Elefunt

[Sezoir]

Enable building and execution of the Elefunt application with the LLVM Flang compiler.

[Sezoir]

Next steps: I am not planning to take on this project. This is just an initial report found. Please feel free to work on this.

elefunt:

https://www.netlib.org/elefunt/

elefunt is a benchmark from the netlib repository.

Initial report for elefunt:

• Minimum version of Fortran required using gfortran: F95

• Running make CFLAGS=-DSP also results default compiling with F77

• How to compile with gfortran:

  1. First you need to download the project. From what I can tell there is no easy download "button" for the repository. Instead, I had to use wget with a few parameters to ensure we download the correct files. This can be downloaded with:

  wget -r -np -nH -l1 -e robots=off -R master_counts2.html index.html http://www.netlib.org/elefunt
  cd elefunt
  

  The parameters given are used for the following reason: -r for recursive download; -e robots=off to not download the robot file; -R master_counts2.html index.html to exclude the unrelated "web" files; -l1 limits recursive search to 1 layer; -np stops ascending to the parent directory; -nh to not create a host directory.

  2. Now you can compile the project by running:

  make FC=gfortran CC=gcc CFLAGS=-DSP
  

  Correctly substituting the path to your GNU compiler if required.
  The flag definition given can either be -DSP or -DDP representing single precision vs double precision respectively. This is required in machar.c.

• Does it compile with flang-new: Yes
  We can compile elefunt by running:

  make FC=flang-new CC=clang-12 CFLAGS="-DSP -Wno-return-type"
  

  We require the -Wno-return-type flag due to the rmachar function in machar.c not returning an explicit value (returns void) and clang defaulting to erroring at this warning type.

Versions:

• gcc version used: 9.3.0
• gfortran version used: 9.3.0
• GNU f77 version used: 9.3.0
• flang-new, fir-dev branch, HEAD: fb8eb63
• clang-12: 12.0.0
• Architecture for compilation: aarch64