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

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

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

chrbr at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |chrbr at gcc dot gnu.org

--- Comment #27 from chrbr at gcc dot gnu.org ---

> 
> 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.