From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 558 invoked by alias); 13 May 2009 19:19:17 -0000 Received: (qmail 32425 invoked by uid 48); 13 May 2009 19:18:51 -0000 Date: Wed, 13 May 2009 19:19:00 -0000 Message-ID: <20090513191851.32424.qmail@sourceware.org> X-Bugzilla-Reason: CC References: Subject: [Bug target/39942] Nonoptimal code - leaveq; xchg %ax,%ax; retq In-Reply-To: Reply-To: gcc-bugzilla@gcc.gnu.org To: gcc-bugs@gcc.gnu.org From: "vvv at ru dot ru" 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: 2009-05/txt/msg01144.txt.bz2 ------- Comment #28 from vvv at ru dot ru 2009-05-13 19:18 ------- (In reply to comment #24) > Using padding to avoid 4 branches in 16byte chunk may not be a good idea since > it will increase code size. It's enough only one byte NOP per 16-byte chunk for padding. But, IMHO, four branches in 16 byte chunk - is very-very infrequent. Especially for 64-bit mode. BTW, it's difficult to understand, what Intel mean ander term "branch". Is it CALL, JMP, conditional branches, or returns (same as AMD), or only JMP and conditional branches. I beleave last case right. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39942