[PATCH] D142556: [DebugInfo] Merge partially matching chains of inlined locations

Wed Feb 15 11:24:35 PST 2023

dstenb added a comment.

In D142556#4126647 <https://reviews.llvm.org/D142556#4126647>, @dstenb wrote:

> In D142556#4124049 <https://reviews.llvm.org/D142556#4124049>, @dblaikie wrote:
>
>> compile-time-tracker results?
>
> I have gotten results now, but I will not have time to look at them tonight: https://llvm-compile-time-tracker.com/compare.php?from=f7b10467b63f09ab74e67d4002b3e11601091882&to=d200692f433fbc5b8edaa68e92ab04124d0c7e6a

Looking at the instruction count we have the following geomeans:

  # NewPM-O3:
  geomean         72506M         72501M (-0.01%)
  # NewPM-ReleaseThinLTO:
  geomean         95895M         95901M (+0.01%)
  # NewPM-ReleaseLTO-g:
  geomean        110051M        110076M (+0.02%)
  # NewPM-O0-g:
  geomean         21463M         21473M (+0.05%)

and cycles:

  # NewPM-O3:
  geomean         54478M         54520M (+0.08%)
  # NewPM-ReleaseThinLTO:
  geomean         70324M         70367M (+0.06%)
  # NewPM-ReleaseLTO-g:
  geomean         82451M         82524M (+0.09%)
  # NewPM-O0-g:
  geomean         16404M         16423M (+0.12%)

I assume that the NewPM-O3 and NewPM-ReleaseThinLTO configurations are not interesting since they do not use -g (there's no file-size changes for those), and that NewPM-O0-g is not interesting since we'd only (?) inline always_inline functions (there are no file-size changes there also). So, there is a slight instruction and cycle count increase for the geometric mean for NewPM-ReleaseLTO-g, but that is similar to the uninteresting configurations. I assume that the uninteresting configurations may move a bit due to different program layout (cache effects, etc.).

In terms of file size increase there is a slight increase for the geometric mean, around in the same ballpark as I saw with my `opt` compilations.

**size-file, NewPM-ReleaseLTO-g:**

| *Benchmark*      | *Old*    | *New*             |
| kimwitu++        | 3610KiB  | 3638KiB (+0.77%)  |
| sqlite3          | 1911KiB  | 1917KiB (+0.31%)  |
| consumer-typeset | 1382KiB  | 1383KiB (+0.05%)  |
| Bullet           | 2448KiB  | 2453KiB (+0.21%)  |
| tramp3d-v4       | 12535KiB | 12552KiB (+0.14%) |
| mafft            | 579KiB   | 580KiB (+0.17%)   |
| ClamAV           | 2213KiB  | 2221KiB (+0.39%)  |
| lencod           | 2514KiB  | 2522KiB (+0.34%)  |
| SPASS            | 2616KiB  | 2629KiB (+0.47%)  |
| 7zip             | 5495KiB  | 5505KiB (+0.18%)  |
| geomean          | 2589KiB  | 2597KiB (+0.30%)  |

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D142556/new/

https://reviews.llvm.org/D142556