[Bug target/90513] asm thunks do not work on PowerPC64/VxWorks (kernel mode)

[Umesh Kalappa]

Hi Segher ,

We would like to know comments on the  below  proposed change ?

Thank you
~Umesh

On Tue, Jun 11, 2019 at 10:23 PM umesh.kalappa0 at gmail dot com
<gcc-bugzilla@gcc.gnu.org> wrote:
>
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90513
>
> --- Comment #17 from Umesh Kalappa <umesh.kalappa0 at gmail dot com> ---
> the following change
>
> #undef TARGET_ASM_CAN_OUTPUT_MI_THUNK
> #define TARGET_ASM_CAN_OUTPUT_MI_THUNK rs6000_can_output_mi_thunk
>
> /* Return true if rs6000_output_mi_thunk would be able to output the
>    assembler code for the thunk function specified by the arguments
>    it is passed, and false otherwise.  */
>
> static bool
> rs6000_can_output_mi_thunk (const_tree, HOST_WIDE_INT, HOST_WIDE_INT,
>                             const_tree)
> {
>   if (rs6000_default_long_calls)
>     return false;
>
>   /* The loader neither creates the glue code sequence that loads r12 nor uses
>      the local entry point for the sibcall's target in the ELFv2 ABI.  */
>   return DEFAULT_ABI != ABI_ELFv2;
> }
>
> when we have longcall enabled ,we fall through regular asm thunk generation
> like above .
>
> is that ok to commit and we regressed for powerpc and no-regress found .