use finvw

3 files changed, 45 insertions, 4 deletions

diff --git a/mppa_k1c/ExtFloats.v b/mppa_k1c/ExtFloats.v
index b2fc6581..d9b9d3a6 100644
--- a/mppa_k1c/ExtFloats.v
+++ b/mppa_k1c/ExtFloats.v
@@ -32,7 +32,8 @@ Definition max (x : float32) (y : float32) : float32 :=
   | Some Lt | None => y
   end.
 
+Definition one := Float32.of_int (Int.repr (1%Z)).
 Definition inv (x : float32) : float32 :=
-  Float32.div (Float32.of_int (Int.repr (1%Z))) x.
+  Float32.div one x.
 
 End ExtFloat32.
diff --git a/mppa_k1c/SelectOp.vp b/mppa_k1c/SelectOp.vp
index c8139ecb..6539184c 100644
--- a/mppa_k1c/SelectOp.vp
+++ b/mppa_k1c/SelectOp.vp
@@ -51,7 +51,7 @@ Require Import Floats.
 Require Import Op.
 Require Import CminorSel.
 Require Import OpHelpers.
-Require Import ExtValues.
+Require Import ExtValues ExtFloats.
 Require Import DecBoolOps.
 Require Import Chunks.
 Require Import Builtins.
@@ -669,9 +669,20 @@ Definition divf_base (e1: expr) (e2: expr) :=
   (* Eop Odivf (e1 ::: e2 ::: Enil). *)
   Eexternal f64_div sig_ff_f (e1 ::: e2 ::: Enil).
 
-Definition divfs_base (e1: expr) (e2: expr) :=
+Definition divfs_base1 (e2 : expr) :=
+  Eop Oinvfs (e2 ::: Enil).
+Definition divfs_baseX (e1 : expr) (e2 : expr) :=
   (* Eop Odivf (e1 ::: e2 ::: Enil). *)
   Eexternal f32_div sig_ss_s (e1 ::: e2 ::: Enil).
+
+Nondetfunction divfs_base (e1: expr) :=
+  match e1 with
+  | Eop (Osingleconst f) Enil =>
+    (if Float32.eq_dec f ExtFloat32.one
+     then divfs_base1
+     else divfs_baseX e1)
+  | _ => divfs_baseX e1
+  end.
 End SELECT.
 
 Definition platform_builtin (b: platform_builtin) (args: exprlist) : option expr :=
diff --git a/mppa_k1c/SelectOpproof.v b/mppa_k1c/SelectOpproof.v
index 65685201..7805a1be 100644
--- a/mppa_k1c/SelectOpproof.v
+++ b/mppa_k1c/SelectOpproof.v
@@ -1622,6 +1622,29 @@ Proof.
   econstructor; split. eapply eval_helper_2; eauto. DeclHelper. UseHelper. auto.
 Qed.
 
+
+Lemma eval_divfs_base1:
+  forall le a b x y,
+  eval_expr ge sp e m le a x ->
+  eval_expr ge sp e m le b y ->
+  exists v, eval_expr ge sp e m le (divfs_base1 b) v /\ Val.lessdef (ExtValues.invfs y) v.
+Proof.
+  intros; unfold divfs_base1.
+  econstructor; split.
+  repeat (try econstructor; try eassumption).
+  trivial.
+Qed.
+
+Lemma eval_divfs_baseX:
+  forall le a b x y,
+  eval_expr ge sp e m le a x ->
+  eval_expr ge sp e m le b y ->
+  exists v, eval_expr ge sp e m le (divfs_baseX a b) v /\ Val.lessdef (Val.divfs x y) v.
+Proof.
+  intros; unfold divfs_base.
+  econstructor; split. eapply eval_helper_2; eauto. DeclHelper. UseHelper. auto.
+Qed.
+
 Theorem eval_divfs_base:
   forall le a b x y,
   eval_expr ge sp e m le a x ->
@@ -1629,7 +1652,13 @@ Theorem eval_divfs_base:
   exists v, eval_expr ge sp e m le (divfs_base a b) v /\ Val.lessdef (Val.divfs x y) v.
 Proof.
   intros; unfold divfs_base.
-  econstructor; split. eapply eval_helper_2; eauto. DeclHelper. UseHelper. auto.
+  destruct (divfs_base_match _).
+  - destruct (Float32.eq_dec _ _).
+    + exists (Val.divfs x y).
+      split; trivial. repeat (try econstructor; try eassumption).
+      simpl. InvEval. reflexivity.
+    + apply eval_divfs_baseX; assumption.
+  - apply eval_divfs_baseX; assumption.
 Qed.
 
 (** Platform-specific known builtins *)