776a97986d
use at as at and only compute difference when needed (to determine if there is a jump in binary) Easier to understand that way
46 lines
1.5 KiB
Ruby
46 lines
1.5 KiB
Ruby
module Risc
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module Position
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# Instructions are also a linked list, but their position is not really
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# the position of the object.
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# Rather it is the position of the assembled code in the binary.
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# (Luckily arm is sane, so this is realtively simple)
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#
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# Really we only need to calculate Positions at a jump, so between the
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# Jump and the label it jumps too. The other instructions are "just" fill.
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# But off course we need to propagate positions to get it right.
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#
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# Assembled instructions are kept in BinaryCode objects.
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# When propagating positions we have to see that the next position assembles into
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# the same BinaryCode, or else move it and the code along
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#
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class InstructionPosition < ObjectPosition
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attr_reader :instruction , :binary
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def initialize(instruction, pos , binary)
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raise "not set " unless binary
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super(pos, instruction)
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@instruction = instruction
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@binary = binary
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end
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def init(at)
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diff = at - Position.get(@binary).at
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if( diff % 60 == 13*4)
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@binary.extend_one unless @binary.next
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@binary = @binary.next
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raise "end of line " unless @binary
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at = Position.get(@binary).at + 3*4
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end
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return unless instruction.next
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at += instruction.byte_length
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Position.set(instruction.next, at , binary)
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end
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def reset_to(pos)
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super(pos)
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#puts "Reset (#{changed}) #{instruction}"
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init(pos)
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end
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end
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end
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end
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