wm: 5551

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add mulitbit adder

--- a/5551e.c

+++ b/5551e.c

@@ -11,14 +11,29 @@

 	int regs[8];

 }reg_t;

-bool add_bit(bool a, bool b, bool *carry)

+bool carry = false;

+bool add_bit(bool a, bool b)

 {

-	bool out, temp = *carry;

-	out = ((a ^ b) ^ temp);

-	*carry = (((a ^ b) & temp) | (a & b));

+	bool out;

+	out = ((a ^ b) ^ carry);

+	carry = (((a ^ b) & carry) | (a & b));

 	return out;

 }

+int btoi(bool b[], int len)

+{

+  char arr[10];

+  int res = 0, i = 0, j = len;

+  while (i <= len) 

+    {

+		arr[i] = b[j] ? '1' : '0';

+		i++;

+		j--;

+    }

+  sscanf(arr, "%d", &res);

+    return res;

+}

+

 int main()

 {

@@ -29,7 +44,8 @@

 	char string[16];

 	r.flags[ON] = 1;

 	r.flags[NSIGN] = 0;

-	unsigned int op, a, b, c;

+	unsigned int op, a, b, c, ind = 0;

+    bool barr[10];

 		/* there is no space between op and args

 			since some can have no args */

@@ -63,10 +79,20 @@

 				break;

 			case SUB:

 				b = ~b;

-				r.regs[CARRY] = 1;

+				carry = 1;

 			case ADD:

-				r.regs[c] = add_bit(a, b, &r.flags[CARRY]);

+				while (a > 0 && b > 0) {

+					int diga = a % 10;

+					int digb = b % 10;

+					barr[ind] = add_bit(diga, digb);

+					a /= 10;

+					b /= 10;

+					ind++;

+				}

+				barr[ind] = carry;

+				r.regs[c] = btoi(barr,ind);

 				break;

+				break;

 			case SHR:

 				r.regs[c] = a >> b;

 				break;

@@ -85,7 +111,7 @@

 				r.regs[c] = a >> b;

 				break;

 			default:

-				fprintf(stderr, "unkown op\n");

+				fprintf(stderr, "unknown op\n");

 				return 1;

 		}

 		/* clear them */

@@ -93,6 +119,8 @@

 		b = 0;

 		op = 0;

 		string[0] = '\0'; 

+        ind = 0;

+        carry = 0;

 	}

 	return 0;

 }