-nofloat flag => should we destroy it?

[Adam Sakareassen via Digitalmars-d]

No float is probably important for OS kernel and device driver developers.

The kernel of an operating system will usually not save the floating 
point registers during a context switch (to the kernel).  For this 
reason its important the compiler can guarantee never to use floating 
point numbers or the registers.

Removing such a flag may prevent the compiler being used to write things 
like Linux device drivers.  I know this is usually done in C, but there 
might be an OS in D one day.


On 23/04/2014 10:22 AM, Mike via Digitalmars-d wrote:
> On Tuesday, 22 April 2014 at 23:57:49 UTC, Andrej Mitrovic wrote:
>> See: https://issues.dlang.org/show_bug.cgi?id=8196
>>
>> Are there any D platforms where -nofloat is useful? If we're not
>> getting rid of it then it needs to be documented (the above issue).
>
> Well, I couldn't find any documentation on what this means, so I can't
> really say.  Does it disable floating point usage completely, or does it
> force software emulation?
>
> There are a couple people in this community interested in bringing D to
> 32-bit microcontrollers. Most of the 32-bit ARM Cortex microcontrollers
> don't have an FPU.  For the few that do, here are the attributes in GCC
> (http://gcc.gnu.org/onlinedocs/gcc/ARM-Options.html) needed to specify
> the configuration.
>
> -mfloat-abi=name
> -mfpu=name
> -mfp16-format=name
>
> But, these are target specific. Since DMD doesn't support any ARM
> platform, I suspect this is irrelevant, but there, you have it anyway.
>
> Mike
>