> From: Ian Bolton [mailto:bol...@icerasemi.com] > > Is there any reason why BB reorder has been disabled > > in bb-reorder.c for -Os, such that you can't even > > turn it on with -freorder-blocks?
On Tue, Mar 23, 2010 at 12:21:05PM -0700, Paul Koning wrote: > Does -Os mean "optimize even if it makes things a bit bigger" or does it > mean "optimize only to make it smaller"? If the latter then the current > behavior would appear to be the correct one. The intent of -Os is to say that speed matters less than size. This would argue against using any optimization that can increase code size *by default*. However, if the user explicitly says -freorder-blocks on the command line, then he/she is overriding part of -Os, saying that desired behavior is to do the specified optimization, but otherwise optimize for space. Also, while some combinations of options might not be possible, at the least, if a user asks for some pass to run with an -f switch and the pass isn't run, there should at least be a warning to that effect (IMHO).
