[MPFR] Re: digits of Pi

[Torbjorn Granlund]

Paul Zimmermann <Paul.Zimmermann at loria.fr> writes:

  are you sure? Here are some timings:
  
  GMP 4.3.2:
  achille% ./speed -s 20000000 mpn_mul_n
  overhead 0.000000003 secs, precision 10000 units of 4.17e-10 secs, CPU freq 2400.00 MHz
              mpn_mul_n
  20000000   38.094209000
  
  GMP 5.0.0:
  achille% ./speed -s 20000000 mpn_mul_n
  overhead 0.000000003 secs, precision 10000 units of 4.17e-10 secs, CPU freq 2400.00 MHz
              mpn_mul_n
  20000000   42.456546000
  
I think this is due to that the FFT tables are shorter for the new
release.  I will address that in 5.0.1.

We no longer use the mpn_mul_fft_full function, but instead the new
faster mpn_fft_mul.  So as long as the tables for mpn_mul_fft (note that
mpn_fft_mul != mpn_mul_fft) are not exhausted, things should run perhaps
10% faster.

-- 
Torbjörn