From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 5314 invoked by alias); 18 Jan 2010 13:14:46 -0000 Received: (qmail 5267 invoked by uid 48); 18 Jan 2010 13:14:35 -0000 Date: Mon, 18 Jan 2010 13:14:00 -0000 Message-ID: <20100118131435.5266.qmail@sourceware.org> X-Bugzilla-Reason: CC References: Subject: [Bug rtl-optimization/42621] [4.4 Regression] Computed gotos on AMD 800% slower In-Reply-To: Reply-To: gcc-bugzilla@gcc.gnu.org To: gcc-bugs@gcc.gnu.org From: "carlr at freemail dot gr" Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org X-SW-Source: 2010-01/txt/msg02196.txt.bz2 ------- Comment #10 from carlr at freemail dot gr 2010-01-18 13:14 ------- Please note that computed gotos are factored out because "they are a hell to deal with" in tree-cfg.c:build_gimple_cfg(). This means that they MUST be unfactored out as promised in the comment without leaving this to another optimization step that may or may not be enabled. Also, for our product there are 97 "extra jumps" and 95 of them are long jumps, i.e: 12be0: ff e1 jmp *%ecx ... 12dda: e9 01 fe ff ff jmp 12be0 ... so this is a serious both speed and size pessimisation :( -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42621