Re: [PATCH][ARM] PR target/64405 Disable interworking for non-Thumb targets

[Kyrill Tkachov <kyrylo dot tkachov at arm dot com>]

Ping, with a caveat.

This bug appears on all release branches and is thus not a regression.
Should it be slotted for next stage 1?

Kyrill

On 16/01/15 16:55, Kyrill Tkachov wrote:
> Hi all,
>
> This PR is about GCC emiting 'bx lr' instructions when compiling with
> -march=armv2 or armv3(!). It should be using a move into the pc instead
> on those architectures.
> The cause I found for it is that the functions are marked with the
> ARM_FT_INTERWORKED type and hence in the output_return_instruction
> function they use 'bx lr'.
> Rather than changing output_return_instruction to check for the
> architecture level when outputting the string I think the correct thing
> to do is to disable interworking
> when the target does not support any Thumb at all, like these old
> architectures. Is that correct thinking?
>
> Anyway, with this patch the functions are given the ARM_FT_NORMAL type
> and use 'mov pc, lr' to return.
> Tested arm-none-eabi.
>
> What do people think?
>
> Thanks,
> Kyrill
>
> 2014-01-16  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
>
>       PR target/64405
>       * config/arm/arm.c (arm_option_override): Disable interworking if Thumb
>       is not available.
>
> 2014-01-16  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
>
>       PR target/64405
>       * gcc.target/arm/pr64405_1.c: New test.