Hello, The gcc man page says: Most optimizations are only enabled if an -O level is set on the command line. Otherwise they are disabled, even if individual optimization flags are specified. The man page says to use `-Q --help=optimizers` to find out what is turned on for the different -O levels as configure-time options can make things different from the defaults shown later in that man page. However, I have found that, even when using -O0, I can turn on optimization options, at least according to the help output: $> gcc -Q --help=optimizers | grep "\-fmove-loop-invariants" -fmove-loop-invariants [disabled] $> gcc -Q --help=optimizers -fmove-loop-invariants | grep "\-fmove-loop-invariants" -fmove-loop-invariants [enabled] I get the same result when using "-O0". Given the line from the gcc man page, I would have expected this option to still be disabled even when using it explicitly on the command line. Have I misunderstood the man page line? Or I am misunderstanding the help output? Or is something else altogether going on? Thank for any and all help, David
