[cfe-dev] -no-implicit-float for ARM

[Bob Wilson]

On May 17, 2012, at 9:23 AM, Chad Rosier <mcrosier at apple.com> wrote:

> 
> On May 16, 2012, at 3:30 PM, Sandeep Patel wrote:
> 
>> On Wed, May 16, 2012 at 4:44 PM, Chad Rosier <mcrosier at apple.com> wrote:
>>> 
>>> On May 14, 2012, at 5:43 PM, Sandeep Patel <deeppatel1987 at gmail.com> wrote:
>>> 
>>>> On ARM, if -msoft-float is set, doesn't that already imply -no-implicit-float?
>>> 
>>> No, -msoft-float does not imply -no-implicit-float on ARM.
>> 
>> Perhaps I'm just missing something here, but why would I want the FP
>> hardware to be used implicitly if I have -msoft-float set? I could see
>> doing so if -mfloat-abi=soft, but not if we're fully soft-float.
> 
> I'm no expert in this area and a do see your point.  Unfortunately, I don't have a great answer.  Possibly someone else on the list could provide some insight.

I don't know about recent versions of GCC, but in Apple's gcc-4.2, here is how the ARM -msoft-float option is defined (in gcc/config/arm/arm.opt):

msoft-float
Target RejectNegative
Alias for -mfloat-abi=soft

This has been highly confusing to me and others, but we're kind of stuck with it.