COX: CUDA on X86

Introduction

This project consists of two parts: a series of LLVM passes that achieve a SPMD NVVM IR as input, and output the corresponding MPMD+SIMD version of LLVM IR which can be execute on CPU devices.

Install

Prerequisites

• Linux: Verified on Ubuntu 18.04
• LLVM10.0
• NVIDIA CUDA-toolkit
• x86 CPU
• pthread
• GCC 7.5.0

Installation

1. Clone from github

   git clone https://github.com/drcut/open_source_template
   cd open_source_template
   

2. Build the transformer for NVVM IR to LLVM IR for X86

   mkdir build && cd build
   cmake .. -DLLVM_CONFIG_PATH=`which llvm-config` # need path to llvm-config
   make
   

Run Vecadd samples

# Generate bitcode from human-readable LLVM IR
llvm-as ../compilation/examples/vecadd/kernel-cuda-nvptx64-nvidia-cuda-sm_61.ll
# use LLVM passes to transform NVVM IR (SPMD) to LLVM IR (MPMD+SIMD).
# NOTE: we hard-code the grid size (1, 1, 1)
# and block size (1024, 1, 1) into the generated LLVM IR
./compilation/nvvm2x86 \
    ../compilation/examples/vecadd/kernel-cuda-nvptx64-nvidia-cuda-sm_61.bc \
    kernel.bc 1 1 1 32 1 1
# generate object file from LLVM IR
llc --filetype=obj kernel.bc
# link generated kernel function
# with host function and generate excutable file
g++ ../compilation/examples/vecadd/host.cpp \
    kernel.o -lpthread -o vecadd_example
# execute the executable file
./vecadd_example

Author

Ruobing Han is a CS phd student in Georgia Institute Technology, under the supervision of Prof. Hyesoon Kim.