lh-l4v/lib/Word_Lib_l4v/Machine_Word_64_Basics.thy

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(*
* Copyright 2014, NICTA
*
* SPDX-License-Identifier: BSD-2-Clause
*)
section \<open>64 bit standard platform-specific word size and alignment.\<close>
theory Machine_Word_64_Basics
imports "HOL-Library.Word" Word_64
begin
type_synonym machine_word_len = 64
definition word_bits :: nat
where
\<open>word_bits = LENGTH(machine_word_len)\<close>
lemma word_bits_conv [code]:
\<open>word_bits = 64\<close>
by (simp add: word_bits_def)
text \<open>The following two are numerals so they can be used as nats and words.\<close>
definition word_size_bits :: \<open>'a :: numeral\<close>
where
\<open>word_size_bits = 3\<close>
definition word_size :: \<open>'a :: numeral\<close>
where
\<open>word_size = 8\<close>
lemma n_less_word_bits:
"(n < word_bits) = (n < 64)"
by (simp add: word_bits_def word_size_def)
lemmas upper_bits_unset_is_l2p_64 = upper_bits_unset_is_l2p [where 'a=64, folded word_bits_def]
lemmas le_2p_upper_bits_64 = le_2p_upper_bits [where 'a=64, folded word_bits_def]
lemmas le2p_bits_unset_64 = le2p_bits_unset[where 'a=64, folded word_bits_def]
lemmas unat_power_lower64 [simp] = unat_power_lower64'[folded word_bits_def]
lemmas word64_less_sub_le[simp] = word64_less_sub_le' [folded word_bits_def]
lemmas word64_power_less_1[simp] = word64_power_less_1'[folded word_bits_def]
lemma of_nat64_0:
"\<lbrakk>of_nat n = (0::word64); n < 2 ^ word_bits\<rbrakk> \<Longrightarrow> n = 0"
by (erule of_nat_0, simp add: word_bits_def)
lemmas unat_of_nat64 = unat_of_nat64'[folded word_bits_def]
lemmas word_power_nonzero_64 = word_power_nonzero [where 'a=64, folded word_bits_def]
lemmas div_power_helper_64 = div_power_helper [where 'a=64, folded word_bits_def]
lemmas of_nat_less_pow_64 = of_nat_power [where 'a=64, folded word_bits_def]
lemmas unat_mask_word64 = unat_mask_word64'[folded word_bits_def]
end