diff options
| -rw-r--r-- | riscV/ExtValues.v | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/riscV/ExtValues.v b/riscV/ExtValues.v index 0f29e837..5e6ebf02 100644 --- a/riscV/ExtValues.v +++ b/riscV/ExtValues.v @@ -38,3 +38,41 @@ Proof. rewrite Int.or_commut. apply Int.or_zero. Qed. + +Definition bitwise_select_long b vtrue vfalse := + let b' := Val.longofint b in + Val.orl (Val.andl (Val.negl b') vtrue) + (Val.andl (Val.subl b' (Vlong Int64.one)) vfalse). + +Lemma bitwise_select_long_true : + forall vtrue vfalse, + bitwise_select_long (Val.of_optbool (Some true)) (Vlong vtrue) (Vlong vfalse) + = Vlong vtrue. +Proof. + intros. cbn. f_equal. + change (Int64.neg Int64.one) with Int64.mone. + rewrite Int64.and_commut. + rewrite Int64.and_mone. + rewrite Int64.sub_idem. + rewrite Int64.and_commut. + rewrite Int64.and_zero. + apply Int64.or_zero. +Qed. + +Lemma bitwise_select_long_false : + forall vtrue vfalse, + bitwise_select_long (Val.of_optbool (Some false)) (Vlong vtrue) (Vlong vfalse) + = Vlong vfalse. +Proof. + intros. cbn. f_equal. + change (Int64.repr (Int.signed Int.zero)) with Int64.zero. + rewrite Int64.neg_zero. + rewrite Int64.and_commut. + rewrite Int64.and_zero. + rewrite Int64.sub_zero_r. + change (Int64.neg Int64.one) with Int64.mone. + rewrite Int64.and_commut. + rewrite Int64.and_mone. + rewrite Int64.or_commut. + apply Int64.or_zero. +Qed. |