/halide_riscv

Examples of Halide language algorithms running on RISC-V

Primary LanguageAssemblyApache License 2.0Apache-2.0

Halide language experiments on RISC-V

This repository contains a number of examples written in Halide language which work on RISC-V CPU with RVV 0.7.1. Follow the steps below to reproduce the experiments or some of their parts.

NOTE: At this moment project relies on the Ahead-Of-Time (AOT) compilation of Halide kernels. However there are precompiled files for easy start.

Project uses OpenCV as a reference implementation for some algorithms. Also, we benchmark it to compare with Halide implemention. Fetch OpenCV source code by submodules update after clonning the repository.

git submodule update --init

Build and go

  1. Download THead toolchain: Xuantie-900-gcc-linux-5.10.4-glibc-x86_64-V2.6.1-20220906.tar.gz (registration needed)

  2. Clone Halide source code (no build required)

    git clone --depth 1 https://github.com/halide/Halide

  3. Build a project for RISC-V CPU:

    export PATH=$HOME/Xuantie-900-gcc-linux-5.10.4-glibc-x86_64-V2.6.1/bin/:$PATH

cmake \
    -DCMAKE_BUILD_TYPE=Release \
    -DCMAKE_TOOLCHAIN_FILE=$HOME/halide_riscv/riscv64-071.toolchain.cmake \
    -DHalide_INCLUDE_DIRS=$HOME/Halide/src/runtime \
    -S halide_riscv -B build_rv64

cmake --build build_rv64 -j$(nproc --all)

  4. Transfer build directory to the RISC-V board and run test_algo (accuracy tests) or perf_algo (performance tests).

    scp test_algo perf_algo libalgos.so opencv-prefix/src/opencv-build/lib/* sipeed@x.x.x.x:/home/sipeed/
    export LD_LIBRARY_PATH=./
./test_algo
./perf_algo

Performance results

HW: Sipeed Lichee RV Dock (Allwinner D1 aka XuanTie C906 CPU)

OS: 20211230_LicheeRV_debian_d1_hdmi_8723ds

BGR2Gray
input: 1080x1920		 Median time
Reference (interleaved) 37.80ms
OpenCV (interleaved), no RVV 32.18ms
Halide (interleaved) 30.78ms
Halide (planar) 6.65ms
Box filter
input: 1080x1920
output: 1078x1918		 Median time
OpenCV, no RVV 75.17ms
Halide 62.89ms
Histogram
input: 1080x1920x3
output: 256x3		 Median time
Reference 72.06ms
OpenCV, no RVV 57.35ms
Halide 92.44ms
Convolution FP32
input: 1x16x128x128
kernel: 32x16x3x3		 Layout Median time
OpenCV, no RVV NCHW 829.13ms
Halide NCHW 698.27ms
Halide NHWC 418.95ms

Generate AOT kernels

If you want regenerate AOT artifacts or add new algorithms, build the project on x86:

  1. Build LLVM from https://github.com/dkurt/llvm-rvv-071/tree/rvv-071

    cmake -DCMAKE_BUILD_TYPE=Release \
  -DLLVM_ENABLE_PROJECTS="clang;lld" \
  -DLLVM_TARGETS_TO_BUILD="RISCV" \
  -DLLVM_ENABLE_TERMINFO=OFF -DLLVM_ENABLE_ASSERTIONS=ON \
  -DLLVM_ENABLE_EH=ON -DLLVM_ENABLE_RTTI=ON -DLLVM_BUILD_32_BITS=OFF \
  -GNinja \
  -S llvm-project/llvm -B llvm-build

cmake --build llvm-build -j4

  2. Build Halide with the following patch (tested on revision https://github.com/halide/Halide/commit/7963cd4e3c23856b82567c99e0a3d16035ffe895):

    diff --git a/src/CodeGen_RISCV.cpp b/src/CodeGen_RISCV.cpp
index ba9abe04d..454558d11 100644
--- a/src/CodeGen_RISCV.cpp
+++ b/src/CodeGen_RISCV.cpp
@@ -151,6 +151,7 @@ string CodeGen_RISCV::mattrs() const {
            arch_flags += ",+zvl" + std::to_string(target.vector_bits) + "b";
        }
#endif
+        arch_flags += ",-zve64x";
    }
    return arch_flags;
}
diff --git a/src/autoschedulers/CMakeLists.txt b/src/autoschedulers/CMakeLists.txt
index 9b88f0a66..10088bb9b 100644
--- a/src/autoschedulers/CMakeLists.txt
+++ b/src/autoschedulers/CMakeLists.txt
@@ -24,6 +24,6 @@ endfunction()

add_subdirectory(common)

-add_subdirectory(adams2019)
+# add_subdirectory(adams2019)
add_subdirectory(li2018)
add_subdirectory(mullapudi2016)
    export LLVM_ROOT=$HOME/llvm-build

cmake -DLLVM_DIR=$LLVM_ROOT/lib/cmake/llvm \
    -DClang_DIR=$LLVM_ROOT/lib/cmake/clang \
    -DCMAKE_BUILD_TYPE=Release \
    -DWITH_TESTS=OFF \
    -DWITH_TUTORIALS=OFF \
    -DWITH_PYTHON_BINDINGS=OFF \
    -S Halide -B halide-build

cmake --build halide-build -j4
cmake --install halide-build --prefix halide-install

  3. Build a project on x86

    export LD_LIBRARY_PATH=$HOME/halide-build/src/autoschedulers/mullapudi2016:$LD_LIBRARY_PATH

cmake \
    -DCMAKE_BUILD_TYPE=Release \
    -DHalide_DIR=$HOME/halide-install/lib/cmake/Halide \
    -S halide_riscv -B build

cmake --build build -j$(nproc --all)

  4. Run perf_algo once and find the generated *.h and *.s files in the working directory.