finish quiz8

lab2/datalab-handout/bits.c

@@ -259,7 +259,7 @@ int isLessOrEqual(int x, int y) {
   int absy = y & sign1;
   int diff = absy + (~absx) + 1;
   int signdiff = diff >> 31;
-  int res = !!isnegpos | (!isnegpos & !signdiff & !isposneg);
+  int res = !(!isnegpos) | (!isnegpos & !signdiff & !isposneg);
   return res;
 }
 //4
@@ -272,7 +272,14 @@ int isLessOrEqual(int x, int y) {
  *   Rating: 4 
  */
 int logicalNeg(int x) {
-  return 2;
+  int sign = (x ^ (~x + 1)) >> 31;
+  int one = 1;
+  int singlesign = sign & one;
+  int intmin = 1 << 31;
+  int isnotmin = (~x) >> 31; // if x is 00000, get 1111 and if x is 1000 get 00000
+  int notmin = isnotmin & one;
+  int res = singlesign ^ one & notmin;
+  return res;
 }
 /* howManyBits - return the minimum number of bits required to represent x in
  *             two's complement