From 71bd7d1e5408bc52fdb96a63efc23023233aeba3 Mon Sep 17 00:00:00 2001 From: Chandler Carruth Date: Sun, 4 Mar 2012 12:02:57 +0000 Subject: 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 --- llvm/lib/Support/APFloat.cpp | 31 +++++++++++++++---------------- 1 file changed, 15 insertions(+), 16 deletions(-) (limited to 'llvm/lib/Support/APFloat.cpp') diff --git a/llvm/lib/Support/APFloat.cpp b/llvm/lib/Support/APFloat.cpp index 525aea2..409d4fb 100644 --- a/llvm/lib/Support/APFloat.cpp +++ b/llvm/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 @@ -2681,21 +2682,19 @@ APFloat::convertNormalToHexString(char *dst, unsigned int hexDigits, 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 -- cgit v1.1