How do you measure instruction latency?
To measure latency yourself, you make the output of each instruction an input for the next. This dependency chain of 7 inc instructions will bottleneck the loop at 1 iteration per 7 * inc_latency cycles.
Who is Agner Fog?
Agner Fog is a Danish evolutionary anthropologist and computer scientist. He is currently an Associate Professor of computer science at the Technical University of Denmark (DTU), and has been present at DTU since 1995.
What is reciprocal throughput?
Reciprocal throughput is simply the reciprocal of the maximum throughput of a particular instruction. Throughput is measured in instructions/cycle, so reciprocal throughput is cycles/instruction.
What is instruction table?
Instruction tables: Lists of instruction latencies, throughputs and micro-operation breakdowns for Intel, AMD, and VIA CPUs. The latest versions of these manuals are always available from www.agner.org/optimize. Copyright conditions are listed below.
What is latency of CPU?
Latency is the number of processor clocks it takes for an instruction to have its data available for use by another instruction. Therefore, an instruction which has a latency of 6 clocks will have its data available for another instruction that many clocks after it starts its execution.
What is throughput and latency?
Latency indicates how long it takes for packets to reach their destination. Throughput is the term given to the number of packets that are processed within a specific period of time. Throughput and latency have a direct relationship in the way they work within a network.
How do I optimize my C++ code?
Summary of Strategies for Optimizing C++ Code
- Use a Better Compiler, Use Your Compiler Better. C++ compilers are complex software artifacts.
- Use Better Algorithms.
- Use Better Libraries.
- Reduce Memory Allocation and Copying.
- Remove Computation.
- Use Better Data Structures.
- Increase Concurrency.
- Optimize Memory Management.
What is latency in pipelining?
Instruction latency and pipeline stalls An instruction’s latency is the number of clock cycles it takes for the instruction to pass through the pipeline. For a single-cycle processor, all instructions have a latency of one clock cycle.
What is Pshufb?
PSHUFB performs in-place shuffles of bytes in the destination operand (the first operand) according to the shuffle control mask in the source operand (the second operand). The instruction permutes the data in the destination operand, leaving the shuffle mask unaffected.