[PATCH] D23565: [ELF] Linkerscript: fix relocation offsets

[Rui Ueyama via llvm-commits]

I don't think this would slow down the relocation process because the
number of function calls will be the same. A quick performance test would
be appreciated, though.

On Wed, Aug 17, 2016 at 6:28 PM, Sean Silva <chisophugis at gmail.com> wrote:

> silvas added a comment.
>
> In https://reviews.llvm.org/D23565#518608, @ruiu wrote:
>
> > Eugene,
> >
> > Thank you for your description. I agree that the order we compute offset
> is the cause of the problem. In scanRelocs, we compute a symbol offset for
> each symbol and assign it to a local variable `Offset` -- but that value
> may change if linker scripts are in use. That value is computed too early,
> and we want to do it lazily.
> >
> > As to this patch, I'd refactor instead of applying a quick fix. It
> doesn't seem hard to do. For `C.Relocations` in `scanRelocs`, we are able
> to not store `Offset` to them because it can be computed from `Body`.
>
>
> This makes sense, but it may have performance implications to get the
> offset later (at least more pointer chasing for data that we already had in
> cache in scanRelocs); it will need to be measured to make sure that we
> implement it without costing too much performance.
>
>
> https://reviews.llvm.org/D23565
>
>
>
>
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