41 lines
1.0 KiB
Ruby
41 lines
1.0 KiB
Ruby
module Risc
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# simulate memory during compile time.
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#
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# Memory comes in chunks, power of 2 chunks actually.
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#
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# Currently typed instance variables map to ruby instance variables and so do not
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# end up in memory. Memory being only for indexed word aligned access.
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#
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# Parfait really does everything else, apart from the internal_get/set
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# And our fake memory (other than hte previously used array, does bound check)
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class FakeMemory
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attr_reader :min
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def initialize(from , size)
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@min = from
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@memory = Array.new(size)
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raise "only multiples of 2 !#{size}" unless size == 2**(Math.log2(size).to_i)
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end
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def set(index , value)
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range_check(index)
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@memory[index] = value
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value
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end
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alias :[]= :set
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def get(index)
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range_check(index)
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@memory[index]
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end
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alias :[] :get
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def size
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@memory.length
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end
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def range_check(index)
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raise "index too low #{index} < #{min}" if index < min
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raise "index too big #{index} < #{min}" if index >= size
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end
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end
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end
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