MimIR 0.1
MimIR is my Intermediate Representation
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tail_rec_elim.cpp
Go to the documentation of this file.
2
3#include "mim/pass/eta_red.h"
4
5namespace mim {
6
9 eta_red_ = man->find<EtaRed>();
10}
11
12const Def* TailRecElim::rewrite(const Def* def) {
13 if (auto [app, old] = isa_apped_mut_lam(def); old) {
14 if (auto i = old2rec_loop_.find(old); i != old2rec_loop_.end()) {
15 auto [rec, loop] = i->second;
16 auto args = app->args();
17 if (auto ret_var = rec->ret_var(); app->args().back() == ret_var)
18 return world().app(loop, args.view().rsubspan(1));
19 else
20 return world().app(rec, args);
21 }
22 }
23
24 return def;
25}
26
28 if (auto [app, old] = isa_apped_mut_lam(def); old) {
29 if (auto ret_var = old->ret_var(); ret_var && app->args().back() == ret_var) {
30 if (auto [i, ins] = old2rec_loop_.emplace(old, std::pair<Lam*, Lam*>(nullptr, nullptr)); ins) {
31 auto& [rec, loop] = i->second;
32 rec = old->stub(old->type());
33 auto doms = rec->doms();
34 auto loop_dom = doms.view().rsubspan(1);
35 loop = rec->stub(world().cn(loop_dom));
36 DLOG("old {} -> (rec: {}, loop: {})", old, rec, loop);
37
38 auto n = rec->num_doms();
39 DefVec loop_args(n - 1);
40 DefVec loop_vars(n);
41 for (size_t i = 0; i != n - 1; ++i) {
42 loop_args[i] = rec->var(i);
43 loop_vars[i] = loop->var(i);
44 }
45 loop_vars.back() = rec->vars().back();
46
47 loop->set(old->reduce(world().tuple(loop_vars)));
48 rec->app(false, loop, loop_args);
49 if (eta_red_) eta_red_->mark_irreducible(loop);
50
51 return undo_visit(old);
52 }
53 }
54 }
55
56 return No_Undo;
57}
58
59} // namespace mim
Base class for all Defs.
Definition def.h:251
Performs η-reduction.
Definition eta_red.h:9
undo_t undo_visit(Def *mut) const
Definition pass.h:360
An optimizer that combines several optimizations in an optimal way.
Definition pass.h:172
virtual void init(PassMan *)
Definition pass.cpp:30
PassMan & man()
Definition pass.h:97
World & world()
Definition pass.h:64
undo_t analyze(const Def *) override
void init(PassMan *) final
const Def * rewrite(const Def *) override
const Def * app(const Def *callee, const Def *arg)
Definition world.cpp:195
#define DLOG(...)
Vaporizes to nothingness in Debug build.
Definition log.h:95
Definition ast.h:14
Vector< const Def * > DefVec
Definition def.h:77
std::pair< const App *, Lam * > isa_apped_mut_lam(const Def *def)
Definition lam.h:354
size_t undo_t
Definition pass.h:21
static constexpr undo_t No_Undo
Definition pass.h:22