🚀 go-pugleaf

I'm retargeting gcc 1.29 to a new architecture, and while the process is,
by and large, going fairly smoothly, I sometimes run into bugs that are
extremely difficult to fix.  These usually are bugs caused by subtle
ill-formed aspects of the machine-description.  The manifest themselves
by the compiler decising to abort at some stage because of invalid RTL.

For example, the most recent problem I've been tearing my hair out over
is an abort from insn_extract() from regclass().  The former routine is
clearly getting a bad insn, but there doesn't seem to be a conveniant
way of isolating the region of RTL that is causing the problem, much less
the original RTL template that are at fault.  The debugging dumps are
generally far too impenetrable to be of assistance, unless I factor the
program down to a tiny subset of its original size.

So, my question is, does anyone have tools, tips, sympathy, or other
advice for someone coming up to speed on debugging gcc?  Much thanks
for any help.

S. McGeady
mcg@iwarp.intel.com	(mcg@intel-iwarp.arpa)
mcg@omepd.intel.com	tektronix!ogcvax!omepd!mcg