## Table of Contents

<!-- toc -->

- [Prerequisites](#Prerequisites)
- [Build HIP on AMD platform](#build-hip-on-amd-platform)
  * [Get HIP source code](#get-hip-source-code)
  * [Set the environment variables](#set-the-environment-variables)
  * [Build HIP](#build-hip)
  * [Default paths and environment variables](#default-paths-and-environment-variables)
- [Build HIP on NVIDIA platform](#build-hip-on-NVIDIA-platform)
  * [Get HIP source code](#get-hip-source-code)
  * [Set the environment variables](#set-the-environment-variables)
  * [Build HIP](#build-hip)
- [Run HIP](#run-hip)
<!-- tocstop -->

# Prerequisites

HIP code can be developed either on AMD ROCm platform using HIP-Clang compiler, or a CUDA platform with nvcc installed.
Before build and run HIP, make sure drivers and pre-build packages are installed properly on the platform.

## AMD platform
Install ROCm packages (see ROCm Installation Guide on AMD public documentation site (https://docs.amd.com/)) or install pre-built binary packages using the package manager,

```
sudo apt install mesa-common-dev
sudo apt install clang
sudo apt install comgr
sudo apt-get -y install rocm-dkms
```


## NVIDIA platform

Install Nvidia driver and pre-build packages (see HIP Installation Guide at https://docs.amd.com/ for the release)

## Branch of repository

Before get HIP source code, set the expected branch of repository at the variable HIP_BRANCH.
For example, for ROCm5.0 release branch, set
```
export HIP_BRANCH=rocm-5.0.x
```

ROCm5.1 release branch, set
```
export HIP_BRANCH=rocm-5.1.x
```
Similiar format for future branches.

ROCM_PATH is path where ROCM is installed. BY default ROCM_PATH is at /opt/rocm.


# Build HIP on AMD platform


## Get HIP source code

```
git clone -b $HIP_BRANCH https://github.com/ROCm-Developer-Tools/hipamd.git
git clone -b $HIP_BRANCH https://github.com/ROCm-Developer-Tools/hip.git
git clone -b $HIP_BRANCH https://github.com/ROCm-Developer-Tools/ROCclr.git
git clone -b $HIP_BRANCH https://github.com/RadeonOpenCompute/ROCm-OpenCL-Runtime.git
```

## Set the environment variables

```
export HIPAMD_DIR="$(readlink -f hipamd)"
export HIP_DIR="$(readlink -f hip)"
export ROCclr_DIR="$(readlink -f ROCclr)"
export OPENCL_DIR="$(readlink -f ROCm-OpenCL-Runtime)"
```

ROCclr is defined on AMD platform that HIP use Radeon Open Compute Common Language Runtime (ROCclr), which is a virtual device interface that HIP runtimes interact with different backends.
See https://github.com/ROCm-Developer-Tools/ROCclr

HIPAMD repository provides implementation specifically for AMD platform.
See https://github.com/ROCm-Developer-Tools/hipamd

## Build HIP

```
cd "$HIPAMD_DIR"
mkdir -p build; cd build
cmake -DHIP_COMMON_DIR=$HIP_DIR -DAMD_OPENCL_PATH=$OPENCL_DIR -DROCCLR_PATH=$ROCCLR_DIR -DCMAKE_PREFIX_PATH="<ROCM_PATH>/" -DCMAKE_INSTALL_PREFIX=$PWD/install ..
make -j$(nproc)
sudo make install
```

Note: If you don't specify CMAKE_INSTALL_PREFIX, hip runtime will be installed to "<ROCM_PATH>/hip".
By default, release version of AMDHIP is built.

## Default paths and environment variables

   * By default HIP looks for HSA in <ROCM_PATH>/hsa (can be overridden by setting HSA_PATH environment variable).
   * By default HIP is installed into <ROCM_PATH>/hip (can be overridden by setting HIP_PATH environment variable).
   * By default HIP looks for clang in <ROCM_PATH>/llvm/bin (can be overridden by setting HIP_CLANG_PATH environment variable)
   * By default HIP looks for device library in <ROCM_PATH>/lib (can be overridden by setting DEVICE_LIB_PATH environment variable).
   * Optionally, consider adding <ROCM_PATH>/bin to your PATH to make it easier to use the tools.
   * Optionally, set HIPCC_VERBOSE=7 to output the command line for compilation.

After make install command, make sure HIP_PATH is pointed to $PWD/install/hip.


# Build HIP on NVIDIA platform


## Get HIP source code

```
git clone -b $HIP_BRANCH https://github.com/ROCm-Developer-Tools/hip.git
git clone -b $HIP_BRANCH https://github.com/ROCm-Developer-Tools/hipamd.git
```

## Set the environment variables

```
export HIP_DIR="$(readlink -f hip)"
export HIPAMD_DIR="$(readlink -f hipamd)"
```

## Build HIP

```
cd "$HIPAMD_DIR"
mkdir -p build; cd build
cmake -DHIP_COMMON_DIR=$HIP_DIR -DHIP_PLATFORM=nvidia -DCMAKE_INSTALL_PREFIX=$PWD/install ..
make -j$(nproc)
sudo make install
```

# Run HIP

Compile and run the [square sample](https://github.com/ROCm-Developer-Tools/HIP/tree/rocm-5.0.x/samples/0_Intro/square).