.text
.org 0x20
STEV1:  .hword -10
STEV2:  .byte 0x64
STEV3:  .byte -2
.align
.global _start
_START:
  adr r0, STEV2
  ldrsb r2, [r0]

  adr r0, STEV3
  ldrsb r3, [r0]

  add r2, r2, r3

  adr r0, STEV1
  ldrsh r1, [r0]

  sub r1, r2, r1

  strh r1, [r0]
END:
  b end