The value of unwind_breg may reference register %r0, but we need to avoid
accessing gr0 directly and use the value 0 instead.
At runtime I've seen unwind_breg being zero with the Linux kernel when
rfi is used to jump to smp_callin().
Signed-off-by: Helge Deller <deller@gmx.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Bruno Haible <bruno@clisp.org>
cpu_restore_state(cs, retaddr);
- b = env->gr[env->unwind_breg];
+ b = env->unwind_breg ? env->gr[env->unwind_breg] : 0;
b >>= (env->psw & PSW_W ? 62 : 30);
env->cr[CR_IOR] |= b << 62;