46 lines
1.3 KiB
Ruby
46 lines
1.3 KiB
Ruby
module Asm
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# ADDRESSING MODE 4
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class StackBuilder
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include Asm::InstructionTools
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def initialize(pre_post, up_down, write, store_load)
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@cond = 0b1110
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@inst_class = Asm::Instruction::OPC_STACK
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@pre_post_index = 0
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@up_down = 0
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@s = 0
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@write_base = 0
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@store_load = 0
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@rn = 0
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@operand = 0
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@pre_post_index = pre_post
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@up_down = up_down
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@write_base = write
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@store_load = store_load
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end
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attr_accessor :cond, :inst_class, :pre_post_index, :up_down,
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:s, :write_base, :store_load, :rn, :operand
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# Build representation for source value
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def build_operand(arg)
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if (arg.is_a?(Array))
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@operand = 0
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arg.each do |reg |
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reg = reg_ref(reg)
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@operand |= (1 << reg)
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end
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else
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raise Asm::AssemblyError.new("invalid operand argument #{arg.inspect}")
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end
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end
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def assemble(io, as)
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val = operand | (rn << 16) | (store_load << 16+4) |
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(write_base << 16+4+1) | (s << 16+4+1+1) | (up_down << 16+4+1+1+1) |
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(pre_post_index << 16+4+1+1+1+1) | (inst_class << 16+4+1+1+1+1+2) |
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(cond << 16+4+1+1+1+1+2+2)
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io.write_uint32 val
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end
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end
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end
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