l</code>,
     <code>__builtin_clzl</code> and <code>__builtin_popcountl</code> using
     the corresponding CIX <code>ct</code> instructions, and
     <code>__builtin_alpha_cmpbge</code>.  These should give GCC more
     information about scheduling etc than the <code>asm</code> blocks
     currently used in longlong.h and gmp-impl.h.
<li> Alpha Unicos: Apparently there's no <code>alloca</code> on this system,
     making <code>configure</code> choose the slower
     <code>malloc-reentrant</code> allocatio