Re: [PATCH 04/10] target/tricore: Implement FTOU insn

[Richard Henderson <richard.henderson@linaro.org>]

On 8/27/23 04:07, Bastian Koppelmann wrote:
> On Sat, Aug 26, 2023 at 09:50:51PM -0700, Richard Henderson wrote:
>> On 8/26/23 09:02, Bastian Koppelmann wrote:
>>> +uint32_t helper_ftou(CPUTriCoreState *env, uint32_t arg)
>>> +{
>>> +    float32 f_arg = make_float32(arg);
>>> +    uint32_t result;
>>> +    int32_t flags = 0;
>>> +
>>> +    if (float32_is_any_nan(f_arg)) {
>>> +        result = 0;
>>> +        flags |= float_flag_invalid;
>>> +    } else if (float32_lt_quiet(f_arg, 0, &env->fp_status)) {
>>> +        result = 0;
>>> +        flags = float_flag_invalid;
>>> +    } else {
>>> +        result = float32_to_uint32(f_arg, &env->fp_status);
>>> +        flags = f_get_excp_flags(env);
>>> +    }
>>
>> You should allow softfloat to diagnose the special cases, and negative -> 0
>> is standard behaviour.  Therefore:
> 
> You're right. However, there is one special case, negative -> 0 ought to raise
> float_flags_invalid.

https://gitlab.com/qemu-project/qemu/-/blob/master/fpu/softfloat-parts.c.inc?ref_type=heads#L1162

Already done.  As I say, this is all standard IEEE behaviour.


r~