Connecting: reading heads

This commit is contained in:
Adam Chlipala 2018-04-29 21:08:12 -04:00
parent d537e28266
commit daebf21dc0

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@ -1060,7 +1060,7 @@ Module DeeplyEmbedded(Import BW : BIT_WIDTH).
}.
End fn.
Definition heap := fmap (wrd) (wrd * wrd).
Definition heap := fmap wrd wrd.
Definition valuation := fmap var wrd.
Inductive eval : heap -> valuation -> exp -> wrd -> Prop :=
@ -1073,13 +1073,13 @@ Module DeeplyEmbedded(Import BW : BIT_WIDTH).
eval H V e1 n1
-> eval H V e2 n2
-> eval H V (Add e1 e2) (n1 ^+ n2)
| VHead : forall H V e1 p ph pt,
| VHead : forall H V e1 p ph,
eval H V e1 p
-> H $? p = Some (ph, pt)
-> H $? p = Some ph
-> eval H V (Head e1) ph
| VTail : forall H V e1 p ph pt,
| VTail : forall H V e1 p pt,
eval H V e1 p
-> H $? p = Some (ph, pt)
-> H $? (p ^+ ^1) = Some pt
-> eval H V (Tail e1) pt
| VNotNull : forall H V e1 p,
eval H V e1 p
@ -1089,16 +1089,16 @@ Module DeeplyEmbedded(Import BW : BIT_WIDTH).
| StAssign : forall H V x e v,
eval H V e v
-> step (H, V, Assign x e) (H, V $+ (x, v), Skip)
| StWriteHead : forall H V x e a v hv tv,
| StWriteHead : forall H V x e a v hv,
V $? x = Some a
-> eval H V e v
-> H $? a = Some (hv, tv)
-> step (H, V, WriteHead x e) (H $+ (a, (v, tv)), V, Skip)
| StWriteTail : forall H V x e a v hv tv,
-> H $? a = Some hv
-> step (H, V, WriteHead x e) (H $+ (a, v), V, Skip)
| StWriteTail : forall H V x e a v tv,
V $? x = Some a
-> eval H V e v
-> H $? a = Some (hv, tv)
-> step (H, V, WriteTail x e) (H $+ (a, (hv, v)), V, Skip)
-> H $? a = Some tv
-> step (H, V, WriteTail x e) (H $+ (a, v), V, Skip)
| StSeq1 : forall H V s2,
step (H, V, Seq Skip s2) (H, V, s2)
| StSeq2 : forall H V s1 s2 H' V' s1',
@ -1167,17 +1167,18 @@ Module MixedToDeep(Import BW : BIT_WIDTH).
| TrDone : forall V (v : RT) s,
translate_return V v s
-> translate translate_return V (Return v) s
| TrAssign : forall V (B : Set) (v : wrd) (c : wrd -> cmd B) e x s1,
| TrAssign : forall V B (v : wrd) (c : wrd -> cmd B) e x s1,
translate_exp V v e
-> (forall w, translate translate_return (V $+ (x, w)) (c w) s1)
-> translate translate_return V (Bind (Return v) c) (Seq (Assign x e) s1)
| TrAssigned : forall V (B : Set) (v : wrd) (c : wrd -> cmd B) x s1,
| TrAssigned : forall V B (v : wrd) (c : wrd -> cmd B) x s1,
V $? x = Some v
-> translate translate_return (V $+ (x, v)) (c v) s1
-> translate translate_return V (Bind (Return v) c) (Seq Skip s1).
Example adder (a b c : wrd) :=
Bind (Return (a ^+ b)) (fun ab => Return (ab ^+ c)).
-> translate translate_return V (c v) s1
-> translate translate_return V (Bind (Return v) c) (Seq Skip s1)
| TrReadHead : forall V B (a : wrd) (c : wrd -> cmd B) e x s1,
translate_exp V a e
-> (forall w, translate translate_return (V $+ (x, w)) (c w) s1)
-> translate translate_return V (Bind (Read a) c) (Seq (Assign x (Head e)) s1).
Ltac freshFor vm k :=
let rec keepTrying x :=
@ -1199,8 +1200,14 @@ Module MixedToDeep(Import BW : BIT_WIDTH).
| [ |- translate _ ?V (Bind (Return _) _) _ ] =>
freshFor V ltac:(fun y =>
eapply TrAssign with (x := y); [ | intro ])
| [ |- translate _ ?V (Bind (Read _) _) _ ] =>
freshFor V ltac:(fun y =>
eapply TrReadHead with (x := y); [ | intro ])
end.
Example adder (a b c : wrd) :=
Bind (Return (a ^+ b)) (fun ab => Return (ab ^+ c)).
Lemma translate_adder : sig (fun s =>
forall a b c, translate (translate_result "result") ($0 $+ ("a", a) $+ ("b", b) $+ ("c", c)) (adder a b c) s).
Proof.
@ -1211,18 +1218,23 @@ Module MixedToDeep(Import BW : BIT_WIDTH).
Definition adder_compiled := Eval simpl in proj1_sig translate_adder.
Record heaps_compat (H : DE.heap) (h : ME.heap) : Prop := {
DeepToMixedHd : forall a v1 v2, H $? a = Some (v1, v2) -> h $? a = Some v1;
DeepToMixedTl : forall a v1 v2, H $? a = Some (v1, v2) -> h $? (a ^+ ^1) = Some v2;
MixedToDeep : forall a v1 v2, h $? a = Some v1 -> h $? (a ^+ ^1) = Some v2
-> H $? a = Some (v1, v2)
}.
Example reader (p1 p2 : wrd) :=
Bind (Read p1) (fun v1 => Bind (Read p2) (fun v2 => Return (v1 ^+ v2))).
Lemma translate_reader : sig (fun s =>
forall p1 p2, translate (translate_result "result") ($0 $+ ("p1", p1) $+ ("p2", p2)) (reader p1 p2) s).
Proof.
eexists; simplify.
unfold reader.
repeat translate.
Defined.
Definition reader_compiled := Eval simpl in proj1_sig translate_reader.
Inductive translated : forall {A}, DE.heap * valuation * stmt -> ME.heap * cmd A -> Prop :=
| Translated : forall A H h V s (c : cmd A),
| Translated : forall A H V s (c : cmd A),
translate (translate_result "result") V c s
-> heaps_compat H h
-> translated (H, V, s) (h, c).
-> translated (H, V, s) (H, c).
Lemma eval_translate : forall H V e v,
eval H V e v
@ -1253,75 +1265,57 @@ Module MixedToDeep(Import BW : BIT_WIDTH).
eauto.
Qed.
Lemma step_translate : forall H V s H' V' s',
DE.step (H, V, s) (H', V', s')
-> forall h (c : cmd wrd) out,
translate (translate_result out) V c s
-> heaps_compat H h
-> exists c' h', ME.step^* (h, c) (h', c')
/\ translate (translate_result out) V' c' s'
/\ heaps_compat H' h'.
Lemma step_translate : forall out V (c : cmd wrd) s,
translate (translate_result out) V c s
-> forall H H' V' s',
DE.step (H, V, s) (H', V', s')
-> exists c', ME.step^* (H, c) (H', c')
/\ translate (translate_result out) V' c' s'.
Proof.
induct 1; invert 1; simplify.
induct 1.
invert H3.
apply inj_pair2 in H1; subst.
eapply eval_translate in H4; eauto; subst.
invert H; invert 1; simplify.
eapply eval_translate in H0; eauto; subst.
do 2 eexists; propositional.
eauto.
apply TrDone; apply TrReturned; simplify; auto.
assumption.
invert 1; simplify.
invert H6.
eapply eval_translate in H5; eauto; subst.
do 2 eexists; propositional.
eauto.
econstructor.
instantiate (1 := x); simplify.
reflexivity.
eauto.
invert H6.
invert H2.
apply inj_pair2 in H0; subst.
invert 1; simplify.
do 2 eexists; propositional.
eapply TrcFront.
eauto.
eauto.
replace V' with (V' $+ (x, v)).
assumption.
maps_equal.
symmetry; assumption.
assumption.
invert H5.
invert H4.
apply inj_pair2 in H2; subst.
invert H0.
do 2 eexists; propositional.
eauto.
eapply TrAssigned.
instantiate (1 := x).
invert 1.
invert H6.
invert H5.
eapply eval_translate in H4; eauto; subst.
simplify.
eapply eval_translate in H7; eauto.
subst.
reflexivity.
match goal with
| [ |- translate _ ?V' _ _ ] => replace V' with (V $+ (x, v)) by (maps_equal; equality)
end.
do 2 eexists; propositional.
eapply TrcFront.
eauto.
eauto.
econstructor.
instantiate (1 := x); simplify; reflexivity.
eauto.
assumption.
invert H0.
invert H4.
invert H3.
invert H4.
invert H3.
Qed.
Theorem translated_simulates : forall H V c h s,
Theorem translated_simulates : forall H V c s,
translate (translate_result "result") V c s
-> heaps_compat H h
-> simulates (translated (A := wrd)) (DE.trsys_of H V s) (ME.multistep_trsys_of h c).
-> simulates (translated (A := wrd)) (DE.trsys_of H V s) (ME.multistep_trsys_of H c).
Proof.
constructor; simplify.
@ -1332,16 +1326,15 @@ Module MixedToDeep(Import BW : BIT_WIDTH).
eauto.
auto.
invert H2.
apply inj_pair2 in H5; subst.
invert H1.
apply inj_pair2 in H4; subst.
cases st1'.
cases p.
eapply step_translate in H6; eauto.
eapply step_translate in H7; eauto.
simp.
eexists; split; [ | eassumption ].
econstructor.
assumption.
eauto.
Qed.
Hint Constructors eval DE.step.
@ -1355,10 +1348,11 @@ Module MixedToDeep(Import BW : BIT_WIDTH).
Hint Resolve translate_exp_sound.
Lemma not_stuck : forall A h (c : cmd A) h' c',
step (h, c) (h', c')
-> forall out V s, translate (translate_result out) V c s
-> forall H, exists p', DE.step (H, V, s) p'.
Lemma not_stuck : forall out V (c : cmd wrd) s,
translate (translate_result out) V c s
-> forall H H' c',
step (H, c) (H', c')
-> exists p', DE.step (H, V, s) p'.
Proof.
induct 1; invert 1; simplify.
@ -1369,20 +1363,27 @@ Module MixedToDeep(Import BW : BIT_WIDTH).
eexists.
econstructor.
econstructor.
eauto.
eexists.
econstructor.
econstructor.
eauto.
apply inj_pair2 in H8; subst.
invert H6.
eexists.
econstructor.
econstructor.
econstructor.
eauto.
eauto.
Qed.
Theorem hoare_triple_sound : forall P (c : cmd wrd) Q V s h H,
Theorem hoare_triple_sound : forall P (c : cmd wrd) Q V s H,
hoare_triple P c Q
-> P h
-> heaps_compat H h
-> P H
-> translate (translate_result "result") V c s
-> V $? "result" = None
-> invariantFor (DE.trsys_of H V s)
@ -1394,25 +1395,24 @@ Module MixedToDeep(Import BW : BIT_WIDTH).
eapply invariant_simulates.
apply translated_simulates.
eassumption.
eassumption.
apply invariant_multistepify with (sys := trsys_of h c).
apply invariant_multistepify with (sys := trsys_of H c).
eauto using hoare_triple_sound.
invert 1; simp.
cases st2; simplify; subst.
invert H6; simplify.
apply inj_pair2 in H8; subst.
invert H11.
apply inj_pair2 in H6; subst.
invert H8.
invert H5; simplify.
apply inj_pair2 in H10; subst.
invert H9.
apply inj_pair2 in H4; subst.
invert H6.
right; eexists.
econstructor; eauto.
auto.
invert H6; simp.
apply inj_pair2 in H8; subst; simplify.
invert H5; simp.
apply inj_pair2 in H7; subst; simplify.
cases x.
eapply not_stuck in H7; eauto.
eapply not_stuck in H10; eauto.
Qed.
Theorem adder_ok : forall a b c,
@ -1441,10 +1441,50 @@ Module MixedToDeep(Import BW : BIT_WIDTH).
eapply hoare_triple_sound.
apply adder_ok.
constructor; auto.
constructor; simplify; equality.
apply (proj2_sig translate_adder).
simplify; equality.
Qed.
Theorem reader_ok : forall p1 p2 v1 v2,
{{p1 |-> v1 * p2 |-> v2}}
reader p1 p2
{{r ~> [| r = v1 ^+ v2 |] * p1 |-> v1 * p2 |-> v2}}.
Proof.
unfold reader.
simplify.
step.
step.
simp.
step.
step.
simp.
step.
cancel.
equality.
Qed.
Theorem reader_compiled_ok : forall p1 p2 v1 v2,
p1 <> p2
-> invariantFor (DE.trsys_of ($0 $+ (p1, v1) $+ (p2, v2)) ($0 $+ ("p1", p1) $+ ("p2", p2)) reader_compiled)
(fun p => snd p = Skip
\/ exists p', DE.step p p').
Proof.
simplify.
eapply hoare_triple_sound.
apply reader_ok.
exists ($0 $+ (p1, v1)), ($0 $+ (p2, v2)); propositional.
unfold split.
maps_equal.
rewrite lookup_join2; simplify; auto; sets.
rewrite lookup_join1; simplify; auto; sets.
rewrite lookup_join2; simplify; auto; sets.
unfold disjoint; simplify.
cases (weq a p1); simplify; propositional.
constructor.
constructor.
apply (proj2_sig translate_reader).
simplify; equality.
Qed.
End MixedToDeep.