Compare CPU Roofline Results
Use the
Roofline Compare
functionality to display Roofline chart data from other
Intel® Advisor
results or non-archived snapshots for comparison purposes to track optimization progress.
To compare the CPU Roofline results you need:
- A baseline CPU Rooflineprojectorsnapshot
- One or more CPU Roofline projects or snapshots of the same application with an optimization applied
For example, to compare the results using snapshots:
- Open a baseline CPU Roofline snapshot.
- From theComparedrop-down toolbar, click+to load a comparison snapshot. You can load multiple snapshots for comparison one by one.
When the comparison snapshot is uploaded:
- The filenames for uploaded results/snapshots are displayed in theCompared Resultsregion.
- The Roofline Compare feature automatically recognizes similar loops from both snapshots. It connects related loops with a dashed arrow line and displays the performance improvement between the loops, in per cent, which is calculated as the difference in FLOPS (or INTOPS or OPS) and Total Time.The arrowed lines showing the relationship among loops/functions do not reappear if you upload the comparison file.
- Loops from different snapshots are shown as different icons on the chart. For example, on the picture below, the baseline loops are shown as circles and comparison loops are triangles and diamonds.
- To highlight all dots from a specific result, open theComparedrop-down and hover over the result name.
- Each time you change the Roofline configuration or filter the dots on the chart, the comparison is updated automatically.
- You can remove a selected result/snapshot from Compared Results and move it to theReady for comparisonregion.Click a filename in theReady for comparisonregion to reload the result/snapshot.
- You can save the comparison itself to a file using the export feature.
- To find the same loops among the results,Intel® Advisorcompares several loop features, such as loop type, nesting level, source code file name and line, and name of the function. When a certain threshold of similar or equal features is reached, the two loops are considered a match and connected with a dashed line.
- However, this method still has few limitations. Sometimes there can be no match for the same loop if one is optimized or parallelized or moved in the source code to four or more lines from the original code.
- Intel Advisor tries to ensure some balance between matching source code changes and false positives.