Jochen,
your timings:
Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz (SSE4)
21892 cycles for 100 * memchr scasb
3007 cycles for 100 * memchr SSE2 lps/hps
2690 cycles for 100 * memchr SSE2 nidud
2500 cycles for 100 * memchr SSE2 ups
21951 cycles for 100 * memchr scasb
2981 cycles for 100 * memchr SSE2 lps/hps
2721 cycles for 100 * memchr SSE2 nidud
6211 cycles for 100 * memchr SSE2 ups
21827 cycles for 100 * memchr scasb
3003 cycles for 100 * memchr SSE2 lps/hps
2510 cycles for 100 * memchr SSE2 nidud
2721 cycles for 100 * memchr SSE2 ups
36 bytes for memchr scasb
88 bytes for memchr SSE2 lps/hps
92 bytes for memchr SSE2 nidud
84 bytes for memchr SSE2 ups
--- ok ---
Gunther