On Tue, May 30, 2017 at 05:13:46PM -0700, Ali Çehreli via Digitalmars-d-learn wrote: [...] > I could not make the D program come close to wc's performance when the > data was piped from stdin. [...]
Hmm. This is a particularly interesting case, because I adapted some of my algorithms to handle reading from stdin (i.e., std.mmfile is not an option), and I could not get it to reach wc's performance! I even installed ldc just to see if that made a difference... it was somewhat faster than gdc, but still, the timings were about twice as slow as wc. I did some digging around, and it seems that wc is using glibc's memchr, which is highly-optimized, whereas std.algorithm.count just uses a simplistic loop. Which is strange, because I'm pretty sure somebody optimized std.algorithm some time ago to use memchr() instead of a loop when searching for a byte value in an array. Whatever happened to that?? T -- Sometimes the best solution to morale problems is just to fire all of the unhappy people. -- despair.com
