HOP - Header Only Porting

A light-weight header-only library for GPU porting between CUDA and HIP.

No code modifications needed. Just add a few extra compile flags to hop between CUDA and HIP!

Works by automatically redefining identifiers at compile time and catching include statements in C and C++ (also Fortran with ISO C bindings).

Install

export HOP_ROOT=/path/to/install/hop
git clone https://github.com/cschpc/hop.git $HOP_ROOT

Usage

Compile flags

Translate from CUDA to HIP:

-x hip -I$HOP_ROOT -I$HOP_ROOT/source/cuda -DHOP_TARGET_HIP

Translate from HIP to CUDA:

-x cu -I$HOP_ROOT -I$HOP_ROOT/source/hip -DHOP_TARGET_CUDA

List of compile flags

• Include path for HOP headers:
  -I$HOP_ROOT
• Catch source code headers:
  -I$HOP_ROOT/source/cuda or -I$HOP_ROOT/source/hip
• Define target GPU backend:
  -DHOP_TARGET_HIP or -DHOP_TARGET_CUDA
• (optional) Override automatic filetype detection:
  -x cu (if target is CUDA) or -x hip (if target is HIP)
• (optional) Define source language (e.g. if no headers are included in the source code):
  -DHOP_SOURCE_CUDA or -DHOP_SOURCE_HIP
• (optional) Manually include HOP headers (e.g. if some header includes are missing in the source code):
  -include $HOP_ROOT/hop/hop_runtime.h or similar

Examples

CUDA ⇒ HIP

If the source file includes CUDA headers:

export HOP_FLAGS="-I$HOP_ROOT -I$HOP_ROOT/source/cuda -DHOP_TARGET_HIP"
$CC -x hip $HOP_FLAGS foo.cu -o foo

If the source file does not include CUDA headers:

export HOP_FLAGS="-I$HOP_ROOT -I$HOP_ROOT/source/cuda -DHOP_TARGET_HIP -DHOP_SOURCE_CUDA -include $HOP_ROOT/hop/hop_runtime.h"
$CC -x hip $HOP_FLAGS foo.cu -o foo

HIP ⇒ CUDA

export HOP_FLAGS="-I$HOP_ROOT -I$HOP_ROOT/source/hip -DHOP_TARGET_CUDA"
$CC -x cu $HOP_FLAGS foo.cpp -o foo

where $CC is the compiler to be used.