Changeset 2999 for src/ASM/Fetch.ma

Timestamp:

Mar 28, 2013, 12:47:55 PM (8 years ago)

Author:

sacerdot

Message:

code_memory added to labelled_object_code to avoid recomputing it every time.
This gives a major speed up in the semantics of the extracted code.

File:

• src/ASM/Fetch.ma (modified) (1 diff)

src/ASM/Fetch.ma

@@ -173 +173 @@
 definition code_memory_size ≝ bitvector_max_nat 16.
 
-include alias "ASM/BitVectorTrie.ma".
-include alias "ASM/Arithmetic.ma".
-
-definition next: BitVectorTrie Byte 16 → ∀program_counter: Word. Word × Byte ≝
-  λpmem: BitVectorTrie Byte 16.
-  λpc: Word.
-    〈add … pc (bitvector_of_nat 16 1), lookup … pc pmem (zero …)〉.
-
-definition load_code_memory0:
- ∀program: object_code. Σres: BitVectorTrie Byte 16.
-  let program_size ≝ |program| in
-   program_size ≤ 2^16 →
-    ∀pc. ∀pc_ok: pc < program_size.
-     nth_safe ? pc program pc_ok = \snd (next res (bitvector_of_nat … pc))
-≝
- λprogram. \snd
-  (foldl_strong ?
-   (λprefix.
-     Σres: nat × (BitVectorTrie Byte 16).
-      let 〈i,mem〉 ≝ res in
-      i = |prefix| ∧
-      (i ≤ 2^16 →
-        ∀pc. ∀pc_ok: pc < |prefix|.
-         nth_safe ? pc prefix pc_ok = \snd (next mem (bitvector_of_nat … pc))))
-   program 
-   (λprefix,v,tl,prf,i_mem.
-     let 〈i,mem〉 ≝ i_mem in
-      〈S i,insert … (bitvector_of_nat … i) v mem〉)
-  〈0,Stub Byte 16〉).
-[3: cases (foldl_strong ? (λprefix.Σres.?) ???) * #i #mem * #H1 >H1 #H2 @H2
-| % // #_ #pc #abs @⊥ @(absurd … abs (not_le_Sn_O …))
-| cases i_mem in p; * #i' #mem' #H #EQ destruct(EQ) cases H -H #H1 #H2 %
-  [ >length_append >H1 normalize //
-  | #LE #pc #pc_ok
-    cases (le_to_or_lt_eq … pc_ok)
-    [2: #EQ_Spc >(?: pc = |prefix| + 0) in pc_ok;
-      [2: >length_append in EQ_Spc; normalize #EQ @injective_S >EQ //]
-      #pc_ok <nth_safe_prepend [2: //] whd in ⊢ (??%?);
-      <H1 <plus_n_O whd in ⊢ (???%); //
-    | >length_append <plus_n_Sm <plus_n_O #LT <shift_nth_prefix [2: /2/]
-      >H2 [2: @(transitive_le … LE) //]
-      cut (pc ≠ i) [ >H1 @lt_to_not_eq @lt_S_S_to_lt //] #NEQ
-      whd in ⊢ (??%%); @sym_eq @lookup_insert_miss >eq_bv_false %
-      #EQ @(absurd ?? NEQ) @(eq_bitvector_of_nat_to_eq … EQ) try assumption
-      @(transitive_lt … LE) >H1 @lt_S_S_to_lt //]]
-qed.
-
-definition load_code_memory: object_code → BitVectorTrie Byte 16 ≝
- λprogram.load_code_memory0 program.
-
-lemma load_code_memory_ok:
- ∀program: object_code.
-  let program_size ≝ |program| in
-   program_size ≤ 2^16 →
-    ∀pc. ∀pc_ok: pc < program_size.
-     nth_safe ? pc program pc_ok = \snd (next (load_code_memory program) (bitvector_of_nat … pc)).
-whd in match load_code_memory; normalize nodelta #program @pi2
-qed.
-
 lemma Prod_inv_rect_Type0:
  ∀A,B. ∀P: A × B → Type[0].∀ab.