===================================================================
RCS file: /home/cvs/OpenXM_contrib2/asir2000/engine/M.c,v
retrieving revision 1.7
retrieving revision 1.8
diff -u -p -r1.7 -r1.8
--- OpenXM_contrib2/asir2000/engine/M.c	2001/06/25 04:11:42	1.7
+++ OpenXM_contrib2/asir2000/engine/M.c	2001/07/03 01:41:26	1.8
@@ -45,7 +45,7 @@
  * DEVELOPER SHALL HAVE NO LIABILITY IN CONNECTION WITH THE USE,
  * PERFORMANCE OR NON-PERFORMANCE OF THE SOFTWARE.
  *
- * $OpenXM: OpenXM_contrib2/asir2000/engine/M.c,v 1.6 2001/06/25 01:35:21 noro Exp $ 
+ * $OpenXM: OpenXM_contrib2/asir2000/engine/M.c,v 1.7 2001/06/25 04:11:42 noro Exp $ 
 */
 #include "ca.h"
 #include "base.h"
@@ -174,6 +174,7 @@ UM f1,f2,a,b;
 {
 	UM g1,g2,a1,a2,a3,wm,q,tum;
 	int d,dr;
+	UM t1,t2,t3;
 
 	d = DEG(f1) + DEG(f2) + 10;
 	g1 = W_UMALLOC(d); g2 = W_UMALLOC(d); a1 = W_UMALLOC(d);
@@ -199,8 +200,85 @@ UM f1,f2,a,b;
 		DEG(wm) = 0; COEF(wm)[0] = mod - 1;
 	}
 	divum(mod,wm,f2,q); mulsum(mod,q,mod-1,b);
+#if 0
+	t1 = W_UMALLOC(d);
+	t2 = W_UMALLOC(d);
+	t3 = W_UMALLOC(d);
+	mulum(mod,a,f1,t1);
+	mulum(mod,b,f2,t2);
+	addum(mod,t1,t2,t3);
+#endif
 }
 
+void eucum2(mod,f1,f2,a,b)
+register int mod;
+UM f1,f2,a,b;
+{
+	UM gk,gk1,gk2,ak,ak1,ak2,bk,bk1,bk2,q,t,wm1,wm2,wz;
+	int d,inv;
+	UM t1,t2;
+
+	d = 2*(DEG(f1) + DEG(f2));
+	gk = W_UMALLOC(d); gk1 = W_UMALLOC(d); gk2 = W_UMALLOC(d);
+	ak = W_UMALLOC(d); ak1 = W_UMALLOC(d); ak2 = W_UMALLOC(d);
+	bk = W_UMALLOC(d); bk1 = W_UMALLOC(d); bk2 = W_UMALLOC(d);
+	q = W_UMALLOC(d); wm1 = W_UMALLOC(d); wm2 = W_UMALLOC(d);
+	wz = W_UMALLOC(d);
+	
+	t1 = UMALLOC(1000);
+	t2 = UMALLOC(1000);
+	cpyum(f1,t1);
+	cpyum(f2,t2);
+
+	DEG(ak) = 0; COEF(ak)[0] = 1;
+	DEG(ak1) = -1;
+	DEG(bk) = -1;
+	DEG(bk1) = 0; COEF(bk1)[0] = 1;
+
+	cpyum(f1,gk); cpyum(f2,gk1);
+
+	while ( 1 ) {
+		/* ak*f1+bk*f2 = gk, ak1*f1+bk1*f2 = gk1 */
+		cpyum(gk,gk2);
+		DEG(gk2) = divum(mod,gk2,gk1,q);
+		/* gk2 = gk - q*gk1 */
+		if ( DEG(gk2) == -1 ) 
+			break;
+		/* ak2 = ak - q*ak1, bk2 = bk - q*bk1 */
+		mulum(mod,ak1,q,wm1); subum(mod,ak,wm1,ak2);
+		mulum(mod,bk1,q,wm1); subum(mod,bk,wm1,bk2);
+
+		/* shift */
+		t = ak; ak = ak1; ak1 = ak2; ak2 = t;
+		t = bk; bk = bk1; bk1 = bk2; bk2 = t;
+		t = gk; gk = gk1; gk1 = gk2; gk2 = t;
+	}
+	/* ak1*f1+bk1*f2 = gk1 = GCD(f1,f2) */
+	mulum(mod,ak1,t1,wm1); 
+	mulum(mod,bk1,t2,wm2);
+	addum(mod,wm1,wm2,wz);
+	if ( DEG(wz) != 0 )
+		error("euc 1");
+
+	DEG(ak1) = divum(mod,ak1,f2,q);
+	DEG(bk1) = divum(mod,bk1,f1,q);
+	mulum(mod,ak1,f1,wm1); 
+	mulum(mod,bk1,f2,wm2);
+	addum(mod,wm1,wm2,wz);
+	if ( DEG(wz) != 0 )
+		error("euc 2");
+
+
+	if ( COEF(wz)[0] != 1 ) {
+		inv = invm(COEF(wz)[0],mod);
+		mulsum(mod,ak1,inv,a);
+		mulsum(mod,bk1,inv,b);
+	} else {
+		cpyum(ak1,a);
+		cpyum(bk1,b);
+	}
+}
+
 void sqfrum(index,count,f,nindex,dcr,pl)
 int index,count,*nindex;
 P f;
@@ -400,21 +478,20 @@ int n,bound;
 	return p;
 }
 
-/* n = deg in x, bound = deg in y, c[i] <-> the coef of y^i (poly in x) */
+/* dx = deg in x, dy = deg in y, c[i] <-> the coef of y^i (poly in x) */
 
-BM BMALLOC(n,bound)
-int n,bound;
+BM BMALLOC(dx,dy)
+int dx,dy;
 {
 	BM p;
 	UM *c;
 	int i;
 
-	p = (BM)MALLOC(TRUESIZE(oBM,bound,UM));
-	DEG(p) = bound;
-	for ( i = 0, c = (UM *)COEF(p); i < bound; i++ ) {
-		c[i] = UMALLOC(n);
-		DEG(c[i]) = -1;
-		bzero((char *)COEF(c[i]),(n+1)*sizeof(int));
+	p = (BM)MALLOC(TRUESIZE(oBM,dy,UM));
+	DEG(p) = dy;
+	for ( i = 0, c = (UM *)COEF(p); i <= dy; i++ ) {
+		c[i] = UMALLOC(dx);
+		clearum(c[i],dx);
 	}
 	return p;
 }