Commit b841d0a5 authored by Guillaume Melquiond's avatar Guillaume Melquiond
Browse files

Use Zfast_div_eucl.

parent 98ed6236
......@@ -1427,7 +1427,7 @@ Definition Fdiv_core_binary m1 e1 m2 e2 :=
| Zpos p => (m1 * Zpower_pos 2 p, e + Zneg p)%Z
| _ => (m1, e)
end in
let '(q, r) := Zdiv_eucl m m2 in
let '(q, r) := Zfast_div_eucl m m2 in
(q, e', new_location m2 r loc_Exact).
Lemma Bdiv_correct_aux :
......@@ -1449,7 +1449,6 @@ Lemma Bdiv_correct_aux :
intros m sx mx ex sy my ey.
replace (Fdiv_core_binary (Zpos mx) ex (Zpos my) ey) with (Fdiv_core radix2 prec (Zpos mx) ex (Zpos my) ey).
2: now unfold Fdiv_core_binary ; rewrite 2!Zdigits2_Zdigits.
refine (_ (Fdiv_core_correct radix2 prec (Zpos mx) ex (Zpos my) ey _ _ _)) ; try easy.
destruct (Fdiv_core radix2 prec (Zpos mx) ex (Zpos my) ey) as ((mz, ez), lz).
intros (Pz, Bz).
......@@ -1526,6 +1525,15 @@ now apply F2R_ge_0_compat.
apply Rlt_le.
apply Rinv_0_lt_compat.
now apply F2R_gt_0_compat.
unfold Fdiv_core_binary, Fdiv_core.
rewrite 2!Zdigits2_Zdigits.
change 2%Z with (radix_val radix2).
destruct (match (Zdigits radix2 (Z.pos my) + prec - Zdigits radix2 (Z.pos mx))%Z with
| 0%Z => (Z.pos mx, (ex - ey)%Z)
| Z.pos p => ((Z.pos mx * Z.pow_pos radix2 p)%Z, (ex - ey + Z.neg p)%Z)
| Z.neg _ => (Z.pos mx, (ex - ey)%Z)
end) as [m' e'].
now rewrite Zfast_div_eucl_correct.
Definition Bdiv div_nan m x y :=
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