Re: inlining inefficiencies

[Dan Nicolaescu <dann at godzilla dot ICS dot UCI dot EDU>]

Daniel Berlin <dberlin@dberlin.org> writes:

  > On Thu, 30 May 2002, Kurt Garloff wrote:
  > 
  > > Hi Dan,
  > > 
  > > On Wed, May 29, 2002 at 10:31:46PM -0700, Dan Nicolaescu wrote:
  > > > Andreas Jaeger <aj@suse.de> writes:
  > > > 
  > > >   > Can you have a look at Kurt Garloff's patches which have been
  > > >   > discussed here some weeks agao?  A current version is at
  > > >   > http://www.garloff.de/kurt/freesoft/gcc/
  > > > 
  > > > Those patches deal with deciding what functions to inline. 
  > > > What I've shown is that the code generated after inlining all the
  > > > functions (desired in that case) is inefficient and the optimizers
  > > > can't deal with it.
  > > 
  > > The problem that I spotted in gcc is that it's unable to remove 
  > > temporaries too often. I have some Matrix class whose [] operator
  > > return a temporary object, basically having a pointer to the 
  > > Matrix and the information which line was selected. This can
  > > be used to create a Vector or an element with a second [] and
  > > the temporary should be removed by the compiler.
  > 
  > Just out of curiosity, does the patch I posted yesterday to make the 
  > inliner 
  > generate proper statement expressions help at all?

It doesn't help the testcase I posted. The generated code is identical
before and after your patch.