ref: 1018d7a7091fd5e0433f501a3474cdc3fec322cc
dir: /libmp/port/mpaux.c/
#include "os.h" #include <mp.h> #include "dat.h" static mpdigit _mptwodata[1] = { 2 }; static mpint _mptwo = { 1, 1, 1, _mptwodata, MPstatic }; mpint *mptwo = &_mptwo; static mpdigit _mponedata[1] = { 1 }; static mpint _mpone = { 1, 1, 1, _mponedata, MPstatic }; mpint *mpone = &_mpone; static mpdigit _mpzerodata[1] = { 0 }; static mpint _mpzero = { 1, 1, 0, _mpzerodata, MPstatic }; mpint *mpzero = &_mpzero; static int mpmindigits = 33; // set minimum digit allocation void mpsetminbits(int n) { if(n < 0) sysfatal("mpsetminbits: n < 0"); if(n == 0) n = 1; mpmindigits = DIGITS(n); } // allocate an n bit 0'd number mpint* mpnew(int n) { mpint *b; if(n < 0) sysfatal("mpsetminbits: n < 0"); b = mallocz(sizeof(mpint), 1); if(b == nil) sysfatal("mpnew: %r"); n = DIGITS(n); if(n < mpmindigits) n = mpmindigits; b->p = (mpdigit*)mallocz(n*Dbytes, 1); if(b->p == nil) sysfatal("mpnew: %r"); b->size = n; b->sign = 1; return b; } // guarantee at least n significant bits void mpbits(mpint *b, int m) { int n; n = DIGITS(m); if(b->size >= n){ if(b->top >= n) return; memset(&b->p[b->top], 0, Dbytes*(n - b->top)); b->top = n; return; } b->p = (mpdigit*)realloc(b->p, n*Dbytes); if(b->p == nil) sysfatal("mpbits: %r"); memset(&b->p[b->top], 0, Dbytes*(n - b->top)); b->size = n; b->top = n; } void mpfree(mpint *b) { if(b == nil) return; if(b->flags & MPstatic) sysfatal("freeing mp constant"); memset(b->p, 0, b->size*Dbytes); // information hiding free(b->p); free(b); } void mpnorm(mpint *b) { int i; for(i = b->top-1; i >= 0; i--) if(b->p[i] != 0) break; b->top = i+1; if(b->top == 0) b->sign = 1; } mpint* mpcopy(mpint *old) { mpint *new; new = mpnew(Dbits*old->size); new->top = old->top; new->sign = old->sign; memmove(new->p, old->p, Dbytes*old->top); return new; } void mpassign(mpint *old, mpint *new) { mpbits(new, Dbits*old->top); new->sign = old->sign; new->top = old->top; memmove(new->p, old->p, Dbytes*old->top); } // number of significant bits in mantissa int mpsignif(mpint *n) { int i, j; mpdigit d; if(n->top == 0) return 0; for(i = n->top-1; i >= 0; i--){ d = n->p[i]; for(j = Dbits-1; j >= 0; j--){ if(d & (((mpdigit)1)<<j)) return i*Dbits + j + 1; } } return 0; } // k, where n = 2**k * q for odd q int mplowbits0(mpint *n) { int k, bit, digit; mpdigit d; if(n->top==0) return 0; k = 0; bit = 0; digit = 0; d = n->p[0]; for(;;){ if(d & (1<<bit)) break; k++; bit++; if(bit==Dbits){ if(++digit >= n->top) return 0; d = n->p[digit]; bit = 0; } } return k; }