From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 5807 invoked by alias); 13 May 2003 13:42:33 -0000 Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org Received: (qmail 5777 invoked from network); 13 May 2003 13:42:32 -0000 Received: from unknown (HELO vlsi1.ultra.nyu.edu) (128.122.140.213) by sources.redhat.com with SMTP; 13 May 2003 13:42:32 -0000 Received: by vlsi1.ultra.nyu.edu (4.1/1.34) id AA14037; Tue, 13 May 03 09:47:18 EDT Date: Tue, 13 May 2003 13:42:00 -0000 From: kenner@vlsi1.ultra.nyu.edu (Richard Kenner) Message-Id: <10305131347.AA14037@vlsi1.ultra.nyu.edu> To: matz@suse.de Subject: Re: [tree-ssa] Out of SSA status and issues Cc: gcc@gcc.gnu.org X-SW-Source: 2003-05/txt/msg01302.txt.bz2 Suppose there is register pressure and we are in the register allocator and decide that p1 doesn't get a hardreg. If you now don't allow the use of p1 to be replaced with *p2, you are forced to emit such code: Of course, but we weren't talking about the register allocator. Instead, we were talking about a high-level optimization. The register allocator indeed needs to know what a psuedo corresponds to so that it can undo the optimization is there aren't enough hard registers. We do some of this, but not enough.