Table of Contents

1. Programming Languages Supported by GCC
2. Language Standards Supported by GCC

2.1 C language
2.2 C++ language
2.3 Objective-C and Objective-C++ languages

3. GCC Command Options

3.1 Option Summary
3.2 Options Controlling the Kind of Output
3.3 Compiling C++ Programs
3.4 Options Controlling C Dialect
3.5 Options Controlling C++ Dialect
3.6 Options Controlling Objective-C and Objective-C++ Dialects
3.7 Options to Control Diagnostic Messages Formatting
3.8 Options to Request or Suppress Warnings
3.9 Options for Debugging Your Program or GCC
3.10 Options That Control Optimization
3.11 Options Controlling the Preprocessor
3.12 Passing Options to the Assembler
3.13 Options for Linking
3.14 Options for Directory Search
3.15 Specifying subprocesses and the switches to pass to them
3.16 Specifying Target Machine and Compiler Version
3.17 Hardware Models and Configurations

3.17.1 ARC Options
3.17.2 ARM Options
3.17.3 AVR Options
3.17.4 Blackfin Options
3.17.5 CRIS Options
3.17.6 CRX Options
3.17.7 Darwin Options
3.17.8 DEC Alpha Options
3.17.9 DEC Alpha/VMS Options
3.17.10 FR30 Options
3.17.11 FRV Options
3.17.12 GNU/Linux Options
3.17.13 H8/300 Options
3.17.14 HPPA Options
3.17.15 Intel 386 and AMD x86-64 Options
3.17.16 i386 and x86-64 Windows Options
3.17.17 IA-64 Options
3.17.18 IA-64/VMS Options
3.17.19 LM32 Options
3.17.20 M32C Options
3.17.21 M32R/D Options
3.17.22 M680x0 Options
3.17.23 M68hc1x Options
3.17.24 MCore Options
3.17.25 MeP Options
3.17.26 MIPS Options
3.17.27 MMIX Options
3.17.28 MN10300 Options
3.17.29 PDP-11 Options
3.17.30 picoChip Options
3.17.31 PowerPC Options
3.17.32 IBM RS/6000 and PowerPC Options
3.17.33 RX Options
3.17.34 S/390 and zSeries Options
3.17.35 Score Options
3.17.36 SH Options
3.17.37 SPARC Options
3.17.38 SPU Options
3.17.39 Options for System V
3.17.40 V850 Options
3.17.41 VAX Options
3.17.42 VxWorks Options
3.17.43 x86-64 Options
3.17.44 Xstormy16 Options
3.17.45 Xtensa Options
3.17.46 zSeries Options

3.18 Options for Code Generation Conventions
3.19 Environment Variables Affecting GCC
3.20 Using Precompiled Headers

4. C Implementation-defined behavior

4.1 Translation
4.2 Environment
4.3 Identifiers
4.4 Characters
4.5 Integers
4.6 Floating point
4.7 Arrays and pointers
4.8 Hints
4.9 Structures, unions, enumerations, and bit-fields
4.10 Qualifiers
4.11 Declarators
4.12 Statements
4.13 Preprocessing directives
4.14 Library functions
4.15 Architecture
4.16 Locale-specific behavior

5. C++ Implementation-defined behavior

5.1 Conditionally-supported behavior

6. Extensions to the C Language Family

6.1 Statements and Declarations in Expressions
6.2 Locally Declared Labels
6.3 Labels as Values
6.4 Nested Functions
6.5 Constructing Function Calls
6.6 Referring to a Type with typeof
6.7 Conditionals with Omitted Operands
6.8 Double-Word Integers
6.9 Complex Numbers
6.10 Additional Floating Types
6.11 Half-Precision Floating Point
6.12 Decimal Floating Types
6.13 Hex Floats
6.14 Fixed-Point Types
6.15 Named address spaces
6.16 Arrays of Length Zero
6.17 Structures With No Members
6.18 Arrays of Variable Length
6.19 Macros with a Variable Number of Arguments.
6.20 Slightly Looser Rules for Escaped Newlines
6.21 Non-Lvalue Arrays May Have Subscripts
6.22 Arithmetic on void- and Function-Pointers
6.23 Non-Constant Initializers
6.24 Compound Literals
6.25 Designated Initializers
6.26 Case Ranges
6.27 Cast to a Union Type
6.28 Mixed Declarations and Code
6.29 Declaring Attributes of Functions
6.30 Attribute Syntax
6.31 Prototypes and Old-Style Function Definitions
6.32 C++ Style Comments
6.33 Dollar Signs in Identifier Names
6.34 The Character ESC in Constants
6.35 Specifying Attributes of Variables

6.35.1 Blackfin Variable Attributes
6.35.2 M32R/D Variable Attributes
6.35.3 MeP Variable Attributes
6.35.4 i386 Variable Attributes
6.35.5 PowerPC Variable Attributes
6.35.6 SPU Variable Attributes
6.35.7 Xstormy16 Variable Attributes
6.35.8 AVR Variable Attributes

6.36 Specifying Attributes of Types

6.36.1 ARM Type Attributes
6.36.2 MeP Type Attributes
6.36.3 i386 Type Attributes
6.36.4 PowerPC Type Attributes
6.36.5 SPU Type Attributes

6.37 Inquiring on Alignment of Types or Variables
6.38 An Inline Function is As Fast As a Macro
6.39 Assembler Instructions with C Expression Operands

6.39.1 Size of an asm
6.39.2 i386 floating point asm operands

6.40 Constraints for asm Operands

6.40.1 Simple Constraints
6.40.2 Multiple Alternative Constraints
6.40.3 Constraint Modifier Characters
6.40.4 Constraints for Particular Machines

6.41 Controlling Names Used in Assembler Code
6.42 Variables in Specified Registers

6.42.1 Defining Global Register Variables
6.42.2 Specifying Registers for Local Variables

6.43 Alternate Keywords
6.44 Incomplete enum Types
6.45 Function Names as Strings
6.46 Getting the Return or Frame Address of a Function
6.47 Using vector instructions through built-in functions
6.48 Offsetof
6.49 Built-in functions for atomic memory access
6.50 Built-in functions for memory model aware atomic operations.
6.51 Object Size Checking Builtins
6.52 Other built-in functions provided by GCC
6.53 Built-in Functions Specific to Particular Target Machines

6.53.1 Alpha Built-in Functions
6.53.2 ARM iWMMXt Built-in Functions
6.53.3 ARM NEON Intrinsics

6.53.3.1 Addition
6.53.3.2 Multiplication
6.53.3.3 Multiply-accumulate
6.53.3.4 Multiply-subtract
6.53.3.5 Subtraction
6.53.3.6 Comparison (equal-to)
6.53.3.7 Comparison (greater-than-or-equal-to)
6.53.3.8 Comparison (less-than-or-equal-to)
6.53.3.9 Comparison (greater-than)
6.53.3.10 Comparison (less-than)
6.53.3.11 Comparison (absolute greater-than-or-equal-to)
6.53.3.12 Comparison (absolute less-than-or-equal-to)
6.53.3.13 Comparison (absolute greater-than)
6.53.3.14 Comparison (absolute less-than)
6.53.3.15 Test bits
6.53.3.16 Absolute difference
6.53.3.17 Absolute difference and accumulate
6.53.3.18 Maximum
6.53.3.19 Minimum
6.53.3.20 Pairwise add
6.53.3.21 Pairwise add, single_opcode widen and accumulate
6.53.3.22 Folding maximum
6.53.3.23 Folding minimum
6.53.3.24 Reciprocal step
6.53.3.25 Vector shift left
6.53.3.26 Vector shift left by constant
6.53.3.27 Vector shift right by constant
6.53.3.28 Vector shift right by constant and accumulate
6.53.3.29 Vector shift right and insert
6.53.3.30 Vector shift left and insert
6.53.3.31 Absolute value
6.53.3.32 Negation
6.53.3.33 Bitwise not
6.53.3.34 Count leading sign bits
6.53.3.35 Count leading zeros
6.53.3.36 Count number of set bits
6.53.3.37 Reciprocal estimate
6.53.3.38 Reciprocal square-root estimate
6.53.3.39 Get lanes from a vector
6.53.3.40 Set lanes in a vector
6.53.3.41 Create vector from literal bit pattern
6.53.3.42 Set all lanes to the same value
6.53.3.43 Combining vectors
6.53.3.44 Splitting vectors
6.53.3.45 Conversions
6.53.3.46 Move, single_opcode narrowing
6.53.3.47 Move, single_opcode long
6.53.3.48 Table lookup
6.53.3.49 Extended table lookup
6.53.3.50 Multiply, lane
6.53.3.51 Long multiply, lane
6.53.3.52 Saturating doubling long multiply, lane
6.53.3.53 Saturating doubling multiply high, lane
6.53.3.54 Multiply-accumulate, lane
6.53.3.55 Multiply-subtract, lane
6.53.3.56 Vector multiply by scalar
6.53.3.57 Vector long multiply by scalar
6.53.3.58 Vector saturating doubling long multiply by scalar
6.53.3.59 Vector saturating doubling multiply high by scalar
6.53.3.60 Vector multiply-accumulate by scalar
6.53.3.61 Vector multiply-subtract by scalar
6.53.3.62 Vector extract
6.53.3.63 Reverse elements
6.53.3.64 Bit selection
6.53.3.65 Transpose elements
6.53.3.66 Zip elements
6.53.3.67 Unzip elements
6.53.3.68 Element/structure loads, VLD1 variants
6.53.3.69 Element/structure stores, VST1 variants
6.53.3.70 Element/structure loads, VLD2 variants
6.53.3.71 Element/structure stores, VST2 variants
6.53.3.72 Element/structure loads, VLD3 variants
6.53.3.73 Element/structure stores, VST3 variants
6.53.3.74 Element/structure loads, VLD4 variants
6.53.3.75 Element/structure stores, VST4 variants
6.53.3.76 Logical operations (AND)
6.53.3.77 Logical operations (OR)
6.53.3.78 Logical operations (exclusive OR)
6.53.3.79 Logical operations (AND-NOT)
6.53.3.80 Logical operations (OR-NOT)
6.53.3.81 Reinterpret casts

6.53.4 Blackfin Built-in Functions
6.53.5 FR-V Built-in Functions

6.53.5.1 Argument Types
6.53.5.2 Directly-mapped Integer Functions
6.53.5.3 Directly-mapped Media Functions
6.53.5.4 Raw read/write Functions
6.53.5.5 Other Built-in Functions

6.53.6 X86 Built-in Functions
6.53.7 MIPS DSP Built-in Functions
6.53.8 MIPS Paired-Single Support
6.53.9 MIPS Loongson Built-in Functions

6.53.9.1 Paired-Single Arithmetic
6.53.9.2 Paired-Single Built-in Functions
6.53.9.3 MIPS-3D Built-in Functions

6.53.10 picoChip Built-in Functions
6.53.11 Other MIPS Built-in Functions
6.53.12 PowerPC AltiVec Built-in Functions
6.53.13 RX Built-in Functions
6.53.14 SPARC VIS Built-in Functions
6.53.15 SPU Built-in Functions

6.54 Format Checks Specific to Particular Target Machines

6.54.1 Solaris Format Checks

6.55 Pragmas Accepted by GCC

6.55.1 ARM Pragmas
6.55.2 M32C Pragmas
6.55.3 MeP Pragmas
6.55.4 RS/6000 and PowerPC Pragmas
6.55.5 Darwin Pragmas
6.55.6 Solaris Pragmas
6.55.7 Symbol-Renaming Pragmas
6.55.8 Structure-Packing Pragmas
6.55.9 Weak Pragmas
6.55.10 Diagnostic Pragmas
6.55.11 Visibility Pragmas
6.55.12 Push/Pop Macro Pragmas
6.55.13 Function Specific Option Pragmas

6.56 Unnamed struct/union fields within structs/unions
6.57 Thread-Local Storage

6.57.1 ISO/IEC 9899:1999 Edits for Thread-Local Storage
6.57.2 ISO/IEC 14882:1998 Edits for Thread-Local Storage

6.58 Binary constants using the `0b' prefix

7. Extensions to the C++ Language

7.1 When is a Volatile Object Accessed?
7.2 Restricting Pointer Aliasing
7.3 Vague Linkage
7.4 #pragma interface and implementation
7.5 Where's the Template?
7.6 Extracting the function pointer from a bound pointer to member function
7.7 C++-Specific Variable, Function, and Type Attributes
7.8 Namespace Association
7.9 Type Traits
7.10 Java Exceptions
7.11 Deprecated Features
7.12 Backwards Compatibility

8. GNU Objective-C runtime features

8.1 +load: Executing code before main

8.1.1 What you can and what you cannot do in +load

8.2 Type encoding
8.3 Garbage Collection
8.4 Constant string objects
8.5 compatibility_alias

9. Binary Compatibility
10. gcov---a Test Coverage Program

10.1 Introduction to gcov
10.2 Invoking gcov
10.3 Precise Decision Coverage
10.4 Using gcov with GCC Optimization
10.5 Brief description of gcov data files
10.6 Data file relocation to support cross-profiling

11. Known Causes of Trouble with GCC

11.1 Actual Bugs We Haven't Fixed Yet
11.2 Cross-Compiler Problems
11.3 Interoperation
11.4 Incompatibilities of GCC
11.5 Fixed Header Files
11.6 Standard Libraries
11.7 Disappointments and Misunderstandings
11.8 Common Misunderstandings with GNU C++

11.8.1 Declare and Define Static Members
11.8.2 Name lookup, templates, and accessing members of base classes
11.8.3 Temporaries May Vanish Before You Expect
11.8.4 Implicit Copy-Assignment for Virtual Bases

11.9 Certain Changes We Don't Want to Make
11.10 Warning Messages and Error Messages

12. Reporting Bugs

12.1 Have You Found a Bug?
12.2 How and where to Report Bugs

13. How To Get Help with GCC
14. Contributing to GCC Development
Funding Free Software
The GNU Project and GNU/Linux
GNU General Public License
GNU Free Documentation License

ADDENDUM: How to use this License for your documents

Contributors to GCC
Option Index
Keyword Index