[PATCH] D156811: [InstCombine] Fold `select` of `srem` and conditional add

[Craig Topper via Phabricator via llvm-commits]

craig.topper added inline comments.


================
Comment at: llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp:2604
+  // %cnd = icmp slt i32 %rem, 0
+  // %add = add nsw i32 %rem, %n
+  // %sel = select i1 %cnd, i32 %add, i32 %rem
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craig.topper wrote:
> antoniofrighetto wrote:
> > goldstein.w.n wrote:
> > > Can you remove the NSW from the comment / all the alive2 links. It makes it seem like the `nsw` is necessary for correctness.
> > Dropped, thanks.
> Use `InstCombiner::isSignBitCheck` so you can handle the case where the condition is inverted and the add and srem operands are swapped.
Or does something already canonicalize to have the compare be ICMP SLT?


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https://reviews.llvm.org/D156811