The Intel® System Debugger is able to highlight source lines and instructions that were executed recently according to trace information. The highlighting allows you to visually distinguish recently executed code lines from the code lines executed earlier. It also allows you to detect which branches of an “if” statement or a “switch” were most recently taken.
When execution trace data is available either via LBR or RTIT/PT, the source viewer and assembly window automatically highlight the execution of the last 128 source lines or instructions. Lines that have been executed more than once in the last 128 lines are marked with a black “plus” sign.
You can choose between disabled, simple or full coloring via Options > GUI Preferences. The screenshot shows the assembler window using the “simple” version, where the highlighting is only shown next to the line, and the source window using the “full” mode where the color covers the whole line.
The colors range from dark green for recent execution to faded and light green for earlier execution.