Table of Contents
[TOC]
Pre-defined C/C++ Compiler Macros
The macros are found here:
General guidelines are found here:
Please send updates/corrections to predef-contribute.
Introduction
C and C++ compilers automatically define certain macros that can be used to check for compiler or operating system features. This is useful when writing portable software.
These pages lists various pre-defined compiler macros that can be used to identify standards, compilers, operating systems, hardware architectures, and even basic run-time libraries at compile-time.
For example, if we want to use a generic or opaque pointer type, we use void pointers. However, ancient K&R compilers (from the time before the first ANSI C standard) do not support void pointers. Instead we can define our own type:
#if defined(__STDC__) || defined(__cplusplus) || defined(_MSC_EXTENSIONS)
typedef void * t_pointer;
#else
typedef char * t_pointer;
#endif
Another example, Microsoft Visual C++ version 4.2 added a pragma to reduce compilation times by only including a file once (if _MSC_VER
is not defined then it will evaluate to 0 (zero) — however, some compilers may complain about an undefined macro)
#if defined(_MSC_VER) && (_MSC_VER >= 1020)
#pragma once
#endif
The macros contained in these pages have been obtained through vendor documentation, the defines script, contributors, and third-party source code. No guarantee about the correctness of the macros is given.
An often-used alternative is Autoconf, which is a more powerful tool to examine various types of features, including compilation options. However, Autoconf is fairly Unix-centric, and requires a Unix layer on other platforms (e.g. Cygwin on Windows). Other alternatives are Buildtool, CMake, SCons, PMK, Jam, Ant, and Bakefile.
Architectures
Type |
Macro |
Description |
Identification |
__alpha__ |
Defined by GNU C |
Version |
__alpha_ev'V'__ |
V = Version |
Identification |
__alpha |
Defined by DEC C |
Identification |
_M_ALPHA |
Defined by Visual Studio |
Example
CPU |
Macro |
Alpha EV4 |
__alpha_ev4__ |
Alpha EV5 |
__alpha_ev5__ |
Alpha EV6 |
__alpha_ev6__ |
Type |
Macro |
Description |
Identification |
__amd64__ __amd64 __x86_64__ __x86_64 |
Defined by GNU C and Sun Studio |
Identification |
_M_X64 _M_AMD64 |
Defined by Visual Studio |
Notice that x32 can be detected by checking if the CPU uses the ILP32 data model.
Type |
Macro |
Description |
Identification |
__arm__ |
Defined by GNU C and RealView |
Identification |
__thumb__ |
Defined by GNU C and RealView in Thumb mode |
Version |
__ARM_ARCH_'V'__ |
V = Version Defined by GNU C 1 |
Identification |
__TARGET_ARCH_ARM __TARGET_ARCH_THUMB |
Defined by RealView |
Version |
__TARGET_ARCH_ARM = V __TARGET_ARCH_THUMB = V |
V = Version |
Version |
__TARGET_ARCH_'VR' |
VR = Version and Revision |
Identification |
_ARM |
Defined by ImageCraft C |
Identification |
_M_ARM |
Defined by Visual Studio |
Identification |
_M_ARMT |
Defined by Visual Studio in Thumb mode |
Version |
_M_ARM = V |
V = Version |
Identification |
__arm |
Defined by Diab |
Example
CPU |
Macro |
_M_ARM |
ARM 2 |
__ARM_ARCH_2__ |
|
ARM 3 |
__ARM_ARCH_3__ __ARM_ARCH_3M__ |
|
ARM 4T |
__ARM_ARCH_4T__ __TARGET_ARM_4T |
|
ARM 5 |
__ARM_ARCH_5__ __ARM_ARCH_5E__ |
5 |
ARM 5T |
__ARM_ARCH_5T__ __ARM_ARCH_5TE__ __ARM_ARCH_5TEJ__ |
|
ARM 6 |
__ARM_ARCH_6__ __ARM_ARCH_6J__ __ARM_ARCH_6K__ __ARM_ARCH_6Z__ __ARM_ARCH_6ZK__ |
6 |
ARM 6T2 |
__ARM_ARCH_6T2__ |
|
ARM 7 |
__ARM_ARCH_7__ __ARM_ARCH_7A__ __ARM_ARCH_7R__ __ARM_ARCH_7M__ __ARM_ARCH_7S__ |
7 |
Type |
Macro |
Description |
Identification |
__aarch64__ |
Defined by GNU C 1 |
Type |
Macro |
Description |
Identification |
__bfin __BFIN__ |
Defined by GNU C |
Type |
Macro |
Description |
Identification |
__convex__ |
Defined by GNU C |
Version |
__convex_'V'__ |
V = Version |
Example
CPU |
Macro |
Convex C1 |
__convex_c1__ |
Convex C2 |
__convex_c2__ |
Convex C32xx series |
__convex_c32__ |
Convex C34xx series |
__convex_c34__ |
Convex C38xx series |
__convex_c38__ |
Type |
Macro |
|
Identification |
__epiphany__ |
|
Type |
Macro |
Description |
Identification |
__hppa__ |
Defined by GNU C |
Identification |
__HPPA__ |
Defined by Stratus VOS C |
Identification |
__hppa |
|
Version |
_PA_RISC'V'_'R' |
V = Version R = Revision |
See also OpenPA.net.
Example
CPU |
Macro |
PA RISC 1.0 |
_PA_RISC1_0 |
PA RISC 1.1 |
_PA_RISC1_1 __HPPA11__ __PA7100__ |
PA RISC 2.0 |
_PA_RISC2_0 __RISC2_0__ __HPPA20__ __PA8000__ |
Type |
Macro |
Format |
Description |
Identification |
i386 __i386 __i386__ |
|
Defined by GNU C |
Version |
__i386__ __i486__ __i586__ __i686__ |
|
Defined by GNU C |
Identification |
__i386 |
|
Defined by Sun Studio |
Identification |
__i386 __IA32__ |
|
Defined by Stratus VOS C |
Identification |
_M_I86 |
|
Only defined for 16-bits architectures Defined by Visual Studio, Digital Mars, and Watcom C/C++ (see note below) |
Identification |
_M_IX86 |
|
Only defined for 32-bits architectures Defined by Visual Studio, Intel C/C++, Digital Mars, and Watcom C/C++ |
Version |
_M_IX86 |
V00 |
V = Version |
Identification |
__X86__ |
|
Defined by Watcom C/C++ |
Identification |
_X86_ |
|
Defined by MinGW32 |
Identification |
__THW_INTEL__ |
|
Defined by XL C/C++ |
Identification |
__I86__ |
|
Defined by Digital Mars |
Version |
__I86__ |
V |
V = Version |
Identification |
__INTEL__ |
|
Defined by CodeWarrior |
Identification |
__386 |
|
Defined by Diab |
Notice that Watcom C/C++ defines _M_IX86
for both 16-bits and 32-bits architectures. Use __386__
or _M_I386
to detect 32-bits architectures in this case.
Notice that the Stratus VOS is big-endian on IA32, so these macros cannot be used to detect endianness if __VOS__
is set.
Example
CPU |
_M_IX86 |
__I86__ |
80386 |
300 |
3 |
80486 |
400 |
4 |
Pentium |
500 |
5 |
Pentium Pro/II |
600 |
6 |
Type |
Macro |
Format |
Description |
Identification |
__ia64__ _IA64 __IA64__ |
|
Defined by GNU C |
Identification |
__ia64 |
|
Defined by HP aCC |
Identification |
_M_IA64 |
|
Defined by Visual Studio |
Identification |
_M_IA64 |
|
Defined by Intel C/C++ |
Version |
_M_IA64 |
? |
|
Identification |
__itanium__ |
|
Defined by Intel C/C++ |
Example
CPU |
_M_IA64 (Intel C/C++) |
|
64100 |
Type |
Macro |
Description |
Identification |
__m68k__ |
Defined by GNU C |
Version |
__mc'V'__ __mc'V' mc'V' |
V = Version |
Identification |
M68000 |
Defined by SAS/C |
Identification |
__MC68K__ |
Defined by Stratus VOS C |
Version |
__MC'V'__ |
V = Version |
Example
CPU |
Macro |
68000 |
__mc68000__ __MC68000__ |
68010 |
__mc68010__ |
68020 |
__mc68020__ __MC68020__ |
68030 |
__mc68030__ __MC68030__ |
68040 |
__mc68040__ |
68060 |
__mc68060__ |
Type |
Macro |
Description |
Identification |
__mips__ mips |
Defined by GNU C |
Version |
_MIPS_ISA = _MIPS_ISA_MIPS'V' |
V = MIPS ISA level |
Version |
_R3000 _R4000 _R5900 |
|
Identification |
__mips |
Defined by MIPSpro and GNU C |
Version |
__mips |
The value indicates the MIPS ISA (Instruction Set Architecture) level |
Version |
__MIPS_ISA'V'__ |
V = MIPS ISA level |
Identification |
__MIPS__ |
Defined by Metrowerks |
Example
CPU |
_MIPS_ISA |
GNU C Macro |
__mips |
MIPSpro Macro |
R2000 |
_MIPS_ISA_MIPS1 |
|
1 |
|
R3000 |
_MIPS_ISA_MIPS1 |
_R3000 |
1 |
|
R6000 |
_MIPS_ISA_MIPS2 |
|
2 |
__MIPS_ISA2__ |
R4000 |
|
_R4000 |
|
|
R4400 |
_MIPS_ISA_MIPS3 |
|
3 |
__MIPS_ISA3__ |
R8000 |
_MIPS_ISA_MIPS4 |
|
4 |
__MIPS_ISA4__ |
R10000 |
_MIPS_ISA_MIPS4 |
|
4 |
__MIPS_ISA4__ |
Type |
Macro |
Description |
Identification |
__powerpc __powerpc__ __powerpc64__ __POWERPC__ __ppc__ __ppc64__ __PPC__ __PPC64__ _ARCH_PPC _ARCH_PPC64 |
Defined by GNU C |
Version |
__ppc'V'__ |
V = Version |
Identification |
_M_PPC |
Defined by Visual Studio |
Version |
_M_PPC |
? |
Identification |
_ARCH_PPC _ARCH_PPC64 |
Defined by XL C/C++ |
Version |
_ARCH_'V' |
V = Version |
Version |
__PPCGECKO__ |
Gekko Defined by CodeWarrior |
Version |
__PPCBROADWAY__ |
Broadway Defined by CodeWarrior |
Version |
_XENON |
Xenon |
Identification |
__ppc |
Defined by Diab |
Example
CPU |
_M_PPC |
Macro |
XL Macro |
PowerPC 440 |
|
|
_ARCH_440 |
PowerPC 450 |
|
|
_ARCH_450 |
PowerPC 601 |
601 |
__ppc601__ |
_ARCH_601 |
PowerPC 603 |
603 |
__ppc603__ |
_ARCH_603 |
PowerPC 604 |
604 |
__ppc604__ |
_ARCH_604 |
PowerPC 620 |
620 |
|
|
Pyramid 9810
Type |
Macro |
Identification |
pyr |
Type |
Macro |
Description |
Identification |
__THW_RS6000 |
Defined by XL C/C++ |
Identification |
_IBMR2 |
|
Identification |
_POWER |
|
Identification |
_ARCH_PWR _ARCH_PWR2 _ARCH_PWR3 _ARCH_PWR4 |
|
Type |
Macro |
Description |
Identification |
__sparc__ |
Defined by GNU C |
Identification |
__sparc |
Defined by Sun Studio |
Version |
__sparc_v8__ __sparc_v9__ |
Defined by GNU C |
Version |
__sparcv8 __sparcv9 |
Defined by Sun Studio |
Example
CPU |
Sun Studio Macro |
GNU C Macro |
SPARC v8 (SuperSPARC) |
__sparcv8 |
__sparc_v8__ |
SPARC v9 (UltraSPARC) |
__sparcv9 |
__sparc_v9__ |
Type |
Macro |
Description |
Identification |
__sh__ |
Defined by GNU C |
Version |
__sh1__ __sh2__ __sh3__ __SH3__ __SH4__ __SH5__ |
|
Type |
Macro |
Description |
Identification |
__370__ __THW_370__ |
Identifies System/370 Defined by XL C/C++ |
Identification |
__s390__ |
Identifies System/390 Defined by GNU C |
Identification |
__s390x__ |
Identifies z/Architecture Defined by GNU C |
Identification |
__zarch__ |
Identifies z/Architecture Defined by clang |
Identification |
__SYSC_ZARCH__ |
Identifies z/Architecture Defined by Systems/C |
Type |
Macro |
Description |
Identification |
_TMS320C2XX __TMS320C2000__ |
C2000 series |
Identification |
_TMS320C5X __TMS320C55X__ |
C5000 series |
Identification |
_TMS320C6X __TMS320C6X__ |
C6000 series |
Example
DSP |
Macro |
C28xx |
_TMS320C28X |
C54x |
_TMS320C5XX |
C55x |
__TMS320C55X__ |
C6200 |
_TMS320C6200 |
C6400 |
_TMS320C6400 |
C6400+ |
_TMS320C6400_PLUS |
C6600 |
_TMS320C6600 |
C6700 |
_TMS320C6700 |
C6700+ |
_TMS320C6700_PLUS |
C6740 |
_TMS320C6740 |
TMS470
Type |
Macro |
Identification |
__TMS470__ |
Data type |
LP32 |
ILP32 |
LP64 |
LLP64 |
ILP64 |
SILP64 |
char |
8 |
8 |
8 |
8 |
8 |
8 |
short |
16 |
16 |
16 |
16 |
16 |
64 |
int |
16 |
32 |
32 |
32 |
64 |
64 |
long |
32 |
32 |
64 |
32 |
64 |
64 |
long long |
|
|
64 |
64 |
64 |
64 |
pointer |
32 |
32 |
64 |
64 |
64 |
64 |
ILP32
Macro |
Description |
_ILP32 |
Defined by HP aCC and Sun Studio |
__ILP32__ |
Defined by GNU C |
LP64
Macro |
Description |
_LP64 |
Defined by HP aCC and Sun Studio |
__LP64__ |
Defined by GNU C |
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