0ff6addd92
This ensures the invariant that cpu_cc_op matches s->cc_op when calling the helpers. The next patches need this because gen_compute_eflags and gen_compute_eflags_c will take care of setting cpu_cc_op. Always compute EFLAGS first since it is needed whenever the shift is non-zero, i.e. most of the time. This makes it possible to remove some writes of CC_OP_EFLAGS to cpu_cc_op and more importantly removes cases where s->cc_op becomes CC_OP_DYNAMIC. These are slow and we want to avoid them: CC_OP_EFLAGS is quite efficient once we paid the initial cost of computing the flags. Finally, always follow gen_compute_eflags(cpu_cc_src) by setting s->cc_op and discarding cpu_cc_dst. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Richard Henderson <rth@twiddle.net>
Read the documentation in qemu-doc.html or on http://wiki.qemu.org - QEMU team