2F992         ; mapped                 ; 52B3          # 3.1  CJK COMPATIBILITY IDEOGRAPH-2F992
2F993         ; mapped                 ; 82B1          # 3.1  CJK COMPATIBILITY IDEOGRAPH-2F993
2F994         ; mapped                 ; 82B3          # 3.1  CJK COMPATIBILITY IDEOGRAPH-2F994
2F995         ; mapped                 ; 82BD          # 3.1  CJK COMPATIBILITY IDEOGRAPH-2F995

b.l4 // Limb multiplication works like pen-and-paper columnar multiplication, but // with 51-bit limbs instead of digits. // // a4 a3 a2 a1 a0 x // b4 b3 b2 b1 b0 = // ---------- // a4b0 a3b0 a2b0 a1b0 a0b0 + // a4b1 a3b1 a2b1 a1b1 a0b1 + // a4b2 a3b2 a2b2 a1b2 a0b2 + // a4b3 a3b3 a2b3 a1b3 a0b3 + // a4b4 a3b4 a2b4 a1b4 a0b4 = // ---------- // r8 r7 r6 r5 r4 r3 r2 r1 r0 // // We can then use the reduction identity (a * 2²⁵⁵ + b = a * 19 + b) to // reduce the limbs that would overflow 255 bits. r5 * 2²⁵⁵...