diff options
Diffstat (limited to 'include/llvm/ADT/APFloat.h')
| -rw-r--r-- | include/llvm/ADT/APFloat.h | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/include/llvm/ADT/APFloat.h b/include/llvm/ADT/APFloat.h index d2566a4..d40727d 100644 --- a/include/llvm/ADT/APFloat.h +++ b/include/llvm/ADT/APFloat.h @@ -328,8 +328,16 @@ namespace llvm { APFloat& operator=(const APFloat &); - /* Return an arbitrary integer value usable for hashing. */ - uint32_t getHashValue() const; + /// \brief Overload to compute a hash code for an APFloat value. + /// + /// Note that the use of hash codes for floating point values is in general + /// frought with peril. Equality is hard to define for these values. For + /// example, should negative and positive zero hash to different codes? Are + /// they equal or not? This hash value implementation specifically + /// emphasizes producing different codes for different inputs in order to + /// be used in canonicalization and memoization. As such, equality is + /// bitwiseIsEqual, and 0 != -0. + friend hash_code hash_value(const APFloat &Arg); /// Converts this value into a decimal string. /// |