On 2/12/19 3:03 AM, David Hildenbrand wrote:
> -uint64_t HELPER(cegb)(CPUS390XState *env, int64_t v2, uint32_t m3)
> +uint64_t HELPER(cegb)(CPUS390XState *env, int64_t v2, uint32_t m)
> {
> - int old_mode = s390_swap_bfp_rounding_mode(env, m3);
> + int old_mode = s390_swap_bfp_rounding_mode(env, m & 0xf);
>
> float32 ret = int64_to_float32(v2, &env->fpu_status);
> s390_restore_bfp_rounding_mode(env, old_mode);
> - handle_exceptions(env, false, GETPC());
> + handle_exceptions(env, (m >> 8) & 1, GETPC());
> return ret;
> }
It might be helpful to have inlines for these extractions. E.g
static inline uint32_t round_from_m34(uint32_t m);
static inline bool xxc_from_m34(uint32_t m);
> static DisasJumpType op_cfeb(DisasContext *s, DisasOps *o)
> {
> - TCGv_i32 m3 = tcg_const_i32(get_field(s->fields, m3));
> - gen_helper_cfeb(o->out, cpu_env, o->in2, m3);
> - tcg_temp_free_i32(m3);
> + TCGv_i32 m;
> +
> + if (!valid_bfp_rounding_mode(get_field(s->fields, m3))) {
> + gen_program_exception(s, PGM_SPECIFICATION);
> + return DISAS_NORETURN;
> + }
> + m = tcg_const_i32(get_fields2(s->fields, m3, m4));
> + gen_helper_cfeb(o->out, cpu_env, o->in2, m);
> + tcg_temp_free_i32(m);
> gen_set_cc_nz_f32(s, o->in2);
> return DISAS_NEXT;
> }
The m4 field does not exist unless fp extension facility is enabled. You
should ignore the field if not installed.
It would be good to split this out to a helper, since there are so many copies.
E.g.
static bool extract_m3_m4(DisasContext *s, uint32_t *m34)
{
int m3 = get_field(s->fields, m3);
int m4 = get_field(s->fields, m4);
if (!valid_bfp_rounding_mode(m3)) {
gen_program_exception(s, PGM_SPECIFICATION);
return false;
}
if (feature) {
return deposit32(m3, 8, 1, m4);
}
return m3;
}
Hmm.. Except that I see we don't have enough stored in DisasContext to allow
you to look up the proper feature. So perhaps just a FIXME for now?
r~
