Avoid sign compare warning.

[oota-llvm.git] / include / llvm / ADT / APFloat.h

diff --git a/include/llvm/ADT/APFloat.h b/include/llvm/ADT/APFloat.h
index d2566a44bac9cfc1940fa25fa92bf6693a4773bb..2b466f900c81f4ba1c778893b69bcc28c3a91b5a 100644 (file)
--- a/include/llvm/ADT/APFloat.h
+++ b/include/llvm/ADT/APFloat.h
@@ -320,6 +320,7 @@ namespace llvm {
     const fltSemantics &getSemantics() const { return *semantics; }
     bool isZero() const { return category == fcZero; }
     bool isNonZero() const { return category != fcZero; }
+    bool isNormal() const { return category == fcNormal; }
     bool isNaN() const { return category == fcNaN; }
     bool isInfinity() const { return category == fcInfinity; }
     bool isNegative() const { return sign; }
@@ -328,8 +329,16 @@ 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.
     ///