[PATCH] D104060: Machine IR Profile

Sun Jun 13 10:28:49 PDT 2021

ellis added a comment.

In D104060#2815509 <https://reviews.llvm.org/D104060#2815509>, @davidxl wrote:

> Thinking about MIP's use case a little, it seems that it actually matches
> what xray does.  Xray has very low runtime overhead and can be turned on
> always : xra https://llvm.org/docs/XRay.htmly. Have you compare with xray
> and consider using that?

In the space we care about, any increase in binary size regresses runtime performance. Yes there are other instrumentations that provide similar features with low runtime overhead, but MIP seems to be the only one that extracts out all metadata to minimize binary size overhead.

I've collected some section size data from the `fourinarow` test and have more size comparisons in https://gist.github.com/ellishg/92a68cf82bfdeccd10225154425edc69#gistcomment-3778753
Please let me know if there are more flags I can use to turn off XRay features so that this is a more fair comparison.

XRay
----

`-fxray-instrument -fxray-instrumentation-bundle=function-entry`
----------------------------------------------------------------

  size..text: 154802
  size..data: 10468
  size.xray_instr_map: 512
  size..bss: 594144

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D104060/new/

https://reviews.llvm.org/D104060