[PATCH] Fix ira.c indirect_jump_optimize (PR rtl-optimization/70460)

[Bernd Schmidt]

On 03/30/2016 11:27 PM, Jakub Jelinek wrote:
> Hi!
>
> As mentioned in the PR, we are miscompiling glibc on i686-linux, because
> the new indirect_jump_optimize mini-pass thinks that a insn
> which has REG_LABEL_OPERAND note necessarily has to set the target register
> to that label, while in the glibc case it is actually that label + some
> offset, where the offset is read from a table which contains other labels -
> this label differences.
>
> The following patch changes it to just look at SET_SRC of single_set and/or
> REG_EQUAL note, and only consider those if one of them is a LABEL_REF.
> That alone broke lots of tests, which contain non-local gotos, so I had
> to add a check that we don't do anything in this mini-pass (like old ira.c
> code did) if there is REG_NON_LOCAL_GOTO note.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk/5/4.9?
> Bernd has preapproved the patch, but that was before the REG_NON_LOCAL_GOTO
> changes.

Still ok.


Bernd