The "Why" is @seppo010's to answer (but having it run as is on all OSs is a big plus for one). As for writing it in Assembler, that makes little practical sense since Redis is written in (ANSI) C and it quite well optimized. In fact, if you profile Redis you'll see that very little time is actually spent by the code itself - OS, storage and network are the real bottlenecks usually.
Comments
The "Why" is @seppo010's to answer (but having it run as is on all OSs is a big plus for one). As for writing it in Assembler, that makes little practical sense since Redis is written in (ANSI) C and it quite well optimized. In fact, if you profile Redis you'll see that very little time is actually spent by the code itself - OS, storage and network are the real bottlenecks usually.