[PATCH] D38313: [InstCombine] Introducing Aggressive Instruction Combine pass

[Zvi Rackover via Phabricator via llvm-commits]

zvi added a comment.

In https://reviews.llvm.org/D38313#937269, @zvi wrote:

> In https://reviews.llvm.org/D38313#936670, @davide wrote:
>
> > I'm really worried that the compile time hit of this for LTO will be non-negligible. Do you have numbers?
>
>
> Will follow-up on this.


Measured CTMark and internal tests and was not able to observe significant compile time changes with -flto. Below are the results for CTMark:

| Workload         | ToT: stdev/average of 10 runs [%] | This patch:  stdev/average of 10 runs [%] | Average compile-time speedup of this patch over ToT (higher is better for this patch) |
| 7zip             | 0.19%                             | 0.19%                                     | 0.999                                                                                 |
| Bullet           | 0.30%                             | 0.37%                                     | 0.998                                                                                 |
| ClamAV           | 0.39%                             | 0.19%                                     | 1.000                                                                                 |
| SPASS            | 0.52%                             | 0.33%                                     | 1.000                                                                                 |
| consumer-typeset | 0.27%                             | 0.36%                                     | 0.999                                                                                 |
| kimwitu++        | 0.45%                             | 0.49%                                     | 0.998                                                                                 |
| lencod           | 0.20%                             | 0.51%                                     | 1.001                                                                                 |
| mafft            | 0.63%                             | 0.29%                                     | 1.006                                                                                 |
| sqlite3          | 0.70%                             | 0.82%                                     | 1.002                                                                                 |
| tramp3d-v4       | 1.23%                             | 1.78%                                     | 0.990                                                                                 |


https://reviews.llvm.org/D38313