The basic structure of the code was changed to the same as sub

Author: SakiTakamachi

ext/bcmath/libbcmath/src/doaddsub.c

@@ -41,75 +41,67 @@
 bc_num _bc_do_add(bc_num n1, bc_num n2, size_t scale_min)
 {
 	bc_num sum;
-	size_t sum_scale, sum_digits;
+	size_t sum_len = MAX(n1->n_len, n2->n_len) + 1;
+	size_t sum_scale = MAX(n1->n_scale, n2->n_scale);
+	size_t min_len = MIN (n1->n_len, n2->n_len);
+	size_t min_scale = MIN(n1->n_scale, n2->n_scale);
+	size_t min_bytes = min_len + min_scale;
 	char *n1ptr, *n2ptr, *sumptr;
-	size_t n1bytes, n2bytes;
-	bool carry;
+	bool carry = 0;
+	size_t count;
 
 	/* Prepare sum. */
-	sum_scale = MAX (n1->n_scale, n2->n_scale);
-	sum_digits = MAX (n1->n_len, n2->n_len) + 1;
-	sum = bc_new_num (sum_digits, MAX(sum_scale, scale_min));
+	sum = bc_new_num (sum_len, MAX(sum_scale, scale_min));
 
 	/* Start with the fraction part.  Initialize the pointers. */
-	n1bytes = n1->n_scale;
-	n2bytes = n2->n_scale;
-	n1ptr = (char *) (n1->n_value + n1->n_len + n1bytes - 1);
-	n2ptr = (char *) (n2->n_value + n2->n_len + n2bytes - 1);
-	sumptr = (char *) (sum->n_value + sum_scale + sum_digits - 1);
+	n1ptr = (char *) (n1->n_value + n1->n_len + n1->n_scale - 1);
+	n2ptr = (char *) (n2->n_value + n2->n_len + n2->n_scale - 1);
+	sumptr = (char *) (sum->n_value + sum_scale + sum_len - 1);
 
 	/* Add the fraction part.  First copy the longer fraction.*/
-	if (n1bytes != n2bytes) {
-		if (n1bytes > n2bytes) {
-			while (n1bytes > n2bytes) {
-				*sumptr-- = *n1ptr--;
-				n1bytes--;
-			}
-		} else {
-			while (n2bytes > n1bytes) {
-				*sumptr-- = *n2ptr--;
-				n2bytes--;
-			}
+	if (n1->n_scale != min_scale) {
+		/* n1 has the longer scale */
+		for (count = n1->n_scale - min_scale; count > 0; count--) {
+			*sumptr-- = *n1ptr--;
+		}
+	} else {
+		/* n2 has the longer scale */
+		for (count = n2->n_scale - min_scale; count > 0; count--) {
+			*sumptr-- = *n2ptr--;
 		}
 	}
 
 	/* Now add the remaining fraction part and equal size integer parts. */
-	n1bytes += n1->n_len;
-	n2bytes += n2->n_len;
-	carry = 0;
-	while ((n1bytes > 0) && (n2bytes > 0)) {
+	for (count = 0; count < min_bytes; count++) {
 		*sumptr = *n1ptr-- + *n2ptr-- + carry;
-		if (*sumptr > (BASE - 1)) {
-			carry = 1;
+		if (*sumptr >= BASE) {
 			*sumptr -= BASE;
+			carry = 1;
 		} else {
 			carry = 0;
 		}
 		sumptr--;
-		n1bytes--;
-		n2bytes--;
 	}
 
 	/* Now add carry the longer integer part. */
-	if (n1bytes == 0) {
-		n1bytes = n2bytes;
-		n1ptr = n2ptr;
-	}
-	while (n1bytes-- > 0) {
-		*sumptr = *n1ptr-- + carry;
-		if (*sumptr > (BASE - 1)) {
-			carry = true;
-			*sumptr -= BASE;
-		} else {
-			carry = false;
+	if (sum_len != min_len) {
+		if (n2->n_len > n1->n_len) {
+			n1ptr = n2ptr;
+		}
+		for (count = sum_len - min_len; count > 0; count--) {
+			*sumptr = *n1ptr-- + carry;
+			if (*sumptr >= BASE) {
+				*sumptr -= BASE;
+				carry = 1;
+			} else {
+				carry = 0;
+			}
+			sumptr--;
 		}
-		sumptr--;
 	}
 
 	/* Set final carry. */
-	if (carry) {
-		*sumptr += 1;
-	}
+	*sumptr += carry;
 
 	/* Adjust sum and return. */
 	_bc_rm_leading_zeros(sum);