[PATCH] D103009: [DSE] Transform memset + malloc --> calloc (PR25892)

[Evgenii Stepanov via Phabricator via llvm-commits]

eugenis added a comment.

+1 to revert.

I'm not sure what is the LangRef change requested. This is a valid transformation, sure. It just makes the code run slower and use more memory.

It goes against the user intent in the code that is explicitly trying to avoid zero-initializing the allocated memory.

IMHO this transformation should only apply if memset can be proven to postdominate malloc *for the entire allocation size* (or at least a large part of it).


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  https://reviews.llvm.org/D103009/new/

https://reviews.llvm.org/D103009