[PATCH] D28926: [ValueTracking] Clarify comments on CannotBeOrderedLessThanZero and SignBitMustBeZero.

[Justin Lebar via Phabricator via llvm-commits]

This revision was automatically updated to reflect the committed changes.
Closed by commit rL292691: [ValueTracking] Clarify comments on CannotBeOrderedLessThanZero and… (authored by jlebar).

Changed prior to commit:
  https://reviews.llvm.org/D28926?vs=85061&id=85218#toc

Repository:
  rL LLVM

https://reviews.llvm.org/D28926

Files:
  llvm/trunk/include/llvm/Analysis/ValueTracking.h


Index: llvm/trunk/include/llvm/Analysis/ValueTracking.h
===================================================================
--- llvm/trunk/include/llvm/Analysis/ValueTracking.h
+++ llvm/trunk/include/llvm/Analysis/ValueTracking.h
@@ -167,13 +167,25 @@
   bool CannotBeNegativeZero(const Value *V, const TargetLibraryInfo *TLI,
                             unsigned Depth = 0);
 
-  /// Return true if we can prove that the specified FP value is either a NaN or
-  /// never less than 0.0.
-  /// If \p IncludeNeg0 is false, -0.0 is considered less than 0.0.
+  /// Return true if we can prove that the specified FP value is either NaN or
+  /// never less than -0.0.
+  ///
+  ///      NaN --> true
+  ///       +0 --> true
+  ///       -0 --> true
+  ///   x > +0 --> true
+  ///   x < -0 --> false
+  ///
   bool CannotBeOrderedLessThanZero(const Value *V, const TargetLibraryInfo *TLI);
 
-  /// \returns true if we can prove that the specified FP value has a 0 sign
-  /// bit.
+  /// Return true if we can prove that the specified FP value's sign bit is 0.
+  ///
+  ///      NaN --> true/false (depending on the NaN's sign bit)
+  ///       +0 --> true
+  ///       -0 --> false
+  ///   x > +0 --> true
+  ///   x < -0 --> false
+  ///
   bool SignBitMustBeZero(const Value *V, const TargetLibraryInfo *TLI);
 
   /// If the specified value can be set by repeating the same byte in memory,


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