From: Christian Bauer Date: Fri, 19 Nov 1999 19:22:11 +0000 (+0000) Subject: - rotate_31() and golden_hash_ratio() moved to utils.h X-Git-Tag: release_0-5-0~145 X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=commitdiff_plain;h=8bcccf834ad41e94a1a4f3a0304c2945b228b4f4;ds=sidebyside - rotate_31() and golden_hash_ratio() moved to utils.h - golden_hash_ratio() looks for a suitable data type by means of defines from config.h --- diff --git a/ginac/basic.h b/ginac/basic.h index f397b778..ef4e8cfb 100644 --- a/ginac/basic.h +++ b/ginac/basic.h @@ -179,6 +179,7 @@ extern type_info const & typeid_basic; extern int max_recursion_level; // convenience macros + #define is_of_type(OBJ,TYPE) \ (dynamic_cast(const_cast(&OBJ))!=0) @@ -191,40 +192,6 @@ extern int max_recursion_level; #define is_ex_exactly_of_type(OBJ,TYPE) \ ((*(OBJ).bp).tinfo()==GiNaC::TINFO_##TYPE) - -// global functions - -inline unsigned rotate_left_31(unsigned n) -{ - // clear highest bit and shift 1 bit to the left - n=(n & 0x7FFFFFFFU) << 1; - - // overflow? clear highest bit and set lowest bit - if (n & 0x80000000U) { - n=(n & 0x7FFFFFFFU) | 0x00000001U; - } - - ASSERT(n<0x80000000U); - - return n; -} - -inline unsigned golden_ratio_hash(unsigned n) -{ -#if 0 - // This requires ´long long´ (or an equivalent 64 bit type)---which is, - // unfortunately, not ANSI-compliant: - unsigned long long l = n * 0x4f1bbcddLL; - return (l & 0x7fffffffU) ^ (l >> 32); -#else - // This requires ´long double´ to have a mantissa of at least 64 bit--- - // which is not guaranteed by any standard: - const static long double golden_ratio=.618033988749894848204586834370; - long double m=golden_ratio*n; - return unsigned((m-int(m))*0x80000000); -#endif -} - } // namespace GiNaC #endif // ndef __GINAC_BASIC_H__ diff --git a/ginac/expairseq.cpp b/ginac/expairseq.cpp index f74be45e..05b7233d 100644 --- a/ginac/expairseq.cpp +++ b/ginac/expairseq.cpp @@ -27,6 +27,7 @@ #include "expairseq.h" #include "lst.h" #include "debugmsg.h" +#include "utils.h" namespace GiNaC { diff --git a/ginac/inifcns.cpp b/ginac/inifcns.cpp index cee71b18..de48b858 100644 --- a/ginac/inifcns.cpp +++ b/ginac/inifcns.cpp @@ -247,4 +247,9 @@ ex ncpower(ex const &basis, unsigned exponent) return ncmul(v,1); } +/** Force inclusion of functions from initcns_gamma and inifcns_zeta + * for static lib (so ginsh will see them). */ +unsigned force_include_gamma = function_index_gamma; +unsigned force_include_zeta = function_index_zeta; + } // namespace GiNaC diff --git a/ginac/inifcns.h b/ginac/inifcns.h index f7622dd4..ee737818 100644 --- a/ginac/inifcns.h +++ b/ginac/inifcns.h @@ -81,13 +81,13 @@ DECLARE_FUNCTION_1P(Li3) /** Riemann's Zeta-function. */ DECLARE_FUNCTION_1P(zeta) -DECLARE_FUNCTION_2P(zeta) - +//DECLARE_FUNCTION_2P(zeta) + /** Gamma-function. */ DECLARE_FUNCTION_1P(gamma) /** Psi-function (aka polygamma-function). */ -DECLARE_FUNCTION_1P(psi) +//DECLARE_FUNCTION_1P(psi) DECLARE_FUNCTION_2P(psi) /** Factorial function. */ diff --git a/ginac/utils.cpp b/ginac/utils.cpp index 446377b2..0c99ad59 100644 --- a/ginac/utils.cpp +++ b/ginac/utils.cpp @@ -24,6 +24,7 @@ namespace GiNaC { +/** Integer binary logarithm */ unsigned log2(unsigned n) { unsigned k; @@ -31,6 +32,8 @@ unsigned log2(unsigned n) return k; } +/** Compare two pointers (just to establish some sort of canonical order). + * @return -1, 0, or 1 */ int compare_pointers(void const * a, void const * b) { if (a #include #include "config.h" +#include "assertion.h" namespace GiNaC { @@ -41,6 +42,47 @@ unsigned log2(unsigned n); int compare_pointers(void const * a, void const * b); +/** Rotate lower 31 bits of unsigned value by one bit to the left + * (upper bits get cleared). */ +inline unsigned rotate_left_31(unsigned n) +{ + // clear highest bit and shift 1 bit to the left + n=(n & 0x7FFFFFFFU) << 1; + + // overflow? clear highest bit and set lowest bit + if (n & 0x80000000U) { + n=(n & 0x7FFFFFFFU) | 0x00000001U; + } + ASSERT(n<0x80000000U); + + return n; +} + +/** Golden ratio hash function. */ +inline unsigned golden_ratio_hash(unsigned n) +{ + // This function requires arithmetic with at least 64 significant bits +#if SIZEOF_LONG_DOUBLE > 8 + // If "long double" is bigger than 64 bits, we assume that the mantissa + // has at least 64 bits. This is not guaranteed but it's a good guess. + const static long double golden_ratio = .618033988749894848204586834370; + long double m = golden_ratio * n; + return unsigned((m - int(m)) * 0x80000000); +#elif SIZEOF_LONG >= 8 + // "long" has 64 bits, so we prefer it because it might be more efficient + // than "long long" + unsigned long l = n * 0x4f1bbcddL; + return (l & 0x7fffffffU) ^ (l >> 32); +#elif SIZEOF_LONG_LONG >= 8 + // This requires ´long long´ (or an equivalent 64 bit type)---which is, + // unfortunately, not ANSI-compliant: + unsigned long long l = n * 0x4f1bbcddLL; + return (l & 0x7fffffffU) ^ (l >> 32); +#else +#error "No 64 bit data type. You lose." +#endif +} + // modified from stl_algo.h: always do com(*first1,*first2) instead of comp(*first2,*first1) template