Failure to extract features for MPI programs

[twang15]

Feature extraction for MPI programs in c language fails with the following message:

mpicc -o amg_linklist.o -c -I.. -v -O3 --ct-extract-features -frounding-math -fsignaling-nans -DTIMER_USE_MPI -DHYPRE_USING_OPENMP -DHYPRE_LONG_LONG -DHYPRE_TIMING amg_linklist.c
mpicc for MVAPICH2 version 2.2
Using built-in specs.
Target: x86_64-unknown-linux-gnu
Configured with: ../milepost-gcc-4.4.4/configure --prefix=/home/twang15/CK-TOOLS/gcc-milepost-4.4.4-linux-64 --enable-languages=c,c++,fortran --disable-multilib --with-gmp=/home/twang15/CK-TOOLS/gmp-5.0.5-linux-64 --with-mpfr=/home/twang15/CK-TOOLS/mpfr-3.1.0-linux-64 --with-mpc=
Thread model: posix
gcc version 4.4.4 (GCC)
COLLECT_GCC_OPTIONS='-o' 'amg_linklist.o' '-c' '-I..' '-v' '-O3' '-fct-extract-features' '-frounding-math' '-fsignaling-nans' '-DTIMER_USE_MPI' '-DHYPRE_USING_OPENMP' '-DHYPRE_LONG_LONG' '-DHYPRE_TIMING' '-I/opt/ohpc/pub/mpi/mvapich2-gnu/2.2/include' '-mtune=generic'
/home/twang15/CK-TOOLS/gcc-milepost-4.4.4-linux-64/libexec/gcc/x86_64-unknown-linux-gnu/4.4.4/cc1 -quiet -v -I.. -I/opt/ohpc/pub/mpi/mvapich2-gnu/2.2/include -DTIMER_USE_MPI -DHYPRE_USING_OPENMP -DHYPRE_LONG_LONG -DHYPRE_TIMING amg_linklist.c -quiet -dumpbase amg_linklist.c -mtune=generic -auxbase-strip amg_linklist.o -O3 -version -fct-extract-features -frounding-math -fsignaling-nans -o /tmp/ccRaiVDZ.s
cc1: error: unrecognized command line option "-fct-extract-features"

[twang15]

It seems to me that ctuning-cc/c++ is a wrapper around milepost gcc/g++.
If this is true, then the root cause for this error is that mpicc should invoke ctuning-cc first, not directly invoking cc1.

The invocation relation should look like this:
mpicc -> ctuning-cc ->milepost gcc ->cc1

But the current invocation is like:
mpicc-> milepost gcc ->cc1.

But, milepost gcc does not understand feature extraction option "--ct-extract-features" while ctuning-cc does.

[twang15]

The challenges is that mpicc does not know the existence of ctuning-cc and thus has no way to invoke it.

To address this challenge, we can rename ctuning-cc as gcc, so that mpicc will invoke it.
However, the fact that ctuning-cc invokes milepost gcc with name as gcc prevents us from doing this. The solution seems to be:

Solution 1:

1. rename ctuning-cc as gcc, so that mpicc will invoke it.
2. rename milepost gcc's binary as milepost-gcc.
3. modify ctuning-cc's source code to invoke milepost-gcc.

Solution 2:

1. Extract mpicc's flags, which includes include/header paths (in the form as -Ixx), link paths (in the form as -Lxx for dynamic library, -lxx for static library)
2. Use ctuning-cc to replace mpicc as the compilation driver.

[twang15]

@gfursin

[twang15]

The solution turns out to be very simple.

1. copy system mpicc to my local directory $HOME/benchmark. (because I want to modify it, but I do not have root access)
2. Modify local copy mpicc, replace CC=gcc to CC=$(CK_CC)
3. export PATH=$HOME/benchmark:$PATH.
4. Everything as before ck compilation error #4 How to extract features for a large program #5 Failure to extract features for c++ programs #6

[gfursin]

You are right, @twang15 - ctuning-cc is a wrapper around MILEPOST GCC, so your solution is correct! Thanks a lot for figuring it out and reporting. I also added this info to MILEPOST readme!!!