Re: [Qemu-devel] [PATCH 6/7] target-tricore: Add cmp.f instruction

[Bastian Koppelmann <kbastian@mail.uni-paderborn.de>]

On 03/08/2016 03:42 PM, Richard Henderson wrote:
> On 03/08/2016 05:20 AM, Bastian Koppelmann wrote:
>> On 03/01/2016 07:21 PM, Richard Henderson wrote:
>>> On 03/01/2016 08:24 AM, Bastian Koppelmann wrote:
>>>> +
>>>> +    lt = float32_lt_quiet(arg1, arg2, &env->fp_status);
>>>> +    eq = float32_eq_quiet(arg1, arg2, &env->fp_status);
>>>> +    uo = float32_unordered(arg1, arg2, &env->fp_status);
>>>
>>> Do it in one step with float32_compare.
>>> You don't want _quiet; see below re psw_flags.
>>>
>> Unfortunately, if I don't use _quiet my tests fail against real
>> hardware...
> 
> Fail in what way?  I don't think _quiet computes all of the bits you need.

For example, if we have arg1 = 0 and arg2 = 0xffffffff then
float32_compare will assert the invalid bit, but the hardware doesn't.

Cheers,
Bastian