From 62316a8e94d8cdcbf9e7aeadd1caf8e29507e6b0 Mon Sep 17 00:00:00 2001
From: xleroy <xleroy@fca1b0fc-160b-0410-b1d3-a4f43f01ea2e>
Date: Fri, 24 Feb 2012 16:43:38 +0000
Subject: Take advantage of Cmaskzero and Cmasknotzero.

git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@1825 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
---
 arm/SelectOp.vp          |  2 +-
 arm/SelectOpproof.v      | 15 +++++++++++++++
 backend/Selection.v      |  5 ++++-
 backend/Selectionproof.v | 20 ++++++++++----------
 ia32/SelectOp.vp         |  7 +++++++
 ia32/SelectOpproof.v     | 23 +++++++++++++++++++++++
 powerpc/SelectOp.vp      |  7 +++++++
 powerpc/SelectOpproof.v  | 23 +++++++++++++++++++++++
 8 files changed, 90 insertions(+), 12 deletions(-)

diff --git a/arm/SelectOp.vp b/arm/SelectOp.vp
index 7b8851c9..27b5f536 100644
--- a/arm/SelectOp.vp
+++ b/arm/SelectOp.vp
@@ -454,4 +454,4 @@ Nondetfunction addressing (chunk: memory_chunk) (e: expr) :=
   | _ => (Aindexed Int.zero, e:::Enil)
   end.
 
-
+Definition cond_of_expr (e: expr) := (Ccompuimm Cne Int.zero, e:::Enil).
diff --git a/arm/SelectOpproof.v b/arm/SelectOpproof.v
index 0a5ee645..1a2f5606 100644
--- a/arm/SelectOpproof.v
+++ b/arm/SelectOpproof.v
@@ -769,4 +769,19 @@ Proof.
   exists (v :: nil); split. eauto with evalexpr. subst. simpl. rewrite Int.add_zero; auto.
 Qed.
 
+Theorem eval_cond_of_expr:
+  forall le a v b,
+  eval_expr ge sp e m le a v ->
+  Val.bool_of_val v b ->
+  match cond_of_expr a with (cond, args) =>
+    exists vl,
+    eval_exprlist ge sp e m le args vl /\
+    eval_condition cond vl m = Some b
+  end.
+Proof.
+  intros. unfold cond_of_expr; simpl.
+  exists (v :: nil); split; auto with evalexpr.
+  simpl. inversion H0; simpl. rewrite Int.eq_false; auto. auto. auto. 
+Qed.
+
 End CMCONSTR.
diff --git a/backend/Selection.v b/backend/Selection.v
index 2d6c9017..ef627d79 100644
--- a/backend/Selection.v
+++ b/backend/Selection.v
@@ -62,6 +62,9 @@ Definition is_compare_eq_zero (c: condition) : bool :=
   | _ => false
   end.
 
+Definition condexpr_of_expr_base (e: expr) : condexpr :=
+  let (c, args) := cond_of_expr e in CEcond c args.
+
 Fixpoint condexpr_of_expr (e: expr) : condexpr :=
   match e with
   | Eop (Ointconst n) Enil =>
@@ -78,7 +81,7 @@ Fixpoint condexpr_of_expr (e: expr) : condexpr :=
   | Econdition ce e1 e2 =>
       CEcondition ce (condexpr_of_expr e1) (condexpr_of_expr e2)
   | _ =>
-      CEcond (Ccompuimm Cne Int.zero) (e:::Enil)
+      condexpr_of_expr_base e
   end.
 
 (** Conversion of loads and stores *)
diff --git a/backend/Selectionproof.v b/backend/Selectionproof.v
index 9681c66b..b5bc216b 100644
--- a/backend/Selectionproof.v
+++ b/backend/Selectionproof.v
@@ -81,17 +81,17 @@ Proof.
   intros. simpl. auto.
 Qed.
 
-Lemma eval_base_condition_of_expr:
+Lemma eval_condition_of_expr_base:
   forall le a v b,
   eval_expr ge sp e m le a v ->
   Val.bool_of_val v b ->
-  eval_condexpr ge sp e m le 
-                (CEcond (Ccompuimm Cne Int.zero) (a ::: Enil))
-                b.
+  eval_condexpr ge sp e m le (condexpr_of_expr_base a) b.
 Proof.
-  intros. 
-  eapply eval_CEcond. eauto with evalexpr. 
-  inversion H0; simpl. rewrite Int.eq_false; auto. auto. auto.
+  intros. unfold condexpr_of_expr_base. 
+  exploit eval_cond_of_expr; eauto. 
+  destruct (cond_of_expr a) as [cond args]. 
+  intros [vl [A B]].
+  econstructor; eauto. 
 Qed.
 
 Lemma is_compare_neq_zero_correct:
@@ -135,15 +135,15 @@ Lemma eval_condition_of_expr:
 Proof.
   intro a0; pattern a0.
   apply expr_induction_principle; simpl; intros;
-    try (eapply eval_base_condition_of_expr; eauto; fail).
+    try (eapply eval_condition_of_expr_base; eauto; fail).
   
-  destruct o; try (eapply eval_base_condition_of_expr; eauto; fail).
+  destruct o; try (eapply eval_condition_of_expr_base; eauto; fail).
 
   destruct e0. inv H0. inv H5. simpl in H7. inv H7.  
   inversion H1. 
   rewrite Int.eq_false; auto. constructor.
   subst i; rewrite Int.eq_true. constructor.
-  eapply eval_base_condition_of_expr; eauto.
+  eapply eval_condition_of_expr_base; eauto.
 
   inv H0. simpl in H7.
   assert (eval_condition c vl m = Some b).
diff --git a/ia32/SelectOp.vp b/ia32/SelectOp.vp
index 98db3885..62de4ce1 100644
--- a/ia32/SelectOp.vp
+++ b/ia32/SelectOp.vp
@@ -429,3 +429,10 @@ Nondetfunction addressing (chunk: memory_chunk) (e: expr) :=
   | _ => (Aindexed Int.zero, e:::Enil)
   end.
 
+(** ** Turning an expression into a condition *)
+
+Nondetfunction cond_of_expr (e: expr) :=
+  match e with
+  | Eop (Oandimm n) (t1:::Enil) => (Cmasknotzero n, t1:::Enil)
+  | _ => (Ccompuimm Cne Int.zero, e:::Enil)
+  end.
diff --git a/ia32/SelectOpproof.v b/ia32/SelectOpproof.v
index e6fd8098..658a7550 100644
--- a/ia32/SelectOpproof.v
+++ b/ia32/SelectOpproof.v
@@ -753,4 +753,27 @@ Proof.
   exists (v :: nil); split. constructor; auto. constructor. subst; simpl. rewrite Int.add_zero; auto. 
 Qed.
 
+Theorem eval_cond_of_expr:
+  forall le a v b,
+  eval_expr ge sp e m le a v ->
+  Val.bool_of_val v b ->
+  match cond_of_expr a with (cond, args) =>
+    exists vl,
+    eval_exprlist ge sp e m le args vl /\
+    eval_condition cond vl m = Some b
+  end.
+Proof.
+  intros until v. unfold cond_of_expr; case (cond_of_expr_match a); intros; InvEval.
+  subst v. exists (v1 :: nil); split; auto with evalexpr.
+  simpl. destruct b.
+  generalize (Val.bool_of_true_val2 _ H0); clear H0; intro ISTRUE.
+  destruct v1; simpl in ISTRUE; try contradiction. 
+  rewrite Int.eq_false; auto.
+  generalize (Val.bool_of_false_val2 _ H0); clear H0; intro ISFALSE.
+  destruct v1; simpl in ISFALSE; try contradiction.
+  rewrite ISFALSE. rewrite Int.eq_true; auto.
+  exists (v :: nil); split; auto with evalexpr.
+  simpl. inversion H0; simpl. rewrite Int.eq_false; auto. auto. auto. 
+Qed.
+
 End CMCONSTR.
diff --git a/powerpc/SelectOp.vp b/powerpc/SelectOp.vp
index 290704bc..943c4006 100644
--- a/powerpc/SelectOp.vp
+++ b/powerpc/SelectOp.vp
@@ -460,3 +460,10 @@ Nondetfunction addressing (chunk: memory_chunk) (e: expr) :=
   | _ => (Aindexed Int.zero, e:::Enil)
   end.
   
+(** ** Turning an expression into a condition *)
+
+Nondetfunction cond_of_expr (e: expr) :=
+  match e with
+  | Eop (Oandimm n) (t1:::Enil) => (Cmasknotzero n, t1:::Enil)
+  | _ => (Ccompuimm Cne Int.zero, e:::Enil)
+  end.
diff --git a/powerpc/SelectOpproof.v b/powerpc/SelectOpproof.v
index 39205dbd..1d35d9f8 100644
--- a/powerpc/SelectOpproof.v
+++ b/powerpc/SelectOpproof.v
@@ -817,5 +817,28 @@ Proof.
   rewrite Int.add_zero. auto.
 Qed.
 
+Theorem eval_cond_of_expr:
+  forall le a v b,
+  eval_expr ge sp e m le a v ->
+  Val.bool_of_val v b ->
+  match cond_of_expr a with (cond, args) =>
+    exists vl,
+    eval_exprlist ge sp e m le args vl /\
+    eval_condition cond vl m = Some b
+  end.
+Proof.
+  intros until v. unfold cond_of_expr; case (cond_of_expr_match a); intros; InvEval.
+  subst v. exists (v1 :: nil); split; auto with evalexpr.
+  simpl. destruct b.
+  generalize (Val.bool_of_true_val2 _ H0); clear H0; intro ISTRUE.
+  destruct v1; simpl in ISTRUE; try contradiction. 
+  rewrite Int.eq_false; auto.
+  generalize (Val.bool_of_false_val2 _ H0); clear H0; intro ISFALSE.
+  destruct v1; simpl in ISFALSE; try contradiction.
+  rewrite ISFALSE. rewrite Int.eq_true; auto.
+  exists (v :: nil); split; auto with evalexpr.
+  simpl. inversion H0; simpl. rewrite Int.eq_false; auto. auto. auto. 
+Qed.
+
 End CMCONSTR.
 
-- 
cgit