On 11/08/2016 04:12 PM, Bastian Koppelmann wrote:
On 11/08/2016 04:06 PM, Richard Henderson wrote:
On 11/08/2016 02:37 PM, Bastian Koppelmann wrote:
Consider 0x836d4e86 as an input which is clearly negative, however
float_flag_invalid is not set. The hardware on the other hand does set
it.
Hmm. This is -0x1.da9d0cp-121. Softfloat claims that we should round
to zero first, and only if the result is still < 0, raise invalid.
Which does sound plausible as a common behaviour.
TriCore does it the other way round.
Does your hardware raise invalid for true -0.0, i.e. 0x80000000?
No, -0.0 does not raise invalid.
Then I suppose the check should look like
flags = f_get_excp_flags(env);
if (flags & float_flag_invalid) {
flags &= ~float_flag_inexact;
} else if (float32_lt_quiet(f_arg, 0, &env->status)) {
flags = float_flag_invalid;
}
if (flags) {
f_update_psw_flags(env, flags);
}
Note that the 0.0 that you use is truncated to 0 by C for the uint32_t argument.
r~
