egcs-2.91.05 on i586-pc-linux-gnu gives bad assembly

[Horst von Brand]

egcs was configured with --enable-{shared,haifa,threads} and compiled
with CFLAGS='-O2 -fomit-frame-pointer -march=pentium'

When compiling the attached program as follows, I get:
[root@pc16 /tmp]# gcc -O2 -fomit-frame-pointer -march=pentium -g -save-temps -c
bug.c
bug.s: Assembler messages:
bug.s:84: Error: operands given don't match any known 386 instruction