ISO_IEC_TR_18015_2006E.pdf

Reference numberISO/IEC TR 18015:2006(E)ISO/IEC 2006 TECHNICAL REPORT ISO/IECTR18015First edition2006-09-01 Information technology Programming languages,their environments and system software interfaces Technical Report on C+Performance Technologies de linformation Langages de programmation,leurs environnements et interfaces du logiciel systme Rapport technique sur la performance C+ISO/IEC TR 18015:2006(E)PDF disclaimer This PDF file may contain embedded typefaces.In accordance with Adobes licensing policy,this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing.In downloading this file,parties accept therein the responsibility of not infringing Adobes licensing policy.The ISO Central Secretariat accepts no liability in this area.Adobe is a trademark of Adobe Systems Incorporated.Details of the software products used to create this PDF file can be found in the General Info relative to the file;the PDF-creation parameters were optimized for printing.Every care has been taken to ensure that the file is suitable for use by ISO member bodies.In the unlikely event that a problem relating to it is found,please inform the Central Secretariat at the address given below.ISO/IEC 2006 All rights reserved.Unless otherwise specified,no part of this publication may be reproduced or utilized in any form or by any means,electronic or mechanical,including photocopying and microfilm,without permission in writing from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel.+41 22 749 01 11 Fax +41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO/IEC 2006 All rights reserved ISO/IEC TR 18015:2006(E)Technical Report on C+Performance ISO/IEC 2006 All rights reserved iii Contents Contents.iii Foreword.v Introduction.vi Participants.vii 1 Scope.1 2 Normative References.3 3 Terms and definitions.4 4 Typical Application Areas.13 4.1 Embedded Systems.13 4.2 Servers.15 5 Language Features:Overheads and Strategies.16 5.1 Namespaces.16 5.2 Type Conversion Operators.17 5.3 Classes and Inheritance.18 5.4 Exception Handling.27 5.5 Templates.37 5.6 Programmer Directed Optimizations.41 6 Creating Efficient Libraries.63 6.1 The Standard IOStreams Library Overview.63 6.2 Optimizing Libraries Reference Example:An Efficient Implementation of Locales and IOStreams.64 7 Using C+in Embedded Systems.77 7.1 ROMability.77 7.2 Hard Real-Time Considerations.81 8 Hardware Addressing Interface.85 8.1 Introduction to Hardware Addressing.86 8.2 The Interface for C and C+.102 8.3 The Interface for C+.108 Technical Report on C+Performance ISO/IEC TR 18015:2006(E)iv ISO/IEC 2006 All rights reserved Annex A:Guidelines on Using the Interface.118 A.1 Usage Introduction.118 A.2 Using Hardware Register Designator Specifications.118 A.3 Hardware Access.121 Annex B:Implementing the iohw Interfaces.124 B.1 General Implementation Considerations.124 B.2 Overview of Hardware Device Connection Options.125 B.3 Hardware Register Designators for Different Device Addressing Methods.128 B.4 Atomic Operation.130 B.5 Read-Modify-Write Operations and Multi-Addressing.130 B.6 Initialization.131 B.7 Intrinsic Features for Hardware Register Access.133 B.8 Implementation Guidelines for the Interface.134 Annex C:A Implementation for the Interface.149 C.1 Implementation of the Basic Access Functions.149 C.2 Buffer Functions.150 C.3 Group Functionality.151 C.4 Remarks.155 Annex D:Timing Code.156 D.1 Measuring the Overhead of Class Operations.156 D.2 Measuring Template Overheads.165 D.3 The Stepanov Abstraction Penalty Benchmark.171 D.4 Comparing Function Objects to Function Pointers.177 D.5 Measuring the Cost of Synchronized I/O.181 Annex E:Bibliography.184 Technical Report on C+Performance ISO/IEC TR 18015:2006(E)ISO/IEC 2006 All rights reserved v Foreword ISO(the International Organization for Standardization)and IEC(the International Electrotechnical Commission)form the specialized system for worldwide standardization.National bodies that are members of ISO or IEC participate in the development of International Standards through technical committees established by the respective organization to deal with particular fields of technical activity.ISO and IEC technical committees collaborate in fields of mutual interest.Other international organizations,governmental and non-governmental,in liaison with ISO and IEC,also take part in the work.In the field of information technology,ISO and IEC have established a joint technical committee,ISO/IEC JTC 1.International Standards are drafted in accordance with the rules given in the ISO/IEC Directives,Part 2.The main task of the joint technical committee is to prepare International Standards.Draft International Standards adopted by the joint technical committee are circulated to national bodies for voting.Publicati