This is about twice as fast as the current hash, and removes the
need for double hashing (improving locality of reference). The
hash function is based on Bob Jenkins' design, slightly adapted
wherever Make needs to hash NUL-terminated strings. The old hash
function is kept for case-insensitive hashing.
This saves 8.5% on QEMU's no-op build (from 12.87s to 11.78s).
* configure.ac: Check endianness.
* hash.c (rol32, jhash_mix, jhash_final, JHASH_INITVAL,
sum_get_unaligned_32, jhash): New.
* hash.h (STRING_HASH_1, STRING_N_HASH_1): Use jhash.
(STRING_HASH_2, STRING_N_HASH_2): Return a dummy value.
(STRING_N_COMPARE, return_STRING_N_COMPARE): Prefer memcmp to strncmp.
GNU make. Also he provides some other performance fixups after doing
some profiling of make on large makefiles.
Modify the test suite to allow the use of Valgrind to find memory problems.
* Define COFLAGS to avoid unknown variable warning.
* Fix some usec problems on UnixWare.
* Don't remove .INTERMEDIATE targets specified on the command line.
