Nice work! I don't find all implementations using "while" or "goto loop" surprising though.

"Now test if q̂ ≥ b or q̂·vₙ₋₂ > b·r̂ + uₙ₋₂; if so, decrease q̂ by 1, increase r̂ by vₙ₋₁, and repeat this test if r̂ < b."

That clearly a while loop. Lather, rinse, repeat.