[llvm] r215862 - ARM: improve RTABI 4.2 conformance on Linux

[Renato Golin]

On 17 August 2014 23:51, Saleem Abdulrasool <compnerd at compnerd.org> wrote:
> Author: compnerd
> Date: Sun Aug 17 17:51:02 2014
> New Revision: 215862
>
> URL: http://llvm.org/viewvc/llvm-project?rev=215862&view=rev
> Log:
> ARM: improve RTABI 4.2 conformance on Linux
>
> The set of functions defined in the RTABI was separated for no real reason.
> This brings us closer to proper utilisation of the functions defined by the
> RTABI.  It also sets the ground for correctly emitting function calls to AEABI
> functions on all AEABI conforming platforms.
>
> The previously existing lie on the behaviour of __ldivmod and __uldivmod is
> propagated as it is beyond the scope of the change.
>
> The changes to the test are due to the fact that we now use the divmod functions
> which return both the quotient and remainder and thus we no longer need to
> invoke two functions on Linux (making it closer to EABI's behaviour).


Hi Saleem,

64-bit divmod was broken on ARM and AFAIK hasn't been fixed. Your
tests seem to remove the [[sum]] dependency, making them a bit weaker
than they were. I just want to make sure that 64-bit divmod is working
as it should by making sure the generated code is *really* correct.

Moritz (cc'd) had some concerns about it, it may be linked.

cheers,
--renato