--- /n/sources/plan9/sys/src/libmp/port/mpvecadd.c	Sat Jan 10 10:00:05 2015
+++ /sys/src/libmp/port/mpvecadd.c	Sun Jun 28 00:00:00 2026
@@ -14,21 +14,14 @@ mpvecadd(mpdigit *a, int alen, mpdigit *b, int blen, mpdigit *sum)
 		x = *a++;
 		y = *b++;
 		x += carry;
-		if(x < carry)
-			carry = 1;
-		else
-			carry = 0;
+		carry = x < carry;
 		x += y;
-		if(x < y)
-			carry++;
+		carry += x < y;
 		*sum++ = x;
 	}
 	for(; i < alen; i++){
 		x = *a++ + carry;
-		if(x < carry)
-			carry = 1;
-		else
-			carry = 0;
+		carry = x < carry;
 		*sum++ = x;
 	}
 	*sum = carry;
--- /n/sources/plan9/sys/src/libmp/port/mpvecdigmuladd.c	Sat Jan 10 10:00:05 2015
+++ /sys/src/libmp/port/mpvecdigmuladd.c	Sun Jun 28 00:00:00 2026
@@ -2,7 +2,7 @@
 #include <mp.h>
 #include "dat.h"
 
-#define LO(x) ((x) & ((1<<(Dbits/2))-1))
+#define LO(x) ((x) & ((1ll<<(Dbits/2))-1))
 #define HI(x) ((x) >> (Dbits/2))
 
 static void
@@ -24,15 +24,12 @@ mpdigmul(mpdigit a, mpdigit b, mpdigit *p)
 	p4 = ah*bh;
 
 	// p = ((p1+p2)<<(Dbits/2)) + (p4<<Dbits) + p3
-	carry = 0;
 	x = p1<<(Dbits/2);
 	p3 += x;
-	if(p3 < x)
-		carry++;
+	carry = p3 < x;
 	x = p2<<(Dbits/2);
 	p3 += x;
-	if(p3 < x)
-		carry++;
+	carry += p3 < x;
 	p4 += carry + HI(p1) + HI(p2);	// can't carry out of the high digit
 	p[0] = p3;
 	p[1] = p4;
@@ -49,18 +46,13 @@ mpvecdigmuladd(mpdigit *b, int n, mpdigit m, mpdigit *p)
 	part[1] = 0;
 	for(i = 0; i < n; i++){
 		x = part[1] + carry;
-		if(x < carry)
-			carry = 1;
-		else
-			carry = 0;
+		carry = x < carry;
 		y = *p;
 		mpdigmul(*b++, m, part);
 		x += part[0];
-		if(x < part[0])
-			carry++;
+		carry += x < part[0];
 		x += y;
-		if(x < y)
-			carry++;
+		carry += x < y;
 		*p++ = x;
 	}
 	*p = part[1] + carry;
@@ -78,18 +70,13 @@ mpvecdigmulsub(mpdigit *b, int n, mpdigit m, mpdigit *p)
 	for(i = 0; i < n; i++){
 		x = *p;
 		y = x - borrow;
-		if(y > x)
-			borrow = 1;
-		else
-			borrow = 0;
+		borrow = y > x;
 		x = part[1];
 		mpdigmul(*b++, m, part);
 		x += part[0];
-		if(x < part[0])
-			borrow++;
+		borrow += x < part[0];
 		x = y - x;
-		if(x > y)
-			borrow++;
+		borrow += x > y;
 		*p++ = x;
 	}
 
--- /n/sources/plan9/sys/src/libmp/port/mpvecsub.c	Sat Jan 10 10:00:05 2015
+++ /sys/src/libmp/port/mpvecsub.c	Sun Jun 28 00:00:00 2026
@@ -14,21 +14,14 @@ mpvecsub(mpdigit *a, int alen, mpdigit *b, int blen, mpdigit *diff)
 		x = *a++;
 		y = *b++;
 		y += borrow;
-		if(y < borrow)
-			borrow = 1;
-		else
-			borrow = 0;
-		if(x < y)
-			borrow++;
+		borrow = y < borrow;
+		borrow += x < y;
 		*diff++ = x - y;
 	}
 	for(; i < alen; i++){
 		x = *a++;
 		y = x - borrow;
-		if(y > x)
-			borrow = 1;
-		else
-			borrow = 0;
+		borrow = y > x;
 		*diff++ = y;
 	}
 }