Untag dispatch find #2380
Untag dispatch find #2380
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Co-authored-by: Michael Schellenberger Costa <[email protected]>
StephanTLavavej
added
throughput
| if (!_Within_limits(_First, _Val)) { | ||
| return _Last; | ||
| } |
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No change requested: I observe that originally, in C++20 when is_constant_evaluated() was true, we would perform the _Within_limits check and early return if possible. Now, when is_constant_evaluated() is true, we simply activate the classic algorithm fallback. This seems fine, since at most there would be a minor throughput improvement, and it seems fairly unusual for the _Within_limits check to actually be successful (when it isn't, we pay the cost of a branch).
That is, _Within_limits is necessary for the runtime memchr optimization, but it's not really valuable for the constexpr case, and the new code is organized accordingly. 😸
Co-authored-by: S. B. Tam <[email protected]>
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I'm going to add this to the next batch of changes to merge - please notify me if any further commits are pushed. |
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Thanks for |
Towards #189
Extracted from #2219