], [&] (Vreg r) {
--env.use_counts[r];
});
}
// Update use counts and def instructions for to-be-added instructions.
for (auto const& inst : blocks[Vlabel(v)].code) {
visitUses(unit, inst, [&] (Vreg r) {
if (r >= env.use_counts.size()) {
env.use_counts.resize(size_t{r}+1);
}
++env.use_counts[r];
});
visitDefs(unit, inst, [&] (Vreg r) {
if (r >= env.def_insts.size()) {
env.def_insts.resize(size_t{r}+1, Vinstr::nop);
}
env.def_insts[r] = inst.op;
});
}
return nremove;
});
}
void lower_impl(Vunit& unit, Vlabel b, size_t i, Lower lower) {
vmodify(unit, b, i, [&] (Vout& v) { lower(v); return 1; });
}
