I do not see this flag in gcc3.4.4.
perflab2% gcc -o conftest -O3 -march=pentium4 -fmove-loop-invariants conftest.c cc1: error: unrecognized command line option "-fmove-loop-invariants" Am I missing something? -girish --- Zdenek Dvorak <[EMAIL PROTECTED]> wrote: > Hello, > > > >A more likely source of performance degradation > is that loop unrolling > > >is enabled when profiling, and loop unrolling is > almost always a bad > > >pessimization on 32 bits x86 targets. > > > > To clarify, I was compiling with -funroll-loops > and -fpeel-loops > > enabled in both cases. > > > > The FDO slowdown in my case was caused by the > presence of some loop > > invariant code that was getting removed from the > loop by the loop > > optimizer pass in the non-FDO case. > > you may try adding -fmove-loop-invariants flag, > which enables new > invariant motion pass. > > Zdenek >
