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).

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

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
>

"Adam Sakareassen via Digitalmars-d"  wrote in message news:mailman.510.1399697057.2907.digitalmars-d@puremagic.com...

> 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.

DMD will likely never be used for that anyway, and I seriously doubt -nofloat works correctly these days. 

if you say so... (and god spoke "there will be light"...and there was light)

I just mean, if you restrict users to some subset of possibilities they will never be easily able to explore the wider space of the set/superset...