The compiler maintains and recognizes the predefined macro names listed in Table 2-30.
| Macro Name | Description |
|---|---|
| _ _16bis_ _ | Defined if 16-BIS state is selected (the -code_state=16 option is used); otherwise, it is undefined. |
| _ _32bis_ _ | Defined if 32-BIS state is selected (the -code_state=16 option is not used); otherwise, it is undefined. |
| _AEABI_PORTABILITY_LEVEL | Define to 1 to enable full object file portability when headers files are included. Define to 0 to require full C standard compatibility. See the ARM standard for details. |
| _ _DATE_ _(1) | Expands to the compilation date in the form mmm dd yyyy |
| _ _FILE_ _(1) | Expands to the current source filename |
| _ _LINE_ _(1) | Expands to the current line number |
| _ _signed_chars_ _ | Defined if char types are signed by default |
| _ _STDC_ _(1) | Defined to 1 to indicate that compiler conforms to ISO C Standard. See Section 5.1 for exceptions to ISO C conformance. |
| _ _STDC_VERSION_ _ | C standard macro. |
| _ _STDC_HOSTED_ _ | C standard macro. Always defined to 1. |
| _ _STDC_NO_THREADS_ _ | C standard macro. Always defined to 1. |
| _ _TI_COMPILER_VERSION_ _ | Defined to a 7-9 digit integer, depending on if X has 1, 2, or 3 digits. The number does not contain a decimal. For example, version 3.2.1 is represented as 3002001. The leading zeros are dropped to prevent the number being interpreted as an octal. |
| _ _TI_EABI_SUPPORT_ _ | Defined to 1 if the EABI ABI is enabled (this is the default); otherwise, it is undefined. |
| _ _TI_FPALIB_SUPPORT_ _ | Defined to 1 if the FPA endianness is used to store double-precision floating-point values; otherwise, it is undefined. |
| _ _TI_GNU_ATTRIBUTE_SUPPORT_ _ | Defined to 1 if GCC extensions are enabled (which is the default) |
| _ _TI_NEON_SUPPORT_ _ | Defined to 1 if NEON SIMD extension is targeted (the --neon option is used); otherwise, it is undefined. |
| _ _TI_STRICT_ANSI_MODE_ _ | Defined to 1 if strict ANSI/ISO mode is enabled (the --strict_ansi option is used); otherwise, it is defined as 0. |
| _ _TI_STRICT_FP_MODE_ _ | Defined to 1 if --fp_mode=strict is used (default); otherwise, it is defined as 0. |
| _ _TI_ ARM_V4_ _ | Defined to 1 if the v4 architecture (ARM7) is targeted (the -mv4 option is used); otherwise, it is undefined. |
| _ _TI_ ARM_V5_ _ | Defined to 1 if the v5E architecture (ARM9E) is targeted (the -mv5e option is used); otherwise, it is undefined. |
| _ _TI_ ARM_V6_ _ | Defined to 1 if the v6 architecture (ARM11) is targeted (the -mv6 option is used); otherwise, it is undefined. |
| _ _TI_ ARM_V6M0_ _ | Defined to 1 if the v6M0 architecture (Cortex-M0) is targeted (the -mv6M0 option is used); otherwise, it is undefined. |
| _ _TI_ ARM_V7_ _ | Defined to 1 if any v7 architecture (Cortex) is targeted; otherwise, it is undefined. |
| _ _TI_ ARM_V7A8_ _ | Defined to 1 if the v7A8 architecture (Cortex-A8) is targeted (the -mv7A8 option is used); otherwise, it is undefined. |
| _ _TI_ ARM_V7M3_ _ | Defined to 1 if the v7M3 architecture (Cortex-M3) is targeted (the -mv7M3 option is used); otherwise, it is undefined. |
| _ _TI_ ARM_V7M4_ _ | Defined to 1 if the v7M4 architecture (Cortex-M4) is targeted (the -mv7M4 option is used); otherwise, it is undefined. |
| _ _TI_ ARM_V7R4_ _ | Defined to 1 if the v7R4 architecture (Cortex-R4) is targeted (the -mv7R4 option is used); otherwise, it is undefined. |
| _ _TI_ ARM_V7R5_ _ | Defined to 1 if the v7R5 architecture (Cortex-R5) is targeted (the -mv7R5 option is used); otherwise, it is undefined. |
| _ _TI_VFP_SUPPORT_ _ | Defined to 1 if the VFP coprocessor is enabled (any --float_support option is used); otherwise, it is undefined. |
| _ _TI_VFPLIB_SUPPORT_ _ | Defined to 1 if the VFP endianness is used to store double-precision floating-point values; otherwise, it is undefined. |
| _ _TI_VFPV3_SUPPORT_ _ | Defined to 1 if the VFP coprocessor is enabled (the --float_support=vfpv3 option is used); otherwise, it is undefined. |
| _ _TI_VFPV3D16_SUPPORT_ _ | Defined to 1 if the VFP coprocessor is enabled (the --float_support=vfpv3d16 option is used); otherwise, it is undefined. |
| _ _TI_FPV4SPD16_SUPPORT_ _ | Defined to 1 if the VFP coprocessor is enabled (the --float_support=fpv4spd16 option is used); otherwise, it is undefined. |
| _ _TI_WCHAR_T_BITS_ _ | Set to the type of wchar_t. |
| _ _TIME_ _(1) | Expands to the compilation time in the form "hh:mm:ss" |
| _ _TI_ ARM_ _ | Always defined |
| _ _unsigned_chars_ _ | Defined if char types are unsigned by default (default) |
| _ _big_endian_ _ | Defined if big-endian mode is selected (the --endian=big option is used or the --endian=little option is not used); otherwise, it is undefined. |
| _ _WCHAR_T_TYPE_ _ | Set to the type of wchar_t. |
| _INLINE | Expands to 1 if optimization is used (--opt_level or -O option); undefined otherwise. |
| _ _little_endian_ _ | Defined if little-endian mode is selected (the --endian=little option is used); otherwise, it is undefined. |
NOTE
Macros with names that contain _ _TI_ARM are duplicates of the older _ _TI_TMS470 macros. For example, _ _TI_ARM_V7_ _ is the newer name for the _ _TI_TMS470_V7_ _ macro. The old macro names still exist and can continue to be used.
You can use the names listed in Table 2-30 in the same manner as any other defined name. For example,
printf ( "%s %s" , __TIME__ , __DATE__);
translates to a line such as:
printf ("%s %s" , "13:58:17", "Jan 14 1997");
In addition, the ARM C Language Extensions (ACLE) v2.0 specification describes macros that identify features of the ARM architecture and how the C/C++ implementation uses the architecture. All ACLE predefined macros begin with the prefix __ARM. Table 2-31 lists the macros mentioned in the ACLE specification and the section of the specification that provides more information. Some macros are undefined because they are not applicable for any Cortex-M or Cortex-R processor variant.
| Macro Name | Description | Section in ACLE Specification |
|---|---|---|
| __ARM_32BIT_STATE | Defined as 1 if the compiler is generating code for an ARM 32-bit processor variant (-mv6m0, -mv7m3, -mv7m4, -mv7a8, -mv7r4, and -mv7r5); undefined otherwise. | (Section 5.4.1) |
| __ARM_64BIT_STATE | Undefined | (Section 5.4.1) |
| __ARM_ACLE | Defined as 200 for all Cortex-M and Cortex-R processor variants (-mv6m0, -mv7m3, -mv7m4, -mv7r4, and -mv7r5). | (Sections 3.4, 5.2) |
| __ARM_ALIGN_MAX_PWR | Not supported | (Section 6.5.2) |
| __ARM_ALIGN_MAX_STACK_PWR | Not supported | (Section 6.5.3) |
| __ARM_ARCH | Identifies the version of ARM architecture selected on the compiler command line.
|
(Section 5.1) |
| __ARM_ARCH_ISA_A64 | Undefined | (Section 5.4.1) |
| __ARM_ARCH_ISA_ARM | Defined as 1 if the compiler is generating code for a processor variant that supports the ARM instruction set (-mv7a8, -mv7r4, and -mv7r5); undefined otherwise. | (Section 5.4.1) |
| __ARM_ARCH_ISA_THUMB | Defined as 1 if the compiler is generating code for a processor variant that supports the THUMB-1 instruction set. Defined as 2 if the compiler is generating code for a processor variant that supports the THUMB-2 instruction set; undefined otherwise. | (Section 5.4.1) |
| __ARM_ARCH_PROFILE | Not supported | (Section 5.4.2) |
| __ARM_BIG_ENDIAN | Defined as 1 by default; not defined if --little-endian (-me) option is used. | (Section 5.3) |
| __ARM_FEATURE_CLZ | Defined as 1 if the compiler is generating code for a processor variant that supports the CLZ instruction (-mv7m3, -mv7m4, -mv7a8, -mv7r4, and -mv7r5); undefined otherwise. | (Section 5.4.5) |
| __ARM_FEATURE_COPROC | Not supported | (Section 5.9) |
| __ARM_FEATURE_CRC32 | Undefined | (Section 5.5.8) |
| __ARM_FEATURE_CRYPTO | Undefined | (Section 5.5.7) |
| __ARM_FEATURE_DIRECTED_ROUNDING | Undefined | (Section 5.5.9) |
| __ARM_FEATURE_DSP | Defined as 1 if the compiler is generating code for a Cortex-M or Cortex-R processor that supports DSP instructions/intrinsics (-mv7m4, -mv7r4, and -mv7r5); undefined otherwise. | (Section 5.4.7) |
| __ARM_FEATURE_FMA | Not supported | (Section 5.5.3) |
| __ARM_FEATURE_FP16_SCALAR_ ARITHMETIC | Undefined | (Sections 3.4, 5.5.13) |
| __ARM_FEATURE_FP16_VECTOR_ ARITHMETIC | Undefined | (Section 5.5.13) |
| __ARM_FEATURE_IDIV | Not supported | (Section 5.4.10) |
| __ARM_FEATURE_JCVT | Undefined | (Section 5.5.14) |
| __ARM_FEATURE_LDREX | Undefined | (Section 5.4.4) |
| __ARM_FEATURE_NUMERIC_MAXMIN | Undefined | (Section 5.5.10) |
| __ARM_FEATURE_QBIT | Not supported | (Section 5.4.6) |
| __ARM_FEATURE_QRDMX | Undefined | (Section 5.5.12) |
| __ARM_FEATURE_SAT | Defined as 1 if the compiler is generating code for a processor variant that supports SSAT/USAT instructions/intrinsics (-mv7m3, -mv7m4, -mv7a8, -mv7r4, and -mv7r5); undefined otherwise. | (Section 5.4.8) |
| __ARM_FEATURE_SIMD32 | Defined as 1 if the compiler is generating code for a processor variant that supports all SIMD instructions/intrinsics (-mv7m4, -mv7r4, and -mv7r5); undefined otherwise. | (Section 5.4.9) |
| __ARM_FEATURE_UNALIGNED | Defined as 1 if the compiler is generating code for a processor variant that supports unaligned access to memory (-mv7m3, -mv7m4, -mv7a8, -mv7r4, and -mv7r5); undefined otherwise. | (Section 5.4.3) |
| __ARM_FP | Defined as 6 for --float_support={fpv4spd16 | fpv5spd16}. Defined as 12 for --float_support={vfpv2 | vfpv3 | vfpv3d16}; undefined otherwise. | (Section 5.5.1) |
| __ARM_FP16_ARGS | Defined as 1 if a 16-bit float type can be used for an argument and/or result; undefined otherwise. | (Section 5.5.11) |
| __ARM_FP16_FORMAT_ALTERNATIVE | Undefined | (Section 5.5.2) |
| __ARM_FP16_FORMAT_IEEE | Defined as 1 if the IEEE format for 16-bit floating-point (according to IEEE 754-2008 standard) is used; undefined otherwise. | (Section 5.5.2) |
| __ARM_FP_FAST | Not supported | (Section 5.6) |
| __ARM_FP_FENV_ROUNDING | Not supported | (Section 5.6) |
| __ARM_NEON | Undefined | (Sections 3.4, 5.5.4) |
| __ARM_NEON_FP | Undefined | (Section 5.5.5) |
| __ARM_PCS | Defined as 1 if the compiler can assume the default procedure calling standard for a translation unit conforms to the "base procedure call standard" as prescribed in the ARM Architecture Procedure Call Standard (AAPCS) specification (-mv7m3, -mv7m4, -mv7r4, and -mv7r5); undefined otherwise. | (Section 5.7) |
| __ARM_PCS_AAPCS64 | Undefined | (Section 5.7) |
| __ARM_PCS_VFP | Defined as 1 if the default procedure calling convention is to pass floating-point arguments / return values in hardware floating-point registers; undefined otherwise. | (Section 5.7) |
| __ARM_ROPI | Undefined | (Section 5.8) |
| __ARM_RWPI | Undefined | (Section 5.8) |
| __ARM_SIZEOF_MINIMAL_ENUM | Defined to the smallest possible enum type size (1 byte for packed, 4 bytes for int). This mirrors the --enum_type=[packed | int] option where packed is the default. | (Section 3.1.1) |
| __ARM_SIZEOF_WCHAR_T | Defined as 2 if --wchar_t=16 (default). Defined as 4 if --wchar_t=32. | (Section 3.1.1) |
| __ARM_WMMX | Undefined | (Section 5.5.6) |
| __STDC_IEC_559__ | Undefined | (Section 5.6) |
| __SUPPORT_SNAN__ | Not supported | (Section 5.6) |