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Re: [tree-ssa] Simplifying TARGET_EXPR
- From: Gabriel Dos Reis <gdr at codesourcery dot com>
- To: Mark Mitchell <mark at codesourcery dot com>
- Cc: Jason Merrill <jason at redhat dot com>, Richard Henderson <rth at redhat dot com>, "gcc at gcc dot gnu dot org" <gcc at gcc dot gnu dot org>
- Date: 21 Jul 2002 23:49:28 +0200
- Subject: Re: [tree-ssa] Simplifying TARGET_EXPR
- Organization: CodeSourcery, LLC
- References: <27410000.1027287015@warlock.codesourcery.com>
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