Problems compiling X11R3 on SPARCstation 1

[3417]

I'm getting the following error when I try to compile the X11R3 source on
my SPARCstation 1. Anyone have any ideas on what might be causing it.

Here is the 'make World' output:

...(stuff deleted)...
making ddx/cfb
...(stuff deleted)...
rm -f cfbbitblt.o
cc -c -O -I. -I../../include -I../../.././X11 -I../mfb   cfbbitblt.c
cc: Fatal error in iropt: Illegal instruction (core dumped)
*** Error code 1
...(stuff deleted)...
make: Warning: Target `all' not remade because of errors
Current working directory /u1/X11R3/server/ddx/cfb
...(stuff deleted)...

I've tried applying 'cfbmskbits.h.patch' from the X11R3 update tape, but
it didn't help.