Tartan C compiler revisited

[William L. Sebok]

My Tartan C tape arrived here yesterday.  The first thing I've done is to
recompile  /lib/libc.a.  I substituted tcc for cc in everything except the
stuff in /usr/src/lib/libc/vax,  where assembler stuff resides.  There were
no compilation errors.

I will say more when I get more experience.  I intend to recompile the
utilities a bit at a time.  In the compiler's documentaion they list 4.2 BSD
programs with which they have had trouble. The problems are mostly bugs in the
sources being compiled and read like articles in net.bugs.4bsd or entries in
the MtXinu bugs tape.

Things that they say to watch out for:
1) their C preprocessor only works on source with legal C tokens and cannot be
used to massage assembler programs.
2) although they recognize the "asm" construction, such constructions often
contain compiler dependent assumptions that are not valid with tcc.  In
particular  the first item declared "register" will not necessarily be in r11,
the 2nd in r10, and so on, as is the case in "cc".
3) The same considerations as in 2) also apply to sed scripts which massage
assembler output.
4) the C optimizer c2 can not usefully be applied to tcc assembler output.
-- 
Bill Sebok			Princeton University, Astrophysics
{allegra,akgua,burl,cbosgd,decvax,ihnp4,noao,princeton,vax135}!astrovax!wls