48 lines
1.1 KiB
Plaintext
48 lines
1.1 KiB
Plaintext
(*
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* Copyright 2014, NICTA
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*
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* This software may be distributed and modified according to the terms of
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* the BSD 2-Clause license. Note that NO WARRANTY is provided.
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* See "LICENSE_BSD2.txt" for details.
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*
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* @TAG(NICTA_BSD)
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*)
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section "64-Bit Machine Word Setup"
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theory Word_Setup_64
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imports Word_Enum
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begin
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text \<open>This theory defines standard platform-specific word size and alignment.\<close>
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type_synonym machine_word_len = 64
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type_synonym machine_word = "machine_word_len word"
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definition word_bits :: nat
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where
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"word_bits = LENGTH(machine_word_len)"
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text \<open>The following two are numerals so they can be used as nats and words.\<close>
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definition word_size_bits :: "'a :: numeral"
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where
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"word_size_bits = 3"
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definition word_size :: "'a :: numeral"
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where
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"word_size = 8"
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lemma word_bits_conv[code]:
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"word_bits = 64"
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unfolding word_bits_def by simp
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lemma word_size_word_size_bits:
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"(word_size::nat) = 2 ^ word_size_bits"
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unfolding word_size_def word_size_bits_def by simp
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lemma word_bits_word_size_conv:
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"word_bits = word_size * 8"
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unfolding word_bits_def word_size_def by simp
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end
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