Definition in gmp-param.h

Torbjorn Granlund tg at
Wed Jan 2 18:01:45 CET 2013

Vy Bui <01bui at> writes:

  Dear all,
  I found these parameters were defined in gmp-mparam.h in
  #define DC_DIV_QR_THRESHOLD                 38
  #define DC_DIVAPPR_Q_THRESHOLD            77
  #define DC_BDIV_QR_THRESHOLD               54
  #define DC_BDIV_Q_THRESHOLD                 97
  I found they are different for different CPU types, they are the thresholds
  for division to choose the most efficient division algorithms. What these
  numbers mean?
It would be a long message if we were to explan these.  Please instead
grep through the sources to see how they are used.  That should give a
good idea of what each threshold parameter means.


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