Intel® Advisor Help
To plot a Roofline chart, the Intel® Advisor does the following:
Intel® Advisor calculates compute operations (FLOP and INTOP) as a weighted sum of the following groups of instructions: BASIC COMPUTE, FMA, BIT, DIV, POW, MATH.
Intel Advisor automatically determines data type in the collected operations using the dst register.
Set Intel Advisor environment variables with an automated script to enable the advisor command line interface (CLI).
There are two methods to run the CPU Roofline. Use one of the following:
Note: In the commands below, make sure to replace the myApplication with your application executable path and name before executing a command. If your application requires additional command line options, add them after the executable name.
Method 1. Run the Shortcut Command
To collect data for a CPU Roofline chart with a shortcut, run the following command:
advisor --collect=roofline --project-dir=./advi_results -- ./myApplicationThis command collects data for a basic CPU Roofline chart based on the Cache-Aware Roofline model. You can add other option to the command to collect more data. See Analysis Details below for more options.
Method 2. Run the Analyses Separately
Use this method if you want to analyze an MPI application.
advisor --collect=survey --project-dir=./advi_results -- ./myApplicationadvisor --collect=tripcounts --flop --project-dir=./advi_results -- ./myApplicationThese commands collect data for a basic CPU Roofline chart based on the Cache-Aware Roofline model. You can add other option to the command to collect more data. See Analysis Details below for more options.
You can view the results in the Intel Advisor graphical user interface (GUI), or generate an interactive HTML report. See View the Results below for details.
Analysis Details
The CPU / Memory Roofline Insights workflow includes the following analyses:
Each analysis has a set of additional options that modify its behavior and collect additional performance data. The more analyses you run and option you use, the more useful data about your application you get.
Consider the following options:
Roofline Options
To run the Roofline analysis, use the following command line action: --collect=roofline.
Recommended action options:
Options |
Description |
|---|---|
--stacks |
Enable advanced collection of call stack data. Use this option to get a CPU Roofline with callstacks. |
--enable-cache-simulation |
Model CPU cache behavior on your target application. Use this option to get a Memory-level CPU Roofline that shows data for all memory levels. |
--cache-config=<config> |
Set the cache hierarchy to collect modeling data for CPU cache behavior. Use with enable-cache-simulation. The value should follow the template: [<num_of_caches>]:[<num_of_ways_caches_connected> ]:[<cache_size>]:[<cacheline_size>] for each of three cache levels separated with a /. |
--cachesim-associativity=<num> |
Set the cache associativity for modeling CPU cache behavior: 1 | 2 | 4 | 8 (default) | 16. Use with enable-cache-simulation. |
--cachesim-mode=<mode> |
Set the focus for modeling CPU cache behavior: cache-misses | footprint | utilization. Use with enable-cache-simulation. |
See advisor Command Option Reference for more options.
Memory Access Patterns Options
The Memory Access Patterns analysis is optional because it adds a high overhead. This analysis does not add more information to the CPU Roofline chart. The results are added to the Refinement report, which you can view from GUI or from CLI. Use it to understand the Memory-Level Roofline chart better and get more detailed optimization recommendations.
To run the Memory Access Patterns analysis, use the following command line action: --collect=map.
Recommended action options:
Options |
Description |
|---|---|
--select=<string> |
Select loops for the analysis by loop IDs, source locations, or criteria such as scalar, has-issue, or markup=<markup-mode>. This option is required. See select for more selection options. |
--enable-cache-simulation |
Model CPU cache behavior on your target application. |
--cachesim-cacheline-size=<num> |
Set the cache line size (in bytes) for modeling CPU cache behavior: 4 | 8 | 16 | 32 | 64 (default) | 128 | 256 | 512 | 1024 | 2048 | 4096 | 8192 | 16384 | 32768 | 65536. Use with enable-cache-simulation. |
--cachesim-sets=<num> |
Set the cache set size (in bytes) for modeling CPU cache behavior: 256 | 512 | 1024 | 2048 | 4096 (default) | 8192. Use with enable-cache-simulation. |
See advisor Command Option Reference for more options.
Dependencies Options
The Dependencies analysis is optional because it adds a high overhead and is mostly necessary if you have scalar loops/functions in your application. This analysis does not add more information to the CPU Roofline chart. The results are added to the Refinement report, which you can view from GUI or from CLI. Use it to get more detailed optimization recommendations.
To run the Dependencies analysis, use the following command line action: --collect=dependencies.
Recommended action options:
Options |
Description |
|---|---|
--select=<string> |
Select loops for the analysis by loop IDs, source locations, criteria such as scalar, has-issue, or markup=<markup-mode>. This option is required. See select for more selection options. |
--filter-reductions |
Mark all potential reductions with a specific diagnostic. |
See advisor Command Option Reference for more options.
Continue to explore the CPU / Memory Roofline Insights results with a preferred method. For details about the metrics reported, see CPU and Memory Metrics.