[mpich-discuss] Compiler optimization flags in MPICH 3.0 rc1

[Yauheni Zelenko]

Hi!

I tried to build optimize and debug version of MPICH 3.0 rc1 and noticed some problems with compiler optimization flags. Looks like -O2 is set implicitly.

For optimize configuration command like contains -O2 and -O3:

./configure --prefix=${InstallDir}                                              \
        --with-pm=hydra --with-device=ch3:nemesis                               \
        --disable-chekpointing                                                  \
        --enable-strict --enable-fast=O3                                        \
        --disable-f77 --disable-fc                                              \
        CC=${GCCDir}/bin/gcc CFLAGS="-m32 -fPIC"                                \
        CPP=${GCCDir}/bin/cpp                                                   \
        CXX=${GCCDir}/bin/g++ CXXFLAGS="-m32 -fPIC"                             \
        CXXCPP=${GCCDir}/bin/cpp

For debug one -O2, but optimization is disabled:

./configure --prefix=${InstallDir}                                              \
        --with-pm=hydra --with-device=ch3:nemesis                               \
        --disable-chekpointing                                                  \
        --enable-strict --disable-fast -enable-g=debug                          \
        --disable-f77 --disable-fc                                              \
        CC=${GCCDir}/bin/gcc CFLAGS="-m32 -fPIC"                                \
        CPP=${GCCDir}/bin/cpp                                                   \
        CXX=${GCCDir}/bin/g++ CXXFLAGS="-m32 -fPIC"                             \
        CXXCPP=${GCCDir}/bin/cpp

Eugene.