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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152004 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/APFloat.cpp b/lib/Support/APFloat.cpp
index 525aea2..409d4fb 100644
--- a/lib/Support/APFloat.cpp
+++ b/lib/Support/APFloat.cpp
@@ -14,8 +14,9 @@
#include "llvm/ADT/APFloat.h"
#include "llvm/ADT/APSInt.h"
-#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/FoldingSet.h"
+#include "llvm/ADT/Hashing.h"
+#include "llvm/ADT/StringRef.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
#include <limits.h>
@@ -2681,21 +2682,19 @@
return writeSignedDecimal (dst, exponent);
}
-// For good performance it is desirable for different APFloats
-// to produce different integers.
-uint32_t
-APFloat::getHashValue() const
-{
- if (category==fcZero) return sign<<8 | semantics->precision ;
- else if (category==fcInfinity) return sign<<9 | semantics->precision;
- else if (category==fcNaN) return 1<<10 | semantics->precision;
- else {
- uint32_t hash = sign<<11 | semantics->precision | exponent<<12;
- const integerPart* p = significandParts();
- for (int i=partCount(); i>0; i--, p++)
- hash ^= ((uint32_t)*p) ^ (uint32_t)((*p)>>32);
- return hash;
- }
+hash_code llvm::hash_value(const APFloat &Arg) {
+ if (Arg.category != APFloat::fcNormal)
+ return hash_combine((uint8_t)Arg.category,
+ // NaN has no sign, fix it at zero.
+ Arg.isNaN() ? (uint8_t)0 : (uint8_t)Arg.sign,
+ Arg.semantics->precision);
+
+ // Normal floats need their exponent and significand hashed.
+ return hash_combine((uint8_t)Arg.category, (uint8_t)Arg.sign,
+ Arg.semantics->precision, Arg.exponent,
+ hash_combine_range(
+ Arg.significandParts(),
+ Arg.significandParts() + Arg.partCount()));
}
// Conversion from APFloat to/from host float/double. It may eventually be
diff --git a/lib/Support/APInt.cpp b/lib/Support/APInt.cpp
index 0d4e0f9..031bbb8 100644
--- a/lib/Support/APInt.cpp
+++ b/lib/Support/APInt.cpp
@@ -14,9 +14,10 @@
#define DEBUG_TYPE "apint"
#include "llvm/ADT/APInt.h"
-#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/FoldingSet.h"
+#include "llvm/ADT/Hashing.h"
#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
@@ -675,93 +676,11 @@
}
}
-// From http://www.burtleburtle.net, byBob Jenkins.
-// When targeting x86, both GCC and LLVM seem to recognize this as a
-// rotate instruction.
-#define rot(x,k) (((x)<<(k)) | ((x)>>(32-(k))))
+hash_code llvm::hash_value(const APInt &Arg) {
+ if (Arg.isSingleWord())
+ return hash_combine(Arg.VAL);
-// From http://www.burtleburtle.net, by Bob Jenkins.
-#define mix(a,b,c) \
- { \
- a -= c; a ^= rot(c, 4); c += b; \
- b -= a; b ^= rot(a, 6); a += c; \
- c -= b; c ^= rot(b, 8); b += a; \
- a -= c; a ^= rot(c,16); c += b; \
- b -= a; b ^= rot(a,19); a += c; \
- c -= b; c ^= rot(b, 4); b += a; \
- }
-
-// From http://www.burtleburtle.net, by Bob Jenkins.
-#define final(a,b,c) \
- { \
- c ^= b; c -= rot(b,14); \
- a ^= c; a -= rot(c,11); \
- b ^= a; b -= rot(a,25); \
- c ^= b; c -= rot(b,16); \
- a ^= c; a -= rot(c,4); \
- b ^= a; b -= rot(a,14); \
- c ^= b; c -= rot(b,24); \
- }
-
-// hashword() was adapted from http://www.burtleburtle.net, by Bob
-// Jenkins. k is a pointer to an array of uint32_t values; length is
-// the length of the key, in 32-bit chunks. This version only handles
-// keys that are a multiple of 32 bits in size.
-static inline uint32_t hashword(const uint64_t *k64, size_t length)
-{
- const uint32_t *k = reinterpret_cast<const uint32_t *>(k64);
- uint32_t a,b,c;
-
- /* Set up the internal state */
- a = b = c = 0xdeadbeef + (((uint32_t)length)<<2);
-
- /*------------------------------------------------- handle most of the key */
- while (length > 3) {
- a += k[0];
- b += k[1];
- c += k[2];
- mix(a,b,c);
- length -= 3;
- k += 3;
- }
-
- /*------------------------------------------- handle the last 3 uint32_t's */
- switch (length) { /* all the case statements fall through */
- case 3 : c+=k[2];
- case 2 : b+=k[1];
- case 1 : a+=k[0];
- final(a,b,c);
- case 0: /* case 0: nothing left to add */
- break;
- }
- /*------------------------------------------------------ report the result */
- return c;
-}
-
-// hashword8() was adapted from http://www.burtleburtle.net, by Bob
-// Jenkins. This computes a 32-bit hash from one 64-bit word. When
-// targeting x86 (32 or 64 bit), both LLVM and GCC compile this
-// function into about 35 instructions when inlined.
-static inline uint32_t hashword8(const uint64_t k64)
-{
- uint32_t a,b,c;
- a = b = c = 0xdeadbeef + 4;
- b += k64 >> 32;
- a += k64 & 0xffffffff;
- final(a,b,c);
- return c;
-}
-#undef final
-#undef mix
-#undef rot
-
-uint64_t APInt::getHashValue() const {
- uint64_t hash;
- if (isSingleWord())
- hash = hashword8(VAL);
- else
- hash = hashword(pVal, getNumWords()*2);
- return hash;
+ return hash_combine_range(Arg.pVal, Arg.pVal + Arg.getNumWords());
}
/// HiBits - This function returns the high "numBits" bits of this APInt.