[Bug target/65837] [arm-linux-gnueabihf] lto1 target specific builtin not available

["ramana at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65837

--- Comment #28 from Ramana Radhakrishnan <ramana at gcc dot gnu.org> ---
(In reply to chrbr from comment #27)
> > 
> > Should be reproducible without LTO with
> > 
> > int __attribute__((target("fpu=neon"))) main() 
> > {
> > ...
> > }
> > 
> > and compiling without -mfpu=neon.
> > 
> 
> note that #include "arm_neon.h" can't be preprocessed and that the builtins
> are not recognized without a global flag:
> 
> "arm_neon.h:31:2: error: #error You must enable NEON instructions (e.g.
> -mfloat-abi=softfp -mfpu=neon) to use arm_neon.h"
> 
> A further improvement for that might be to set the attribute for all the
> functions defines in  neon.h and remove the #error check.
>   
> e.g:
> 
> __extension__ static __inline float32x2_t 
> __attribute__ ((__always_inline__))
> __attribute__((target("fpu=neon")))
> vadd_f32 (float32x2_t __a, float32x2_t __b)
> {
>   return (float32x2_t) __builtin_neon_vaddv2sf (__a, __b);
> }
> 
> or use a #pragma target (("mfpu=neon")) region.

The #pragma is what I would expect.