[PATCH] D107353: [LoopIdiom] let the pass deal with runtime memset size

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri added a comment.

Actually, we've talked about not needing the overflow check, but IIRC just saturating the number of bytes.
Can you point me at the code that does that?



================
Comment at: llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp:1076-1102
 /// Compute the number of bytes as a SCEV from the backedge taken count.
 ///
 /// This also maps the SCEV into the provided type and tries to handle the
 /// computation in a way that will fold cleanly.
 static const SCEV *getNumBytes(const SCEV *BECount, Type *IntPtr,
                                unsigned StoreSize, Loop *CurLoop,
                                const DataLayout *DL, ScalarEvolution *SE) {
----------------
This doesn't look right.
1. There absolutely should not be two almost identical functions
2. Shouldn't this be saturating unsigned multiplication?


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https://reviews.llvm.org/D107353