Intel® Advisor User Guide

User Guide

Contents

Run
Vectorization and Code Insights
 Perspective from Command Line

Vectorization and Code Insights
 perspective includes several analyses that you can run depending on the desired result. The main analysis is the Survey, which collects performance data for loops and functions in your application and identifies under-vectorized and non-vectorized loops/functions. The Survey analysis is enough to get the basic insights about your application performance.
See
Intel Advisor
 cheat sheet for quick reference on command line interface.

Prerequisites

Set
Intel Advisor
 environment variables with an automated script to enable the command line interface (CLI).

Run
Vectorization and Code Insights
 Perspective

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.
  1. Run the Survey analysis. 
    advisor --collect=survey --project-dir=./advi_results -- ./myApplication
  2. Run the Characterization analysis to collect trip counts and FLOP data: 
    advisor --collect=tripcounts --flop --stacks --project-dir=./advi_results -- ./myApplication
  3. Optional
    : Run the Memory Access Patterns analysis for loops/functions with the
    Possible Inefficient Memory Access Patter
     issue. 
    advisor --collect=map --select=has-issue --project-dir=./advi_results -- ./myApplication
  4. Optional
    : Run the Dependencies analysis to check for loop-carried dependencies in loops/functions with
    Assumed dependency present
     issue: 
    advisor --collect=dependencies --project-dir=./advi_results --select=has-issue -- ./myApplication
You can view the results in the Intel Advisor graphical user interface (GUI), print a summary to a command prompt/terminal, or save to a file. See View the Results below for details.
Analysis Details
The
Vectorization and Code Insights
 workflow includes the following analyses:
  1. Survey to collect initial performance data.
  2. Characterization with trip counts and FLOP data to collect additional performance details.
  3. Memory Access Patterns (optional) to identify memory traffic data and memory usage issues.
  4. Dependencies (optional) to identify loop-carried dependencies.
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:
Characterization Options
To run the Characterization analysis, use the following command line action:
--collect=tripcounts
.
Recommended action options:
Options
Description
--flop
Collect data about floating-point and integer operations, memory traffic, and mask utilization metrics for AVX-512 platforms.
--stacks
Enable advanced collection of call stack data.
--enable-cache-simulation
Model CPU cache behavior on your target application.
--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. 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. 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.

Next Steps

Continue to explore the
Vectorization and Code Insights
 results with a preferred method. For details about the metrics reported, see CPU and Memory Metrics.

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.