Compilation problem (unsupported instruction on processor?)

Hi,
I was unable to compile postgresql on my system. I have an IRIX
operating system on an SGI platform. It occurred during the
compilation of s_lock.c. The problem occurred as following:

make[2]: Entering directory
`/max/mark/src/postgresql-6.5.3/src/backend/storage'

for i in buffer file ipc large_object lmgr page smgr; do make -C $i
SUBSYS.o; done

make[3]: Entering directory
`/max/mark/src/postgresql-6.5.3/src/backend/storage/buffer'

gcc -I../../../include -I../../../backend -U_NO_XOPEN4 -Wall
-Wmissing-prototypes -I../.. -c s_lock.c -o s_lock.o

s_lock.c: In function `s_lock': s_lock.c:74: warning: passing arg 1
discards `volatile' from pointer target type
s_lock.c: At top level:
s_lock.c:149: warning: `tas_dummy' defined but not used

/var/tmp/cca001na.s: Assembler messages:

/var/tmp/cca001na.s:266: Warning: Instruction not supported on this
processor

/var/tmp/cca001na.s:266: Internal error! Assertion failure at targ-cpu.c
line 1478.

Please report this bug.

make[3]: *** [s_lock.o] Error 1

make[3]: Leaving directory
`/max/mark/src/postgresql-6.5.3/src/backend/storage/buffer'

Is there a relatively simple way for me to patch this up? Thanks,
-Mark

**************************************
Mark Allen Sales
UC Berkeley
Depts. of Physics & MCB
**************************************