update datalab01/bits.c

.gitattributes

@@ -1,3 +1,5 @@
+* text=auto eol=lf
+
 [attr]lfs-file filter=lfs diff=lfs merge=lfs -text
 
 "*.pdf" lfs-file

labs/01_datalab/bits.c

@@ -187,7 +187,7 @@ int bitAnd(int x, int y) {
  *   Rating: 1
  */
 int bitXor(int x, int y) {
-    return x & ~y | ~x & y;
+    return ~((~(x & ~y)) & (~(~x & y)));
 }
 /*
  * isTmin - returns 1 if x is the minimum, two's complement number,
@@ -196,8 +196,8 @@ int bitXor(int x, int y) {
  *   Max ops: 10
  *   Rating: 1
  */
-int isTmin(int x) {
-    return !!x & !(x ^ (~x + 1)); 
+volatile int isTmin(int x) {
+    return (!(!x)) & (!(((~(x) + 1) ^ x)));
 }
 //2
 /* 
@@ -208,7 +208,7 @@ int isTmin(int x) {
  *   Rating: 2
  */
 int isEqual(int x, int y) {
-    
+    return !(x ^ y);
 }
 /* 
  * negate - return -x 
@@ -229,7 +229,7 @@ int negate(int x) {
  *   Rating: 2
  */
 int getByte(int x, int n) {
-    return 2;
+    return (x >> (n << 3)) & 0xFF;
 }
 //3
 /* 
@@ -240,7 +240,7 @@ int getByte(int x, int n) {
  *   Rating: 3
  */
 int isLess(int x, int y) {
-    return 2;
+    return ((x >> 31) & 1 & ~((y >> 31) & 1)) | (~(((x >> 31) & 1) ^ ((y >> 31) & 1)) & (((x + (~y + 1)) >> 31) & 1));
 }
 /* 
  * conditional - same as x ? y : z 
@@ -250,7 +250,7 @@ int isLess(int x, int y) {
  *   Rating: 3
  */
 int conditional(int x, int y, int z) {
-    return 2;
+    return (((x | (~x + 1)) >> 31) & y) | (~((x | (~x + 1)) >> 31) & z);
 }
 //4
 /* 
@@ -265,7 +265,7 @@ int conditional(int x, int y, int z) {
  *   Rating: 4
  */
 unsigned floatScale2(unsigned uf) {
-    return 2;
+    return (((uf >> 23) & 0xFF) == 0xFF) ? uf : ((((uf >> 23) & 0xFF) == 0) ? ((uf << 1) | (uf & (1 << 31))) : (uf + (1 << 23)));
 }
 /* 
  * floatFloat2Int - Return bit-level equivalent of expression (int) f
@@ -280,5 +280,31 @@ unsigned floatScale2(unsigned uf) {
  *   Rating: 4
  */
 int floatFloat2Int(unsigned uf) {
-    return 2;
+    unsigned exp, sign, frac, m;
+    int value, shift;
+    exp = (uf >> 23) & ((1 << 8) - 1);
+    sign = (uf >> 31) & 1;
+    frac = uf & ((1 << 23) - 1);
+
+    if (exp >= 158) {
+        return 1 << 31;
+    }
+
+    if (exp < 127) {
+        return 0;
+    }
+
+    shift = exp - 150;
+    m = ((1 << 23) | frac);
+    
+    if (shift > 0) {
+        value = m << shift;
+    } else {
+        value = m >> -shift;
+    }
+    if (sign) {
+        return -value;
+    } else {
+        return value;
+    }
 }