Measure the time a program and its functions take to execute as part of the diagnosis phase of performance optimization. Such measurements are extremely valuable as a simple means to become familiar with how an application behaves during execution.
Use either the Linux time command or the clock function in the C library, and profile the application during compilation. The time command is used as follows:
prompt> time
It gives the following information:
Determine what memory accesses are causing EXE pipeline stalls accumulated by the BE_EXE_Bubble counter. Most memory-access stall cycles are accumulated by the BE_EXE_Bubble counter. This counter accumulates stall cycles in the EXE stage of the pipeline. These stall cycles occur mostly because the data loaded into registers is not ready for consumption by the functional units.
These dependency stalls break down to two sources:
Our tuning guides explain how to identify common software performance issues using VTune Amplifier XE, and give suggestions for optimization.
