Search results
Results from the WOW.Com Content Network
A bit array (also known as bitmask, [1] bit map, bit set, bit string, or bit vector) is an array data structure that compactly stores bits. It can be used to implement a simple set data structure . A bit array is effective at exploiting bit-level parallelism in hardware to perform operations quickly.
The operation may be used to determine whether a particular bit is set (1) or cleared (0). For example, given a bit pattern 0011 (decimal 3), to determine whether the second bit is set we use a bitwise AND with a bit pattern containing 1 only in the second bit: 0011 (decimal 3) AND 0010 (decimal 2) = 0010 (decimal 2)
For example, in the Pascal programming language, the declaration type MyTable = array [1.. 4, 1.. 2] of integer, defines a new array data type called MyTable. The declaration var A: MyTable then defines a variable A of that type, which is an aggregate of eight elements, each being an integer variable identified by two indices.
This table illustrates an example of an 8 bit signed decimal value using the two's complement method. The MSb most significant bit has a negative weight in signed integers, in this case -2 7 = -128. The other bits have positive weights. The lsb (least significant bit) has weight 1. The signed value is in this case -128+2 = -126.
A 1-bit saturating counter (essentially a flip-flop) records the last outcome of the branch. This is the most simple version of dynamic branch predictor possible, although it is not very accurate. A 2-bit saturating counter [1] is a state machine with four states: Figure 2: State diagram of 2-bit saturating counter. Strongly not taken; Weakly ...
If, for example, the output is constrained to 32-bit integer values, then the hash values can be used to index into an array. Such hashing is commonly used to accelerate data searches. [ 10 ] Producing fixed-length output from variable-length input can be accomplished by breaking the input data into chunks of specific size.
For example, each of 65,536 single-bit processors in a Thinking Machines CM-2 would execute the same instruction at the same time, allowing, for instance, to logically combine 65,536 pairs of bits at a time, using a hypercube-connected network or processor-dedicated RAM to find its operands.
In Java, the growable bit-array data structure BitSet has a BitSet.cardinality() method that counts the number of bits that are set. In addition, there are Integer.bitCount(int) and Long.bitCount(long) functions to count bits in primitive 32-bit and 64-bit integers, respectively.