44 lines
1001 B
Plaintext
44 lines
1001 B
Plaintext
(*
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* Copyright 2020, Data61, CSIRO (ABN 41 687 119 230)
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*)
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section "32-Bit Machine Word Setup"
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theory Word_Setup_32
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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 = 32
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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 = 2"
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definition word_size :: "'a :: numeral"
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where
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"word_size = 4"
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lemma word_bits_conv[code]:
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"word_bits = 32"
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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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