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I've now committed the following change to the repository: 1998-11-06 Mikael Djurfeldt <mdj@barbara.nada.kth.se> * ports.h (SCM_CUC): #define as ~SCM_CRDY instead of 0x001fffffL. This is quite important since the latter clears the FPORT_READ_SAFE and FPORT_WRITE_SAFE flags causing flushes at every single character read... Mikael Djurfeldt <mdj@nada.kth.se> writes: > OK, found it: > > 1998-10-09 Jim Blandy <jimb@zwingli.cygnus.com> > > Do magic to mix reads and writes on stdio FILE-based ports. > (Thanks to Christian Lynbech.) > > [...] > > The former gives a startup speed of 4.68 on my Ultra. > The latter gives 0.86 s. I had planned to take the mix read/write code out of Guile because a slowdown of loading of more than 4 times is unacceptable. I had edited the code, written a NEWS entry explaining the workaround people should use when this code was removed and prepared a letter to send to the guile list. But then I got this feeling that something wasn't alright. I had noted earlier that the definition of SCM_CUC cleared the SAFE-flags, so I realized that the code didn't just slow down loading by 300 percent---it was also non-functional, I thought. Just before committing, I got this feeling and had a closer look. I discovered that the 300 percent slowdown was due to flushes being made at EVERY SINGLE character being read...! The startup speed is now 0.88 s which is a slowdown of 2 percent... I'll let the mix read/write code be while we wait for Gary's code. > I actually got angry when I saw this change. It's completely insane > to do that much work for every character being read in the innermost > loop of the reader. > > Doesn't people have any feeling for what is time critical and what is > not? I guess the conclusion I have to draw from this is that *I* don't have a good feeling for what is time critical and what is not. I should have suspected that there was something more going on here. Sigh... Sorry for all the fuzz. :( /mdj