Commit 8e757f1c authored by BOLDO Sylvie's avatar BOLDO Sylvie

Un peu de traduction

parent e054e05d
......@@ -27,7 +27,7 @@ Require Import Fappli_IEEE.
Section Bounds.
Definition nat_to_N (n:nat) := match n with
(*Definition nat_to_N (n:nat) := match n with
| 0 => N0
| (S m) => (Npos (P_of_succ_nat m))
end.
......@@ -36,15 +36,20 @@ Lemma nat_to_N_correct: forall n:nat, Z_of_N (nat_to_N n)=n.
intros.
intros; induction n; simpl; auto.
Qed.
*)
Definition make_bound (p E:Z) := Bound
(Z.to_pos (Zpower 2%Z p))
(Z.abs_N E).
Definition make_bound (p E:nat) := Bound
(P_of_succ_nat (Peano.pred (Zabs_nat (Zpower_nat 2%Z p))))
(nat_to_N E).
Lemma make_EGivesEmin: forall p E:nat,
Lemma make_EGivesEmin: forall p E:Z,
(Z_of_N (dExp (make_bound p E)))=E.
intros; simpl; apply nat_to_N_correct.
intros; simpl.
OUIIIIIIIIIIIIIIIIIIIINNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN.
emin n'est pas forcément positif en Flocq, alors qu'il l'est en pff...
Zabs2N.abs_N_nonneg
easy.
nat_to_N_correct.
Qed.
Lemma make_pGivesBound: forall p E:nat,
......@@ -102,7 +107,7 @@ Hypothesis pGivesBound : Zpos (vNum b) = Zpower_nat 2%Z p.
Hypothesis precisionNotZero : 1 < p.
Lemma equiv_RNDs_aux1: forall f, Fbounded b f ->
Lemma pff_format_is_format: forall f, Fbounded b f ->
(generic_format radix2 (FLT_exp (-dExp b) p) (FtoR 2 f)).
intros f Hf.
apply generic_format_FLT; auto with zarith.
......@@ -121,7 +126,7 @@ exact H0.
Qed.
Lemma equiv_RNDs_aux2: forall r,
Lemma format_is_pff_format: forall r,
(generic_format radix2 (FLT_exp (-dExp b) p) r)
-> exists f, FtoR 2 f = r /\ Fbounded b f.
intros r Hr.
......@@ -143,7 +148,7 @@ unfold Prec_gt_0;auto with zarith.
Qed.
Lemma equiv_RNDs_aux3: forall z, Zeven z = true -> Even z.
Lemma equiv_RNDs_aux: forall z, Zeven z = true -> Even z.
intros z; unfold Zeven, Even.
case z.
intros; exists 0%Z; auto with zarith.
......@@ -159,7 +164,7 @@ exists (Zneg p1); auto with zarith.
intros H; contradict H; auto.
Qed.
Lemma equiv_RNDs_aux4: forall f, Fcanonic 2 b f -> FtoR 2 f <> 0 ->
Lemma pff_canonic_is_canonic: forall f, Fcanonic 2 b f -> FtoR 2 f <> 0 ->
canonic radix2 (FLT_exp (- dExp b) p)
(Float radix2 (Float.Fnum f) (Float.Fexp f)).
intros f Hf1 Hf2; unfold canonic; simpl.
......@@ -241,7 +246,7 @@ rewrite Z2R_IZR; reflexivity.
Qed.
Lemma equiv_RNDs_aux5: forall (r:R),
Lemma pff_round_NE_is_round: forall (r:R),
(FtoR 2 (RND_EvenClosest b 2 p r)
= round radix2 (FLT_exp (-dExp b) p) rndNE r).
intros.
......@@ -254,7 +259,7 @@ apply exists_NE_FLT.
right; auto with zarith.
unfold Rnd_NE_pt, Rnd_NG_pt, Rnd_N_pt, NE_prop in H.
destruct H as ((H1,H2),H3).
destruct (equiv_RNDs_aux2 _ H1) as (f,(Hf1,Hf2)).
destruct (format_is_pff_format _ H1) as (f,(Hf1,Hf2)).
rewrite <- Hf1.
generalize (EvenClosestUniqueP b 2 p); unfold UniqueP; intros T.
apply sym_eq; apply T with r; auto with zarith; clear T.
......@@ -263,7 +268,7 @@ split.
split; auto; intros g Hg.
rewrite Hf1.
apply H2.
apply equiv_RNDs_aux1; auto.
apply pff_format_is_format; auto.
(* *)
case (Req_dec (FtoR 2 (Fnormalize 2 b p f)) 0%R); intros L.
left.
......@@ -280,13 +285,13 @@ destruct H3.
destruct H as (g,(Hg1,(Hg2,Hg3))).
left.
unfold FNeven, Feven.
apply equiv_RNDs_aux3.
apply equiv_RNDs_aux.
replace (Float.Fnum (Fnormalize 2 b p f)) with (Fnum g); try assumption.
replace g with (Float radix2 (Float.Fnum (Fnormalize 2 b p f)) (Float.Fexp (Fnormalize 2 b p f))).
easy.
apply canonic_unicity with (FLT_exp (- dExp b) p).
2: assumption.
apply equiv_RNDs_aux4.
apply pff_canonic_is_canonic.
apply FnormalizeCanonic; auto with zarith real.
exact L.
rewrite <- Hg1, <- Hf1.
......@@ -299,16 +304,16 @@ right; intros q (Hq1,Hq2).
rewrite Hf1.
apply H.
split.
apply equiv_RNDs_aux1; auto.
apply pff_format_is_format; auto.
intros g Hg.
destruct (equiv_RNDs_aux2 _ Hg) as (v,(Hv1,Hv2)).
destruct (format_is_pff_format _ Hg) as (v,(Hv1,Hv2)).
rewrite <- Hv1.
apply Hq2; auto.
apply RND_EvenClosest_correct; auto with zarith.
Qed.
Lemma equiv_RNDs: forall (r:R),
Lemma round_NE_is_pff_round: forall (r:R),
exists f:Float.float, (Fcanonic 2 b f /\ (EvenClosest b 2 p r f) /\
FtoR 2 f = round radix2 (FLT_exp (-dExp b) p) rndNE r).
intros r.
......@@ -317,26 +322,26 @@ split.
apply RND_EvenClosest_canonic; auto with zarith.
split.
apply RND_EvenClosest_correct; auto with zarith.
apply equiv_RNDs_aux5.
apply pff_round_NE_is_round.
Qed.
End Equiv.
Section Equiv_instanc.
Lemma equiv_RNDs_s: forall (r:R),
Lemma round_NE_is_pff_round_b32: forall (r:R),
exists f:Float.float, (Fcanonic 2 bsingle f /\ (EvenClosest bsingle 2 24 r f) /\
FtoR 2 f = round radix2 (FLT_exp (-149) 24) rndNE r).
apply equiv_RNDs.
apply round_NE_is_pff_round.
apply psGivesBound.
apply psGreaterThanOne.
Qed.
Lemma equiv_RNDs_d: forall (r:R),
Lemma round_NE_is_pff_round_b64: forall (r:R),
exists f:Float.float, (Fcanonic 2 bdouble f /\ (EvenClosest bdouble 2 53 r f) /\
FtoR 2 f = round radix2 (FLT_exp (-1074) 53) rndNE r).
apply equiv_RNDs.
apply round_NE_is_pff_round.
apply pdGivesBound.
apply pdGreaterThanOne.
Qed.
......
Require Import Fcore.
Require Import Fprop_plus_error.
Require Import Fprop_mult_error.
Require Import FmaErr.
Require Import Ftranslate_flocq2Pff.
Open Scope R_scope.
Section ErrFMA.
Variable emin prec : Z.
Context { prec_gt_0_ : Prec_gt_0 prec }.
Notation format := (generic_format radix2 (FLT_exp emin prec)).
Notation round_flt :=(round radix2 (FLT_exp emin prec) ZnearestE).
Notation ulp_flt :=(ulp radix2 (FLT_exp emin prec)).
(** inputs *)
Variable a x y:R.
Hypothesis Fa: format a.
Hypothesis Fx: format x.
Hypothesis Fy: format y.
(** algorith *)
Let r1 := round_flt (a*x+y).
Let u1 := round_flt (a*x).
Let u2 := u1-a*x.
Let alpha1 := round_flt (y+u2).
Let alpha2 := alpha1 -(y+u2).
Let beta1 := round_flt (u1+alpha1).
Let beta2 := beta1 -(u1+alpha1).
Let gamma := round_flt (round_flt (beta1-r1)+beta2).
Let r2 := round_flt (gamma+alpha2).
Let r3 := r2 - (gamma+alpha2).
(** Non-underflow hypotheses *)
(** theorems *)
Lemma ErrFMA_bounded: format r1 /\ format r2 /\ format r3.
Proof with auto with typeclass_instances.
split.
apply generic_format_round...
split.
apply generic_format_round...
apply plus_error...
apply generic_format_round...
apply plus_error...
apply mult_error_FLT...
admit. (* underflow *)
Qed.
Lemma ErrFMA_correct:
r1+r2+r3 = a*x+y.
Proof with auto with typeclass_instances.
destruct (format_is_pff_format (make_bound emin prec) _ _ _ r1).
apply sym_eq; apply FmaErr_Even.
Admitted.
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