diff options
Diffstat (limited to 'arm')
-rw-r--r-- | arm/ConstpropOp.vp | 26 | ||||
-rw-r--r-- | arm/ConstpropOpproof.v | 8 |
2 files changed, 24 insertions, 10 deletions
diff --git a/arm/ConstpropOp.vp b/arm/ConstpropOp.vp index f94606b0..bd08d597 100644 --- a/arm/ConstpropOp.vp +++ b/arm/ConstpropOp.vp @@ -160,18 +160,24 @@ Definition make_mulimm (n: int) (r1 r2: reg) := end. Definition make_divimm (n: int) (r1 r2: reg) := - match Int.is_power2 n with - | Some l => if Int.ltu l (Int.repr 31) - then (Oshrximm l, r1 :: nil) - else (Odiv, r1 :: r2 :: nil) - | None => (Odiv, r1 :: r2 :: nil) - end. + if Int.eq n Int.one then + (Omove, r1 :: nil) + else + match Int.is_power2 n with + | Some l => if Int.ltu l (Int.repr 31) + then (Oshrximm l, r1 :: nil) + else (Odiv, r1 :: r2 :: nil) + | None => (Odiv, r1 :: r2 :: nil) + end. Definition make_divuimm (n: int) (r1 r2: reg) := - match Int.is_power2 n with - | Some l => (Oshift (Slsr (mk_shift_amount l)), r1 :: nil) - | None => (Odivu, r1 :: r2 :: nil) - end. + if Int.eq n Int.one then + (Omove, r1 :: nil) + else + match Int.is_power2 n with + | Some l => (Oshift (Slsr (mk_shift_amount l)), r1 :: nil) + | None => (Odivu, r1 :: r2 :: nil) + end. Definition make_andimm (n: int) (r: reg) (a: aval) := if Int.eq n Int.zero then (Ointconst Int.zero, nil) diff --git a/arm/ConstpropOpproof.v b/arm/ConstpropOpproof.v index 93ef2475..1eec5923 100644 --- a/arm/ConstpropOpproof.v +++ b/arm/ConstpropOpproof.v @@ -356,6 +356,10 @@ Lemma make_divimm_correct: exists w, eval_operation ge (Vptr sp Ptrofs.zero) op rs##args m = Some w /\ Val.lessdef v w. Proof. intros; unfold make_divimm. + predSpec Int.eq Int.eq_spec n Int.one; intros. subst. rewrite H0 in H. + destruct (rs#r1) eqn:?; + try (rewrite Val.divs_one in H; exists (Vint i); split; simpl; try rewrite Heqv0; auto); + inv H; auto. destruct (Int.is_power2 n) eqn:?. destruct (Int.ltu i (Int.repr 31)) eqn:?. exists v; split; auto. simpl. eapply Val.divs_pow2; eauto. congruence. @@ -371,6 +375,10 @@ Lemma make_divuimm_correct: exists w, eval_operation ge (Vptr sp Ptrofs.zero) op rs##args m = Some w /\ Val.lessdef v w. Proof. intros; unfold make_divuimm. + predSpec Int.eq Int.eq_spec n Int.one; intros. subst. rewrite H0 in H. + destruct (rs#r1) eqn:?; + try (rewrite Val.divu_one in H; exists (Vint i); split; simpl; try rewrite Heqv0; auto); + inv H; auto. destruct (Int.is_power2 n) eqn:?. replace v with (Val.shru rs#r1 (Vint i)). econstructor; split. simpl. rewrite mk_shift_amount_eq. eauto. |