Deceptive comment in toom33_mul.c

[Itai Bar-Natan]

This isn't really a bug, but I don't know where else to report it. In
the beginning of mpn/generic/toom33_mul.c, the following diagram is
shown to illustrate the subdivision of the arguments:

  <-s--><--n--><--n--><--n-->
   ____ ______ ______ ______
  |_a3_|___a2_|___a1_|___a0_|
   |b3_|___b2_|___b1_|___b0_|
   <-t-><--n--><--n--><--n-->

However, this is the subdivision used for the Toom-4 algorithm, not the
Toom-3 algorithm. The proper diagram would be

  <-s--><--n--><--n-->
   ____ ______ ______
  |_a2_|___a1_|___a0_|
   |b2_|___b1_|___b0_|
   <-t-><--n--><--n-->