Yesterday I commited a patch allows using GMP for bignum

computation in 32-bit sbcl on Intel/AMD processors.

To use it configure using '--with-gmp' option -- you must

have gmp installed (including C header files, that is devel

package), otherwise build will fail.

Actually, there a chance that the code will work on other

32-bit processors, but I have no way of testing on such

processors. Consequently, currently configure will

signal error if you try to use '--with-gmp' on something

other than 32-bit or 64-bit Intel/AMD processors.

Also '--with-gmp' will fail if you try to use different Lisp:

ECL and GCL already use GMP and currently using GMP

with Closure CL and Clisp is unsupported (I have code for

64-bit Closure CL on AMD64, but since number of users of

FriCAS on top of Closure CL seem to be low (0???), I did

not integrate that code in FriCAS build process).

BTW, updated timings for 10^6 digits of e:

native sbcl sbcl + GMP 5.0.1

32-bit 69s 1.35s

64-bit 15s 0.6

As you can see going to 64-bit gives substantial speedup

for arithmetic, which in practice may be more significant

than speedup due to use of GMP: GMP gives large speedup

for large numbers, but for smaller ones effect is smaller.

64-bit arithmetic gives speedups at almost all sizes:

huge speedup between 30 and 60 bits (due to use of fixnums

instead of bignums), small speedup for slightly more than

60 bits growing to about 4 when having about few hunded bits.

--

Waldek Hebisch

heb...@math.uni.wroc.pl