diff options
Diffstat (limited to 'common/Values.v')
| -rw-r--r-- | common/Values.v | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/common/Values.v b/common/Values.v index 27d4f50c..8182d7a5 100644 --- a/common/Values.v +++ b/common/Values.v @@ -918,6 +918,23 @@ Proof. elim H0; intro; subst v; reflexivity. Qed. +Lemma rolm_lt_zero: + forall v, rolm v Int.one Int.one = cmp Clt v (Vint Int.zero). +Proof. + intros. destruct v; simpl; auto. + transitivity (Vint (Int.shru i (Int.repr (Z_of_nat wordsize - 1)))). + decEq. symmetry. rewrite Int.shru_rolm. auto. auto. + rewrite Int.shru_lt_zero. destruct (Int.lt i Int.zero); auto. +Qed. + +Lemma rolm_ge_zero: + forall v, + xor (rolm v Int.one Int.one) (Vint Int.one) = cmp Cge v (Vint Int.zero). +Proof. + intros. rewrite rolm_lt_zero. destruct v; simpl; auto. + destruct (Int.lt i Int.zero); auto. +Qed. + (** The ``is less defined'' relation between values. A value is less defined than itself, and [Vundef] is less defined than any value. *) |