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In computer science, the fetch-and-add (FAA) CPU instruction atomically increments the contents of a memory location by a specified value.. That is, fetch-and-add performs the following operation: increment the value at address x by a, where x is a memory location and a is some value, and return the original value at x.
In computer science, read–modify–write is a class of atomic operations (such as test-and-set, fetch-and-add, and compare-and-swap) that both read a memory location and write a new value into it simultaneously, either with a completely new value or some function of the previous value.
A non-blocking linked list is an example of non-blocking data structures designed to implement a linked list in shared memory using synchronization primitives: Compare-and-swap; Fetch-and-add; Load-link/store-conditional; Several strategies for implementing non-blocking lists have been suggested.
The instruction cycle (also known as the fetch–decode–execute cycle, or simply the fetch–execute cycle) is the cycle that the central processing unit (CPU) follows from boot-up until the computer has shut down in order to process instructions. It is composed of three main stages: the fetch stage, the decode stage, and the execute stage.
Locks typically require hardware support for efficient implementation. This support usually takes the form of one or more atomic instructions such as "test-and-set", "fetch-and-add" or "compare-and-swap". These instructions allow a single process to test if the lock is free, and if free, acquire the lock in a single atomic operation.
# This gives the memory system two clock ticks to fetch the next # instruction to the memory data register for use by the instruction decode. # The sequencer instruction "next" means just add 1 to the control word address. MDR, NONE, MAR, COPY, NEXT, NONE # This places the address of the next instruction into the PC.
In the instruction fetch stage of a pipeline, the current PC along with a set of branch predictions is checked in the trace cache for a hit. If there is a hit, a trace line is supplied to fetch unit which does not have to go to a regular cache or to memory for these instructions.
Fetching the instruction opcodes from program memory well in advance is known as prefetching and it is served by using a prefetch input queue (PIQ). The pre-fetched instructions are stored in a queue. The fetching of opcodes well in advance, prior to their need for execution, increases the overall efficiency of the processor boosting its speed ...