[35aab3] | 1 | /**************************************** |
---|
| 2 | * Computer Algebra System SINGULAR * |
---|
| 3 | ****************************************/ |
---|
[107986] | 4 | /* $Id: polys-impl.cc,v 1.3 2008-07-25 14:37:55 Singular Exp $ */ |
---|
[35aab3] | 5 | |
---|
| 6 | /*************************************************************** |
---|
| 7 | * |
---|
| 8 | * File: polys-impl.cc |
---|
| 9 | * Purpose: low-level procuders for polys. |
---|
| 10 | * |
---|
| 11 | * If you touch anything here, you better know what you are doing. |
---|
| 12 | * What is here should not be used directly from other routines -- the |
---|
| 13 | * encapsulations in polys.[h,cc] should be used, instead. |
---|
| 14 | * |
---|
| 15 | ***************************************************************/ |
---|
| 16 | #ifndef POLYS_IMPL_CC |
---|
| 17 | #define POLYS_IMPL_CC |
---|
| 18 | |
---|
| 19 | #include <stdio.h> |
---|
| 20 | #include <string.h> |
---|
| 21 | #include "mod2.h" |
---|
| 22 | |
---|
| 23 | #include "omalloc.h" |
---|
| 24 | #ifdef PDEBUG |
---|
| 25 | #undef NO_INLINE3 |
---|
| 26 | #define NO_INLINE3 |
---|
| 27 | #endif |
---|
| 28 | #include "polys-impl.h" |
---|
| 29 | |
---|
| 30 | #include "structs.h" |
---|
| 31 | #include "febase.h" |
---|
| 32 | #include "numbers.h" |
---|
| 33 | #include "polys.h" |
---|
| 34 | #include "ring.h" |
---|
| 35 | #include "p_Procs.h" |
---|
| 36 | #include "dError.h" |
---|
| 37 | |
---|
| 38 | #ifdef PDEBUG |
---|
| 39 | int pDBsyzComp=0; |
---|
| 40 | #endif |
---|
| 41 | |
---|
| 42 | /*************************************************************** |
---|
| 43 | * |
---|
| 44 | * Storage Managament Routines |
---|
| 45 | * |
---|
| 46 | ***************************************************************/ |
---|
| 47 | |
---|
| 48 | |
---|
[107986] | 49 | void ppDelete(poly* p, const ring rg) |
---|
[35aab3] | 50 | { |
---|
| 51 | ring origRing = currRing; |
---|
| 52 | rChangeCurrRing(rg); |
---|
| 53 | pDelete(p); |
---|
| 54 | rChangeCurrRing(origRing); |
---|
| 55 | } |
---|
| 56 | |
---|
| 57 | |
---|
| 58 | poly pHeadProc(poly p) |
---|
| 59 | { |
---|
| 60 | return pHead(p); |
---|
| 61 | } |
---|
| 62 | |
---|
| 63 | |
---|
| 64 | static inline unsigned long GetBitFields(Exponent_t e, |
---|
| 65 | unsigned int s, unsigned int n) |
---|
| 66 | { |
---|
[6f1441] | 67 | #define Sy_bit_L(x) (((unsigned long)1L)<<(x)) |
---|
| 68 | unsigned int i = 0; |
---|
| 69 | unsigned long ev = 0L; |
---|
[35aab3] | 70 | assume(n > 0 && s < BIT_SIZEOF_LONG); |
---|
| 71 | do |
---|
| 72 | { |
---|
| 73 | assume(s+i < BIT_SIZEOF_LONG); |
---|
[6f1441] | 74 | if (e > (Exponent_t) i) ev |= Sy_bit_L(s+i); |
---|
[35aab3] | 75 | else break; |
---|
| 76 | i++; |
---|
| 77 | } |
---|
| 78 | while (i < n); |
---|
| 79 | return ev; |
---|
| 80 | } |
---|
| 81 | |
---|
| 82 | // Short Exponent Vectors are used for fast divisibility tests |
---|
| 83 | // ShortExpVectors "squeeze" an exponent vector into one word as follows: |
---|
| 84 | // Let n = BIT_SIZEOF_LONG / pVariables. |
---|
| 85 | // If n == 0 (i.e. pVariables > BIT_SIZE_OF_LONG), let m == the number |
---|
| 86 | // of non-zero exponents. If (m>BIT_SIZEOF_LONG), then sev = ~0, else |
---|
| 87 | // first m bits of sev are set to 1. |
---|
| 88 | // Otherwise (i.e. pVariables <= BIT_SIZE_OF_LONG) |
---|
| 89 | // represented by a bit-field of length n (resp. n+1 for some |
---|
| 90 | // exponents). If the value of an exponent is greater or equal to n, then |
---|
| 91 | // all of its respective n bits are set to 1. If the value of an exponent |
---|
| 92 | // is smaller than n, say m, then only the first m bits of the respective |
---|
| 93 | // n bits are set to 1, the others are set to 0. |
---|
| 94 | // This way, we have: |
---|
| 95 | // exp1 / exp2 ==> (ev1 & ~ev2) == 0, i.e., |
---|
| 96 | // if (ev1 & ~ev2) then exp1 does not divide exp2 |
---|
| 97 | unsigned long p_GetShortExpVector(poly p, ring r) |
---|
| 98 | { |
---|
| 99 | assume(p != NULL); |
---|
| 100 | if (p == NULL) return 0; |
---|
| 101 | unsigned long ev = 0; // short exponent vector |
---|
| 102 | unsigned int n = BIT_SIZEOF_LONG / r->N; // number of bits per exp |
---|
| 103 | unsigned int m1; // highest bit which is filled with (n+1) |
---|
| 104 | unsigned int i = 0, j=1; |
---|
| 105 | |
---|
| 106 | if (n == 0) |
---|
| 107 | { |
---|
| 108 | if (r->N <2*BIT_SIZEOF_LONG) |
---|
| 109 | { |
---|
| 110 | n=1; |
---|
| 111 | m1=0; |
---|
| 112 | } |
---|
| 113 | else |
---|
| 114 | { |
---|
| 115 | for (; j<=(unsigned long) r->N; j++) |
---|
| 116 | { |
---|
| 117 | if (p_GetExp(p,j,r) > 0) i++; |
---|
| 118 | if (i == BIT_SIZEOF_LONG) break; |
---|
| 119 | } |
---|
| 120 | if (i>0) |
---|
| 121 | ev = ~((unsigned long)0) >> ((unsigned long) (BIT_SIZEOF_LONG - i)); |
---|
| 122 | return ev; |
---|
| 123 | } |
---|
| 124 | } |
---|
| 125 | else |
---|
| 126 | { |
---|
| 127 | m1 = (n+1)*(BIT_SIZEOF_LONG - n*r->N); |
---|
| 128 | } |
---|
| 129 | |
---|
| 130 | n++; |
---|
| 131 | while (i<m1) |
---|
| 132 | { |
---|
| 133 | ev |= GetBitFields(p_GetExp(p, j,r), i, n); |
---|
| 134 | i += n; |
---|
| 135 | j++; |
---|
| 136 | } |
---|
| 137 | |
---|
| 138 | n--; |
---|
| 139 | while (i<BIT_SIZEOF_LONG) |
---|
| 140 | { |
---|
| 141 | ev |= GetBitFields(p_GetExp(p, j,r), i, n); |
---|
| 142 | i += n; |
---|
| 143 | j++; |
---|
| 144 | } |
---|
| 145 | return ev; |
---|
| 146 | } |
---|
| 147 | |
---|
| 148 | |
---|
| 149 | int rComp0_Func(poly p1,poly p2) |
---|
| 150 | { |
---|
| 151 | int i; |
---|
| 152 | for(i=0; i< currRing->CmpL_Size;i++) |
---|
| 153 | { |
---|
| 154 | if (p1->exp[i] != p2->exp[i]) |
---|
| 155 | { |
---|
| 156 | if (p1->exp[i] > p2->exp[i]) |
---|
| 157 | return currRing->ordsgn[i]; |
---|
| 158 | else |
---|
| 159 | return -currRing->ordsgn[i]; |
---|
| 160 | } |
---|
| 161 | } |
---|
| 162 | return 0; |
---|
| 163 | } |
---|
| 164 | |
---|
| 165 | #ifdef PDEBUG |
---|
| 166 | int rComp0(poly p1,poly p2) |
---|
| 167 | { |
---|
| 168 | int i; |
---|
| 169 | for(i=0; i<currRing->CmpL_Size;i++) |
---|
| 170 | { |
---|
| 171 | if (p1->exp[i] != p2->exp[i]) |
---|
| 172 | { |
---|
| 173 | if (p1->exp[i] > p2->exp[i]) |
---|
| 174 | return currRing->ordsgn[i]; |
---|
| 175 | else |
---|
| 176 | return -currRing->ordsgn[i]; |
---|
| 177 | } |
---|
| 178 | } |
---|
| 179 | return 0; |
---|
| 180 | } |
---|
| 181 | #endif |
---|
| 182 | |
---|
| 183 | #endif // POLYS_IMPL_CC |
---|