On Thu, Oct 22, 2009 at 04:52:06PM -0400, Steven Rostedt wrote: > On Thu, 2009-10-22 at 13:30 -0700, Adam Nemet wrote: > > > > Speaking of performance, -pg also affects the instruction scheduling freedom > > of the compiler in the prologue. With profiling, we limit optimizations not > > to move instructions in and out of the prologue. > > > > Also note that for functions invoked via tail call you won't get an exit > > event. E.g. if bar is tail-called from foo: > > > > foo entered > > bar entered > > foo/bar exited > > > > However, this is not MIPS-specific and you can always disable tail calls > > with -fno-optimize-sibling-calls. Ouch.. > The question is, would bar have a _mcount call? So far, we have not had > any issues with this on either x86 nor PPC. Nothing would prevent that I guess. I mean, we are doing a very specific use of -pg, and common uses wouldn't require to disable the mcount call on bar in this situation, so it's not something that -pg is supposed to care about. > /me knocks on wood. Me too (but not so hard...)
