[LLVMdev] large llc footprint

[Eli Friedman]

On Thu, Nov 3, 2011 at 3:02 PM, reed kotler <rkotler at mips.com> wrote:
> We have a large bitcode file produced from a tool. It's about 23 meg.
>
> When we compile this with llc, the footprint is 4-7 gig depending on
> which target.
>
> On a desktop this is not such a problem but it is on mobile devices.
>
> The suspect is that the flow graph for the entire program is built and
> kept for the duration, even if no optimization needing it all is in
> progress.
>
> This would make us think that if we wrote a tool to split the bitcode up
> into separate files that we could work around this.

We already have the infrastructure for such a tool, if necessary; take
a look at llvm-extract.

> Maybe there are other possible solutions.
>
> Any thoughts or experience from others on this problem would be greatly
> appreciated.

If you could figure out where the memory is going, that would be
useful information; it sounds like llc is using more space than it
should need.

-Eli