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Alpha

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 C++

Example

CPU	Macro
Alpha EV4	__alpha_ev4__
Alpha EV5	__alpha_ev5__
Alpha EV6	__alpha_ev6__

AMD64

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 C++

Notice that x32 can be detected by checking if the CPU uses the ILP32 data model.

ARM

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 C++
Identification	_M_ARMT	Defined by Visual C++ 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

ARM64

Type	Macro	Description
Identification	__aarch64__	Defined by GNU C 1
Identification	_M_ARM64	Defined by Visual C++

Blackfin

Type	Macro	Description
Identification	__bfin __BFIN__	Defined by GNU C
Identification	__ADSPBLACKFIN__	Defined by Analog CrossCore compiler
Version	__ADSPBF'V'__	V = Version Defined by Analog CrossCore compiler

Convex

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__

Elbrus

Type	Macro	Description
Identification	__e2k__	Defined by MCST lcc
Version	__iset__ = V	V = Version
Version	__elbrus_V__	V = CPU model

Example

CPU	Macro
Elbrus 1C+	__elbrus_1cplus__
Elbrus 8C	__elbrus_8c__
Elbrus 2C3	__elbrus_2c3__
Elbrus 12C	__elbrus_12c__
Elbrus 16C	__elbrus_16c__

Epiphany

Type	Macro
Identification	__epiphany__

HP/PA RISC

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__

Intel x80

Type	Macro	Format	Description
Identification	__8080__		Defined by Z88DK for 8080 CPUs
Identification	__8085__		Defined by Z88DK for 8085 CPUs; __8080__ is also defined
Identification	__Z80		Defined by Z88DK for Z80 CPUs
Identification	__Z180		Defined by Z88DK for Z180 CPUs

Intel x86

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 C++, Digital Mars, and Watcom C/C++ (see note below)
Identification	_M_IX86		Only defined for 32-bits architectures Defined by Visual C++, 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

Intel Itanium (IA-64)

Type	Macro	Format	Description
Identification	__ia64__ _IA64 __IA64__		Defined by GNU C
Identification	__ia64		Defined by HP aCC
Identification	_M_IA64		Defined by Visual C++
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

LoongArch

Type	Macro	Description
Identification	__loongarch__	Defined by GNU C, Clang and official toolchain conventions
Version	__loongarch_arch = V	V = Version
Version	__loongarch_tune = V	V = Version
Version	_LOONGARCH_ARCH = V	V = Version, legacy
Version	_LOONGARCH_TUNE = V	V = Version, legacy

More info on official toolchain convention

Motorola 68k

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__

MIPS

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__

NEC SX-Aurora TSUBASA

Type	Macro	Description
Identification	__ve__	Defined by NEC C/C++ Compiler and Clang
Identification	__ve	Defined by NEC C/C++ Compiler and Clang
Identification	__NEC__	Defined by NEC C/C++ Compiler and Clang

PNaCl

Type	Macro
Identification	__pnacl__

PowerPC

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 C++
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

RISC-V

Type	Macro	Description
Identification	__riscv
Identification	__riscv_xlen = X	X = 32 for RV32 or 64 for RV64

More info on official toolchain convention.

RS/6000

Type	Macro	Description
Identification	__THW_RS6000	Defined by XL C/C++
Identification	_IBMR2
Identification	_POWER
Identification	_ARCH_PWR _ARCH_PWR2 _ARCH_PWR3 _ARCH_PWR4

SPARC

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__

SuperH

Type	Macro	Description
Identification	__sh__	Defined by GNU C
Version	__sh1__ __sh2__ __sh3__ __SH3__ __SH4__ __SH5__

SystemZ

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

TMS320

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__