There is no benefit in looking through assumptions on UndefValue to
guess known bits. Return early to avoid walking their use-lists, and
assert that all instances of ConstantData are handled here for similar
reasons (UndefValue was the only integer/pointer holdout).
llvm-svn: 282337
// Start out not knowing anything.
KnownZero.clearAllBits(); KnownOne.clearAllBits();
+ // We can't imply anything about undefs.
+ if (isa<UndefValue>(V))
+ return;
+
+ // There's no point in looking through other users of ConstantData for
+ // assumptions. Confirm that we've handled them all.
+ assert(!isa<ConstantData>(V) && "Unhandled constant data!");
+
// Limit search depth.
// All recursive calls that increase depth must come after this.
if (Depth == MaxDepth)