Path: utzoo!attcan!uunet!wuarchive!cs.utexas.edu!mailrus!iuvax!purdue!bu-cs!mirror!prism!rob
From: rob@prism.TMC.COM
Newsgroups: comp.sys.ibm.pc
Subject: Re: why are C compiles so slow?
Message-ID: <206900141@prism>
Date: 24 Nov 89 18:25:00 GMT
References: <19500044@uxh.cso.uiuc.edu>
Lines: 25
Nf-ID: #R:uxh.cso.uiuc.edu:19500044:prism:206900141:000:1282
Nf-From: prism.TMC.COM!rob    Nov 24 13:25:00 1989



>In developing new programs in C I find that the most time is taken in waiting
>for compile and link (including some fairly large libraries). ( I am working 
>with a genuine 6 MHz AT.)  Even if I go to V DISK, it is still slow.  My 
>question is -- What factors most strongly determine the speed of compile?

   A big factor is the speed of the compiler. Given the same program,
different compilers can take very different amounts of time to digest
it. Turbo C and Quick C are quite fast. Microsoft C takes 2 to 3 times 
as long to handle most programs. I've seen one compiler, which I won't name, 
that takes several times as long as Microsoft C.

  Depending on what you're working on, breaking programs down into smaller 
modules, so that you're recompiling smaller programs, may be an option.

  Assuming a reasonably fast disk, compiling is mostly a CPU bound job. Using
VDISK, or a disk cache, will give you some improvement, but isn't likely to 
make a drastic difference except on very small programs.

>If I upgrade to a 386 CPU using, for instance, the MicroWay FastCACHE-AT/SX
>board (which includes 32K cache), will I see a big improvement?

   If you've got the budget, that'll do the job, and it'll make everything, 
not just your compiler, run several times faster.