[PATCH] D147939: ValueTracking: Handle fptrunc in computeKnownFPClass

[Matt Arsenault via Phabricator via llvm-commits]

arsenm added inline comments.


================
Comment at: llvm/lib/Analysis/ValueTracking.cpp:4627
+    if (KnownSrc.isKnownNeverNaN())
+      Known.knownNot(fcNan);
+    break;
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kpn wrote:
> Isn't infinity an issue as well? If the input to be truncated is zero then we know the result can't be infinity. Then again, if the goal is to keep parity with the old implementation then do we need to worry about infinity yet?
fptrunc(inf) => inf so there isn't really an issue as much of a missing optimization 


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D147939/new/

https://reviews.llvm.org/D147939