elouanj / polly Goto Github PK

How to install Polly :
1) Follow the get started web page (https://polly.llvm.org/get_started.html)
It can be very long and commands can changes on the web page but they are the following commands :
git clone https://github.com/llvm/llvm-project.git
mkdir build && cd build
cmake '-DLLVM_ENABLE_PROJECTS=clang;polly' ../llvm
cmake --build .

2)Execute the good version of Polly. Polly can be install by default on your computer.
To execute the one you just built, you need to put, before the command, the path of the bin directory of new Polly build.
For example, to compile a code with Polly, you do :
clang -O3 -mllvm -polly FILE.c
Now, before the clang you will put the good path :
/home/.../llvm-project/build/bin/clang -O3 -mllvm -polly FILE.c
To see all the command that you can do to decompose Polly : https://polly.llvm.org/docs/HowToManuallyUseTheIndividualPiecesOfPolly.html
The command that I used to change the data dependence format : 
/home/elouan/llvm-project/build/bin/opt -fm-path ./FileMapping.txt -basic-aa -polly-use-llvm-names -polly-dependences -analyze FILE.preopt.ll -polly-process-unprofitable -debug
To execute this command :
- You need to do all the previous command in the previous link,
- You need to generate the FileMapping.txt like in DiscoPoP,
- You need to put the "-g" option when you translate the code into LLVM-IR with the previous link.

3)To put this version on Polly into the one install in the first step, you just need to copy paste this Polly folder instead the present one by default.
If it's not working my changes are in the lib/Analysis/DependenceInfo.cpp and include/polly/DependenceInfo.h


4)To rebuild polly, you just need to do the last command of the installation on the same build folder :
cd llvm-project/build/
cmake --build .

BE CAREFULL : These commands may not be up to date, this document was done on October 25, 2021.
To view the updated version, please see the get started web site and all the polly documentation : https://polly.llvm.org/get_started.html



My main changes are between the two "start add" and "end add" comments in the DependenceInfo.cpp file.
There are also a "start add DISCOPOP" and "end add DISCOPOP" comments who are DiscoPoP functions that I used to get the variable name and the line number of the two statements involved in a data dependence.

Now the problem is to combine Polly ith DiscoPoP. When you build DiscoPoP, it will also build LLVM. But, in LLVM there is also, by default a Polly version. And so, DiscoPoP will build this Polly version and not the one I changed. For more explication, you can see the discussion I had with the polly developer : https://groups.google.com/g/polly-dev/c/VE2AmfI-NcI
Here are the errors that I have :


CMake Error at polly/cmake/polly_macros.cmake:23 (add_library):
  add_library cannot create target "PollyISL" because an imported target with
  the same name already exists.
Call Stack (most recent call first):
  polly/lib/External/CMakeLists.txt:284 (add_polly_library)


CMake Error at polly/lib/External/CMakeLists.txt:312 (target_compile_options):
  target_compile_options may only set INTERFACE properties on IMPORTED
  targets


CMake Error at /usr/lib/llvm-13/lib/cmake/llvm/AddLLVM.cmake:538 (add_library):
  add_library cannot create target "Polly" because an imported target with
  the same name already exists.
Call Stack (most recent call first):
  /usr/lib/llvm-13/lib/cmake/llvm/AddLLVM.cmake:796 (llvm_add_library)
  /usr/lib/llvm-13/lib/cmake/llvm/AddLLVM.cmake:997 (add_llvm_library)
  polly/lib/CMakeLists.txt:54 (add_llvm_pass_plugin)


CMake Error at /usr/lib/llvm-13/lib/cmake/llvm/AddLLVM.cmake:662 (target_link_libraries):
  Cannot specify link libraries for target "Polly" which is not built by this
  project.
Call Stack (most recent call first):
  /usr/lib/llvm-13/lib/cmake/llvm/AddLLVM.cmake:796 (llvm_add_library)
  /usr/lib/llvm-13/lib/cmake/llvm/AddLLVM.cmake:997 (add_llvm_library)
  polly/lib/CMakeLists.txt:54 (add_llvm_pass_plugin)


-- Configuring incomplete, errors occurred!
See also "/home/elouan/discopop/build/CMakeFiles/CMakeOutput.log".
See also "/home/elouan/discopop/build/CMakeFiles/CMakeError.log".


For information, I compiled it with this command : CC=clang; CXX=clang++; cmake ..
To have these errors, I just copied the Polly folder into DiscoPoP and I had this line : add_subdirectory(polly) into the CMakeLists.txt file at the root of DiscoPoP.
If you want any more information about the problem or about my work you can contact me here : [email protected]