Re: [Qemu-devel] [PATCH] softfloat: rename make_float[x80|128]_init to const_float[x80|128]

[Richard Henderson]

On 09/19/2017 12:39 PM, Eric Blake wrote:
> On 09/19/2017 11:30 AM, Richard Henderson wrote:
>> On 09/18/2017 05:46 AM, Laurent Vivier wrote:
>>> Redefine make_floatx80() and make_float128() as make_float16(),
>>> make_float32() and make_float64() using a variable and not only
>>> a cast.
> 
>>> -#define make_floatx80(exp, mant) ((floatx80) { mant, exp })
>>> -#define make_floatx80_init(exp, mant) { .low = mant, .high = exp }
>>> +#define make_floatx80(exp, mant) __extension__ \
>>> +    ({ floatx80 f80_val = { .low = mant, .high = exp }; f80_val; })
>>> +#define const_floatx80(exp, mant) { .low = mant, .high = exp }
> 
>>
>> I don't like this part -- (type){ init } is a standard C99 compound literal.
>> There's no point using a gcc extension instead.
> 
> The C99 compound literal is not a const initializer in all situations,
> though :( 

A compound literal not officially a const initializer in any situation.  That
it is accepted by gcc as a const initializer is an extension.

I don't dispute const_floatx80, but the change to make_floatx80.


r~