nixos/nix
1
1
Fork 0
mirror of https://github.com/NixOS/nix.git synced 2025-11-19 16:59:35 +01:00
Code Activity

* 64-bit compatibility fixes (for problems revealed by building on an Athlon

Browse source 
64 running 64-bit SUSE).  A patched ATerm library is required to run Nix
  succesfully.
This commit is contained in:
Eelco Dolstra 2006-05-11 02:19:43 +00:00
parent e3c07782d1
commit 9d72bf8835
10 changed files with 21 additions and 20 deletions
Download patch file Download diff file Expand all files Collapse all files

15
src/libutil/aterm-map.cc
View file

@ -111,34 +111,35 @@ void ATermMap::copy(KeyValue * elements, unsigned int capacity)
}
/* !!! use a bigger shift for 64-bit platforms? */
static const unsigned int shift = 16;
static const unsigned int knuth = (unsigned int) (0.6180339887 * (1 << shift));
static const unsigned long knuth = (unsigned long) (0.6180339887 * (1 << shift));
unsigned int ATermMap::hash1(ATerm key) const
unsigned long ATermMap::hash1(ATerm key) const
{
/* Don't care about the least significant bits of the ATerm
pointer since they're always 0. */
unsigned int key2 = ((unsigned int) key) >> 2;
unsigned long key2 = ((unsigned long) key) >> 2;
/* Approximately equal to:
double d = key2 * 0.6180339887;
unsigned int h = (int) (capacity * (d - floor(d)));
*/
unsigned int h = (capacity * ((key2 * knuth) & ((1 << shift) - 1))) >> shift;
unsigned long h = (capacity * ((key2 * knuth) & ((1 << shift) - 1))) >> shift;
return h;
}
unsigned int ATermMap::hash2(ATerm key) const
unsigned long ATermMap::hash2(ATerm key) const
{
unsigned int key2 = ((unsigned int) key) >> 2;
unsigned long key2 = ((unsigned long) key) >> 2;
/* Note: the result must be relatively prime to `capacity' (which
is a power of 2), so we make sure that the result is always
odd. */
unsigned int h = ((key2 * 134217689) & (capacity - 1)) | 1;
unsigned long h = ((key2 * 134217689) & (capacity - 1)) | 1;
return h;
}