diff options
Diffstat (limited to 'ghc/runtime/profiling/Hashing.lc')
| -rw-r--r-- | ghc/runtime/profiling/Hashing.lc | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/ghc/runtime/profiling/Hashing.lc b/ghc/runtime/profiling/Hashing.lc new file mode 100644 index 0000000000..ec73dfc821 --- /dev/null +++ b/ghc/runtime/profiling/Hashing.lc @@ -0,0 +1,87 @@ +Hashing functions based on: + + "Fast Hashing of Variable Length Text Strings" + Peter K. Pearson, CACM June 1990 + +They return a 32 bit value containing 16 bits of hash value. + +\begin{code} +#include "rtsdefs.h" + +static const StgChar auxTable[] = { +(StgChar)0x01, (StgChar)0x57, (StgChar)0x31, (StgChar)0x0c, (StgChar)0xb0, (StgChar)0xb2, (StgChar)0x66, (StgChar)0xa6, +(StgChar)0x79, (StgChar)0xc1, (StgChar)0x06, (StgChar)0x54, (StgChar)0xf9, (StgChar)0xe6, (StgChar)0x2c, (StgChar)0xa3, +(StgChar)0x0e, (StgChar)0xc5, (StgChar)0xd5, (StgChar)0xb5, (StgChar)0xa1, (StgChar)0x55, (StgChar)0xda, (StgChar)0x50, +(StgChar)0x40, (StgChar)0xef, (StgChar)0x18, (StgChar)0xe2, (StgChar)0xec, (StgChar)0x8e, (StgChar)0x26, (StgChar)0xc8, +(StgChar)0x6e, (StgChar)0xb1, (StgChar)0x68, (StgChar)0x67, (StgChar)0x8d, (StgChar)0xfd, (StgChar)0xff, (StgChar)0x32, +(StgChar)0x4d, (StgChar)0x65, (StgChar)0x51, (StgChar)0x12, (StgChar)0x2d, (StgChar)0x60, (StgChar)0x1f, (StgChar)0xde, +(StgChar)0x19, (StgChar)0x6b, (StgChar)0xbe, (StgChar)0x46, (StgChar)0x56, (StgChar)0xed, (StgChar)0xf0, (StgChar)0x22, +(StgChar)0x48, (StgChar)0xf2, (StgChar)0x14, (StgChar)0xd6, (StgChar)0xf4, (StgChar)0xe3, (StgChar)0x95, (StgChar)0xeb, +(StgChar)0x61, (StgChar)0xea, (StgChar)0x39, (StgChar)0x16, (StgChar)0x3c, (StgChar)0xfa, (StgChar)0x52, (StgChar)0xaf, +(StgChar)0xd0, (StgChar)0x05, (StgChar)0x7f, (StgChar)0xc7, (StgChar)0x6f, (StgChar)0x3e, (StgChar)0x87, (StgChar)0xf8, +(StgChar)0xae, (StgChar)0xa9, (StgChar)0xd3, (StgChar)0x3a, (StgChar)0x42, (StgChar)0x9a, (StgChar)0x6a, (StgChar)0xc3, +(StgChar)0xf5, (StgChar)0xab, (StgChar)0x11, (StgChar)0xbb, (StgChar)0xb6, (StgChar)0xb3, (StgChar)0x00, (StgChar)0xf3, +(StgChar)0x84, (StgChar)0x38, (StgChar)0x94, (StgChar)0x4b, (StgChar)0x80, (StgChar)0x85, (StgChar)0x9e, (StgChar)0x64, +(StgChar)0x82, (StgChar)0x7e, (StgChar)0x5b, (StgChar)0x0d, (StgChar)0x99, (StgChar)0xf6, (StgChar)0xd8, (StgChar)0xdb, +(StgChar)0x77, (StgChar)0x44, (StgChar)0xdf, (StgChar)0x4e, (StgChar)0x53, (StgChar)0x58, (StgChar)0xc9, (StgChar)0x63, +(StgChar)0x7a, (StgChar)0x0b, (StgChar)0x5c, (StgChar)0x20, (StgChar)0x88, (StgChar)0x72, (StgChar)0x34, (StgChar)0x0a, +(StgChar)0x8a, (StgChar)0x1e, (StgChar)0x30, (StgChar)0xb7, (StgChar)0x9c, (StgChar)0x23, (StgChar)0x3d, (StgChar)0x1a, +(StgChar)0x8f, (StgChar)0x4a, (StgChar)0xfb, (StgChar)0x5e, (StgChar)0x81, (StgChar)0xa2, (StgChar)0x3f, (StgChar)0x98, +(StgChar)0xaa, (StgChar)0x07, (StgChar)0x73, (StgChar)0xa7, (StgChar)0xf1, (StgChar)0xce, (StgChar)0x03, (StgChar)0x96, +(StgChar)0x37, (StgChar)0x3b, (StgChar)0x97, (StgChar)0xdc, (StgChar)0x5a, (StgChar)0x35, (StgChar)0x17, (StgChar)0x83, +(StgChar)0x7d, (StgChar)0xad, (StgChar)0x0f, (StgChar)0xee, (StgChar)0x4f, (StgChar)0x5f, (StgChar)0x59, (StgChar)0x10, +(StgChar)0x69, (StgChar)0x89, (StgChar)0xe1, (StgChar)0xe0, (StgChar)0xd9, (StgChar)0xa0, (StgChar)0x25, (StgChar)0x7b, +(StgChar)0x76, (StgChar)0x49, (StgChar)0x02, (StgChar)0x9d, (StgChar)0x2e, (StgChar)0x74, (StgChar)0x09, (StgChar)0x91, +(StgChar)0x86, (StgChar)0xe4, (StgChar)0xcf, (StgChar)0xd4, (StgChar)0xca, (StgChar)0xd7, (StgChar)0x45, (StgChar)0xe5, +(StgChar)0x1b, (StgChar)0xbc, (StgChar)0x43, (StgChar)0x7c, (StgChar)0xa8, (StgChar)0xfc, (StgChar)0x2a, (StgChar)0x04, +(StgChar)0x1d, (StgChar)0x6c, (StgChar)0x15, (StgChar)0xf7, (StgChar)0x13, (StgChar)0xcd, (StgChar)0x27, (StgChar)0xcb, +(StgChar)0xe9, (StgChar)0x28, (StgChar)0xba, (StgChar)0x93, (StgChar)0xc6, (StgChar)0xc0, (StgChar)0x9b, (StgChar)0x21, +(StgChar)0xa4, (StgChar)0xbf, (StgChar)0x62, (StgChar)0xcc, (StgChar)0xa5, (StgChar)0xb4, (StgChar)0x75, (StgChar)0x4c, +(StgChar)0x8c, (StgChar)0x24, (StgChar)0xd2, (StgChar)0xac, (StgChar)0x29, (StgChar)0x36, (StgChar)0x9f, (StgChar)0x08, +(StgChar)0xb9, (StgChar)0xe8, (StgChar)0x71, (StgChar)0xc4, (StgChar)0xe7, (StgChar)0x2f, (StgChar)0x92, (StgChar)0x78, +(StgChar)0x33, (StgChar)0x41, (StgChar)0x1c, (StgChar)0x90, (StgChar)0xfe, (StgChar)0xdd, (StgChar)0x5d, (StgChar)0xbd, +(StgChar)0xc2, (StgChar)0x8b, (StgChar)0x70, (StgChar)0x2b, (StgChar)0x47, (StgChar)0x6d, (StgChar)0xb8, (StgChar)0xd1}; + +hash_t +hash_str(str) + char *str; +{ + hash_t h1, h2; + hash_t ch = (hash_t) *(str++); + + if (ch == 0) return 0; + + h1 = (hash_t) auxTable[ch]; + h2 = (hash_t) auxTable[ch+1]; + + while ( (ch = (hash_t)*(str++) ) != 0) { + h1 = (hash_t) auxTable[h1^ch]; + h2 = (hash_t) auxTable[h2^ch]; + } + + return ( h2 << 8 | h1 ); +} + +hash_t +hash_fixed(data, len) + char *data; + I_ len; /* bytes in data, must be > 0 */ +{ + hash_t ch = (hash_t) *(data++); + hash_t h1 = (hash_t) auxTable[ch]; + hash_t h2 = (hash_t) auxTable[ch+1]; + + ASSERT(len > 0); + + while (--len > 0) { + ch = (hash_t) *(data++); + h1 = (hash_t) auxTable[h1^ch]; + h2 = (hash_t) auxTable[h2^ch]; + } + + return ( h2 << 8 | h1 ); +} +\end{code} + + + |