X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=blobdiff_plain;f=ginac%2Futils.h;h=0f6082a6a7b4d70fdbc195f6ebe45bf6a09c0f56;hp=edde75fcde3ff071cd7e8ed4b88bcfc9a6840d99;hb=955cb185a85535ab328ffedbfccdc508ce80fa91;hpb=9eab44408b9213d8909b7a9e525f404ad06064dd diff --git a/ginac/utils.h b/ginac/utils.h index edde75fc..0f6082a6 100644 --- a/ginac/utils.h +++ b/ginac/utils.h @@ -1,6 +1,7 @@ /** @file utils.h * - * Interface to several small and furry utilities. */ + * Interface to several small and furry utilities needed within GiNaC but not + * of any interest to the user of the library. */ /* * GiNaC Copyright (C) 1999 Johannes Gutenberg University Mainz, Germany @@ -26,8 +27,11 @@ #include #include #include "config.h" +#include "assertion.h" +#ifndef NO_GINAC_NAMESPACE namespace GiNaC { +#endif // ndef NO_GINAC_NAMESPACE template string ToString(T const & t) @@ -37,28 +41,73 @@ string ToString(T const & t) return buf; } +/** Exception thrown by classes which provide their own series expansion to + * signal that ordinary Taylor expansion is safe. */ +class do_taylor {}; + 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; + } + GINAC_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 OutputIterator mymerge(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp) { - while (first1 != last1 && first2 != last2) { - if (comp(*first1, *first2)) { - *result = *first1; - ++first1; + while (first1 != last1 && first2 != last2) { + if (comp(*first1, *first2)) { + *result = *first1; + ++first1; + } + else { + *result = *first2; + ++first2; + } + ++result; } - else { - *result = *first2; - ++first2; - } - ++result; - } - return copy(first2, last2, copy(first1, last1, result)); + return copy(first2, last2, copy(first1, last1, result)); } // like merge(), but three lists with *last2<*first3 @@ -68,27 +117,97 @@ OutputIterator mymerge3(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, InputIterator3 first3, InputIterator3 last3, OutputIterator result, Compare comp) { - while (first1 != last1 && first2 != last2) { - if (comp(*first1, *first2)) { - *result = *first1; - ++first1; + while (first1 != last1 && first2 != last2) { + if (comp(*first1, *first2)) { + *result = *first1; + ++first1; + } + else { + *result = *first2; + ++first2; + } + ++result; } - else { - *result = *first2; - ++first2; + + if (first1==last1) { + // list1 empty, copy rest of list2, then list3 + return copy(first3, last3, copy(first2, last2, result)); + } else { + // list2 empty, merge rest of list1 with list3 + return mymerge(first1,last1,first3,last3,result,comp); } - ++result; - } - - if (first1==last1) { - // list1 empty, copy rest of list2, then list3 - return copy(first3, last3, copy(first2, last2, result)); - } else { - // list2 empty, merge rest of list1 with list3 - return mymerge(first1,last1,first3,last3,result,comp); - } } +// Collection of `construct on first use' wrappers for safely avoiding +// internal object replication without running into the `static +// initialization order fiasco'. This chest of numbers helps speed up +// the library but should not be used outside it since it is +// potentially confusing. + +class numeric; +class ex; + +numeric const & _num_12(void); // -12 +numeric const & _num_11(void); // -11 +numeric const & _num_10(void); // -10 +numeric const & _num_9(void); // -9 +numeric const & _num_8(void); // -8 +numeric const & _num_7(void); // -7 +numeric const & _num_6(void); // -6 +numeric const & _num_5(void); // -5 +numeric const & _num_4(void); // -4 +numeric const & _num_3(void); // -3 +numeric const & _num_2(void); // -2 +numeric const & _num_1(void); // -1 +numeric const & _num_1_2(void); // -1/2 +numeric const & _num_1_3(void); // -1/3 +numeric const & _num0(void); // 0 +numeric const & _num1_3(void); // 1/3 +numeric const & _num1_2(void); // 1/2 +numeric const & _num1(void); // 1 +numeric const & _num2(void); // 2 +numeric const & _num3(void); // 3 +numeric const & _num4(void); // 4 +numeric const & _num5(void); // 5 +numeric const & _num6(void); // 6 +numeric const & _num7(void); // 7 +numeric const & _num8(void); // 8 +numeric const & _num9(void); // 9 +numeric const & _num10(void); // 10 +numeric const & _num11(void); // 11 +numeric const & _num12(void); // 12 +ex const & _ex_12(void); // -12 +ex const & _ex_11(void); // -11 +ex const & _ex_10(void); // -10 +ex const & _ex_9(void); // -9 +ex const & _ex_8(void); // -8 +ex const & _ex_7(void); // -7 +ex const & _ex_6(void); // -6 +ex const & _ex_5(void); // -5 +ex const & _ex_4(void); // -4 +ex const & _ex_3(void); // -3 +ex const & _ex_2(void); // -2 +ex const & _ex_1(void); // -1 +ex const & _ex_1_2(void); // -1/2 +ex const & _ex_1_3(void); // -1/3 +ex const & _ex0(void); // 0 +ex const & _ex1_3(void); // 1/3 +ex const & _ex1_2(void); // 1/2 +ex const & _ex1(void); // 1 +ex const & _ex2(void); // 2 +ex const & _ex3(void); // 3 +ex const & _ex4(void); // 4 +ex const & _ex5(void); // 5 +ex const & _ex6(void); // 6 +ex const & _ex7(void); // 7 +ex const & _ex8(void); // 8 +ex const & _ex9(void); // 9 +ex const & _ex10(void); // 10 +ex const & _ex11(void); // 11 +ex const & _ex12(void); // 12 + +#ifndef NO_GINAC_NAMESPACE } // namespace GiNaC +#endif // ndef NO_GINAC_NAMESPACE #endif // ndef __GINAC_UTILS_H__