mulredc[1..20].asm are size-specific asm functions for mulredc. These are generated by the Python autogen.py script (old version, still used for sizes 1 and 2) and the m4 script mulredc.m4 (all other sizes). In order to avoid dependency on the Python and m4 packages, this generation is not done automatically with the autoconf/automake stuff. If you need to regenerate them, the syntax is ./autogen.py 1 > mulredc1.asm ./autogen.py 2 > mulredc2.asm m4 -DLENGTH=3 mulredc.m4 > mulredc3.asm m4 -DLENGTH=4 mulredc.m4 > mulredc4.asm etc., up to LENGTH=20. If you have problems, you should reconfigure with the --disable-asm-redc option. test_mulredc.c, bench.c and the Makefile.dev are for development.