g++ optimizer and numerical computations

[Jeffrey A Law]

  In message < 19980216125213.40642@dot.cygnus.com >you write:
  > On Mon, Feb 16, 1998 at 06:06:01PM +0100, Marc Espie wrote:
  > > - the refcnt test occurs inside the loop. It has not been moved outside
  > > the loop by the compiler.
  > 
  > No, gcc is not able to notice test domination of that nature.
  > Jeff Law played around with that a bit I remember, but I don't
  > know how succesfulit was.
I don't grok C++, so can someone describe exactly what test we think
should have been eliminated?

And as Jason noted, dealing with aliases, particularly in the
presense of function calls is a tough problem :-)


jeff