Hi Juan, > When using "-fverbose-asm" flag in the commmand line to produce the list of > optimization passes, I suppose you mean adding the "-S" flag to see the > assemble file, don't you? I say this because using the flag in a common > compilation doesn't produce any change. > Anyway, taking a look at the assemble file, I can see the flags employed when > I compile with -O1 option, but if I introduce them all in the command line > instead of -O1 (it is supposed that the executable file would be the same), > optimizations are not performed. What am I doing wrong? I have read source > code and -O1 flag activates some other flags and it seems it does not any > more. -O0 (which is the default if not specified) disables optimizations. So introducing specific flagged optimizations in the context of optimizations disabled has no effect. HTH, --Eljay