cb2256 | /*\ | |||
06983f | ||| This file a part of Pike, and is copyright by Fredrik Hubinette ||| Pike is distributed as GPL (General Public License) | |||
cb2256 | ||| See the files COPYING and DISCLAIMER for more information. \*/ | |||
24ddc7 | /* | |||
c7241b | * $Id: stuff.c,v 1.12 2000/08/10 09:20:00 grubba Exp $ | |||
24ddc7 | */ | |||
ad42b8 | #include "global.h" | |||
5267b7 | #include "stuff.h" | |||
ad42b8 | #include "stralloc.h" | |||
5267b7 | ||||
75920f | /* Not all of these are primes, but they should be adequate */ | |||
1f2133 | PMOD_EXPORT INT32 hashprimes[32] = | |||
75920f | { 31, /* ~ 2^0 = 1 */ 31, /* ~ 2^1 = 2 */ 31, /* ~ 2^2 = 4 */ 31, /* ~ 2^3 = 8 */ 31, /* ~ 2^4 = 16 */ 31, /* ~ 2^5 = 32 */ 61, /* ~ 2^6 = 64 */ 127, /* ~ 2^7 = 128 */ 251, /* ~ 2^8 = 256 */ 541, /* ~ 2^9 = 512 */ 1151, /* ~ 2^10 = 1024 */ 2111, /* ~ 2^11 = 2048 */ 4327, /* ~ 2^12 = 4096 */ 8803, /* ~ 2^13 = 8192 */ 17903, /* ~ 2^14 = 16384 */ 32321, /* ~ 2^15 = 32768 */ 65599, /* ~ 2^16 = 65536 */ 133153, /* ~ 2^17 = 131072 */ 270001, /* ~ 2^18 = 264144 */ 547453, /* ~ 2^19 = 524288 */ 1109891, /* ~ 2^20 = 1048576 */ 2000143, /* ~ 2^21 = 2097152 */ 4561877, /* ~ 2^22 = 4194304 */ 9248339, /* ~ 2^23 = 8388608 */ 16777215, /* ~ 2^24 = 16777216 */ 33554431, /* ~ 2^25 = 33554432 */ 67108863, /* ~ 2^26 = 67108864 */ 134217727, /* ~ 2^27 = 134217728 */ 268435455, /* ~ 2^28 = 268435456 */ 536870911, /* ~ 2^29 = 536870912 */ 1073741823,/* ~ 2^30 = 1073741824 */ 2147483647,/* ~ 2^31 = 2147483648 */ }; | |||
5267b7 | /* same thing as (int)floor(log((double)x) / log(2.0)) */ /* Except a bit quicker :) (hopefully) */ | |||
c7241b | PMOD_EXPORT int my_log2(size_t x) | |||
5267b7 | { | |||
4e882a | static signed char bit[256] = | |||
5267b7 | { -1, 0, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, }; | |||
c7241b | register size_t tmp; #if SIZEOF_CHAR_P > 4 if((tmp=(x>>32))) { if((x=(tmp>>16))) { if((tmp=(x>>8))) return bit[tmp]+56; return bit[x]+48; } if((x=(tmp>>8))) return bit[x]+40; return bit[tmp]+32; } #endif /* SIZEOF_CHAP_P > 4 */ | |||
9c6f7d | if((tmp=(x>>16))) | |||
5267b7 | { | |||
9c6f7d | if((x=(tmp>>8))) return bit[x]+24; | |||
5267b7 | return bit[tmp]+16; } | |||
9c6f7d | if((tmp=(x>>8))) return bit[tmp]+8; | |||
5267b7 | return bit[x]; } /* Return the number of bits in a 32-bit integer */ | |||
1f2133 | PMOD_EXPORT int count_bits(unsigned INT32 x) | |||
5267b7 | { #define B(X) X+0,X+1,X+1,X+2,\ X+1,X+2,X+2,X+3,\ X+1,X+2,X+2,X+3,\ X+2,X+3,X+3,X+4 static char bits[256] = { B(0), B(1), B(1), B(2), B(1), B(2), B(2), B(3), B(1), B(2), B(2), B(3), B(2), B(3), B(3), B(4) }; return (bits[x & 255] + bits[(x>>8) & 255] + bits[(x>>16) & 255] + bits[(x>>24) & 255]); } /* Return true for integers with more than one bit set */ | |||
1f2133 | PMOD_EXPORT int is_more_than_one_bit(unsigned INT32 x) | |||
5267b7 | { | |||
a4f8b7 | return !!(x & (x-1)); | |||
5267b7 | } | |||
574088 | ||||
1f2133 | PMOD_EXPORT double my_strtod(char *nptr, char **endptr) | |||
574088 | { double tmp=STRTOD(nptr,endptr); if(*endptr>nptr) { if(endptr[0][-1]=='.') endptr[0]--; } return tmp; } | |||
a6b98a |