infinite loop in loop.c with -O2

[Mike Stump]

I too am seeing an infinite loop when bootstrapping.  This is on
x86-linux.  I was compiling regclass.o with stage1, 18hr of CPU time
later...  I was using:

File: loop.c            Status: Up-to-date
 
   Working revision:    1.165
   Repository revision: 1.165   /egcs/carton/cvsfiles/egcs/gcc/loop.c,v

stage1/xgcc -Bstage1/ -c  -DIN_GCC    -DUSE_GNULIBC_1 -O2  -DHAVE_CONFIG_H    -I. -I../../egcs/gcc -I../../egcs/gcc/config -I../../egcs/gcc/../include ../../egcs/gcc/regclass.c

was the command.  It loops while compiling init_reg_sets_1.

cvs update -r 1.162 loop.c

and a recompile of loop.c fixes it.  When I do:

cvs update -r 1.163 loop.c

it then breaks.  That was:

revision 1.163
date: 1999/06/17 09:32:59;  author: amylaar;  state: Exp;  lines: +12 -3
        * loop.c (strength_reduce): When doing biv->giv conversion, fix up
        reg_biv_class.
        (recombine_givs): Set ix field after sorting.

Hope this is enough for you to track it down.