PGI Fortran Reference Release 2013 - Docs.nvidia

PGI Fortran Reference Release 2013 The Portland Group

PGI Fortran Reference Copyright 2013 NVIDIA Corporation All rights reserved. Printed in the United States of America First Printing: Release 6.0 March, 2005 Second Printing: Release 6.1 December, 2005 Third Printing: Release 6.1-3 February, 2006 Fourth Printing: Release 7.0-1 December, 2006 Fifth Printing: Release 7.0-2 February, 2007 Sixth Printing: Release 7.2-1 May, 2008 Seventh Printing: Release 7.2-4 August, 2008 Eighth Printing: Release 8.0-1 November, 2008 Ninth Printing: Release 8.1 November, 2008 Tenth Printing: Release 9.0 June, 2009 Eleventh Printing: Release 2010 November, 2009 Twelfth Printing: Release 2010, 10.3 March, 2010 Thirteenth Printing: Release 2010, 10.3 June, 2010 Fourteenth Printing: Release 2011, 11.0 December, 2010 Fifteenth Printing: Release 2011, 11.2 February, 2011 Sixteenth Printing: Release 2012, 12.1 January, 2012 Seventeenth Printing: Release 2012, 12.2 February, 2012 Eighteenth Printing: Release 2012, 12.6 June, 2012 Nineteenth Printing: Release 2012, 12.10 October, 2012 Twentieth Printing: Release 2013, 13.3 March, 2013 Twenty-first Printing: Release 2013, 13.8 August, 2013 Twenty-second Printing: Release 2013, 13.9 September, 2013 www.pgroup.com Technical support: trs@pgroup.com Sales: sales@pgroup.com Web: www.pgroup.com ID: 13254149

Contents Preface . xvii Audience Description . xvii Compatibility and Conformance to Standards . xvii Organization . xviii Hardware and Software Constraints . xviii Conventions . xix Related Publications . xix 1. Language Overview . 1 Elements of a Fortran Program Unit . 1 Statements . 1 Free and Fixed Source . 1 Statement Ordering . 2 The Fortran Character Set . 3 Free Form Formatting . 4 Fixed Formatting . 4 Column Formatting . 4 Fixed Format Label Field . 5 Fixed Format Continuation Field . 5 Fixed Format Statement Field . 5 Fixed Format Debug Statements . 5 Tab Formatting . 6 Fixed Input File Format Summary . 6 Include Fortran Source Files . 6 Components of Fortran Statements . 7 Symbolic Names . 7 Expressions . 8 Forming Expressions . 8 Expression Precedence Rules . 8 Arithmetic Expressions . 9 Relational Expressions . 11 Logical Expressions . 11 Character Expressions . 12 iii

Character Concatenation . Symbolic Name Scope . Assignment Statements . Arithmetic Assignment . Logical Assignment . Character Assignment . Listing Controls . OpenMP Directives . 12 12 12 13 13 14 14 15 2. Fortran Data Types . 17 Intrinsic Data Types . Kind Parameter . Number of Bytes Specification . Constants . Integer Constants . Binary, Octal and Hexadecimal Constants . Real Constants . Double Precision Constants . Complex Constants . Double Complex Constants . Logical Constants . Character Constants . Parameter Constants . Structure Constructors . Derived Types . Deferred Type Parameters . Typed Allocation . Arrays . Array Declaration Element . Deferred Shape Arrays . Subscripts . Character Substring . Array Constructor Syntax . Fortran Pointers and Targets . Fortran Binary, Octal and Hexadecimal Constants . Octal and Hexadecimal Constants - Alternate Forms . Hollerith Constants . Structures . Records . UNION and MAP Declarations . Data Initialization . Pointer Variables . Restrictions . Pointer Assignment . 17 17 18 20 20 21 21 21 22 22 22 22 23 23 24 25 25 26 26 27 27 27 27 28 28 29 30 31 31 32 34 34 35 36 3. Fortran Statements . 37 iv

PGI Fortran Reference Statement Format Overview . Definition of Statement-related Terms . Origin of Statement . List-related Notation . Fortran Statement Summary Table . ACCEPT . ARRAY . BYTE . DECODE . DOUBLE COMPLEX . DOUBLE PRECISION . ENCODE . END MAP . END STRUCTURE . END UNION . INCLUDE . MAP . POINTER (Cray) . PROTECTED . RECORD . REDIMENSION . RETURN . STRUCTURE . UNION . VOLATILE . WAIT . 37 37 37 38 38 44 45 46 46 47 48 49 50 50 51 51 52 53 54 55 56 57 57 59 60 61 4. Fortran Arrays . 63 Array Types . Explicit Shape Arrays . Assumed Shape Arrays . Deferred Shape Arrays . Assumed Size Arrays . Array Specification . Explicit Shape Arrays . Assumed Shape Arrays . Deferred Shape Arrays . Assumed Size Arrays . Array Subscripts and Access . Array Sections and Subscript Triplets . Array Sections and Vector Subscripts . Array Constructors . 63 63 64 64 64 64 64 64 65 65 65 65 66 66 5. Input and Output . 67 File Access Methods . 67 Standard Preconnected Units . 68 v

Opening and Closing Files . Direct Access Files . Closing a File . Data Transfer Statements . Unformatted Data Transfer . Formatted Data Transfer . Implied DO List Input Output List . Format Specifications . Variable Format Expressions . Non-advancing Input and Output . List-directed formatting . List-directed input . List-directed output . Commas in External Field . Character Encoding Format . Namelist Groups . Namelist Input . Namelist Output . Recursive Input/Output . Input and Output of IEEE Infinities and NaNs . Output Format . Input Format . 68 68 69 71 72 72 72 73 82 82 82 82 83 84 85 85 85 86 86 86 86 87 6. Fortran Intrinsics . 89 Intrinsics Support . 89 ACOSD . 103 AND . 103 ASIND . 103 ASSOCIATED . 104 ATAN2D . 104 ATAND . 105 COMPL . 105 CONJG . 105 COSD . 106 DIM . 106 ININT . 106 INT8 . 107 IZEXT . 107 JINT . 108 JNINT . 108 KNINT . 108 LEADZ . 109 LSHIFT . 109 OR . 110 RSHIFT . 110 SHIFT . 111 vi

PGI Fortran Reference SIND . TAND . XOR . ZEXT . Intrinsic Modules . Module IEEE ARITHMETIC . Module IEEE EXCEPTIONS . IEEE FEATURES . Module iso c binding . Module iso fortran env . 111 111 112 112 112 113 117 120 120 121 7. Object Oriented Programming . 123 Inheritance . Polymorphic Entities . Unlimited Polymorphic Entities . Typed Allocation for Polymorphic Variables . Sourced Allocation for Polymorphic Variables . Procedure Polymorphism . Procedure Polymorphism with Type-Bound Procedures . Inheritance and Type-Bound Procedures . Procedure Overriding . Functions as Type-Bound Procedures . Information Hiding . Type Overloading . Data Polymorphism . Pointer Polymorphic Variables . Allocatable Polymorphic Variables . Sourced Allocation . Unlimited Polymorphic Objects . Abstract Types and Deferred Bindings . IEEE Modules . Intrinsic Functions . 123 124 125 126 126 126 127 131 132 134 134 136 137 137 138 139 140 145 148 148 8. OpenMP Directives for Fortran . 151 OpenMP Overview . OpenMP Shared-Memory Parallel Programming Model . Terminology . OpenMP Example . Task Overview . Tasks . Task Characteristics and Activities . Task Scheduling Points . Task Construct . Parallelization Directives . Directive Recognition . Directive Clauses . 151 151 152 153 154 154 155 155 156 157 158 158 vii

COLLAPSE (n) . 161 COPYIN (list) . 161 COPYPRIVATE(list) . 161 DEFAULT . 162 FIRSTPRIVATE(list) . 162 IF() . 162 LASTPRIVATE(list) . 162 NOWAIT . 162 NUM THREADS . 162 ORDERED . 163 PRIVATE .

This manual describes the Portland Group's implementation of the FORTRAN 77, Fortran 90/95, and Fortran 2003 languages. Collectively, The Portland Group compilers that implement these languages are referred to as