Replace the hashing functions on APInt and APFloat with overloads of the

new hash_value infrastructure, and replace their implementations using
hash_combine. This removes a complete copy of Jenkin's lookup3 hash
function (which is both significantly slower and lower quality than the
one implemented in hash_combine) along with a somewhat scary xor-only
hash function.

Now that APInt and APFloat can be passed directly to hash_combine,
simplify the rest of the LLVMContextImpl hashing to use the new
infrastructure.

llvm-svn: 152004

1 files changed, 8 insertions, 3 deletions

diff --git a/llvm/lib/VMCore/LLVMContextImpl.h b/llvm/lib/VMCore/LLVMContextImpl.h
index a29bba2f3b4..f98526de650 100644
--- a/llvm/lib/VMCore/LLVMContextImpl.h
+++ b/llvm/lib/VMCore/LLVMContextImpl.h
@@ -52,12 +52,14 @@ struct DenseMapAPIntKeyInfo {
     bool operator!=(const KeyTy& that) const {
       return !this->operator==(that);
     }
+    friend hash_code hash_value(const KeyTy &Key) {
+      return hash_combine(Key.type, Key.val);
+    }
   };
   static inline KeyTy getEmptyKey() { return KeyTy(APInt(1,0), 0); }
   static inline KeyTy getTombstoneKey() { return KeyTy(APInt(1,1), 0); }
   static unsigned getHashValue(const KeyTy &Key) {
-    return DenseMapInfo<void*>::getHashValue(Key.type) ^ 
-      Key.val.getHashValue();
+    return static_cast<unsigned>(hash_value(Key));
   }
   static bool isEqual(const KeyTy &LHS, const KeyTy &RHS) {
     return LHS == RHS;
@@ -75,6 +77,9 @@ struct DenseMapAPFloatKeyInfo {
     bool operator!=(const KeyTy& that) const {
       return !this->operator==(that);
     }
+    friend hash_code hash_value(const KeyTy &Key) {
+      return hash_combine(Key.val);
+    }
   };
   static inline KeyTy getEmptyKey() { 
     return KeyTy(APFloat(APFloat::Bogus,1));
@@ -83,7 +88,7 @@ struct DenseMapAPFloatKeyInfo {
     return KeyTy(APFloat(APFloat::Bogus,2)); 
   }
   static unsigned getHashValue(const KeyTy &Key) {
-    return Key.val.getHashValue();
+    return static_cast<unsigned>(hash_value(Key));
   }
   static bool isEqual(const KeyTy &LHS, const KeyTy &RHS) {
     return LHS == RHS;