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binutils-gdb
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Use a simpler hash function.

This commit is contained in:
Ian Lance Taylor 2007-12-22 01:53:39 +00:00
parent 06a9731e8a
commit cf88803ada
1 changed files with 9 additions and 21 deletions
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30
gold/stringpool.cc
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@ -151,28 +151,16 @@ size_t
Stringpool_template<Stringpool_char>::string_hash(const Stringpool_char* s,
size_t length)
{
// Fowler/Noll/Vo (FNV) hash (type FNV-1a).
// This is the hash function used by the dynamic linker for
// DT_GNU_HASH entries. I compared this to a Fowler/Noll/Vo hash
// for a C++ program with 385,775 global symbols. This hash
// function was very slightly worse. However, it is much faster to
// compute. Overall wall clock time was a win.
const unsigned char* p = reinterpret_cast<const unsigned char*>(s);
if (sizeof(size_t) > 4)
{
size_t result = static_cast<size_t>(14695981039346656037ULL);
for (size_t i = 0; i < length * sizeof(Stringpool_char); ++i)
{
result ^= static_cast<size_t>(*p++);
result *= 1099511628211ULL;
}
return result;
}
else
{
size_t result = 2166136261UL;
for (size_t i = 0; i < length * sizeof(Stringpool_char); ++i)
{
result ^= static_cast<size_t>(*p++);
result *= 16777619UL;
}
return result;
}
size_t h = 5381;
for (size_t i = 0; i < length * sizeof(Stringpool_char); ++i)
h = h * 33 + *p++;
return h;
}
// Add the string S to the list of canonical strings. Return a