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removed arm and use as gem

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Torsten Ruger
2015-07-18 14:12:20 +03:00
parent bae476657a
commit f4f703975b
32 changed files with 10 additions and 1452 deletions
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92
lib/arm/instructions/call_instruction.rb
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@ -1,92 +0,0 @@
module Arm
# There are only three call instructions in arm branch (b), call (bl) and syscall (swi)
# A branch could be called a jump as it has no notion of returning
# The pc is put into the link register to make a return possible
# a return is affected by moving the stored link register into the pc, effectively a branch
# swi (SoftWareInterrupt) or system call is how we call the kernel.
# in Arm the register layout is different and so we have to place the syscall code into register 7
# Registers 0-6 hold the call values as for a normal c call
class CallInstruction < Instruction
include Arm::Constants
def initialize(first, attributes)
super(attributes)
raise "no target" if first.nil?
@first = first
opcode = @attributes[:opcode].to_s
if opcode.length == 3 and opcode[0] == "b"
@attributes[:condition_code] = opcode[1,2].to_sym
@attributes[:opcode] = :b
end
if opcode.length == 6 and opcode[0] == "c"
@attributes[:condition_code] = opcode[4,2].to_sym
@attributes[:opcode] = :call
end
@attributes[:update_status] = 0
@attributes[:condition_code] = :al if @attributes[:condition_code] == nil
end
def assemble(io)
case @attributes[:opcode]
when :b, :call
arg = @first
if arg.is_a?(Virtual::Block) or arg.is_a?(Parfait::Method)
#relative addressing for jumps/calls
# but because of the arm "theoretical" 3- stage pipeline,
# we have to subtract 2 words (fetch/decode)
if(arg.is_a? Virtual::Block)
diff = arg.position - self.position - 8
else
# But, for methods, this happens to be the size of the object header,
# so there it balances out, but not blocks
# have to use the code, not the mthod object for methods
diff = arg.code.position - self.position
end
arg = diff
end
if (arg.is_a?(Numeric))
jmp_val = arg >> 2
packed = [jmp_val].pack('l')
# signed 32-bit, condense to 24-bit
# TODO add check that the value fits into 24 bits
io << packed[0,3]
else
raise "else not coded arg =\n#{arg.to_s[0..1000]}: #{inspect[0..1000]}"
end
io.write_uint8 op_bit_code | (COND_CODES[@attributes[:condition_code]] << 4)
when :swi
arg = @first
if (arg.is_a?(Numeric))
packed = [arg].pack('L')[0,3]
io << packed
io.write_uint8 0b1111 | (COND_CODES[@attributes[:condition_code]] << 4)
else
raise "invalid operand argument expected literal not #{arg} #{inspect}"
end
else
raise "Should not be the case #{inspect}"
end
end
def uses
if opcode == :call
@first.args.collect {|arg| arg.register }
else
[]
end
end
def assigns
if opcode == :call
[RegisterReference.new(RegisterMachine.instance.return_register)]
else
[]
end
end
def to_s
"#{opcode} #{@first} #{super}"
end
end
end