Benchmark count for vector<bool>#5684
Merged
StephanTLavavej merged 4 commits intomicrosoft:mainfrom Aug 25, 2025
Merged
Conversation
Member
|
5950X results:
|
StephanTLavavej
approved these changes
Aug 22, 2025
Member
|
Thanks! 😻 I pushed minor stylistic changes. |
* Predictable sequence in each benchmark case regardless of other cases * Potentially ninor perf improvement by avoiding magic static
StephanTLavavej
approved these changes
Aug 23, 2025
Member
|
I'm mirroring this to the MSVC-internal repo - please notify me if any further changes are pushed. |
Member
|
Thanks for measuring this performance! ⏱️ 🚀 😻 |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
There is
countforvector<bool>optimization that usespopcnton the integer elements of thevector<bool>internal representation, originally added in #1131. There's open PR #5640 to enhance that optimization further.This PR adds benchmark to measure the results.
I've started off copying
vector_bool_copy.cppto mimic the existing style, then left only the_alginedcase, since unalignment doesn't make significant impact (unlike copying), still left the same name (as justcountmatches the STL algorithm name), and addedDoNotOptimizewhere necessary. The value to count is alternating to explore both branches without adding extra benchmarks.The results for #5640 are mixed for me.
On P cores of i5-1235U I see no improvement:
On E cores I see some improvement, which is not too little for such a small change: