[llvm-commits] [llvm] r151859 - /llvm/trunk/lib/Support/FoldingSet.cpp

[Chandler Carruth]

Author: chandlerc
Date: Thu Mar  1 17:18:44 2012
New Revision: 151859

URL: http://llvm.org/viewvc/llvm-project?rev=151859&view=rev
Log:
Switch FoldingSet over to the new hashing infrastructure. We might want
to do more invasive refactoring here to get FoldingSet to use size_t or
even hash_code directly, but for now this is a good first step to remove
Yet Another Hashing Algorithm from LLVM.

Modified:
    llvm/trunk/lib/Support/FoldingSet.cpp

Modified: llvm/trunk/lib/Support/FoldingSet.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/FoldingSet.cpp?rev=151859&r1=151858&r2=151859&view=diff
==============================================================================
--- llvm/trunk/lib/Support/FoldingSet.cpp (original)
+++ llvm/trunk/lib/Support/FoldingSet.cpp Thu Mar  1 17:18:44 2012
@@ -15,6 +15,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/ADT/FoldingSet.h"
+#include "llvm/ADT/Hashing.h"
 #include "llvm/Support/Allocator.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/MathExtras.h"
@@ -29,24 +30,7 @@
 /// ComputeHash - Compute a strong hash value for this FoldingSetNodeIDRef,
 /// used to lookup the node in the FoldingSetImpl.
 unsigned FoldingSetNodeIDRef::ComputeHash() const {
-  // This is adapted from SuperFastHash by Paul Hsieh.
-  unsigned Hash = static_cast<unsigned>(Size);
-  for (const unsigned *BP = Data, *E = BP+Size; BP != E; ++BP) {
-    unsigned Data = *BP;
-    Hash         += Data & 0xFFFF;
-    unsigned Tmp  = ((Data >> 16) << 11) ^ Hash;
-    Hash          = (Hash << 16) ^ Tmp;
-    Hash         += Hash >> 11;
-  }
-  
-  // Force "avalanching" of final 127 bits.
-  Hash ^= Hash << 3;
-  Hash += Hash >> 5;
-  Hash ^= Hash << 4;
-  Hash += Hash >> 17;
-  Hash ^= Hash << 25;
-  Hash += Hash >> 6;
-  return Hash;
+  return static_cast<unsigned>(hash_combine_range(Data, Data+Size));
 }
 
 bool FoldingSetNodeIDRef::operator==(FoldingSetNodeIDRef RHS) const {