[PATCH] D149185: ValueTracking: Fix computeKnownFPClass handling for copysign

[Jay Foad via Phabricator via llvm-commits]

foad added inline comments.


================
Comment at: llvm/include/llvm/Analysis/ValueTracking.h:403
+    if (Sign.isKnownNever(fcPositive | fcNan) || (SignBit && *SignBit))
+      KnownFPClasses &= (fcNegative | fcNan);
+    if (Sign.isKnownNever(fcNegative | fcNan) || (SignBit && !*SignBit))
----------------
How do you know the result is not nan?


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D149185/new/

https://reviews.llvm.org/D149185