}
+
/**
* Extract the bitfield from position 'first' to 'last' (inclusive)
* from 'val' and right justify it. MSB is numbered 63, LSB is 0.
return (val >> last) & mask(nbits);
}
+/**
+ * Extract the bit from this position from 'val' and right justify it.
+ */
+template <class T>
+inline
+T
+bits(T val, int bit)
+{
+ return bits(val, bit, bit);
+}
+
+/**
+ * Mask off the given bits in place like bits() but without shifting.
+ * msb = 63, lsb = 0
+ */
+template <class T>
+inline
+T
+mbits(T val, int first, int last)
+{
+ return val & (mask(first+1) & ~mask(last));
+}
+
+inline uint64_t
+mask(int first, int last)
+{
+ return mbits((uint64_t)-1LL, first, last);
+}
+
/**
* Sign-extend an N-bit value to 64 bits.
*/
T
insertBits(T val, int first, int last, B bit_val)
{
+ T t_bit_val = bit_val;
T bmask = mask(first - last + 1) << last;
- return ((bit_val << last) & bmask) | (val & ~bmask);
+ return ((t_bit_val << last) & bmask) | (val & ~bmask);
+}
+
+/**
+ * Overloaded for access to only one bit in value
+ */
+template <class T, class B>
+inline
+T
+insertBits(T val, int bit, B bit_val)
+{
+ return insertBits(val, bit, bit, bit_val);
}
/**
val = insertBits(val, first, last, bit_val);
}
+/** Overloaded function to allow to access only 1 bit*/
+template <class T, class B>
+inline
+void
+replaceBits(T& val, int bit, B bit_val)
+{
+ val = insertBits(val, bit, bit, bit_val);
+}
+/**
+ * Returns the bit position of the MSB that is set in the input
+ */
+inline
+int
+findMsbSet(uint64_t val) {
+ int msb = 0;
+ if (!val)
+ return 0;
+ if (bits(val, 63,32)) { msb += 32; val >>= 32; }
+ if (bits(val, 31,16)) { msb += 16; val >>= 16; }
+ if (bits(val, 15,8)) { msb += 8; val >>= 8; }
+ if (bits(val, 7,4)) { msb += 4; val >>= 4; }
+ if (bits(val, 3,2)) { msb += 2; val >>= 2; }
+ if (bits(val, 1,1)) { msb += 1; }
+ return msb;
+}
+
#endif // __BASE_BITFIELD_HH__