[llvmlinux] ARM -mfpu=-softvfp+vfp

[Behan Webster]

Cc-ing Arnd Bergmann as he is relevant to this discussion.

On 02/19/14 03:18, Renato Golin wrote:
> Folks,
>
> Following bug:
>
> http://llvm.org/bugs/show_bug.cgi?id=18689
>
> I think the fix for the second problem (softvfp) is *also* to change
> the compilation flags.
>
> The rationale is in Bernie's email:
>
> http://lists.cs.uiuc.edu/pipermail/cfe-commits/Week-of-Mon-20140217/099354.html
>
> Mainly that "softvfp+vfp" is ambiguous in many different ways and
> implementing it would be promoting differences between the compilers,
> rather than bringing them back together.
>
> Also, we need first to ask what do GAS need to know about the PCS? Is
> this just something that unknowingly got in for the Android build?
> Does that flag really needs to be passed in that way, or can it be
> just -Wa,-mfpu=vfp + -mfloat-abi=softfp? That has the same behaviour
> on the compiler and is supported by both LLVM and GCC.
Arnd Bergman is likely the right person to ask about the flags set in 
arch/arm/vp/Makefile

KBUILD_AFLAGS   :=$(KBUILD_AFLAGS:-msoft-float=-Wa,-mfpu=softvfp+vfp 
-mfloat-abi=soft)

Would there be issues in changing the flags to -Wa,-mfpu=vfp 
-mfloat-abi=softfp?

Behan

-- 
Behan Webster
behanw at converseincode.com