Tim Prince <TimothyPrince@xxxxxxxxxxxxx> writes: > Is there an option in gcc 4.4 or 4.5 to avoid code straightening in > loops with conditionals or select? Intel Core i7 Loop Stream Detector > seems to give up when the code path has more than minimum number of > branches. Code straightening is normally a purely beneficial optimization. That said, gcc 4.5 is much better than 4.4 at avoiding having more than four jumps in a 16 byte span, which I think is what is required to avoid branch mispredictions on Intel/AMD processors. You may be able to avoid some code straightening using -fno-thread-jumps. If this does not help, then I recommend that you file a bug report with a standalone example showing a case where mainline gcc generates suboptimal code. See http://gcc.gnu.org/bugs.html . Thanks. Ian
