[PATCH] D92674: [TableGen] Cache the vectors of records returned by getAllDerivedDefinitions().

[Paul C. Anagnostopoulos via Phabricator via llvm-commits]

Paul-C-Anagnostopoulos added inline comments.


================
Comment at: llvm/lib/TableGen/Record.cpp:2600
+// the same vectors multiple times.
 std::vector<Record *> RecordKeeper::getAllDerivedDefinitions(
+    StringRef ClassName) const {
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dblaikie wrote:
> Now that the result is cached, perhaps this function could return by const ref instead of by value, to avoid unnecessary copies of the resulting vector?
The vector must be copied, because there is nothing stopping the caller from modifying it.

Do you think it's worth the effort to establish the rule that it cannot be modified and then investigate every call to see what's going on?



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  https://reviews.llvm.org/D92674/new/

https://reviews.llvm.org/D92674