Frank Neuhaus wrote: > On Fri, Jun 26, 2009 at 11:33 PM, Andrew Haley<aph@xxxxxxxxxx> wrote: >> Frank Neuhaus wrote: >>> On Fri, Jun 26, 2009 at 8:36 PM, Andrew Haley<aph@xxxxxxxxxx> wrote: >>> >>>> If gcc inlines Image::resize, it knows that pixels does not escape, and whatever >>>> is in pixels cannot have any effect elsewhere. >>>> >>> I still don't precisely understand the reason for this behavior. >> Well, I did tell you. :-) > > Well kind of. You said: "If gcc inlines Image::resize, it knows that > pixels does not escape, and whatever > is in pixels cannot have any effect elsewhere." > > I would just like to know how the behavior prevents those 'bad' things > from happening i.e.: > How does not caching the pixels pointer in a local variable in front > of the loop prevent pixels from "escaping"? (What does that mean by > the way if a pixel "escapes"?) Ahh, okay. This is crucial: see http://en.wikipedia.org/wiki/Escape_analysis Read that first, then my comment should make more sense. Andrew.
