Intel® Fortran Compiler Classic and Intel® Fortran Compiler Developer Guide and Reference

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Date 7/13/2023
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Document Table of Contents
Document Table of Contents x
Intel® Fortran Compiler Classic and Intel® Fortran Compiler Developer Guide and Reference
Intel® Fortran Compiler Classic and Intel® Fortran Compiler Developer Guide and Reference x
Intel® Fortran Compiler Classic and Intel® Fortran Compiler Introduction Compiler Setup Compiler Reference Language Reference Compilation Program Structure Optimization and Programming Compatibility and Portability Notices and Disclaimers
Intel® Fortran Compiler Classic and Intel® Fortran Compiler Introduction x
Get Help and Support Related Information
Compiler Setup x
Use the Command Line Use Microsoft Visual Studio
Use the Command Line x
Specify Component Locations Invoke the Compiler Use the Command Line on Windows Run Fortran Applications from the Command Line File Extensions Use Makefiles for Compilation
Use Microsoft Visual Studio x
Use Microsoft Visual Studio* Solution Explorer Create a New Project Perform Common Tasks with Microsoft Visual Studio* Select a Version of the Intel® Fortran Compiler Use Visual Studio* IDE Automation Objects Specify Fortran File Extensions Understand Solutions, Projects, and Configurations Navigate Programmatic Components in a Fortran File Specify Path, Library, and Include Directories Set Compiler Options in the Microsoft Visual Studio* IDE Property Pages Supported Build Macros Use Manifests Use Intel® Libraries with Microsoft Visual Studio* Use Code Coverage in Microsoft Visual Studio* Use Profile Guided Optimization in Microsoft Visual Studio* Use Source Editor Enhancements in Microsoft Visual Studio* Create the Executable Program Convert and Copy Projects About Fortran Project Types Optimization Reports Dialog Box Help
About Fortran Project Types x
Understand Project Types Specify Project Types with ifort Command Options Use Fortran Console Application Projects Use Fortran Standard Graphics Application Projects Use Fortran QuickWin Application Projects Use Fortran Windowing Application Projects Use Fortran Static Library Projects Use Fortran Dynamic-Link Library Projects Use the Console Create Fortran Applications That Use Windows Features
Dialog Box Help x
Options: General dialog box Options: Compilers dialog box Options: Advanced dialog box
Options: Advanced dialog box x
Options: Optimization Reports dialog box Options: Profile Guided Optimization dialog box Profile Guided Optimization dialog box Options: Code Coverage dialog box Code Coverage dialog box Code Coverage Settings dialog box
Compiler Reference x
Compiler Limits Compiler Options Floating-Point Operations Libraries Data and I/O Mixed-Language Programming Error Handling
Compiler Options x
Alphabetical Option List General Rules for Compiler Options What Appears in the Compiler Option Descriptions Optimization Options Code Generation Options Interprocedural Optimization Options Advanced Optimization Options Profile Guided Optimization Options Optimization Report Options Offload Compilation, OpenMP*, and Parallel Processing Options Floating-Point Options Inlining Options Output, Debug, and Precompiled Header Options Preprocessor Options Component Control Options Language Options Data Options Compiler Diagnostic Options Compatibility Options Linking or Linker Options Miscellaneous Options Deprecated and Removed Compiler Options Display Option Information Alternate Compiler Options
Optimization Options x
falias, Oa fast ffnalias, Ow foptimize-sibling-calls fprotect-parens, Qprotect-parens GF nolib-inline O Syntax Arguments Default Description IDE Equivalent Alternate Options See Also Od Ofast Os Ot
Code Generation Options x
arch ax, Qax fasynchronous-unwind-tables fcf-protection, Qcf-protection fexceptions fomit-frame-pointer, Oy guard hotpatch m, Qm m32, m64, Qm32, Qm64 m80387 march masm mauto-arch, Qauto-arch mbranches-within-32B-boundaries, Qbranches-within-32B-boundaries mconditional-branch, Qconditional-branch minstruction, Qinstruction momit-leaf-frame-pointer mstringop-inline-threshold, Qstringop-inline-threshold mstringop-strategy, Qstringop-strategy mtune, tune Qpatchable-addresses x, Qx xHost, QxHost
Interprocedural Optimization Options x
ffat-lto-objects flto ip, Qip ip-no-inlining, Qip-no-inlining ip-no-pinlining, Qip-no-pinlining ipo, Qipo ipo-c, Qipo-c ipo-jobs, Qipo-jobs ipo-S, Qipo-S ipo-separate, Qipo-separate
Advanced Optimization Options x
ansi-alias, Qansi-alias coarray, Qcoarray coarray-config-file, Qcoarray-config-file coarray-num-images, Qcoarray-num-images complex-limited-range, Qcomplex-limited-range fvec-peel-loops, Qvec-peel-loops fvec-remainder-loops, Qvec-remainder-loops fvec-with-mask, Qvec-with-mask guide, Qguide guide-data-trans, Qguide-data-trans guide-file, Qguide-file guide-file-append, Qguide-file-append guide-opts, Qguide-opts guide-par, Qguide-par guide-vec, Qguide-vec heap-arrays pad, Qpad qmkl, Qmkl qmkl-ilp64, Qmkl-ilp64 qopt-args-in-regs, Qopt-args-in-regs qopt-assume-safe-padding, Qopt-assume-safe-padding qopt-block-factor, Qopt-block-factor qopt-dynamic-align, Qopt-dynamic-align qopt-for-throughput, Qopt-for-throughput qopt-jump-tables, Qopt-jump-tables qopt-malloc-options qopt-matmul, Qopt-matmul qopt-mem-layout-trans, Qopt-mem-layout-trans qopt-multi-version-aggressive, Qopt-multi-version-aggressive qopt-multiple-gather-scatter-by-shuffles, Qopt-multiple-gather-scatter-by-shuffles qopt-prefetch, Qopt-prefetch qopt-prefetch-distance, Qopt-prefetch-distance (ifort only) qopt-prefetch-distance, Qopt-prefetch-distance (ifx only) qopt-prefetch-issue-excl-hint, Qopt-prefetch-issue-excl-hint qopt-prefetch-loads-only, Qopt-prefetch-loads-only qopt-ra-region-strategy, Qopt-ra-region-strategy qopt-streaming-stores, Qopt-streaming-stores qopt-subscript-in-range, Qopt-subscript-in-range qopt-zmm-usage, Qopt-zmm-usage qoverride-limits, Qoverride-limits reentrancy safe-cray-ptr, Qsafe-cray-ptr scalar-rep, Qscalar-rep simd, Qsimd unroll, Qunroll unroll-aggressive, Qunroll-aggressive vec, Qvec vec-guard-write, Qvec-guard-write vec-threshold, Qvec-threshold vecabi, Qvecabi
Profile Guided Optimization Options x
finstrument-functions, Qinstrument-functions fnsplit, Qfnsplit p prof-data-order, Qprof-data-order prof-dir, Qprof-dir prof-file, Qprof-file prof-func-groups prof-func-order, Qprof-func-order prof-gen, Qprof-gen prof-hotness-threshold, Qprof-hotness-threshold prof-src-dir, Qprof-src-dir prof-src-root, Qprof-src-root prof-src-root-cwd, Qprof-src-root-cwd prof-use, Qprof-use prof-value-profiling, Qprof-value-profiling Qcov-dir Qcov-file Qcov-gen
Optimization Report Options x
qopt-report, Qopt-report (ifort only) qopt-report, Qopt-report (ifx only) qopt-report-annotate, Qopt-report-annotate qopt-report-annotate-position, Qopt-report-annotate-position qopt-report-embed, Qopt-report-embed qopt-report-file, Qopt-report-file qopt-report-filter, Qopt-report-filter qopt-report-format, Qopt-report-format qopt-report-help, Qopt-report-help qopt-report-names, Qopt-report-names qopt-report-per-object, Qopt-report-per-object qopt-report-phase, Qopt-report-phase qopt-report-routine, Qopt-report-routine tcollect, Qtcollect tcollect-filter, Qtcollect-filter
Offload Compilation, OpenMP*, and Parallel Processing Options x
device-math-lib fiopenmp, Qiopenmp fmpc-privatize fopenmp fopenmp-declare-target-scalar-defaultmap, Qopenmp-declare-target-scalar-defaultmap fopenmp-default-allocator, Qopenmp-default-allocator fopenmp-device-lib fopenmp-target-buffers, Qopenmp-target-buffers fopenmp-target-do-concurrent, Qopenmp-target-do-concurrent fopenmp-targets, Qopenmp-targets fsycl fsycl-dead-args-optimization fsycl-device-code-split fsycl-device-lib fsycl-instrument-device-code fsycl-link-huge-device-code ftarget-compile-fast nolibsycl par-affinity, Qpar-affinity par-num-threads, Qpar-num-threads par-runtime-control, Qpar-runtime-control par-schedule, Qpar-schedule par-threshold, Qpar-threshold parallel, Qparallel parallel-source-info, Qparallel-source-info qopenmp, Qopenmp qopenmp-lib, Qopenmp-lib qopenmp-link qopenmp-simd, Qopenmp-simd qopenmp-stubs, Qopenmp-stubs qopenmp-threadprivate, Qopenmp-threadprivate Qpar-adjust-stack Xopenmp-target
Floating-Point Options x
fast-transcendentals, Qfast-transcendentals fimf-absolute-error, Qimf-absolute-error fimf-accuracy-bits, Qimf-accuracy-bits fimf-arch-consistency, Qimf-arch-consistency fimf-domain-exclusion, Qimf-domain-exclusion fimf-force-dynamic-target, Qimf-force-dynamic-target fimf-max-error, Qimf-max-error fimf-precision, Qimf-precision fimf-use-svml, Qimf-use-svml fltconsistency fma, Qfma fp-model, fp fp-port, Qfp-port fp-speculation, Qfp-speculation fp-stack-check, Qfp-stack-check fpe fpe-all ftz, Qftz Ge mp1, Qprec pc, Qpc prec-div, Qprec-div prec-sqrt, Qprec-sqrt qsimd-honor-fp-model, Qsimd-honor-fp-model qsimd-serialize-fp-reduction, Qsimd-serialize-fp-reduction rcd, Qrcd recursive
Inlining Options x
finline finline-functions finline-limit inline inline-factor, Qinline-factor inline-forceinline, Qinline-forceinline inline-level, Ob inline-max-per-compile, Qinline-max-per-compile inline-max-per-routine, Qinline-max-per-routine inline-max-size, Qinline-max-size inline-max-total-size, Qinline-max-total-size inline-min-caller-growth, Qinline-min-caller-growth inline-min-size, Qinline-min-size Qinline-dllimport
Output, Debug, and Precompiled Header Options x
bintext c debug (Linux* and macOS) debug (Windows*) debug-parameters exe Fa FA fcode-asm Fd feliminate-unused-debug-types, Qeliminate-unused-debug-types fmerge-constants fmerge-debug-strings fsource-asm ftrapuv, Qtrapuv fverbose-asm g gdwarf grecord-gcc-switches gsplit-dwarf list list-line-len list-page-len map-opts, Qmap-opts o object pdbfile print-multi-lib Quse-msasm-symbols S show use-asm, Quse-asm Zi, Z7 Zo
Preprocessor Options x
B D d-lines, Qd-lines E EP fpp fpp-name gen-dep gen-depformat gen-depshow I idirafter isystem module preprocess-only u (Windows*) U undef X
Component Control Options x
Qinstall Qlocation Qoption
Language Options x
allow altparam assume ccdefault check extend-source fixed free iface names pad-source, Qpad-source stand standard-realloc-lhs standard-semantics syntax-only wrap-margin
Data Options x
align auto auto-scalar, Qauto-scalar convert double-size dyncom, Qdyncom falign-functions, Qfnalign falign-loops, Qalign-loops falign-stack fcommon fkeep-static-consts, Qkeep-static-consts fmath-errno fminshared fpconstant fpic fpie fstack-protector fstack-security-check fvisibility fzero-initialized-in-bss, Qzero-initialized-in-bss Gs GS homeparams init, Qinit intconstant integer-size mcmodel mdynamic-no-pic no-bss-init, Qnobss-init Qsfalign real-size save, Qsave zero, Qzero
Compiler Diagnostic Options x
diag, Qdiag diag-dump, Qdiag-dump diag-error-limit, Qdiag-error-limit diag-file, Qdiag-file diag-file-append, Qdiag-file-append diag-id-numbers, Qdiag-id-numbers diag-once, Qdiag-once gen-interfaces traceback warn WB Winline
Compatibility Options x
f66 f77rtl fpscomp gcc-name gxx-name Qvc vms
Linking or Linker Options x
4Nportlib, 4Yportlib Bdynamic Bstatic Bsymbolic Bsymbolic-functions cxxlib dbglibs dll dynamic-linker dynamiclib extlnk F (Windows*) F (macOS) fuse-ld l L libs link map MD MDs MT nodefaultlibs nofor-main no-intel-lib, Qno-intel-lib nostartfiles nostdlib pie pthread shared shared-intel shared-libgcc static static-intel static-libgcc static-libstdc++ staticlib T threads v Wa winapp Wl Wp Xlinker
Miscellaneous Options x
bigobj dryrun dumpmachine extfor extfpp global-hoist, Qglobal-hoist help intel-freestanding intel-freestanding-target-os libdir logo multiple-processes, MP save-temps, Qsave-temps sox sysroot Tf watch what
Floating-Point Operations x
Programming Tradeoffs in Floating-Point Applications Floating-Point Optimizations Use the -fp-model, /fp Option Subnormal Numbers Floating-Point Environment Set the FTZ and DAZ Flags Check the Floating-Point Stack State Tuning Performance
Libraries x
Create Static Libraries Create Shared Libraries on Linux and macOS Use Shared Libraries on macOS Call Library Routines Comparison of Intel® Visual Fortran and Windows API Routines Specify Consistent Library Types on Windows Redistribute Libraries When Deploying Applications Resolve References to Shared Libraries Store Object Code in Static Libraries Store Routines in Shareable Libraries Use Windows API Routines Math Libraries
Use Windows API Routines x
Include the Intel® Visual Fortran Interface Definitions for Windows API Routines Call Windows API Routines Supplied Windows API Modules
Data and I/O x
Data Representation Fortran I/O
Data Representation x
Integer Data Representations Logical Data Representations Character Representation Hollerith Representation
Integer Data Representations x
INTEGER(KIND=1) Representation INTEGER(KIND=2) Representation INTEGER(KIND=4) Representation INTEGER(KIND=8) Representation
Fortran I/O x
Logical Devices Physical Devices on Windows Types of I/O Statements Forms of I/O Statements Assign Files to Logical Units File Organization Internal Files and Scratch Files File Access and File Structure File Records Record Types Record Length Record Access Record Transfer Specify Default Pathnames and File Names Open Files: OPEN Statement Obtain File Information: INQUIRE Statement Close Files: CLOSE Statement Record I/O Statement Specifiers File Sharing on Linux and macOS Specify the Initial Record Position Advancing and Nonadvancing Record I/O Use USEROPEN to Pass Control To a Routine Microsoft Fortran PowerStation Compatible Files Use Asynchronous I/O
Mixed-Language Programming x
Standard Fortran and C Interoperability Use Standard Fortran Interoperability Syntax for Existing Fortran Extensions Standard Tools for Interoperability Platform Specifics Implementation Specifics Legacy Extensions
Standard Tools for Interoperability x
ISO_C_BINDING BIND(C) Interoperate with Arguments Using C Descriptors C Structures, Typedefs, and Macros for Interoperability Data Types Variables Global Data Procedures
Data Types x
Scalar Types Characters Pointers Derived Types
Platform Specifics x
Mixed-Language Issues Call Subprograms from the Main Program on Windows Pass Arguments in Mixed-Language Programming Stack Considerations in Calling Conventions on Windows Naming Conventions C/C++ Naming Conventions Compile and Link Intel® Fortran and C Programs Build Intel® Fortran and C Mixed-Language Programs on Windows
Implementation Specifics x
Fortran Module Naming Conventions Handle Fortran Array Pointers and Allocatable Arrays Handle Fortran Array Descriptors Return Character Data Types
Legacy Extensions x
ATTRIBUTES Directive Options ALIAS Option for ATTRIBUTES Directive Use the -nofor-main Compiler Option
Error Handling x
Build Process Errors Runtime Errors
Runtime Errors x
Understand Runtime Errors Runtime Default Error Processing Runtime Message Display and Format Values Returned at Program Termination Methods of Handling Errors Locate Runtime Errors List of Runtime Error Messages Signal Handling on Linux* and macOS Override the Default Runtime Library Exception Handler Advanced Exception and Termination Handling
Advanced Exception and Termination Handling x
Default Exception Handling Default Console Event Handling Default Termination Handling Handlers for the Application Types Provide Your Own Exception or Termination Handler Use Windows* Structured Exception Handling Establish Console Event Handlers Use SIGNALQQ
Language Reference x
New Language Features New Features for ifx Language Reference Conventions Program Elements and Source Forms Data Types, Constants, and Variables Expressions and Assignment Statements Specification Statements Dynamic Allocation Execution Control Program Units and Procedures Intrinsic Procedures Data Transfer I/O Statements I/O Formatting File Operation I/O Statements Compilation Control Lines and Statements Directive Enhanced Compilation Scope and Association Deleted and Obsolescent Language Features Additional Language Features Additional Character Sets Data Representation Models Library Modules and Runtime Library Routines Summary of Language Extensions A to Z Reference Glossary
Program Elements and Source Forms x
Program Units Statements Keywords Names Character Sets Source Forms
Source Forms x
Free Source Form Fixed and Tab Source Forms Source Code Useable for All Source Forms
Fixed and Tab Source Forms x
Fixed-Format Lines Tab-Format Lines
Data Types, Constants, and Variables x
Intrinsic Data Types Derived Data Types Binary, Octal, Hexadecimal, and Hollerith Constants Enumerations and Enumerators Variables
Intrinsic Data Types x
Integer Data Types Real Data Types Complex Data Types Logical Data Types Character Data Type
Integer Data Types x
Integer Constants
Real Data Types x
General Rules for Real Constants REAL(4) Constants REAL(8) or DOUBLE PRECISION Constants REAL(16) Constants
Complex Data Types x
General Rules for Complex Constants COMPLEX(4) Constants COMPLEX(8) or DOUBLE COMPLEX Constants COMPLEX(16) Constants
Logical Data Types x
Logical Constants
Character Data Type x
Character Constants C Strings in Character Constants Character Substrings
Derived Data Types x
Default Initialization Procedure Pointers as Derived-Type Components Type-Bound Procedures Type Extension Parameterized Derived-Type Declarations Structure Components Structure Constructors
Parameterized Derived-Type Declarations x
Parameterized TYPE Statements
Parameterized TYPE Statements x
Structure Constructors for Parameterized Derived Types Type Parameter Order for Parameterized Derived Types Deferred-Length Type Parameters for Parameterized Derived Types Assumed-Length Type Parameters for Parameterized Derived Types
Binary, Octal, Hexadecimal, and Hollerith Constants x
Binary Constants Octal Constants Hexadecimal Constants Hollerith Constants Determine the Data Type of Nondecimal Constants
Variables x
Data Types of Scalar Variables Arrays Coarrays Variable-Definition Context
Data Types of Scalar Variables x
Specification of Data Type Implicit Typing Rules
Arrays x
Whole Arrays Array Elements Array Sections Array Constructors
Array Sections x
Subscript Triplets Vector Subscripts
Coarrays x
Image Selectors Established Coarrays Deferred-Coshape Coarrays Explicit-Coshape Coarrays Reference Coarray Images Specify Data Objects for Coarray Images
Expressions and Assignment Statements x
Expressions Assignments
Expressions x
Numeric Expressions Character Expressions Relational Expressions Logical Expressions Defined Operations Summary of Operator Precedence Constant and Specification Expressions
Numeric Expressions x
Parentheses in Numeric Expressions Data Type of Numeric Expressions
Constant and Specification Expressions x
Constant Expressions Specification Expressions
Assignments x
Intrinsic Assignment Statements Defined Assignment Statements Pointer Assignments
Intrinsic Assignment Statements x
Numeric Assignment Statements Logical Assignment Statements Character Assignment Statements Derived-Type Assignment Statements Array Assignment Statements Examples of Intrinsic Assignment to Polymorphic Variables
Specification Statements x
Type Declarations Effects of Equivalency and Interaction with COMMON Statements
Type Declarations x
Declarations for Noncharacter Types Declarations for Character Types Declarations for Derived Types Declarations for Arrays
Declarations for Arrays x
Explicit-Shape Specifications Assumed-Shape Specifications Assumed-Size Specifications Assumed-Rank Specifications Deferred-Shape Specifications Implied-Shape Specifications
Effects of Equivalency and Interaction with COMMON Statements x
Make Arrays Equivalent Make Substrings Equivalent EQUIVALENCE and COMMON Interaction
Dynamic Allocation x
Effects of Allocation Effects of Deallocation
Effects of Allocation x
Allocation of Allocatable Variables Allocation of Allocatable Arrays Allocation of Pointer Targets
Effects of Deallocation x
Deallocation of Allocatable Variables Deallocation of Allocatable Arrays Deallocation of Pointer Targets
Execution Control x
Program Termination Branch Statements Overview Effects of DO Constructs Image Control Statements
Effects of DO Constructs x
Iteration Loop Control Nested DO Constructs Extended Range
Image Control Statements x
STAT= and ERRMSG= Specifiers in Image Control Statements Execution Segments for Images
Program Units and Procedures x
Main Program Procedure Characteristics Modules and Module Procedures Intrinsic Modules Block Data Program Units Overview Functions, Subroutines, and Statement Functions External Procedures Internal Procedures Argument Association in Procedures Procedure Interfaces Interoperability of Procedures and Procedure Interfaces Procedure Pointers
Modules and Module Procedures x
Separate Module Procedures
Intrinsic Modules x
ISO_C_BINDING Module ISO_FORTRAN_ENV Module IEEE Intrinsic Modules and Procedures
ISO_C_BINDING Module x
Named Constants in the ISO_C_BINDING Module Intrinsic Module Procedures - ISO_C_BINDING
ISO_FORTRAN_ENV Module x
Named Constants in the ISO_FORTRAN_ENV Module Derived Types in the ISO_FORTRAN_ENV Module Intrinsic Module Procedures - ISO_FORTRAN_ENV
IEEE Intrinsic Modules and Procedures x
IEEE_ARITHMETIC Intrinsic Module IEEE_EXCEPTIONS Intrinsic Module IEEE_FEATURES Intrinsic Module IEEE Intrinsic Modules Quick Reference Tables
Functions, Subroutines, and Statement Functions x
General Rules for Function and Subroutine Subprograms Functions Overview Subroutines Overview Statement Functions Overview Entry Points in Subprograms
General Rules for Function and Subroutine Subprograms x
Recursive Procedures Pure Procedures Impure Procedures Elemental Procedures
Functions Overview x
RESULT Keyword Overview Function References
Entry Points in Subprograms x
Entry Points in Function Subprograms Entry Points in Subroutine Subprograms
Argument Association in Procedures x
Optional Arguments Array Arguments Pointer Arguments Passed-Object Dummy Arguments Assumed-Length Character Arguments Character Constant and Hollerith Arguments Alternate Return Arguments Dummy Procedure Arguments Coarray Dummy Arguments References to Generic Procedures References to Non-Fortran Procedures
References to Generic Procedures x
References to Generic Intrinsic Functions References to Elemental Intrinsic Procedures
Procedure Interfaces x
Procedures that Require Explicit Interfaces Explicit and Abstract Interfaces Define Generic Names for Procedures Define Generic Operators Define Generic Assignment
Intrinsic Procedures x
Argument Keywords in Intrinsic Procedures Overview of Atomic Subroutines Overview of Collective Subroutines Overview of Bit Functions Categories and Lists of Intrinsic Procedures
Categories and Lists of Intrinsic Procedures x
Categories of Intrinsic Functions Intrinsic Subroutines
Data Transfer I/O Statements x
Records and Files Components of Data Transfer Statements Forms for READ Statements Forms for WRITE Statements User-Defined Derived-Type I/O
Components of Data Transfer Statements x
I/O Control List I/O Lists
I/O Control List x
Unit Specifier (UNIT=) Format Specifier (FMT=) Namelist Specifier (NML=) Record Specifier (REC=) I/O Status Specifier (IOSTAT=) Branch Specifiers (END=, EOR=, ERR=) Advance Specifier (ADVANCE=) Asynchronous Specifier (ASYNCHRONOUS=) Character Count Specifier (SIZE=) ID Specifier (ID=) POS Specifier (POS=) I/O Message Specifier (IOMSG=)
I/O Lists x
Simple List Items in I/O Lists Implied-DO Lists in I/O Lists
Forms for READ Statements x
Forms for Sequential READ Statements Forms for Direct-Access READ Statements Forms for Stream READ Statements Forms and Rules for Internal READ Statements
Forms for Sequential READ Statements x
Rules for Formatted Sequential READ Statements Rules for List-Directed Sequential READ Statements Rules for Namelist Sequential READ Statements Rules for Unformatted Sequential READ Statements
Forms for Direct-Access READ Statements x
Rules for Formatted Direct-Access READ Statements Rules for Unformatted Direct-Access READ Statements
Forms for WRITE Statements x
Forms for Sequential WRITE Statements Forms for Direct-Access WRITE Statements Forms for Stream WRITE Statements Forms and Rules for Internal WRITE Statements
Forms for Sequential WRITE Statements x
Rules for Formatted Sequential WRITE Statements Rules for List-Directed Sequential WRITE Statements Rules for Namelist Sequential WRITE Statements Rules for Unformatted Sequential WRITE Statements
Forms for Direct-Access WRITE Statements x
Rules for Formatted Direct-Access WRITE Statements Rules for Unformatted Direct-Access WRITE Statements
User-Defined Derived-Type I/O x
Specify the User-Defined Derived Type Examples of User-Defined Derived-Type I/O
Specify the User-Defined Derived Type x
DT Edit Descriptor in User-Defined I/O Associate a Procedure with Defined I/O Characteristics of Defined I/O Procedures Defined I/O Data Transfers Resolve Defined I/O Procedure References Recursive Defined I/O
Associate a Procedure with Defined I/O x
Defined I/O Procedures Generic Bindings Generic Interface Block
I/O Formatting x
Format Specifications Data Edit Descriptors Control Edit Descriptors Character String Edit Descriptors Nested and Group Repeat Specifications Variable Format Expressions Print Formatted Records Interaction Between Format Specifications and I/O Lists
Data Edit Descriptors x
Forms for Data Edit Descriptors General Rules for Numeric Editing Integer Editing Real and Complex Editing Logical Editing (L) Character Editing (A) Defined I/O Editing (DT) Default Widths for Data Edit Descriptors Terminating Short Fields of Input Data
Integer Editing x
I Editing B Editing O Editing Z Editing
Real and Complex Editing x
F Editing E and D Editing EN Editing ES Editing EX Editing G Editing Complex Editing
Control Edit Descriptors x
Forms for Control Edit Descriptors Positional Editing Sign Editing Blank Editing Round Editing Decimal Editing Scale-Factor Editing (P) Slash Editing ( / ) Colon Editing (:) Dollar-Sign ($) and Backslash ( \\ ) Editing Character Count Editing (Q)
Positional Editing x
T Editing TL Editing TR Editing X Editing
Sign Editing x
SP Editing SS Editing S Editing
Blank Editing x
BN Editing BZ Editing
Round Editing x
RU Editing RD Editing RZ Editing RN Editing RC Editing RP Editing
Decimal Editing x
DC Editing DP Editing
Character String Edit Descriptors x
Character Constant Editing H Editing
File Operation I/O Statements x
INQUIRE Statement Specifiers OPEN Statement Specifiers
INQUIRE Statement Specifiers x
INQUIRE: ACCESS Specifier INQUIRE: ACTION Specifier INQUIRE: ASYNCHRONOUS Specifier INQUIRE: BINARY Specifier INQUIRE: BLANK Specifier INQUIRE: BLOCKSIZE Specifier INQUIRE: BUFFERED Specifier INQUIRE: CARRIAGECONTROL Specifier INQUIRE: CONVERT Specifier INQUIRE: DECIMAL Specifier INQUIRE: DELIM Specifier INQUIRE: DIRECT Specifier INQUIRE: ENCODING Specifier INQUIRE: EXIST Specifier INQUIRE: FORM Specifier INQUIRE: FORMATTED Specifier INQUIRE: IOFOCUS Specifier INQUIRE: MODE Specifier INQUIRE: NAME Specifier INQUIRE: NAMED Specifier INQUIRE: NEXTREC Specifier INQUIRE: NUMBER Specifier INQUIRE: OPENED Specifier INQUIRE: ORGANIZATION Specifier INQUIRE: PAD Specifier INQUIRE: PENDING Specifier INQUIRE: POS Specifier INQUIRE: POSITION Specifier INQUIRE: READ Specifier INQUIRE: READWRITE Specifier INQUIRE: RECL Specifier INQUIRE: RECORDTYPE Specifier INQUIRE: ROUND Specifier INQUIRE: SEQUENTIAL Specifier INQUIRE: SHARE Specifier INQUIRE: SIGN Specifier INQUIRE: SIZE Specifier INQUIRE: UNFORMATTED Specifier INQUIRE: WRITE Specifier
OPEN Statement Specifiers x
OPEN: ACCESS Specifier OPEN: ACTION Specifier OPEN: ASSOCIATEVARIABLE Specifier OPEN: ASYNCHRONOUS Specifier OPEN: BLANK Specifier OPEN: BLOCKSIZE Specifier OPEN: BUFFERCOUNT Specifier OPEN: BUFFERED Specifier OPEN: CARRIAGECONTROL Specifier OPEN: CONVERT Specifier OPEN: DECIMAL Specifier OPEN: DEFAULTFILE Specifier OPEN: DELIM Specifier OPEN: DISPOSE Specifier OPEN: ENCODING Specifier OPEN: FILE Specifier OPEN: FORM Specifier OPEN: IOFOCUS Specifier OPEN: MAXREC Specifier OPEN: MODE Specifier OPEN: NAME Specifier OPEN: NEWUNIT Specifier OPEN: NOSHARED Specifier OPEN: ORGANIZATION Specifier OPEN: PAD Specifier OPEN: POSITION Specifier OPEN: READONLY Specifier OPEN: RECL Specifier OPEN: RECORDSIZE Specifier OPEN: RECORDTYPE Specifier OPEN: ROUND Specifier OPEN: SHARE Specifier OPEN: SHARED Specifier OPEN: SIGN Specifier OPEN: STATUS Specifier OPEN: TITLE Specifier OPEN: TYPE Specifier OPEN: USEROPEN Specifier
Directive Enhanced Compilation x
Syntax Rules for Compiler Directives General Compiler Directives OpenMP* Fortran Compiler Directives Equivalent Compiler Options
General Compiler Directives x
Rules for Placement of Directives Rules for General Directives that Affect DO Loops Rules for Loop Directives that Affect Array Assignment Statements
OpenMP* Fortran Compiler Directives x
Clauses Used in Multiple OpenMP* Fortran Directives Conditional Compilation Rules Rules for Nesting and Binding
Scope and Association x
Scope Unambiguous Generic Procedure References Resolve Procedure References Association
Resolve Procedure References x
References to Generic Names References to Specific Names References to Nonestablished Names
Association x
Name Association Pointer Association Storage Association Inheritance Association
Name Association x
Argument Association Use and Host Association Linkage Association Construct Association
Use and Host Association x
Use Association Host Association
Construct Association x
Additional Attributes Of Associate Names
Storage Association x
Storage Units and Storage Sequence Array Association
Deleted and Obsolescent Language Features x
Deleted Language Features in the Fortran Standard Obsolescent Language Features in the Fortran Standard
Additional Language Features x
FORTRAN 66 Interpretation of the EXTERNAL Statement Alternative Syntax for the PARAMETER Statement Alternative Syntax for Binary, Octal, and Hexadecimal Constants Alternative Syntax for a Record Specifier Alternative Syntax for the DELETE Statement Alternative Form for Namelist External Records Record Structures
Record Structures x
Structure Declarations References to Record Fields Aggregate Assignment
Structure Declarations x
Type Declarations within Record Structures Substructure Declarations
Additional Character Sets x
Character and Key Code Charts for Windows* ASCII Character Set for Linux* and macOS*
Character and Key Code Charts for Windows* x
ASCII Character Codes for Windows* ANSI Character Codes for Windows* Key Codes for Windows*
ASCII Character Codes for Windows* x
ASCII Character Codes Chart 1 (Windows) ASCII Character Codes Chart 2: IBM* Character Set (Windows)
ANSI Character Codes for Windows* x
ANSI Character Codes Chart (Windows)
Key Codes for Windows* x
Key Codes Chart 1 (Windows) Key Codes Chart 2 (Windows)
Data Representation Models x
Model for Integer Data Model for Real Data Model for Bit Data
Model for Bit Data x
Bit Sequence Comparisons
Library Modules and Runtime Library Routines x
Runtime Library Routines
Runtime Library Routines x
NLS and MCBS Routines on Windows Standard Fortran Routines that Handle MBCS Characters on Windows Portability Routines Serial Port I/O Routines on Windows
Summary of Language Extensions x
Language Extensions: Source Forms Language Extensions: Names Language Extensions: Character Sets Language Extensions: Intrinsic Data Types Language Extensions: Constants Language Extensions: Expressions and Assignment Language Extensions: Specification Statements Language Extensions: Execution Control Language Extensions: Compilation Control Lines and Statements Language Extensions: Built-In Functions Language Extensions: I/O Statements Language Extensions: I/O Formatting Language Extensions: File Operation Statements Language Extensions: Compiler Directives Language Extensions: Intrinsic Procedures Language Extensions: Additional Language Features Language Extensions: Runtime Library Routines
A to Z Reference x
Language Summary Tables A to B C to D E to F G H to I J to L M to N O to P Q to R S T to Z POSIX* Library Routines Automation Server and Component Object Model Library Routines National Language Support Library Routines QuickWin Library Routines Graphics Library Routines Serial Port I/O Library Routines Dialog Library Routines
Language Summary Tables x
Statements for Program Unit Calls and Definitions Statements Affecting Variables Statements for Input and Output Compiler Directives Program Control Statements Inquiry Intrinsic Functions Random Number Intrinsic Procedures Atomic Intrinsic Subroutines Collective Intrinsic Subroutines Date and Time Intrinsic Subroutines Keyboard and Speaker Library Routines Statements and Intrinsic Procedures for Memory Allocation and Deallocation Intrinsic Functions for Arrays Intrinsic Functions for Numeric and Type Conversion Trigonometric, Exponential, Root, and Logarithmic Intrinsic Procedures Intrinsic Functions for Floating-Point Inquiry and Control Character Intrinsic Functions Intrinsic Procedures for Bit Operation and Representation QuickWin Library Routines Summary Graphics Library Routines Summary Portability Library Routines National Language Support Library Routines Summary POSIX* Library Procedures Summary Dialog Library Routines Summary COM and Automation Library Routines (W*S) Miscellaneous Runtime Library Routines
A to B x
ABORT ABS ABSTRACT INTERFACE ACCEPT ACCESS Function ACHAR ACOS ACOSD ACOSH ADJUSTL ADJUSTR AIMAG AINT ALARM ALIAS Directive ALIGNED Clause ALL ALLOCATABLE ALLOCATE Clause ALLOCATE Directive ALLOCATE Statement ALLOCATORS ALLOCATED ANINT ANY ASIN ASIND ASINH ASSIGN - Label Assignment Assignment(=) - Defined Assignment Assignment - Intrinsic Computational ASSOCIATE ASSOCIATED ASSUME ASSUME_ALIGNED ASSUMES Directive for OpenMP ASSUMPTION Clause ASYNCHRONOUS ATAN ATAN2 ATAN2D ATAND ATANH ATOMIC ATOMIC_ADD ATOMIC_AND ATOMIC_CAS ATOMIC_DEFINE ATOMIC_FETCH_ADD ATOMIC_FETCH_AND ATOMIC_FETCH_OR ATOMIC_FETCH_XOR ATOMIC_OR ATOMIC_REF ATOMIC_XOR ATTRIBUTES AUTOMATIC BACKSPACE BADDRESS BARRIER BEEPQQ BESJ0, BESJ1, BESJN, BESY0, BESY1, BESYN BESSEL_J0 BESSEL_J1 BESSEL_JN BESSEL_Y0 BESSEL_Y1 BESSEL_YN BGE BGT BIC, BIS BIND BIT BIT_SIZE BLE BLOCK BLOCK DATA BLOCK_LOOP and NOBLOCK_LOOP BLT BSEARCHQQ BTEST BYTE
ATTRIBUTES x
ATTRIBUTES ALIAS ATTRIBUTES ALIGN ATTRIBUTES ALLOCATABLE ATTRIBUTES ALLOW_NULL ATTRIBUTES C and STDCALL ATTRIBUTES CODE_ALIGN ATTRIBUTES CONCURRENCY_SAFE ATTRIBUTES CVF ATTRIBUTES DECORATE ATTRIBUTES DEFAULT ATTRIBUTES DLLEXPORT and DLLIMPORT ATTRIBUTES EXTERN ATTRIBUTES INLINE, NOINLINE, and FORCEINLINE ATTRIBUTES IGNORE_LOC ATTRIBUTES MIXED_STR_LEN_ARG and NOMIXED_STR_LEN_ARG ATTRIBUTES NO_ARG_CHECK ATTRIBUTES NOCLONE ATTRIBUTES OPTIMIZATION_PARAMETER ATTRIBUTES REFERENCE and VALUE ATTRIBUTES VARYING ATTRIBUTES VECTOR
C to D x
C_ASSOCIATED C_F_POINTER C_F_PROCPOINTER C_FUNLOC C_LOC C_SIZEOF CACHESIZE CALL CANCEL CANCELLATION POINT CASE CDFLOAT CEILING CFI_address CFI_allocate CFI_deallocate CFI_establish CFI_is_contiguous CFI_section CFI_select_part CFI_setpointer CHANGEDIRQQ CHANGEDRIVEQQ CHANGE TEAM and END TEAM CHAR CHARACTER CHDIR CHMOD CLASS CLEARSTATUSFPQQ CLOCK CLOCKX CLOSE CMPLX CO_BROADCAST CO_MAX CO_MIN CO_REDUCE CO_SUM CODE_ALIGN CODIMENSION COLLAPSE Clause COMMAND_ARGUMENT_COUNT COMMITQQ COMMON COMPILER_OPTIONS COMPILER_VERSION COMPLEX Statement COMPLINT, COMPLREAL, COMPLLOG CONJG CONTAINS CONTIGUOUS CONTINUE COPYIN Clause COPYPRIVATE Clause COS COSD COSH COSHAPE COTAN COTAND COUNT CPU_TIME CRITICAL Directive CRITICAL Statement CSHIFT CSMG CTIME CYCLE DATA DATE Intrinsic Procedure DATE Portability Routine DATE4 DATE_AND_TIME DBESJ0, DBESJ1, DBESJN, DBESY0, DBESY1, DBESYN DBLE DCLOCK DCMPLX DEALLOCATE DECLARE and NODECLARE DECLARE MAPPER DECLARE REDUCTION DECLARE SIMD DECLARE TARGET DECLARE VARIANT DECODE DEFAULT Clause DEFINE and UNDEFINE DEFINE FILE DELDIRQQ DELETE DELFILESQQ DEPEND Clause DEPOBJ DEVICE Clause DFLOAT DFLOATI, DFLOATJ, DFLOATK DIGITS DIM DIMENSION DISPATCH DISTRIBUTE DISTRIBUTE PARALLEL DO DISTRIBUTE PARALLEL DO SIMD DISTRIBUTE POINT DISTRIBUTE SIMD DNUM DO Directive DO Statement DO CONCURRENT DO SIMD DO WHILE DOT_PRODUCT DOUBLE COMPLEX DOUBLE PRECISION DPROD DRAND, DRANDM DRANSET DREAL DSHIFTL DSHIFTR DTIME
E to F x
ELEMENTAL ELSE Directive ELSE Statement ELSEIF Directive ELSE IF ELSE WHERE ENCODE END END DO ENDIF Directive END IF ENDFILE END FORALL END INTERFACE END TYPE END WHERE ENTRY EOF EOSHIFT EPSILON EQUIVALENCE ERF ERFC ERFC_SCALED ERROR Directive for OpenMP ERRSNS ESTABLISHQQ ETIME EVENT POST and EVENT WAIT EVENT_QUERY EXECUTE_COMMAND_LINE EXIT Statement EXIT Subroutine EXP EXP10 EXPONENT EXTENDS_TYPE_OF EXTERNAL FAIL IMAGE FAILED_IMAGES FDATE FGETC FINAL Clause FINAL Statement FIND FINDLOC FINDFILEQQ FIRSTPRIVATE FIXEDFORMLINESIZE FLOAT FLOOR FLUSH Directive FLUSH Statement FLUSH Subroutine FMA and NOFMA FOR__SET_FTN_ALLOC FOR_DESCRIPTOR_ASSIGN FOR_GET_FPE FOR_IFCORE_VERSION FOR_IFPORT_VERSION FOR_LFENCE FOR_MFENCE for_rtl_finish_ for_rtl_init_ FOR_SET_FPE FOR_SET_REENTRANCY FOR_SFENCE FORALL FORMAT FORM TEAM FP_CLASS FPUTC FRACTION FREE FREEFORM and NOFREEFORM FSEEK FSTAT FTELL, FTELLI8 FULLPATHQQ FUNCTION
G x
GAMMA GENERIC GERROR GETARG GETC GETCHARQQ GET_COMMAND GET_COMMAND_ARGUMENT GETCONTROLFPQQ GETCWD GETDAT GETDRIVEDIRQQ GETDRIVESIZEQQ GETDRIVESQQ GETENV GET_ENVIRONMENT_VARIABLE GETENVQQ GETEXCEPTIONPTRSQQ GETFILEINFOQQ GETGID GETLASTERROR GETLASTERRORQQ GETLOG GETPID GETPOS, GETPOSI8 GETSTATUSFPQQ GETSTRQQ GET_TEAM GETTIM GETTIMEOFDAY GETUID GMTIME GOTO - Assigned GOTO - Computed GOTO - Unconditional
H to I x
HOSTNAM HUGE HYPOT IACHAR IALL IAND IANY IARGC IBCHNG IBCLR IBITS IBSET ICHAR IDATE Intrinsic Procedure IDATE Portability Routine IDATE4 IDENT IDFLOAT IEEE_CLASS IEEE_COPY_SIGN IEEE_FLAGS IEEE_FMA IEEE_GET_FLAG IEEE_GET_HALTING_MODE IEEE_GET_MODES IEEE_GET_ROUNDING_MODE IEEE_GET_STATUS IEEE_GET_UNDERFLOW_MODE IEEE_HANDLER IEEE_INT IEEE_IS_FINITE IEEE_IS_NAN IEEE_IS_NEGATIVE IEEE_IS_NORMAL IEEE_LOGB IEEE_MAX_NUM IEEE_MAX_NUM_MAG IEEE_MIN_NUM IEEE_MIN_NUM_MAG IEEE_NEXT_AFTER IEEE_NEXT_DOWN IEEE_NEXT_UP IEEE_QUIET_EQ IEEE_QUIET_GE IEEE_QUIET_GT IEEE_QUIET_LE IEEE_QUIET_LT IEEE_QUIET_NE IEEE_REAL IEEE_REM IEEE_RINT IEEE_SCALB IEEE_SELECTED_REAL_KIND IEEE_SET_FLAG IEEE_SET_HALTING_MODE IEEE_SET_MODES IEEE_SET_ROUNDING_MODE IEEE_SET_STATUS IEEE_SET_UNDERFLOW_MODE IEEE_SIGNALING_EQ IEEE_SIGNALING_GE IEEE_SIGNALING_GT IEEE_SIGNALING_LE IEEE_SIGNALING_LT IEEE_SIGNALING_NE IEEE_SIGNBIT IEEE_SUPPORT_DATATYPE IEEE_SUPPORT_DENORMAL IEEE_SUPPORT_DIVIDE IEEE_SUPPORT_FLAG IEEE_SUPPORT_HALTING IEEE_SUPPORT_INF IEEE_SUPPORT_IO IEEE_SUPPORT_NAN IEEE_SUPPORT_ROUNDING IEEE_SUPPORT_SQRT IEEE_SUPPORT_STANDARD IEEE_SUPPORT_SUBNORMAL IEEE_SUPPORT_UNDERFLOW_CONTROL IEEE_UNORDERED IEEE_VALUE IEOR IERRNO IF - Arithmetic IF - Logical IF Clause IF Construct IF Directive Construct IF DEFINED Directive IFIX IFLOATI, IFLOATJ ILEN IMAGE_INDEX IMAGE_STATUS IMPLICIT IMPORT IMPURE IN_REDUCTION INCLUDE INDEX INLINE, FORCEINLINE, and NOINLINE INMAX INQUIRE INT INTC INT_PTR_KIND INTEGER Statement INTEGER Directive INTENT INTERFACE INTERFACE TO INTEROP INTRINSIC INUM IOR IPARITY IRAND, IRANDM IRANGET IRANSET IS_CONTIGUOUS IS_DEVICE_PTR Clause IS_IOSTAT_END IS_IOSTAT_EOR ISATTY ISHA ISHC ISHFT ISHFTC ISHL ISNAN ITERATOR Clause Modifier ITIME IVDEP
J to L x
JABS JDATE JDATE4 JNUM KILL KIND KNUM LASTPRIVATE LBOUND LCOBOUND LCWRQQ LEADZ LEN LEN_TRIM LGE LGT LINEAR Clause LLE LLT LNBLNK LOC %LOC LOCK and UNLOCK LOG LOG_GAMMA LOG10 LOGICAL Function LOGICAL Statement LONG LOOP LOOP COUNT LSHIFT LSTAT LTIME
M to N x
MAKEDIRQQ MALLOC MAP Clause MAP and END MAP MASKED MASKED TASKLOOP MASKED TASKLOOP SIMD MASKL MASKR MASTER MASTER TASKLOOP MASTER TASKLOOP SIMD MATMUL MAX MAXEXPONENT MAXLOC MAXVAL MCLOCK MERGE MERGE_BITS MERGEABLE Clause MESSAGE MIN MINEXPONENT MINLOC MINVAL MM_PREFETCH MOD MODULE MODULE FUNCTION MODULE PROCEDURE MODULE SUBROUTINE MODULO MOVE_ALLOC MVBITS NAMELIST NARGS NEAREST NEW_LINE NINT NOFREEFORM NOFUSION NON_RECURSIVE NOOPTIMIZE NOPREFETCH NORM2 NOSTRICT NOT NOTHING NOUNROLL NOUNROLL_AND_JAM NOVECTOR NOWAIT Clause NULL NULLIFY NUM_IMAGES
O to P x
OBJCOMMENT OPEN OPTIONAL OPTIMIZE and NOOPTIMIZE OPTIONS Directive OPTIONS Statement OR ORDERED OUT_OF_RANGE PACK Directive PACK Function PACKTIMEQQ PARALLEL Directive for OpenMP PARALLEL and NOPARALLEL General Directives PARALLEL DO PARALLEL DO SIMD PARALLEL LOOP PARALLEL MASKED PARALLEL MASKED TASKLOOP PARALLEL MASKED TASKLOOP SIMD PARALLEL MASTER PARALLEL MASTER TASKLOOP PARALLEL MASTER TASKLOOP SIMD PARALLEL SECTIONS PARALLEL WORKSHARE PARAMETER PARITY PAUSE PEEKCHARQQ PERROR POINTER - Fortran POINTER - Integer POPCNT POPPAR PRECISION PREFETCH and NOPREFETCH General Directives PREFETCH Directive for OpenMP PRESENT PRINT PRIORITY PRIVATE Clause PRIVATE Statement PROCEDURE PROCESSOR Clause PRODUCT PROGRAM PROTECTED PSECT PUBLIC PURE PUTC
Q to R x
QCMPLX QEXT QFLOAT QNUM QRANSET QREAL QSORT RADIX RAISEQQ RAN RAND, RANDOM RANDOM Subroutine RANDOM_INIT RANDOM_NUMBER RANDOM_SEED RANDU RANF Intrinsic Procedure RANF Portability Routine RANGE RANGET RANK RANSET READ Statement REAL Directive REAL Function REAL Statement RECORD RECURSIVE and NON_RECURSIVE REDUCE REDUCTION %REF RENAME RENAMEFILEQQ REPEAT REQUIRES RESHAPE RESULT RETURN REWIND REWRITE RINDEX RNUM RRSPACING RSHIFT RTC RUNQQ
S x
SAME_TYPE_AS SAVE SCALE SCAN Directive SCAN Function SCANENV SCOPE SCWRQQ SECNDS Intrinsic Procedure SECNDS Portability Routine SECTIONS SEED SELECT CASE and END SELECT SELECT RANK SELECT TYPE SELECTED_CHAR_KIND SELECTED_INT_KIND SELECTED_REAL_KIND SEQUENCE SETCONTROLFPQQ SETDAT SETENVQQ SETERRORMODEQQ SET_EXPONENT SETFILEACCESSQQ SETFILETIMEQQ SETTIM SHAPE SHARED Clause SHIFTA SHIFTL SHIFTR SHORT SIGN SIGNAL SIGNALQQ SIMD Directive for OpenMP SIMD Loop Directive SIN SIND SINGLE SINH SIZE Function SIZEOF SLEEP SLEEPQQ SNGL SORTQQ SPACING SPLITPATHQQ SPREAD SQRT SRAND SSWRQQ STAT Statement Function STATIC STOP and ERROR STOP STOPPED_IMAGES STORAGE_SIZE STRICT and NOSTRICT STRUCTURE and END STRUCTURE SUBDEVICE SUBMODULE SUBROUTINE SUM SYNC ALL SYNC IMAGES SYNC MEMORY SYNC TEAM SYSTEM SYSTEM_CLOCK SYSTEMQQ
T to Z x
TAN TAND TANH TARGET TARGET DATA TARGET Statement TARGET ENTER DATA TARGET EXIT DATA TARGET PARALLEL TARGET PARALLEL DO TARGET PARALLEL DO SIMD TARGET PARALLEL LOOP TARGET SIMD TARGET TEAMS TARGET TEAMS DISTRIBUTE TARGET TEAMS DISTRIBUTE PARALLEL DO TARGET TEAMS DISTRIBUTE PARALLEL DO SIMD TARGET TEAMS DISTRIBUTE SIMD TARGET TEAMS LOOP TARGET UPDATE TARGET VARIANT DISPATCH TASK TASK_REDUCTION TASKGROUP TASKLOOP TASKLOOP SIMD TASKWAIT TASKYIELD TEAM_NUMBER TEAMS TEAMS DISTRIBUTE TEAMS DISTRIBUTE PARALLEL DO TEAMS DISTRIBUTE PARALLEL DO SIMD TEAMS DISTRIBUTE SIMD TEAMS LOOP THIS_IMAGE THREADPRIVATE TILE TIME Intrinsic Procedure TIME Portability Routine TIMEF TINY TRACEBACKQQ TRAILZ TRANSFER TRANSPOSE TRIM TTYNAM Type Declarations TYPE Statement for Derived Types) UBOUND UCOBOUND UNDEFINE UNION and END UNION UNLINK UNPACK UNPACKTIMEQQ UNROLL Directive for OpenMP UNROLL and NOUNROLL General Directives UNROLL_AND_JAM and NOUNROLL_AND_JAM UNTIED Clause USE USE_DEVICE_PTR Clause %VAL VALUE VECREMAINDER Clause VECTOR and NOVECTOR VERIFY VIRTUAL VOLATILE WAIT WHERE WORKSHARE WRITE Statement XOR ZEXT
POSIX* Library Routines x
IPXFARGC IPXFCONST IPXFLENTRIM IPXFWEXITSTATUS IPXFWSTOPSIG IPXFWTERMSIG PXFGET PXFSET PXFAGET PXFASET PXFACCESS PXFALARM PXFCALLSUBHANDLE PXFCFGETISPEED PXFCFGETOSPEED PXFCFSETISPEED PXFCFSETOSPEED PXFCHDIR PXFCHMOD PXFCHOWN PXFCLEARENV PXFCLOSE PXFCLOSEDIR PXFCONST PXFCREAT PXFCTERMID PXFDUP, PXFDUP2 PXFEGET PXFESET PXFEXECV PXFEXECVE PXFEXECVP PXFEXIT, PXFFASTEXIT PXFFCNTL PXFFDOPEN PXFFFLUSH PXFFGETC PXFFILENO PXFFORK PXFFPATHCONF PXFFPUTC PXFFSEEK PXFFSTAT PXFFTELL PXFGETARG PXFGETC PXFGETCWD PXFGETEGID PXFGETENV PXFGETEUID PXFGETGID PXFGETGRGID PXFGETGRNAM PXFGETGROUPS PXFGETLOGIN PXFGETPGRP PXFGETPID PXFGETPPID PXFGETPWNAM PXFGETPWUID PXFGETSUBHANDLE PXFGETUID PXFISATTY PXFISBLK PXFISCHR PXFISCONST PXFISDIR PXFISFIFO PXFISREG PXFKILL PXFLINK PXFLOCALTIME PXFLSEEK PXFMKDIR PXFMKFIFO PXFOPEN PXFOPENDIR PXFPATHCONF PXFPAUSE PXFPIPE PXFPOSIXIO PXFPUTC PXFREAD PXFREADDIR PXFRENAME PXFREWINDDIR PXFRMDIR PXFSETENV PXFSETGID PXFSETPGID PXFSETSID PXFSETUID PXFSIGACTION PXFSIGADDSET PXFSIGDELSET PXFSIGEMPTYSET PXFSIGFILLSET PXFSIGISMEMBER PXFSIGPENDING PXFSIGPROCMASK PXFSIGSUSPEND PXFSLEEP PXFSTAT PXFSTRUCTCOPY PXFSTRUCTCREATE PXFSTRUCTFREE PXFSYSCONF PXFTCDRAIN PXFTCFLOW PXFTCFLUSH PXFTCGETATTR PXFTCGETPGRP PXFTCSENDBREAK PXFTCSETATTR PXFTCSETPGRP PXFTIME PXFTIMES PXFTTYNAME PXFUCOMPARE PXFUMASK PXFUNAME PXFUNLINK PXFUTIME PXFWAIT PXFWAITPID PXFWIFEXITED PXFWIFSIGNALED PXFWIFSTOPPED PXFWRITE
Automation Server and Component Object Model Library Routines x
AUTOAddArg AUTOAllocateInvokeArgs AUTODeallocateInvokeArgs AUTOGetExceptInfo AUTOGetProperty AUTOGetPropertyByID AUTOGetPropertyInvokeArgs AUTOInvoke AUTOSetProperty AUTOSetPropertyByID AUTOSetPropertyInvokeArgs COMAddObjectReference COMCLSIDFromProgID COMCLSIDFromString COMCreateObject COMCreateObjectByGUID COMCreateObjectByProgID COMGetActiveObjectByGUID COMGetActiveObjectByProgID COMGetFileObject COMInitialize COMIsEqualGUID COMQueryInterface COMReleaseObject COMStringFromGUID COMUninitialize
National Language Support Library Routines x
MBCharLen MBConvertMBToUnicode MBConvertUnicodeToMB MBCurMax MBINCHARQQ MBINDEX MBJISToJMS, MBJMSToJIS MBLead MBLen MBLen_Trim MBLGE, MBLGT, MBLLE, MBLLT, MBLEQ, MBLNE MBNext MBPrev MBSCAN MBStrLead MBVERIFY NLSEnumCodepages NLSEnumLocales NLSFormatCurrency NLSFormatDate NLSFormatNumber NLSFormatTime NLSGetEnvironmentCodepage NLSGetLocale NLSGetLocaleInfo NLSSetEnvironmentCodepage NLSSetLocale
QuickWin Library Routines x
ABOUTBOXQQ APPENDMENUQQ CLICKMENUQQ DELETEMENUQQ FOCUSQQ GETACTIVEQQ GETEXITQQ GETHWNDQQ GETUNITQQ GETWINDOWCONFIG GETWSIZEQQ INCHARQQ INITIALSETTINGS INQFOCUSQQ INSERTMENUQQ INTEGERTORGB MESSAGEBOXQQ MODIFYMENUFLAGSQQ MODIFYMENUROUTINEQQ MODIFYMENUSTRINGQQ PASSDIRKEYSQQ REGISTERMOUSEEVENT RGBTOINTEGER SETACTIVEQQ SETEXITQQ SETMESSAGEQQ SETMOUSECURSOR SETWINDOWCONFIG SETWINDOWMENUQQ SETWSIZEQQ UNREGISTERMOUSEEVENT WAITONMOUSEEVENT
Graphics Library Routines x
ARC, ARC_W CLEARSCREEN DISPLAYCURSOR ELLIPSE, ELLIPSE_W FLOODFILL, FLOODFILL_W FLOODFILLRGB, FLOODFILLRGB_W GETARCINFO GETBKCOLOR GETBKCOLORRGB GETCOLOR GETCOLORRGB GETCURRENTPOSITION, GETCURRENTPOSITION_W GETFILLMASK GETFONTINFO GETGTEXTEXTENT GETGTEXTROTATION GETIMAGE, GETIMAGE_W GETLINESTYLE GETLINEWIDTHQQ GETPHYSCOORD GETPIXEL, GETPIXEL_W GETPIXELRGB, GETPIXELRGB_W GETPIXELS GETPIXELSRGB GETTEXTCOLOR GETTEXTCOLORRGB GETTEXTPOSITION GETTEXTWINDOW GETVIEWCOORD, GETVIEWCOORD_W GETWINDOWCOORD GETWRITEMODE GRSTATUS IMAGESIZE, IMAGESIZE_W INITIALIZEFONTS LINETO, LINETO_W LINETOAR LINETOAREX LOADIMAGE, LOADIMAGE_W MOVETO, MOVETO_W OUTGTEXT OUTTEXT PIE, PIE_W POLYBEZIER, POLYBEZIER_W POLYBEZIERTO, POLYBEZIERTO_W POLYGON, POLYGON_W POLYLINEQQ PUTIMAGE, PUTIMAGE_W RECTANGLE, RECTANGLE_W REMAPALLPALETTERGB, REMAPPALETTERGB SAVEIMAGE, SAVEIMAGE_W SCROLLTEXTWINDOW SETBKCOLOR SETBKCOLORRGB SETCLIPRGN SETCOLOR SETCOLORRGB SETFILLMASK SETFONT SETGTEXTROTATION SETLINESTYLE SETLINEWIDTHQQ SETPIXEL, SETPIXEL_W SETPIXELRGB, SETPIXELRGB_W SETPIXELS SETPIXELSRGB SETTEXTCOLOR SETTEXTCOLORRGB SETTEXTCURSOR SETTEXTPOSITION SETTEXTWINDOW SETVIEWORG SETVIEWPORT SETWINDOW SETWRITEMODE WRAPON
Serial Port I/O Library Routines x
SPORT_CANCEL_IO SPORT_CONNECT SPORT_CONNECT_EX SPORT_GET_HANDLE SPORT_GET_STATE SPORT_GET_STATE_EX SPORT_GET_TIMEOUTS SPORT_PEEK_DATA SPORT_PEEK_LINE SPORT_PURGE SPORT_READ_DATA SPORT_READ_LINE SPORT_RELEASE SPORT_SET_STATE SPORT_SET_STATE_EX SPORT_SET_TIMEOUTS SPORT_SHOW_STATE SPORT_SPECIAL_FUNC SPORT_WRITE_DATA SPORT_WRITE_LINE
Dialog Library Routines x
DLGEXIT DLGFLUSH DLGGET, DLGGETINT, DLGGETLOG, DLGGETCHAR DLGINIT, DLGINITWITHRESOURCEHANDLE DLGISDLGMESSAGE, DLGISDLGMESSAGEWITHDLG DLGMODAL, DLGMODALWITHPARENT DLGMODELESS DLGSENDCTRLMESSAGE DLGSET, DLGSETINT, DLGSETLOG, DLGSETCHAR DLGSETCTRLEVENTHANDLER DLGSETRETURN DLGSETSUB DLGSETTITLE DLGUNINIT
Glossary x
Glossary A Glossary B Glossary C Glossary D Glossary E Glossary F Glossary G Glossary H Glossary I Glossary K Glossary L Glossary M Glossary N Glossary O Glossary P Glossary Q Glossary R Glossary S Glossary T Glossary U Glossary V Glossary W Glossary Z
Compilation x
Supported Environment Variables Use Other Methods to Set Environment Variables Files Associated with Intel® Fortran Applications on Windows Compile and Link Multithreaded Programs Linking Tools and Options Use Configuration Files Use Response Files Create Fortran Executables Link Debug Information Debugging
Debugging x
Prepare Your Program for Debugging Use Breakpoints in the Microsoft Debugger Debug the Squares Example with Microsoft Debugger View Fortran Data Types in the Microsoft Debugger View the Call Stack in the Microsoft Debugger Locate Unaligned Data Debug a Program that Encounters a Signal or Exception Debugging and Optimizations Debug Mixed-Language Programs Debug Multithreaded Programs Use Remote Debugging
Use Remote Debugging x
Remote Debugging Scenario
Program Structure x
Use Module Files Use Include Files Advantages of Internal Procedures Implications for Array Copies
Optimization and Programming x
OpenMP* Support Coarrays Automatic Parallelization Vectorization Profile-Guided Optimization High-Level Optimization Interprocedural Optimization Fortran Language Extensions fpp Preprocessing Methods to Optimize Code Size National Language Support Routines
OpenMP* Support x
Add OpenMP* Support Parallel Processing Model Control Thread Allocation OpenMP* Directives OpenMP* Library Support OpenMP* Advanced Issues OpenMP* Implementation-Defined Behaviors OpenMP* Examples
OpenMP* Library Support x
OpenMP* Runtime Library Routines Intel® Compiler Extension Routines to OpenMP* OpenMP* Support Libraries Use the OpenMP Libraries Thread Affinity Interface OpenMP* Memory Spaces and Allocators
Coarrays x
Use Coarrays Debug a Coarray Application
Automatic Parallelization x
Enable Auto-Parallelization Programming with Auto-Parallelization Enable Further Loop Parallelization for Multicore Platforms
Vectorization x
Automatic Vectorization Explicit Vector Programming
Automatic Vectorization x
Vectorization Programming Guidelines Use Automatic Vectorization Vectorization and Loops Loop Constructs
Explicit Vector Programming x
User-Mandated or SIMD Vectorization Function Annotations and the SIMD Directive for Vectorization
Profile-Guided Optimization x
Profile an Application with Instrumentation Profile-Guided Optimization Report PGO Tools
PGO Tools x
Code Coverage Tool Test Prioritization Tool Profmerge and Proforder Tools Use Function Order Lists, Function Grouping, Function Ordering, and Data Ordering Optimizations Comparison of Function Order Lists and IPO Code Layout
Interprocedural Optimization x
Use Interprocedural Optimization Performance and Large Program Considerations Create a Library from IPO Objects Request Compiler Reports with the xi* Tools Inline Expansion of Functions Inlining Report
Fortran Language Extensions x
Support for 64-bit Architecture on Linux Traceback Allocate Common Blocks Generate Listing and Map Files Create Shared Libraries Specify Alternative Tools and Locations Temporary Files Created by the Compiler or Linker Use the Intel® Fortran COM Server on Windows Use the Intel® Fortran Module Wizard (COM Client) on Windows IFPORT Portability Library
Traceback x
Traceback Tradeoffs and Restrictions Sample Programs and Traceback Information
Use the Intel® Fortran COM Server on Windows x
Advantages of a COM Server COM Server Concepts Create the Fortran COM Server Fortran COM Server Interface Design Considerations Advanced COM Server Topics Deploy the COM Server on Another System
Use the Intel® Fortran Module Wizard (COM Client) on Windows x
COM and Automation Objects The Role of the Module Wizard Use the Module Wizard to Generate Code Call the Routines Generated by the Module Wizard Get a Pointer to an Object's Interface Additional Resources about COM and Automation
fpp Preprocessing x
fpp Preprocessor Directives Predefined Preprocessor Symbols Fortran Preprocessor Options
Compatibility and Portability x
Fortran Language Standards Conformance, Compatibility, and Fortran Features Minimize Operating System-Specific Information Store and Represent Data Data Portability
Data Portability x
Format Data for Transportability Supported Native and Non-Native Numeric Formats Port Non-Native Data Specify the Data Format
Intel® Fortran Compiler Classic and Intel® Fortran Compiler Developer Guide and Reference

O

Specifies the code optimization for applications.

Syntax

Linux:

-O[n]

macOS:

-O[n]

Windows:

/O[n]

Arguments

n

Is the optimization level. Possible values are 1, 2, or 3. On Linux* and macOS systems, you can also specify 0.

Default

O2

Optimizes for code speed. This default may change depending on which other compiler options are specified. For details, see below.

Description

This option specifies the code optimization for applications.

Option

Description

O (Linux* and macOS)

This is the same as specifying O2.

O0 (Linux and macOS)

Disables all optimizations.

This option may set other options. This is determined by the compiler, depending on which operating system and architecture you are using. The options that are set may change from release to release.

This option causes certain warn options to be ignored. This is the default if you specify option -debug (with no keyword).

O1

Enables optimizations for speed and disables some optimizations that increase code size and affect speed.
To limit code size, this option:

  • Enables global optimization; this includes data-flow analysis, code motion, strength reduction and test replacement, split-lifetime analysis, and instruction scheduling.

This option may set other options. This is determined by the compiler, depending on which operating system and architecture you are using. The options that are set may change from release to release.

The O1 option may improve performance for applications with very large code size, many branches, and execution time not dominated by code within loops.

O2

Enables optimizations for speed. This is the generally recommended optimization level.
Vectorization is enabled at O2 and higher levels.

On ifort systems using IA-32 architecture: Some basic loop optimizations such as Distribution, Predicate Opt, Interchange, multi-versioning, and scalar replacements are performed.

This option also enables:

  • Inlining of intrinsics

  • Intra-file interprocedural optimization, which includes:

    • inlining

    • constant propagation

    • forward substitution

    • routine attribute propagation

    • variable address-taken analysis

    • dead static function elimination

    • removal of unreferenced variables

  • The following capabilities for performance gain:

    • constant propagation

    • copy propagation

    • dead-code elimination

    • global register allocation

    • global instruction scheduling and control speculation

    • loop unrolling

    • optimized code selection

    • partial redundancy elimination

    • strength reduction/induction variable simplification

    • variable renaming

    • exception handling optimizations

    • tail recursions

    • peephole optimizations

    • structure assignment lowering and optimizations

    • dead store elimination

This option may set other options, especially options that optimize for code speed. This is determined by the compiler, depending on which operating system and architecture you are using. The options that are set may change from release to release.

On Windows* systems, this option is the same as the Ox option.

On Linux* and macOS systems, if -g is specified, O2 is turned off and O0 is the default unless O2 (or O1 or O3) is explicitly specified in the command line together with -g.

On Linux systems, the -debug inline-debug-info option will be enabled by default if you compile with optimizations (option -O2 or higher) and debugging is enabled (option -g).

Many routines in the shared libraries are more highly optimized for Intel® microprocessors than for non-Intel microprocessors.

O3

Performs O2 optimizations and enables more aggressive loop transformations such as Fusion, Block-Unroll-and-Jam, and collapsing IF statements.

This option may set other options. This is determined by the compiler, depending on which operating system and architecture you are using. The options that are set may change from release to release.

When O3 is used with options -ax or -x (Linux) or with options /Qax or /Qx (Windows), the compiler performs more aggressive data dependency analysis than for O2, which may result in longer compilation times.

The O3 optimizations may not cause higher performance unless loop and memory access transformations take place. The optimizations may slow down code in some cases compared to O2 optimizations.

The O3 option is recommended for applications that have loops that heavily use floating-point calculations and process large data sets.

Many routines in the shared libraries are more highly optimized for Intel® microprocessors than for non-Intel microprocessors.

The last O option specified on the command line takes precedence over any others.

IDE Equivalent

Visual Studio: General > Optimization (/Od, /O1, /O2, /O3, /fast)

Optimization > Optimization (/Od, /O1, /O2, /O3, /fast)

Alternate Options

O2

Linux and macOS: None
Windows: /Ox
Parent topic: Optimization Options

See Also

Od compiler option
fltconsistency compiler option
fast compiler option
Level Two Title