[PATCH] D36742: [LLD][ELF][AArch64] Implement scanner for Cortex-A53 Erratum 843419

[Rafael Avila de Espindola via llvm-commits]

Peter Smith <peter.smith at linaro.org> writes:

>>> At the moment, until https://reviews.llvm.org/D37944 Add support for AArch64 Range Thunks lands the assignAddresses won't be entered. Some merge work will be needed here as Thunks and Errata fixes can impact each other.
>>
>> How? Can't you always put the errata fixes after all regular code?
>>
>
> Not always if the program is large. I've recently been investigating a
> problem with the gold implementation of --fix-cortex-a53-843419
> (https://sourceware.org/bugzilla/show_bug.cgi?id=20765) in that
> program there is over 180 Mb of code (quite a lot for a wiki editor,
> but apparently Haskell tends to produce huge binaries) which in effect
> means:
> ~ 128 Mb code
> Thunks and errata for first ~128Mb
> ~ more code
> Thunks and errata for next ~128Mb
>
> If these are all in the same OutputSection then adding errata fixes to
> the first chunk will affect the ranges of the code after it, which may
> need more Thunks. The gold problem is an internal error when that
> condition occurs.

But the patched errata code could use an adrp to just up to 4g ahead,
no?

Cheers,
Rafael