--- /dev/null
+(**************************************************************************)
+(* ___ *)
+(* ||M|| *)
+(* ||A|| A project by Andrea Asperti *)
+(* ||T|| *)
+(* ||I|| Developers: *)
+(* ||T|| The HELM team. *)
+(* ||A|| http://helm.cs.unibo.it *)
+(* \ / *)
+(* \ / This file is distributed under the terms of the *)
+(* v GNU General Public License Version 2 *)
+(* *)
+(**************************************************************************)
+
+(* ********************************************************************** *)
+(* *)
+(* Sviluppato da: *)
+(* Cosimo Oliboni, oliboni@cs.unibo.it *)
+(* *)
+(* ********************************************************************** *)
+
+include "freescale/word16.ma".
+
+(* *********************** *)
+(* DEFINIZIONE DELLE DWORD *)
+(* *********************** *)
+
+record word32 : Type ≝
+ {
+ w32h: word16;
+ w32l: word16
+ }.
+
+(* \langle \rangle *)
+notation "〈x.y〉" non associative with precedence 80
+ for @{ 'mk_word32 $x $y }.
+interpretation "mk_word32" 'mk_word32 x y = (mk_word32 x y).
+
+(* operatore = *)
+definition eq_w32 ≝ λw1,w2.(eq_w16 (w32h w1) (w32h w2)) ⊗ (eq_w16 (w32l w1) (w32l w2)).
+
+(* operatore < *)
+definition lt_w32 ≝
+λw1,w2:word32.match lt_w16 (w32h w1) (w32h w2) with
+ [ true ⇒ true
+ | false ⇒ match gt_w16 (w32h w1) (w32h w2) with
+ [ true ⇒ false
+ | false ⇒ lt_w16 (w32l w1) (w32l w2) ]].
+
+(* operatore ≤ *)
+definition le_w32 ≝ λw1,w2:word32.(eq_w32 w1 w2) ⊕ (lt_w32 w1 w2).
+
+(* operatore > *)
+definition gt_w32 ≝ λw1,w2:word32.⊖ (le_w32 w1 w2).
+
+(* operatore ≥ *)
+definition ge_w32 ≝ λw1,w2:word32.⊖ (lt_w32 w1 w2).
+
+(* operatore and *)
+definition and_w32 ≝
+λw1,w2:word32.mk_word32 (and_w16 (w32h w1) (w32h w2)) (and_w16 (w32l w1) (w32l w2)).
+
+(* operatore or *)
+definition or_w32 ≝
+λw1,w2:word32.mk_word32 (or_w16 (w32h w1) (w32h w2)) (or_w16 (w32l w1) (w32l w2)).
+
+(* operatore xor *)
+definition xor_w32 ≝
+λw1,w2:word32.mk_word32 (xor_w16 (w32h w1) (w32h w2)) (xor_w16 (w32l w1) (w32l w2)).
+
+(* operatore rotazione destra con carry *)
+definition rcr_w32 ≝
+λw:word32.λc:bool.match rcr_w16 (w32h w) c with
+ [ pair wh' c' ⇒ match rcr_w16 (w32l w) c' with
+ [ pair wl' c'' ⇒ pair ?? (mk_word32 wh' wl') c'' ]].
+
+(* operatore shift destro *)
+definition shr_w32 ≝
+λw:word32.match rcr_w16 (w32h w) false with
+ [ pair wh' c' ⇒ match rcr_w16 (w32l w) c' with
+ [ pair wl' c'' ⇒ pair ?? (mk_word32 wh' wl') c'' ]].
+
+(* operatore rotazione destra *)
+definition ror_w32 ≝
+λw:word32.match rcr_w16 (w32h w) false with
+ [ pair wh' c' ⇒ match rcr_w16 (w32l w) c' with
+ [ pair wl' c'' ⇒ match c'' with
+ [ true ⇒ mk_word32 (or_w16 (mk_word16 (mk_byte8 x8 x0) (mk_byte8 x0 x0)) wh') wl'
+ | false ⇒ mk_word32 wh' wl' ]]].
+
+(* operatore rotazione destra n-volte *)
+let rec ror_w32_n (w:word32) (n:nat) on n ≝
+ match n with
+ [ O ⇒ w
+ | S n' ⇒ ror_w32_n (ror_w32 w) n' ].
+
+(* operatore rotazione sinistra con carry *)
+definition rcl_w32 ≝
+λw:word32.λc:bool.match rcl_w16 (w32l w) c with
+ [ pair wl' c' ⇒ match rcl_w16 (w32h w) c' with
+ [ pair wh' c'' ⇒ pair ?? (mk_word32 wh' wl') c'' ]].
+
+(* operatore shift sinistro *)
+definition shl_w32 ≝
+λw:word32.match rcl_w16 (w32l w) false with
+ [ pair wl' c' ⇒ match rcl_w16 (w32h w) c' with
+ [ pair wh' c'' ⇒ pair ?? (mk_word32 wh' wl') c'' ]].
+
+(* operatore rotazione sinistra *)
+definition rol_w32 ≝
+λw:word32.match rcl_w16 (w32l w) false with
+ [ pair wl' c' ⇒ match rcl_w16 (w32h w) c' with
+ [ pair wh' c'' ⇒ match c'' with
+ [ true ⇒ mk_word32 wh' (or_w16 (mk_word16 (mk_byte8 x0 x0) (mk_byte8 x0 x1)) wl')
+ | false ⇒ mk_word32 wh' wl' ]]].
+
+(* operatore rotazione sinistra n-volte *)
+let rec rol_w32_n (w:word32) (n:nat) on n ≝
+ match n with
+ [ O ⇒ w
+ | S n' ⇒ rol_w32_n (rol_w32 w) n' ].
+
+(* operatore not/complemento a 1 *)
+definition not_w32 ≝
+λw:word32.mk_word32 (not_w16 (w32h w)) (not_w16 (w32l w)).
+
+(* operatore somma con carry *)
+definition plus_w32 ≝
+λw1,w2:word32.λc:bool.
+ match plus_w16 (w32l w1) (w32l w2) c with
+ [ pair l c' ⇒ match plus_w16 (w32h w1) (w32h w2) c' with
+ [ pair h c'' ⇒ pair ?? (mk_word32 h l) c'' ]].
+
+(* operatore somma senza carry *)
+definition plus_w32nc ≝
+λw1,w2:word32.fst ?? (plus_w32 w1 w2 false).
+
+(* operatore carry della somma *)
+definition plus_w32c ≝
+λw1,w2:word32.snd ?? (plus_w32 w1 w2 false).
+
+(* operatore Most Significant Bit *)
+definition MSB_w32 ≝ λw:word32.eq_ex x8 (and_ex x8 (b8h (w16h (w32h w)))).
+
+(* word → naturali *)
+definition nat_of_word32 ≝ λw:word32. (256 * 256 * (w32h w)) + (nat_of_word16 (w32l w)).
+
+coercion nat_of_word32.
+
+(* naturali → word *)
+definition word32_of_nat ≝
+ λn.mk_word32 (word16_of_nat (n / (256*256))) (word16_of_nat n).
+
+(* operatore predecessore *)
+definition pred_w32 ≝
+λw:word32.match eq_w16 (w32l w) (mk_word16 (mk_byte8 x0 x0) (mk_byte8 x0 x0)) with
+ [ true ⇒ mk_word32 (pred_w16 (w32h w)) (pred_w16 (w32l w))
+ | false ⇒ mk_word32 (w32h w) (pred_w16 (w32l w)) ].
+
+(* operatore successore *)
+definition succ_w32 ≝
+λw:word32.match eq_w16 (w32l w) (mk_word16 (mk_byte8 xF xF) (mk_byte8 xF xF)) with
+ [ true ⇒ mk_word32 (succ_w16 (w32h w)) (succ_w16 (w32l w))
+ | false ⇒ mk_word32 (w32h w) (succ_w16 (w32l w)) ].
+
+(* operatore neg/complemento a 2 *)
+definition compl_w32 ≝
+λw:word32.match MSB_w32 w with
+ [ true ⇒ succ_w32 (not_w32 w)
+ | false ⇒ not_w32 (pred_w32 w) ].
+
+(*
+ operatore moltiplicazione senza segno: b*b=[0x00000000,0xFFFE0001]
+ ... in pratica (〈a:b〉*〈c:d〉) = (a*c)<<16+(a*d)<<8+(b*c)<<8+(b*d)
+*)
+definition mul_w16 ≝
+λb1,b2:word16.match b1 with
+[ mk_word16 b1h b1l ⇒ match b2 with
+[ mk_word16 b2h b2l ⇒ match mul_b8 b1l b2l with
+[ mk_word16 t1_h t1_l ⇒ match mul_b8 b1h b2l with
+[ mk_word16 t2_h t2_l ⇒ match mul_b8 b2h b1l with
+[ mk_word16 t3_h t3_l ⇒ match mul_b8 b1h b2h with
+[ mk_word16 t4_h t4_l ⇒
+ plus_w32nc
+ (plus_w32nc
+ (plus_w32nc 〈〈t4_h:t4_l〉.〈〈x0,x0〉:〈x0,x0〉〉〉 〈〈〈x0,x0〉:t3_h〉.〈t3_l:〈x0,x0〉〉〉) 〈〈〈x0,x0〉:t2_h〉.〈t2_l:〈x0,x0〉〉〉)〈〈〈x0,x0〉:〈x0,x0〉〉.〈t1_h:t1_l〉〉
+]]]]]].
+
+(* divisione senza segno (secondo la logica delle ALU): (quoziente resto) overflow *)
+definition div_w16 ≝
+λw:word32.λb:word16.match eq_w16 b 〈〈x0,x0〉:〈x0,x0〉〉 with
+(*
+ la combinazione n/0 e' illegale, segnala solo overflow senza dare risultato
+*)
+ [ true ⇒ tripleT ??? 〈〈xF,xF〉:〈xF,xF〉〉 (w32l w) true
+ | false ⇒ match eq_w32 w 〈〈〈x0,x0〉:〈x0,x0〉〉.〈〈x0,x0〉:〈x0,x0〉〉〉 with
+(* 0 diviso qualsiasi cosa diverso da 0 da' q=0 r=0 o=false *)
+ [ true ⇒ tripleT ??? 〈〈x0,x0〉:〈x0,x0〉〉 〈〈x0,x0〉:〈x0,x0〉〉 false
+(* 1) e' una divisione sensata che produrra' overflow/risultato *)
+(* 2) parametri: dividendo, divisore, moltiplicatore, quoziente, contatore *)
+(* 3) ad ogni ciclo il divisore e il moltiplicatore vengono scalati di 1 a dx *)
+(* 4) il moltiplicatore e' la quantita' aggiunta al quoziente se il divisore *)
+(* puo' essere sottratto al dividendo *)
+ | false ⇒ let rec aux (divd:word32) (divs:word32) (molt:word16) (q:word16) (c:nat) on c ≝
+ let w' ≝ plus_w32nc divd (compl_w32 divs) in
+ match c with
+ [ O ⇒ match le_w32 divs divd with
+ [ true ⇒ tripleT ??? (or_w16 molt q) (w32l w') (⊖ (eq_w16 (w32h w') 〈〈x0,x0〉:〈x0,x0〉〉))
+ | false ⇒ tripleT ??? q (w32l divd) (⊖ (eq_w16 (w32h divd) 〈〈x0,x0〉:〈x0,x0〉〉)) ]
+ | S c' ⇒ match le_w32 divs divd with
+ [ true ⇒ aux w' (ror_w32 divs) (ror_w16 molt) (or_w16 molt q) c'
+ | false ⇒ aux divd (ror_w32 divs) (ror_w16 molt) q c' ]]
+ in aux w (rol_w32_n 〈〈〈x0,x0〉:〈x0,x0〉〉.b〉 15) 〈〈x8,x0〉:〈x0,x0〉〉 〈〈x0,x0〉:〈x0,x0〉〉 15 ]].
+
+(* operatore x in [inf,sup] *)
+definition in_range ≝
+λx,inf,sup:word32.(le_w32 inf sup) ⊗ (ge_w32 x inf) ⊗ (le_w32 x sup).
+
+(* iteratore sulle word *)
+definition forall_word32 ≝
+ λP.
+ forall_word16 (λbh.
+ forall_word16 (λbl.
+ P (mk_word32 bh bl ))).
projects / helm.git / blobdiff