require_relative 'helper'

# try  to test that the generation of basic instructions works
# one instruction at a time, reverse testing from objdump --demangle -Sfghxp
# tests are named as per assembler code, ie test_mov testing mov instruction
#  adc add and bic eor orr rsb rsc sbc sub mov mvn cmn cmp teq tst b bl bx swi strb

class TestArmAsm < MiniTest::Test
  # need Assembler and a block (see those classes) 
  def setup
    @machine = Arm::ArmMachine.new
  end

  # code is what the generator spits out, at least one instruction worth (.first)
  # the op code is wat was witten as assembler in the first place and the binary result
  # is reversed and in 4 bytes as ruby can only do 31 bits and so we can't test with just one int (?)
  def assert_code code , op , should
    assert_equal op ,  code.opcode
    io = StringIO.new
    code.assemble(io)
    binary = io.string
    assert_equal 4 , binary.length
    index = 0
    binary.each_byte do |byte |
      assert_equal should[index] , byte , "byte #{index} 0x#{should[index].to_s(16)} != 0x#{byte.to_s(16)}"
      index += 1
    end
  end
  def test_adc
    code = @machine.adc	:left => :r1, :right => :r3, :extra => :r5
    assert_code code , :adc , [0x05,0x10,0xa3,0xe0] #e0 a3 10 05
  end
  def test_add
    code = @machine.add	:left => :r1 , :right => :r1, :extra => :r3
    assert_code code , :add , [0x03,0x10,0x81,0xe0] #e0 81 10 03
  end
  def test_and # inst eval doesn't really work with and
    code = @machine.and( :left => :r1 , :right => :r2 , :extra => :r3)
    assert_code code , :and , [0x03,0x10,0x02,0xe0] #e0 01 10 03
  end
  def test_b
    # the address is what an assembler calculates (a signed number for the amount of instructions), 
    # ie the relative (to pc) address -8 (pipeline) /4 so save space
    # so the cpu adds the value*4 and starts loading that (load, decode, execute)
    code = @machine.b	:left => -4  #this jumps to the next instruction
    assert_code code , :b , [0xff,0xff,0xff,0xea] #ea ff ff fe
  end
  def test_bl #see comment above. bx not implemented (as it means into thumb, and no thumb here)
    code = @machine.bl	:left => -4  #this jumps to the next instruction
    assert_code code , :bl , [0xff,0xff,0xff,0xeb] #ea ff ff fe
  end
  def test_bic
    code = @machine.bic	:left => :r2 , :right => :r2 , :extra => :r3
    assert_code code , :bic , [0x03,0x20,0xc2,0xe1] #e3 c2 20 44
  end
  def test_cmn
    code = @machine.cmn	:left => :r1 , :right => :r2
    assert_code code , :cmn , [0x02,0x00,0x71,0xe1] #e1 71 00 02
  end
  def test_cmp
    code = @machine.cmp	:left => :r1 , :right => :r2
    assert_code code , :cmp , [0x02,0x00,0x51,0xe1] #e1 51 00 02
  end
  def test_eor
    code = @machine.eor	:left => :r2 , :right => :r2 , :extra => :r3
    assert_code code , :eor , [0x03,0x20,0x22,0xe0] #e0 22 20 03
  end
  def test_ldr
    code = @machine.ldr :left => :r0, :right => :r0
    assert_code code, :ldr ,  [0x00,0x00,0x90,0xe5] #e5 90 00 00
  end
  def test_ldr2
    code = @machine.ldr :left => :r0, :right => :r0 , :offset =>  4
    assert_code code, :ldr ,  [0x04,0x00,0x90,0xe5] #e5 90 00 04
  end
  def test_ldrb
    code = @machine.ldrb :left => :r0, :right => :r0
    assert_code code, :ldrb ,  [0x00,0x00,0xd0,0xe5] #e5 d0 00 00
  end
  def test_orr
    code = @machine.orr	:left => :r2 , :right => :r2 , :extra => :r3
    assert_code code , :orr , [0x03,0x20,0x82,0xe1] #e1 82 20 03
  end
  def test_push
    code = @machine.push :regs => [:lr]
    assert_code code , :push ,  [0x00,0x40,0x2d,0xe9] #e9 2d 40 00
  end
  def test_pop
    code = @machine.pop	:regs => [:pc]
    assert_code code , :pop , [0x00,0x80,0xbd,0xe8] #e8 bd 80 00
  end
  def test_rsb
    code = @machine.rsb	:left => :r1 , :right => :r2 , :extra => :r3
    assert_code code , :rsb , [0x03,0x10,0x62,0xe0]#e0 62 10 03
  end
  def test_rsc
    code = @machine.rsc	:left => :r2 , :right => :r3 , :extra => :r4
    assert_code code , :rsc , [0x04,0x20,0xe3,0xe0]#e0 e3 20 04
  end
  def test_sbc
    code = @machine.sbc	:left => :r3, :right => :r4 , :extra => :r5
    assert_code code , :sbc , [0x05,0x30,0xc4,0xe0]#e0 c4 30 05
  end
  def test_str
    code = @machine.str :left => :r0, :right => :r0
    assert_code code, :str ,  [0x00,0x00,0x80,0xe5] #e5 81 00 00
  end
  def test_strb
    code = @machine.strb :left => :r0, :right => :r0
    assert_code code, :strb ,  [0x00,0x00,0xc0,0xe5] #e5 c0 00 00
  end
  def test_sub
    code = @machine.sub :left => :r2, :right => :r0, :extra => 1
    assert_code code, :sub ,  [0x01,0x20,0x40,0xe2] #e2 40 20 01 
  end
  def test_swi
    code = @machine.swi	:left => 0x05
    assert_code code , :swi , [0x05,0x00,0x00,0xef]#ef 00 00 05
  end
  def test_teq
    code = @machine.teq :left => :r1 , :right => :r2
    assert_code code , :teq , [0x02,0x00,0x31,0xe1] #e1 31 00 02
  end
  def test_tst
    code = @machine.tst :left => :r1 , :right => :r2
    assert_code code , :tst , [0x02,0x00,0x11,0xe1] #e1 11 00 02
  end
  def test_mov
    code = @machine.mov :left => :r0, :right => 5
    assert_code code , :mov , [0x05,0x00,0xa0,0xe3] #e3 a0 10 05
  end
  def test_mvn
    code = @machine.mvn :left => :r1, :right => 5
    assert_code code , :mvn , [0x05,0x10,0xe0,0xe3] #e3 e0 10 05
  end
end