[tree-ssa] Simplifying TARGET_EXPR

[Gabriel Dos Reis]

Mark Mitchell <mark@codesourcery.com> writes:

| --On Saturday, July 20, 2002 05:09:42 PM +0100 Jason Merrill 
| <jason@redhat.com> wrote:
| 
| > I'm interested in what y'all think about the second issue; it's something
| > I've run into previously when thinking about expanding NEW_EXPR.
| >
| > One problem with (b) is that using it requires the frontend to know about
| > passing by invisible reference.
| 
| I think (b) is by far better than (a).
| 
| (What I'd really like to see is the elimination of TARGET_EXPR in the
| front end before we reach the optimizers and code generators.  This
| might miss some opportunities for elimination of copy constructors,
| but, in practice, very few.  And, to be honest, I'm nervous about the
| compiler changing the number of objects constructed and destructed
| when optimization is enabled; that makes debugging optimized code
| that much harder.)

Do you think we should always elide copy-constructors by default,
unless explicitly told the contrary? 

-- Gaby