/* $OpenXM: OpenXM_contrib2/asir2000/engine/Hgfs.c,v 1.3 2001/06/22 08:51:12 noro Exp $ */ #include "ca.h" struct p_pair { UM p0; UM p1; struct p_pair *next; }; void canzassf(UM,int,UM *); void lnfsf(int,UM,UM,struct p_pair *,UM,UM); void minipolysf(UM,UM,UM); void czsfum(UM,UM *); void gensqfrsfum(UM,DUM); void fctrsf(p,dcp) P p; DCP *dcp; { int n,i,j,k; DCP dc,dc0; P lc; P zp; UM mp; UM *tl; struct oDUM *udc,*udc1; simp_ff(p,&zp); p = zp; if ( !p ) { *dcp = 0; return; } mp = W_UMALLOC(UDEG(p)); ptosfum(p,mp); if ( (n = DEG(mp)) < 0 ) { *dcp = 0; return; } else if ( n == 0 ) { NEWDC(dc); COEF(dc) = p; DEG(dc) = ONE; NEXT(dc) = 0; *dcp = dc; return; } lc = COEF(DC(p)); if ( !_isonesf(COEF(mp)[n]) ) { monicsfum(mp); } W_CALLOC(n+1,struct oDUM,udc); gensqfrsfum(mp,udc); tl = (UM *)ALLOCA((n+1)*sizeof(UM)); W_CALLOC(DEG(mp)+1,struct oDUM,udc1); for ( i = 0,j = 0; udc[i].f; i++ ) if ( DEG(udc[i].f) == 1 ) { udc1[j].f = udc[i].f; udc1[j].n = udc[i].n; j++; } else { bzero((char *)tl,(n+1)*sizeof(UM)); czsfum(udc[i].f,tl); for ( k = 0; tl[k]; k++, j++ ) { udc1[j].f = tl[k]; udc1[j].n = udc[i].n; } } udc = udc1; NEWDC(dc0); COEF(dc0) = lc; DEG(dc0) = ONE; dc = dc0; for ( n = 0; udc[n].f; n++ ) { NEWDC(NEXT(dc)); dc = NEXT(dc); STOQ(udc[n].n,DEG(dc)); sfumtop(VR(p),udc[n].f,&COEF(dc)); } NEXT(dc) = 0; *dcp = dc0; } void gensqfrsfum(p,dc) UM p; struct oDUM *dc; { int n,i,j,d,mod; UM t,s,g,f,f1,b; if ( (n = DEG(p)) == 1 ) { dc[0].f = UMALLOC(DEG(p)); cpyum(p,dc[0].f); dc[0].n = 1; return; } t = W_UMALLOC(n); s = W_UMALLOC(n); g = W_UMALLOC(n); f = W_UMALLOC(n); f1 = W_UMALLOC(n); b = W_UMALLOC(n); diffsfum(p,t); cpyum(p,s); gcdsfum(t,s,g); if ( !DEG(g) ) { dc[0].f = UMALLOC(DEG(p)); cpyum(p,dc[0].f); dc[0].n = 1; return; } cpyum(p,b); cpyum(p,t); divsfum(t,g,f); for ( i = 0, d = 0; DEG(f); i++ ) { while ( 1 ) { cpyum(b,t); if ( divsfum(t,f,s) >= 0 ) break; else { cpyum(s,b); d++; } } cpyum(b,t); cpyum(f,s); gcdsfum(t,s,f1); divsfum(f,f1,s); cpyum(f1,f); dc[i].f = UMALLOC(DEG(s)); cpyum(s,dc[i].f); dc[i].n = d; } mod = characteristic_sf(); if ( DEG(b) > 0 ) { d = 1; while ( 1 ) { cpyum(b,t); for ( j = DEG(t); j >= 0; j-- ) if ( COEF(t)[j] && (j % mod) ) break; if ( j >= 0 ) break; else { DEG(s) = DEG(t)/mod; for ( j = 0; j <= DEG(t); j++ ) COEF(s)[j] = COEF(t)[j*mod]; cpyum(s,b); d *= mod; } } gensqfrsfum(b,dc+i); for ( j = i; dc[j].f; j++ ) dc[j].n *= d; } } void randsfum(d,p) int d; UM p; { int i; for ( i = 0; i < d; i++ ) COEF(p)[i] = _randomsf(); for ( i = d-1; i >= 0 && !COEF(p)[i]; i-- ); p->d = i; } void pwrmodsfum(p,e,f,pr) int e; UM p,f,pr; { UM wt,ws,q; if ( e == 0 ) { DEG(pr) = 0; COEF(pr)[0] = _onesf(); } else if ( DEG(p) < 0 ) DEG(pr) = -1; else if ( e == 1 ) { q = W_UMALLOC(DEG(p)); cpyum(p,pr); DEG(pr) = divsfum(pr,f,q); } else if ( DEG(p) == 0 ) { DEG(pr) = 0; COEF(pr)[0] = _pwrsf(COEF(p)[0],e); } else { wt = W_UMALLOC(2*DEG(f)); ws = W_UMALLOC(2*DEG(f)); q = W_UMALLOC(2*DEG(f)); pwrmodsfum(p,e/2,f,wt); if ( !(e%2) ) { mulsfum(wt,wt,pr); DEG(pr) = divsfum(pr,f,q); } else { mulsfum(wt,wt,ws); DEG(ws) = divsfum(ws,f,q); mulsfum(ws,p,pr); DEG(pr) = divsfum(pr,f,q); } } } void spwrsfum(m,f,e,r) UM f,m,r; N e; { UM t,s,q; N e1; int a; if ( !e ) { DEG(r) = 0; COEF(r)[0] = _onesf(); } else if ( UNIN(e) ) cpyum(f,r); else { a = divin(e,2,&e1); t = W_UMALLOC(2*DEG(m)); spwrsfum(m,f,e1,t); s = W_UMALLOC(2*DEG(m)); q = W_UMALLOC(2*DEG(m)); mulsfum(t,t,s); DEG(s) = divsfum(s,m,q); if ( a ) { mulsfum(s,f,t); DEG(t) = divsfum(t,m,q); cpyum(t,r); } else cpyum(s,r); } } void tracemodsfum(m,f,e,r) UM f,m,r; int e; { UM t,s,q,u; int i; q = W_UMALLOC(2*DEG(m)+DEG(f)); /* XXX */ t = W_UMALLOC(2*DEG(m)); s = W_UMALLOC(2*DEG(m)); u = W_UMALLOC(2*DEG(m)); DEG(f) = divsfum(f,m,q); cpyum(f,s); cpyum(f,t); for ( i = 1; i < e; i++ ) { mulsfum(t,t,u); DEG(u) = divsfum(u,m,q); cpyum(u,t); addsfum(t,s,u); cpyum(u,s); } cpyum(s,r); } void make_qmatsf(p,tab,mp) UM p; UM *tab; int ***mp; { int n,i,j; int *c; UM q,r; int **mat; int one; n = DEG(p); *mp = mat = almat(n,n); for ( j = 0; j < n; j++ ) { r = W_UMALLOC(DEG(tab[j])); q = W_UMALLOC(DEG(tab[j])); cpyum(tab[j],r); DEG(r) = divsfum(r,p,q); for ( i = 0, c = COEF(r); i <= DEG(r); i++ ) mat[i][j] = c[i]; } one = _onesf(); for ( i = 0; i < n; i++ ) mat[i][i] = _subsf(mat[i][i],one); } void nullsf(mat,n,ind) int **mat; int *ind; int n; { int i,j,l,s,h,inv; int *t,*u; bzero((char *)ind,n*sizeof(int)); ind[0] = 0; for ( i = j = 0; j < n; i++, j++ ) { for ( ; j < n; j++ ) { for ( l = i; l < n; l++ ) if ( mat[l][j] ) break; if ( l < n ) { t = mat[i]; mat[i] = mat[l]; mat[l] = t; break; } else ind[j] = 1; } if ( j == n ) break; inv = _invsf(mat[i][j]); for ( s = j, t = mat[i]; s < n; s++ ) t[s] = _mulsf(t[s],inv); for ( l = 0; l < n; l++ ) { if ( l == i ) continue; u = mat[l]; h = _chsgnsf(u[j]); for ( s = j; s < n; s++ ) u[s] = _addsf(_mulsf(h,t[s]),u[s]); } } } void null_to_solsf(mat,ind,n,r) int **mat; int *ind; int n; UM *r; { int i,j,k,l; int *c; UM w; for ( i = 0, l = 0; i < n; i++ ) { if ( !ind[i] ) continue; w = UMALLOC(n); for ( j = k = 0, c = COEF(w); j < n; j++ ) if ( ind[j] ) c[j] = 0; else c[j] = mat[k++][i]; c[i] = _chsgnsf(_onesf()); for ( j = n; j >= 0; j-- ) if ( c[j] ) break; DEG(w) = j; r[l++] = w; } } /* make_qmatsf(p,tab,mp) nullsf(mat,n,ind) null_to_solsf(ind,n,r) */ void czsfum(f,r) UM f,*r; { int i,j; int d,n,ord; UM s,t,u,v,w,g,x,m,q; UM *base; n = DEG(f); base = (UM *)ALLOCA(n*sizeof(UM)); bzero((char *)base,n*sizeof(UM)); w = W_UMALLOC(2*n); q = W_UMALLOC(2*n); m = W_UMALLOC(2*n); base[0] = W_UMALLOC(0); DEG(base[0]) = 0; COEF(base[0])[0] = _onesf(); t = W_UMALLOC(1); DEG(t) = 1; COEF(t)[0] = 0; COEF(t)[1] = _onesf(); ord = field_order_sf(); pwrmodsfum(t,ord,f,w); base[1] = W_UMALLOC(DEG(w)); cpyum(w,base[1]); for ( i = 2; i < n; i++ ) { mulsfum(base[i-1],base[1],m); DEG(m) = divsfum(m,f,q); base[i] = W_UMALLOC(DEG(m)); cpyum(m,base[i]); } v = W_UMALLOC(n); cpyum(f,v); DEG(w) = 1; COEF(w)[0] = 0; COEF(w)[1] = _onesf(); x = W_UMALLOC(1); DEG(x) = 1; COEF(x)[0] = 0; COEF(x)[1] = _onesf(); t = W_UMALLOC(n); s = W_UMALLOC(n); u = W_UMALLOC(n); g = W_UMALLOC(n); for ( j = 0, d = 1; 2*d <= DEG(v); d++ ) { for ( DEG(t) = -1, i = 0; i <= DEG(w); i++ ) if ( COEF(w)[i] ) { mulssfum(base[i],COEF(w)[i],s); addsfum(s,t,u); cpyum(u,t); } cpyum(t,w); cpyum(v,s); subsfum(w,x,t); gcdsfum(s,t,g); if ( DEG(g) >= 1 ) { berlekampsf(g,d,base,r+j); j += DEG(g)/d; divsfum(v,g,q); cpyum(q,v); DEG(w) = divsfum(w,v,q); for ( i = 0; i < DEG(v); i++ ) DEG(base[i]) = divsfum(base[i],v,q); } } if ( DEG(v) ) { r[j] = UMALLOC(DEG(v)); cpyum(v,r[j]); j++; } r[j] = 0; } int berlekampsf(p,df,tab,r) UM p; int df; UM *tab,*r; { int n,i,j,k,nf,d,nr; int **mat; int *ind; UM mp,w,q,gcd,w1,w2; UM *u; int *root; n = DEG(p); ind = ALLOCA(n*sizeof(int)); make_qmatsf(p,tab,&mat); nullsf(mat,n,ind); for ( i = 0, d = 0; i < n; i++ ) if ( ind[i] ) d++; if ( d == 1 ) { r[0] = UMALLOC(n); cpyum(p,r[0]); return 1; } u = ALLOCA(d*sizeof(UM *)); r[0] = UMALLOC(n); cpyum(p,r[0]); null_to_solsf(mat,ind,n,u); root = ALLOCA(d*sizeof(int)); w = W_UMALLOC(n); mp = W_UMALLOC(d); w1 = W_UMALLOC(n); w2 = W_UMALLOC(n); for ( i = 1, nf = 1; i < d; i++ ) { minipolysf(u[i],p,mp); nr = find_rootsf(mp,root); for ( j = 0; j < nf; j++ ) { if ( DEG(r[j]) == df ) continue; for ( k = 0; k < nr; k++ ) { cpyum(u[i],w1); cpyum(r[j],w2); COEF(w1)[0] = _chsgnsf(root[k]); gcdsfum(w1,w2,w); if ( DEG(w) > 0 && DEG(w) < DEG(r[j]) ) { gcd = UMALLOC(DEG(w)); q = UMALLOC(DEG(r[j])-DEG(w)); cpyum(w,gcd); divsfum(r[j],w,q); r[j] = q; r[nf++] = gcd; } if ( nf == d ) return d; } } } } void minipolysf(f,p,mp) UM f,p,mp; { struct p_pair *list,*l,*l1,*lprev; int n,d; UM u,p0,p1,np0,np1,q,w; list = (struct p_pair *)MALLOC(sizeof(struct p_pair)); list->p0 = u = W_UMALLOC(0); DEG(u) = 0; COEF(u)[0] = _onesf(); list->p1 = W_UMALLOC(0); cpyum(list->p0,list->p1); list->next = 0; n = DEG(p); w = UMALLOC(2*n); p0 = UMALLOC(2*n); cpyum(list->p0,p0); p1 = UMALLOC(2*n); cpyum(list->p1,p1); q = W_UMALLOC(2*n); while ( 1 ) { COEF(p0)[DEG(p0)] = 0; DEG(p0)++; COEF(p0)[DEG(p0)] = _onesf(); mulsfum(f,p1,w); DEG(w) = divsfum(w,p,q); cpyum(w,p1); np0 = UMALLOC(n); np1 = UMALLOC(n); lnfsf(n,p0,p1,list,np0,np1); if ( DEG(np1) < 0 ) { cpyum(np0,mp); return; } else { l1 = (struct p_pair *)MALLOC(sizeof(struct p_pair)); l1->p0 = np0; l1->p1 = np1; for ( l = list, lprev = 0, d = DEG(np1); l && (DEG(l->p1) > d); lprev = l, l = l->next ); if ( lprev ) { lprev->next = l1; l1->next = l; } else { l1->next = list; list = l1; } } } } void lnfsf(n,p0,p1,list,np0,np1) int n; UM p0,p1; struct p_pair *list; UM np0,np1; { int inv,h,d1; UM t0,t1,s0,s1; struct p_pair *l; cpyum(p0,np0); cpyum(p1,np1); t0 = W_UMALLOC(n); t1 = W_UMALLOC(n); s0 = W_UMALLOC(n); s1 = W_UMALLOC(n); for ( l = list; l; l = l->next ) { d1 = DEG(np1); if ( d1 == DEG(l->p1) ) { h = _divsf(COEF(np1)[d1],_chsgnsf(COEF(l->p1)[d1])); mulssfum(l->p0,h,t0); addsfum(np0,t0,s0); cpyum(s0,np0); mulssfum(l->p1,h,t1); addsfum(np1,t1,s1); cpyum(s1,np1); } } } int find_rootsf(p,root) UM p; int *root; { UM *r; int i,j,n; n = DEG(p); r = ALLOCA((DEG(p))*sizeof(UM)); canzassf(p,1,r); for ( i = 0; i < n; i++ ) root[i] = _chsgnsf(COEF(r[i])[0]); return n; } void canzassf(f,d,r) UM f,*r; int d; { UM t,s,u,w,g,o; N n1,n2,n3,n4,n5; UM *b; int n,m,i,q,ed; if ( DEG(f) == d ) { r[0] = UMALLOC(d); cpyum(f,r[0]); return; } else { n = DEG(f); b = (UM *)ALLOCA(n*sizeof(UM)); bzero((char *)b,n*sizeof(UM)); t = W_UMALLOC(2*d); s = W_UMALLOC(DEG(f)); u = W_UMALLOC(DEG(f)); w = W_UMALLOC(DEG(f)); g = W_UMALLOC(DEG(f)); o = W_UMALLOC(0); DEG(o) = 0; COEF(o)[0] = _onesf(); q = field_order_sf(); if ( q % 2 ) { STON(q,n1); pwrn(n1,d,&n2); subn(n2,ONEN,&n3); STON(2,n4); divsn(n3,n4,&n5); } else ed = d*extdeg_sf(); while ( 1 ) { randsfum(2*d,t); if ( q % 2 ) { spwrsfum(f,t,n5,s); subsfum(s,o,u); } else tracemodsfum(f,t,ed,u); cpyum(f,w); gcdsfum(w,u,g); if ( (DEG(g) >= 1) && (DEG(g) < DEG(f)) ) { canzassf(g,d,r); cpyum(f,w); divsfum(w,g,s); canzassf(s,d,r+DEG(g)/d); return; } } } } /* Hensel related functions */ int sfberle(VL,P,int,GFS *,DCP *); void sfgcdgen(P,ML,ML *); void sfhenmain(LUM,ML,ML,ML *); void ptosflum(int,P,LUM); /* f = f(x,y) */ void sfhensel(count,f,x,listp) int count; P f; V x; ML *listp; { int i,j; int fn,n,bound; int *p; int **pp; ML blist,clist,rlist; UM *b; LUM fl,tl; LUM *l; VL vl,nvl; V y; int dx,dy; GFS ev; P f1,g,g0,t,yev,c; DCP dc; LUM gl; clctv(CO,f,&vl); if ( vl->v != x ) { reordvar(vl,x,&nvl); reorderp(nvl,vl,f,&f1); vl = nvl; f = f1; } y = vl->next->v; dx = getdeg(x,f); dy = getdeg(y,f); if ( dx == 1 ) { *listp = blist = MLALLOC(1); blist->n = 1; blist->c[0] = 0; return; } fn = sfberle(vl,f,count,&ev,&dc); if ( fn <= 1 ) { /* fn == 0 => short of evaluation points */ *listp = blist = MLALLOC(1); blist->n = fn; blist->c[0] = 0; return; } /* pass the the leading coeff. to the first element */ c = dc->c; dc = NEXT(dc); mulp(vl,dc->c,c,&t); dc->c = t; blist = MLALLOC(n); blist->n = fn; for ( i = 0; i < fn; i++, dc = NEXT(dc) ) { blist->c[i] = W_UMALLOC(UDEG(dc->c)); ptosfum(dc->c,blist->c[i]); } /* f(x,y) -> g = f(x,y+ev) */ MKV(y,t); addp(vl,t,(P)ev,&yev); substp(vl,f,y,yev,&g); substp(vl,g,y,0,&g0); sfgcdgen(g0,blist,&clist); blist->bound = clist->bound = dy; W_LUMALLOC(dx,bound,gl); ptosflum(bound,g,gl); sfhenmain(gl,blist,clist,listp); } /* main variable of f = x */ int sfberle(vl,f,count,ev,dcp) VL vl; P f; int count; GFS *ev; DCP *dcp; { UM wf,wf1,wf2,wfs,gcd; ML flist; int fn,fn1,n; GFS m,fm; DCP dc,dct,dc0; VL nvl; V x,y; P g,lc,lc0,f0; int j,q1,index,i; clctv(vl,f,&nvl); vl = nvl; x = vl->v; y = vl->next->v; simp_ff(f,&g); g = f; n = QTOS(DEG(DC(f))); wf = W_UMALLOC(n); wf1 = W_UMALLOC(n); wf2 = W_UMALLOC(n); wfs = W_UMALLOC(n); gcd = W_UMALLOC(n); q1 = field_order_sf()-1; lc = DC(f)->c; for ( j = 0, fn = n + 1, index = 0; index < q1 && j < count && fn > 1; ) { MKGFS(index,m); substp(vl,lc,y,(P)m,&lc0); if ( lc0 ) { substp(vl,f,y,(P)m,&f0); ptosfum(m,f,wf); cpyum(wf,wf1); diffsfum(m,wf1,wf2); gcdsfum(m,wf1,wf2,gcd); if ( DEG(gcd) == 0 ) { fctrsf(f0,&dc); for ( dct = NEXT(dc), i = 0; dct; dct = NEXT(dct), i++ ); if ( i < fn ) { dc0 = dc; fn = i; fm = m; } j++; } } } if ( index == q1 ) return 0; else if ( fn == 1 ) return 1; else { *dcp = dc0; *ev = fm; return fn; } } void sfgcdgen(f,blist,clistp) P f; ML blist,*clistp; { int i; int n,d,np; UM wf,wm,wx,wy,wu,wv,wa,wb,wg,q,tum; UM *in,*out; ML clist; n = UDEG(f); np = blist->n; d = 2*n; q = W_UMALLOC(d); wf = W_UMALLOC(d); wm = W_UMALLOC(d); wx = W_UMALLOC(d); wy = W_UMALLOC(d); wu = W_UMALLOC(d); wv = W_UMALLOC(d); wg = W_UMALLOC(d); wa = W_UMALLOC(d); wb = W_UMALLOC(d); ptosfum(f,wf); DEG(wg) = 0; COEF(wg)[0] = _onesf(); *clistp = clist = MLALLOC(np); clist->n = np; for ( i = 0, in = (UM *)blist->c, out = (UM *)clist->c; i < np; i++ ) { divsfum(wf,in[i],q); tum = wf; wf = q; q = tum; cpyum(wf,wx); cpyum(in[i],wy); eucsfum(wx,wy,wa,wb); mulsfum(wa,wg,wm); DEG(wm) = divsfum(wm,in[i],q); out[i] = UMALLOC(DEG(wm)); cpyum(wm,out[i]); mulsfum(q,wf,wu); mulsfum(wg,wb,wv); addsfum(wu,wv,wg); } } /* sfhenmain(fl,bqlist,cqlist,listp) */ void sfhenmain(f,bqlist,cqlist,listp) LUM f; ML bqlist,cqlist,*listp; { int i,j,k; int *px,*py; int **pp,**pp1; int n,np,bound,dr,tmp; UM wt,wq0,wq,wr,wm,wm0,wa,q; LUM wb0,wb1,tlum; UM *b,*c; LUM *l; ML list; n = DEG(f); np = bqlist->n; bound = bqlist->bound; *listp = list = MLALLOC(n); list->n = np; list->bound = bound; W_LUMALLOC(n,bound,wb0); W_LUMALLOC(n,bound,wb1); wt = W_UMALLOC(n); wq0 = W_UMALLOC(n); wq = W_UMALLOC(n); wr = W_UMALLOC(n); wm = W_UMALLOC(2*n); wm0 = W_UMALLOC(2*n); wa = W_UMALLOC(2*n); q = W_UMALLOC(2*n); b = (UM *)bqlist->c; c = (UM *)cqlist->c; l = (LUM *)list->c; for ( i = 0; i < np; i++ ) { l[i] = LUMALLOC(DEG(b[i]),bound); for ( j = DEG(b[i]), pp = COEF(l[i]), px = COEF(b[i]); j >= 0; j-- ) pp[j][0] = px[j]; } for ( i = 1; i < bound; i++ ) { mulsflum(i+1,l[0],l[1],wb0); for ( j = 2; j < np; j++ ) { mulsflum(i+1,l[j],wb0,wb1); tlum = wb0; wb0 = wb1; wb1 = tlum; } for ( j = n, px = COEF(wt); j >= 0; j-- ) px[j] = 0; for ( j = n, pp = COEF(f), pp1 = COEF(wb0); j >= 0; j-- ) COEF(wt)[j] = _subsf(pp[j][i],pp1[j][i]); degum(wt,n); for ( j = n, px = COEF(wq0); j >= 0; j-- ) px[j] = 0; for ( j = 1; j < np; j++ ) { mulsfum(wt,c[j],wm); dr = divsfum(wm,b[j],q); for ( k = DEG(q), px = COEF(wq0), py = COEF(q); k >= 0; k-- ) px[k] = _addsf(px[k],py[k]); for ( k = dr, pp = COEF(l[j]), px = COEF(wm); k >= 0; k-- ) pp[k][i] = px[k]; } degum(wq0,n); mulsfum(wq0,b[0],wm); mulsfum(wt,c[0],wm0); addsfum(wm,wm0,wa); for ( j = DEG(wa), pp = COEF(l[0]), px = COEF(wa); j >= 0; j-- ) pp[j][i] = px[j]; for ( j = n, px = COEF(wq0); j >= 0; j-- ) px[j] = 0; } } void ptosflum(bound,f,fl) int bound; P f; LUM fl; { DCP dc; int **pp; int d; UM t; t = UMALLOC(bound); for ( dc = DC(f), pp = COEF(fl); dc; dc = NEXT(dc) ) { d = QTOS(DEG(dc)); ptosfum(COEF(dc),t); bcopy(t->c,pp[d],(t->d+1)*sizeof(int)); } }