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zhoujing 2023-01-30 14:09:35 +08:00
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@ -7,78 +7,27 @@ For more architecture detail, please refer to
## Getting Started
### Build the toolchain
### 1: Programs related repositories
Download all the repositories firstly
* llvm-ventus : git clone https://github.com/THU-DSP-LAB/llvm-project.git
* pocl : git clone https://github.com/THU-DSP-LAB/pocl.git
* ocl-icd : git clone https://github.com/OCL-dev/ocl-icd.git
> libclc can be built from llvm-ventus repository
### 2: Build all the programs
Assume you have already installed essential build tools such as cmake, clang, ninja etc.
```
git clone https://github.com/THU-DSP-LAB/llvm-project.git
cd llvm-project
mkdir build && cd build
cmake -DCMAKE_BUILD_TYPE=Debug -DLLVM_CCACHE_BUILD=ON -DLLVM_ENABLE_PROJECTS="clang;lld;libclc" -DLLVM_TARGETS_TO_BUILD="AMDGPU;X86;RISCV" -DLLVM_TARGET_ARCH="riscv32" -DBUILD_SHARED_LIBS=ON -DLLVM_BUILD_LLVM_DYLIB=ON -DLLVM_ENABLE_TERMINFO=ON -DCMAKE_INSTALL_PREFIX=../install -G Ninja ../llvm
ninja
ninja install
```
Run `./build-ventus.sh` to automatically build all the programs, but we need to run firstly
* `export POCL_DIR=<path-to-pocl-dir>`, default folder path will be set to be **`<llvm-ventus-parentFolder>`/pocl**
* `export OCL_ICD_DIR=<path-to-ocl-icd-dir>`, default folder path will be set to be **`<llvm-ventus-parentFolder>`/ocl-icd**
### Build pocl
You can dive into `build-ventus.sh` file to see the detailed information about build process
```
# Add ventus-llvm built llvm-config to PATH
export PATH=<path_to_ventus_llvm_install_bin>:$PATH
git clone https://github.com/THU-DSP-LAB/pocl.git
cd pocl
mkdir build && cd build
cmake -DCMAKE_INSTALL_PREFIX=../install -DENABLE_HOST_CPU_DEVICES=OFF -DENABLE_VENTUS=ON -DENABLE_ICD=ON -DDEFAULT_ENABLE_ICD=ON -DENABLE_TESTS=OFF -DSTATIC_LLVM=OFF -G Ninja ../
ninja
# You can use following command to building pocl with system installed llvm.
cmake -DCMAKE_INSTALL_PREFIX=../install -DENABLE_ICD=ON -DENABLE_TESTS=OFF -DSTATIC_LLVM=OFF -DLLC_HOST_CPU=x86-64 -G Ninja ../
```
> If there are errors about cmake CXX compiler, can add -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ to the cmake build command
Build pocl as libOpenCL.so(icd loader+icd driver) instead of libpocl.so(icd driver), `-DENABLE_ICD=OFF` must be specified to cmake.
NOTE: the install folder of ventus-pocl should be merged with the install folder of ventus-llvm in order to correctly locate shared libraries, header files etc.
NOTE: `-DPOCL_DEBUG_MESSAGES=ON` is default on, you can set env variable `POCL_DEBUG` to enable debugging output(see pocl_debug.c for details).
### Build libclc(llvm version instead of pocl one) (Work in progress)
```
# Add ventus-llvm built llvm-config to PATH
export PATH=<llvm_install_folder>/bin:$PATH
cd llvm-project
mkdir build-libclc && cd build-libclc
cmake ../libclc -DCMAKE_LLAsm_COMPILER_WORKS=ON -DCMAKE_CLC_COMPILER_WORKS=ON -DCMAKE_CLC_COMPILER_FORCED=ON -DCMAKE_LLAsm_FLAGS="-target riscv32 -mcpu=ventus-gpgpu" -DLIBCLC_TARGETS_TO_BUILD="riscv32--" -DCMAKE_CXX_FLAGS="-I <llvm-project-root>/llvm/include -std=c++17" -G Ninja
ninja
# Manually copy kernel builtins to the location where pocl driver can locate
cp riscv32--.bc <pocl_install_dir>/share/pocl/kernel-riscv32.bc
# WORKAROUND: Manually copy libworkitem.a and crt0.o
cp riscv32/lib/libworkitem.a <llvm_install_folder>/lib/
cp riscv32/lib/CMakeFiles/crt0.dir/crt0.S.o <llvm_install_folder>/lib/crt0.o
```
### Build icd loader
You can use `apt install ocl-icd-libopencl1` to install ocl icd loader `libOpenCL.so`, but we want to build our own icd loader with debug information, so here it is.
```
git clone https://github.com/OCL-dev/ocl-icd.git
cd ocl-icd
./bootstrap
./configure
make
ls .libs # libOpenCL.so is located in .libs
```
Then copy `libOpenCL.so*` from ocl-icd/.libs to `ventus-llvm/install/lib` folder(where LLVM shared libraries located)
Run `export LD_LIBRARY_PATH=<path_to>/ventus-llvm/install/lib` to tell OpenCL application to use your own built `libOpenCL.so`, also to correctly locate LLVM shared libraries.
### Bridge icd loader `libOpenCL.so` and pocl ocl device driver `libpocl.so`(pocl built with ENABLE_ICD=ON)
### 3: Bridge icd loader
Run `export OCL_ICD_VENDORS=<path_to>/libpocl.so` to tell ocl icd loader where the icd driver is.
@ -173,7 +122,7 @@ note: missing symbols in the kernel binary might be reported as 'file not found'
Aborted (core dumped)
```
### Compile a OpenCL C program into Ventus GPGPU assembly
### 4: Compile a OpenCL C program into Ventus GPGPU assembly
vector_add.cl:
@ -192,9 +141,10 @@ clang -cl-std=CL2.0 -target riscv32 -mcpu=ventus-gpgpu -O1 -S vector_add.cl -o v
NOTE: OpenCL host side program should be linked with icd loader `-lOpenCL`.
### TODOs
### 5: TODOs
* Emit `barrier` instruction for all stores to local/global memory except sGPR spill.
* Stacks for sGPR spilling and per-thread usage is supported by using RISCV::X2 as warp level stack, RISCV::X4 as per-thread level stack. But the 2 stack size calculation are not yet splitted out, so a lot of stack slots are wasted.
* VentusRegextInsertion pass may generate incorrect register ordering for next instruction, see FIXME in that pass. To avoid breaking def-use chain, we could keep the extended instruction unmodified by removing `Op.setRegIgnoreDUChain()` from the pass, the elf generation pass should ignore the higher bit(>2^5) of the register encoding automatically.
* Pattern match VV and VX optimization. There is only type information in the DAG pattern matching, we can't specify whether to match a DAG to a vop.vv or vop.vx MIR in a tblgen pattern, so a fix pass should be ran after codegen pass.
* Opencl kernel api - get_enqueued_local_size, need to support non-uniform workgroup