There seems to be a discrepancy in the 4.2.2 manual, section 2.6: <div style="margin-left: 40px;">For example, <div style="margin-left: 40px;">cd tune make tuneup ./tuneup </div></div>A brief read through tune/Makefile however appears to show only the target "tune" and not "tuneup", which is also stated in tune/README. Additionally, tuneup fails to build. This could be a bug. I am building from MSYS in Windows XP: <div style="margin-left: 40px;">$ gcc --version gcc.exe (GCC) 3.4.5 (mingw special) [...] $ make --version GNU Make version 3.79.1, by Richard Stallman and Roland McGrath. Built for i686-pc-msys [...] $ sh --version GNU bash, version 2.04.0(1)-release (i686-pc-msys) $ configure --enable-cxx [...] $ make [...] $ make check [...] $ cd tune $ make tune [...] gcc -DHAVE_CONFIG_H -I. -I. -I.. -I.. -I../tests -m32 -O2 -fomit-frame-pointer -mtune=k8 -march=k8 -mno-cygwin -c set_strs.c -o set_strs.o /bin/sh ../libtool --mode=compile gcc -DHAVE_CONFIG_H -I. -I. -I.. -I.. -I../tests    -m32 -O2 -fomit-frame-pointer -mtune=k8 -march=k8 -mno-cygwin -c -o time.lo time.c gcc -DHAVE_CONFIG_H -I. -I. -I.. -I.. -I../tests -m32 -O2 -fomit-frame-pointer -mtune=k8 -march=k8 -mno-cygwin -c time.c -o time.o time.c: In function `getrusage_backwards_p': time.c:650: error: storage size of 'start' isn't known time.c:650: error: storage size of 'prev' isn't known time.c:650: error: storage size of 'next' isn't known make[1]: *** [time.lo] Error 1 make[1]: Leaving directory `/d/c++/gmp/gmp-4.2.2 /tune' make: *** [tune] Error 2 </div> -- Jafet