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# vim: set filetype=ruby:
# Multiplication: C = A * B, A >= 0 and B >= 0
register.A = 3
register.B = 7
# Save A in T
label(SaveA) { decrement A, MoveS1, IncT }
label(IncT) { increment T, IncS1 }
label(IncS1) { increment S, SaveA }
label(MoveS1) { decrement S, SaveB, IncA1 }
label(IncA1) { increment A, MoveS1 }
# Save B in U
label(SaveB) { decrement B, MoveS2, IncU }
label(IncU) { increment U, IncS2 }
label(IncS2) { increment S, SaveB }
label(MoveS2) { decrement S, Mul, IncB1 }
label(IncB1) { increment B, MoveS2 }
# Multiply A * B
label(Mul) { decrement A, MoveT, DecB }
# Add B to C
label(DecB) { decrement B, MoveU, IncC }
label(IncC) { increment C, DecB }
# Move U back to B
label(MoveU) { decrement U, SaveB, IncB2 }
label(IncB2) { increment B, MoveU }
# Move T back to A
label(MoveT) { decrement T, ClearU, IncA2 }
label(IncA2) { increment A, MoveT }
# Clear U
label(ClearU) { decrement U, Stop, ClearU }
# Stop
label(Stop) { halt }
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