Intel® VTune™ Amplifier
For better understanding of a performance problem, it is important to associate a hotspot with the source code and exact machine instruction(s) that caused this hotspot. To do this, open the source/assembly code directly from the Intel® VTune™ Amplifier viewpoints.
To open the source/assembly code of a specific item, double-click the selected item in the grid view, Call Stack, or Timeline pane.
The Source/Assembly window provides the following panes:
Source pane shows your code written on a high-level programming language such as C, C++, or Fortran. The Source pane opens if the symbol information for the selected function is available.
Assembly pane provides disassembled code. This code shows the exact order of the assembly instructions executed by the processor. Instructions on the Assembly pane are grouped into basic blocks.
The Source/Assembly window displays accurate information provided that your code is compiled with the debug information and debug information is written correctly in the binary file.
If there is no correct debug information, the assembly data may be incorrect. In this case, the VTune Amplifier uses heuristics to define function boundaries in the binary module.
To manage your source view and toggle the Source/Assembly panes, use the Source and Assembly buttons on the Source window toolbar.
The information available from the Source/Assembly window helps you find all local hotspots within a function and identify code sections that require optimization. To simplify scanning the code, the VTune Amplifier provides the following features:
Options to group the assembly code by address, basic blocks, and function ranges
Hotspot navigation buttons to quickly identify and switch between the hotspot code lines of the selected function
Heat map markers to easily find hotspot lines
The content displayed on the panes is correlated. When you select an element on one pane, another pane scrolls to the corresponding elements and highlights them.
One source code line may have one or more related assembly instructions while one instruction has only one related code line.
Synchronization is possible only if the debug line information is available for the selected function.
When you mouse over a column header in the Source/Assembly pane, the VTune Amplifier displays a tooltip with the following information:
Description of the column that corresponds to a performance metric, for example: Overhead Time.
Formula (if available) used to calculate the performance metric.
You may also locate a metric column in the grid, right-click and select the What's This Column? context menu option to open a help topic for a metric column.
The Source/Assembly analysis is not supported for the source code using the #line directive.