[PATCH 2/2 v3][IRA,LRA] Fix PR86939, IRA incorrectly creates an interference between a pseudo register and a hard register

[Peter Bergner]

On 11/1/18 1:50 PM, Renlin Li wrote:
> Is there any update on this issues?
> arm-none-linux-gnueabihf native toolchain has been mis-compiled for a while.

>From the analysis I've done, my commit is just exposing latent issues
in LRA.  Can you try the patch I submitted here to see if it helps?

  https://gcc.gnu.org/ml/gcc-patches/2018-10/msg01757.html

It survives on powerpc64le-linux, x86_64-linux and s390x-linux.
Jeff threw it on his testers and said he saw an arm issue and was
trying to come up with a test case for me to debug.

The specific issue you mentioned with the inline asm and the casp insn
is a bug in LRA where is will spill a user defined hard register and
it shouldn't do that.  My patch above stops that.  The question is
whether we've quashed the rest of the latent bugs.

Peter