INGREDIENTS
DIRECTIONS:
Prepare your application for analysis
Run Advanced Hotspots analysis
Identify hotspots in the managed code
Optimize the code with loop interchange
Verify the optimization

Ingredients

Application:
a sample C# application that adds all the elements of an integer List. The application is used as a demo and not available for download.
Tools:
Intel® VTune™ Profiler 2018
Starting with the 2020 release, Intel® VTune™ Amplifier has been renamed to
Intel® VTune™
Profiler
.
Most recipes in the
Intel® VTune™
Profiler
Performance Analysis Cookbook are flexible. You can apply them to different versions of
Intel® VTune™
Profiler
. In some cases, minor adjustments may be required.
Get the latest version of
Intel® VTune™
Profiler
:
From the
Intel® VTune™
Profiler
product page.
Download the latest standalone package from the Intel® oneAPI standalone components page.
.NET Core 2.0 SDK
Operating system:
Microsoft* Windows* 10
CPU
: Intel microarchitecture code name Skylake

Prepare Your Application for Analysis

Open a new command window for the .NET environment variables to take effect. Make sure that .NET Core 2.0 is successfully installed:

dotnet --version

Create a new

listadd

directory for the application:

mkdir C:\listadd
> cd C:\listadd

Enter

dotnet new console

to create a new skeleton project with the following structure:



Replace the contents of

Program.cs

in the

listadd

folder with C# code that adds the elements of an integer List:

using System;
using System.Linq;
using System.Collections.Generic;

namespace listadd
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Starting calculation...");            
            List<int> numbers = Enumerable.Range(1,10000).ToList();
            for (int i =0; i < 100000; i ++)
            {
                ListAdd(numbers);
            }
            
            Console.WriteLine("Calculation complete");            
        }

        static int ListAdd(List<int> candidateList)
        {
            int result = 0;
            foreach (int item in candidateList)
            {
                result += item;
            }
            
            return result;
        }        
    }
}

Create

listadd.dll

in the

C:\listadd\bin\Release\netcoreapp2.0

folder:

dotnet build -c Release

Run the sample application:

dotnet C:\listadd\bin\Release\netcoreapp2.0\listadd.dll

Run Advanced Hotspots Analysis

Launch VTune Profiler with administrator privileges.
Click the
New Project
button on the toolbar and specify a name for the new project, for example:
dotnet
.
In the
Analysis Target
window, select
local host
and
Launch Application
target type from the left pane.
On the
Launch Application
pane, specify the application to analyze:
Application
:
C:\Program Files\dotnet\dotnet.exe
Application parameters
:
C:\listadd\bin\Release\netcoreapp2.0\listadd.dll

The location of
dotnet.exe
depends on your environment and can be identified with the command:
where dotnet
.
Click the
Choose Analysis
button on the right and select the
Advanced Hotspots
analysis from the left pane.
Advanced Hotspots analysis was integrated into the generic Hotspots analysis starting with Intel VTune Amplifier 2019, and is available via the Hardware Event-Based Sampling collection mode.
Click
Start
to run the analysis.

Identify Hotspots in the Managed Code

Optimize the Code with Loop Interchange

using System;
using System.Linq;
using System.Collections.Generic;

namespace listadd
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Starting calculation...");            
            List<int> numbers = Enumerable.Range(1,10000).ToList();
            for (int i =0; i < 100000; i ++)
            {
                ListAdd(numbers);
            }
            
            Console.WriteLine("Calculation complete");            
        }

        static int ListAdd(List<int> candidateList)
        {
            int result = 0;
            for (int i = 0; i < candidateList.Count; i++)
            {
                result += candidateList[i];
            }

            return result;
        }        
    }
}

Verify the Optimization