[PATCH] D31107: Check source value precision when reducing cast intrinsic

[Hal Finkel via Phabricator via llvm-commits]

hfinkel accepted this revision.
hfinkel added a comment.
This revision is now accepted and ready to land.

LGTM.



================
Comment at: lib/Transforms/InstCombine/InstCombineCasts.cpp:1449
+
+      if (II->getIntrinsicID() != Intrinsic::fabs) {
+        FPExtInst *FPExtSrc = dyn_cast<FPExtInst>(Src);
----------------
It would help to have a comment here, maybe something like:

 // Except for fabs, this transformation requires the input of the unary FP operation to be itself an fpext from the type to which we're truncating.



https://reviews.llvm.org/D31107