rubyx/lib/arm/instructions/memory_instruction.rb
Torsten Ruger a46b2d5c56 update to use parfait not virtual
more ripples
reverting to integers (not virtual::integer)
2015-05-29 12:33:40 +03:00

113 lines
4.1 KiB
Ruby

module Arm
# ADDRESSING MODE 2
# Implemented: immediate offset with offset=0
class MemoryInstruction < Instruction
include Arm::Constants
def initialize result , left , right = nil , attributes = {}
super(attributes)
@result = result
@left = left
@right = right
@attributes[:update_status] = 0 if @attributes[:update_status] == nil
@attributes[:condition_code] = :al if @attributes[:condition_code] == nil
@operand = 0
raise "alert" if right.is_a? Virtual::Block
@pre_post_index = 0 #P flag
@add_offset = 0 #U flag
@is_load = opcode.to_s[0] == "l" ? 1 : 0 #L (load) flag
end
def assemble(io )
# don't overwrite instance variables, to make assembly repeatable
rn = @rn
operand = @operand
add_offset = @add_offset
arg = @left
arg = arg.symbol if( arg.is_a? ::Register::RegisterReference )
#str / ldr are _serious instructions. With BIG possibilities not half are implemented
if (arg.is_a?(Symbol) or arg.is_a?(::Register::RegisterReference)) #symbol is register
rn = arg
if @right
operand = @right
#TODO better test, this operand integer (register) does not work. but sleep first
operand = operand.symbol if operand.is_a? ::Register::RegisterReference
unless( operand.is_a? Symbol)
#puts "operand #{operand.inspect}"
if (operand < 0)
add_offset = 0
#TODO test/check/understand
operand *= -1
else
add_offset = 1
end
if (@operand.abs > 4095)
raise "reference offset too large/small (max 4095) #{arg} #{inspect}"
end
end
end
elsif (arg.is_a?(Parfait::Object) ) #use pc relative
rn = :pc
operand = arg.position - self.position - 8 #stringtable is after code
add_offset = 1
if (operand.abs > 4095)
raise "reference offset too large/small (max 4095) #{arg} #{inspect}"
end
elsif( arg.is_a?(Numeric) )
#TODO untested brach, probably not working
raise "is this working ?? #{arg} #{inspect}"
@pre_post_index = 1
@rn = pc
@use_addrtable_reloc = true
@addrtable_reloc_target = arg
else
raise "invalid operand argument #{arg.inspect} #{inspect}"
end
#not sure about these 2 constants. They produce the correct output for str r0 , r1
# but i can't help thinking that that is because they are not used in that instruction and
# so it doesn't matter. Will see
add_offset = 1
# TODO to be continued
add_offset = 0 if @attributes[:add_offset]
@pre_post_index = 1
@pre_post_index = 0 if @attributes[:flaggie]
w = 0 #W flag
byte_access = opcode.to_s[-1] == "b" ? 1 : 0 #B (byte) flag
instuction_class = 0b01 # OPC_MEMORY_ACCESS
if (operand.is_a?(Symbol) or operand.is_a?(::Register::RegisterReference))
val = reg_code(operand)
@pre_post_index = 0
i = 1 # not quite sure about this, but it gives the output of as. read read read.
else
i = 0 #I flag (third bit)
val = operand
end
val = shift(val , 0 ) # for the test
val |= shift(reg_code(@result) , 12 )
val |= shift(reg_code(rn) , 12+4) #16
val |= shift(@is_load , 12+4 +4)
val |= shift(w , 12+4 +4+1)
val |= shift(byte_access , 12+4 +4+1+1)
val |= shift(add_offset , 12+4 +4+1+1+1)
val |= shift(@pre_post_index, 12+4 +4+1+1+1+1)#24
val |= shift(i , 12+4 +4+1+1+1+1 +1)
val |= shift(instuction_class,12+4 +4+1+1+1+1 +1+1)
val |= shift(cond_bit_code , 12+4 +4+1+1+1+1 +1+1+2)
io.write_uint32 val
end
def shift val , by
raise "Not integer #{val}:#{val.class} #{inspect}" unless val.is_a? Fixnum
val << by
end
def uses
ret = [@left.register ]
ret << @right.register unless @right.nil?
ret
end
def assigns
[@result.register]
end
end
end