Trahrhe Collapse - Automatic Collapsing of Non Rectangular Loops

A tool to collapse loops in C, C++, C# and Java code automatically using Ehrhart polynomials and the polyhedral model.

Installation

To install the library, you need to follow these steps:

• Clone the repository
• Ensure you have the necessary prerequisites
• Run the install script with

sudo bash install.sh

Then, specify the path to Trahrhe's root directory. This is the directory where the trahrhe binary is located. The default path is /usr/local/bin. If you have installed Trahrhe in a different directory, you can specify the path by running the following command:

export TRAHRHE_INSTALL_DIR=<path_to_trahrhe>

Finally, add the utility folder to the PATH environment variable by running the following command:

export PATH=$PATH:<PATH_TO_TRAHRHE_COLLAPSE>/utility

To make the changes permanent, add the above commands to the .bashrc file.

Uninstalling

Run

sudo bash uninstall.sh

Prerequisites

• GMP
• NTL
• Polylib
• isl
• ntl
• Barvinok
• trahrhe
• osl
• clan
• cloog

To install Barvinok, you need to follow these steps:

1. Get GMP using the procedure described in https://libntl.org/doc/tour-gmp.html (note the $HOME/sw)
2. Get NTL using the info in this same page
3. Get ISL
4. You should now be able to get Barvinok

. ./configure --with-isl=bundled
make
make install

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You may need to create a symbolic link to the library in the /usr/lib directory. You can do this by running the following command:

sudo ln -s /usr/local/lib/libbarvinok.so.0 /usr/lib/libbarvinok.so.0

Troubleshooting

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If you are having trouble with the installation of the library, you can try the following commands to copy the library to the /usr/lib directory (assuming you have the library in /usr/local/lib directory):

sudo cp /usr/local/lib/lib<LIB_NAME>* /usr/lib

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If your machine is missing autoreconf command, you can install it by running the following command:

apt-get install dh-autoreconf

Feature Definitions

Refer to the feature definitions.

Usage

This section provides a guide on how to use the Automatic Loop Collapsing tool.

Prerequisites

Before using the Automatic Loop Collapsing tool, ensure that you have the following prerequisites:

• Installed all the dependencies as described in the installation guide.
• Installed the Automatic Loop Collapsing tool as described in the installation guide.
• Familiarized yourself with the feature definitions.
• Ensure that your input file is in the correct format i.e., it should contain the loops that you want to collapse along with the #pragma trahrhe collapse(N) directive.

Steps

To use the Automatic Loop Collapsing tool, follow these steps:

1. Run the following command:

   trahrhe-collapse [input.c] -o [output.c]

   You can also specify additional options that are:

   • -h or --help: Display the help message.
   • -v or --version: Display the version of the tool.
   • -o or --output: Specify the output file.

2. The tool will automatically collapse the loops in the input file and generate the output file.

Example

Consider the following example:

#pragma trahrhe collapse(2)
for(i = 0; i < N - 1; i++) {
    for(j = i + 1; j < N; j++) {
        for(k = 0; k < N; k++) {
            A[i][j] += B[k][i] * C[k][j];
        }
        A[j][i] = A[i][j];
    }
}
#pragma endtrahrhe

After running the tool, the output file would be:

unsigned int pc_0;
unsigned upper_bound_0 = i_Ehrhart0(N);
unsigned int first_iteration_0 = 1;
#pragma omp parallel for private(i, j, k) firstprivate(first_iteration_0) schedule(static)
for(pc_0 = 1; pc_0 <= upper_bound_0; pc_0++) {
    if(first_iteration_0) {
        i = i_trahrhe0(pc_0, N);
        j = j_trahrhe0(pc_0, N, i);
        first_iteration_0 = 0;
    }
    for(k = 0; k < N; k++) {
        A[i][j] += B[k][i] * C[k][j];
    }
    A[j][i] = A[i][j];
    j++;
    if(j >= N) {
        i++;
        j = i + 1;
    }
}

License

TBD