Re: [Qemu-devel] [PATCH] target/m68k: Change fpu_rom from const static array to switch

[Kamil Rytarowski]

On 04.09.2017 02:27, Philippe Mathieu-Daudé wrote:
> On 09/03/2017 02:05 PM, Laurent Vivier wrote:
>> Le 03/09/2017 à 18:31, Kamil Rytarowski a écrit :
>>> GCC 4.7.2 on SunOS reports that the values assigned to array members
>>> are not
>>> real constants:
>>>
>>> target/m68k/fpu_helper.c:32:5: error: initializer element is not
>>> constant
>>> target/m68k/fpu_helper.c:32:5: error: (near initialization for
>>> 'fpu_rom[0]')
>>> rules.mak:66: recipe for target 'target/m68k/fpu_helper.o' failed
>>>
>>> Convert the array to switch() to workaround the issue.
>>
>> I don't like the idea. It's really an array and should be managed as an
>> array.
> 
> I agree with Laurent.
> 
>>
>> Could you try to use make_floatx80_init() instead of make_floatx80() ?
> 
> I guess the problem comes from the macro which cast as not const:
> 
> #define make_floatx80(exp, mant) ((floatx80) { mant, exp })
> 

Adding const to make_floatx80 - ((const floatx80) { mant, exp }) - does
not fix the problem.

> make_floatx80_init() doesn't cast so it might work,
> else we could add a macro such const_floatx80():
> 
> #define const_floatx80(exp, mant) ((const floatx80) { mant, exp })

Switching make_floatx80() to make_floatx80_init() in works.

How about floatx80_zero, floatx80_one etc? We cannot translate them to
make_floatx80_init() as this breaks in other parts of the code in
functions like:

void helper_fldpi_ST0(CPUX86State *env)
{
    ST0 = floatx80_pi;
}

-- target/i386/fpu_helper.c

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