通过以下命令可以查看gcc的内置宏定义
gcc -E -dM - </dev/null
[email protected]>gcc -E -dM - </dev/null #define __DBL_MIN_EXP__ (-1021) #define __FLT_MIN__ 1.17549435e-38F #define __CHAR_BIT__ 8 #define __WCHAR_MAX__ 2147483647 #define __DBL_DENORM_MIN__ 4.9406564584124654e-324 #define __FLT_EVAL_METHOD__ 0 #define __DBL_MIN_10_EXP__ (-307) #define __FINITE_MATH_ONLY__ 0 #define __SHRT_MAX__ 32767 #define __LDBL_MAX__ 1.18973149535723176502e+4932L #define __UINTMAX_TYPE__ long unsigned int #define __linux 1 #define __unix 1 #define __linux__ 1 #define __SCHAR_MAX__ 127 #define __USER_LABEL_PREFIX__ #define __STDC_HOSTED__ 1 #define __DBL_DIG__ 15 #define __FLT_EPSILON__ 1.19209290e-7F #define __LDBL_MIN__ 3.36210314311209350626e-4932L #define __unix__ 1 #define __DECIMAL_DIG__ 21 #define __gnu_linux__ 1 #define __LDBL_HAS_QUIET_NAN__ 1 #define __GNUC__ 4 #define __MMX__ 1 #define __DBL_MAX__ 1.7976931348623157e+308 #define __DBL_HAS_INFINITY__ 1 #define __DBL_MAX_EXP__ 1024 #define __SSE2_MATH__ 1 #define __amd64 1 #define __LONG_LONG_MAX__ 9223372036854775807LL #define __GXX_ABI_VERSION 1002 #define __FLT_MIN_EXP__ (-125) #define __x86_64 1 #define __DBL_MIN__ 2.2250738585072014e-308 #define __LP64__ 1 #define __DBL_HAS_QUIET_NAN__ 1 #define __REGISTER_PREFIX__ #define __NO_INLINE__ 1 #define __FLT_MANT_DIG__ 24 #define __VERSION__ "4.1.2 20080704 (Red Hat 4.1.2-54)" #define unix 1 #define __SIZE_TYPE__ long unsigned int #define __ELF__ 1 #define __FLT_RADIX__ 2 #define __LDBL_EPSILON__ 1.08420217248550443401e-19L #define __GNUC_RH_RELEASE__ 54 #define __SSE_MATH__ 1 #define __k8 1 #define __LDBL_DIG__ 18 #define __x86_64__ 1 #define __FLT_HAS_QUIET_NAN__ 1 #define __FLT_MAX_10_EXP__ 38 #define __LONG_MAX__ 9223372036854775807L #define __FLT_HAS_INFINITY__ 1 #define linux 1 #define __LDBL_MANT_DIG__ 64 #define __k8__ 1 #define __WCHAR_TYPE__ int #define __FLT_DIG__ 6 #define __INT_MAX__ 2147483647 #define __FLT_MAX_EXP__ 128 #define __DBL_MANT_DIG__ 53 #define __WINT_TYPE__ unsigned int #define __SSE__ 1 #define __LDBL_MIN_EXP__ (-16381) #define __amd64__ 1 #define __LDBL_MAX_EXP__ 16384 #define __LDBL_MAX_10_EXP__ 4932 #define __DBL_EPSILON__ 2.2204460492503131e-16 #define _LP64 1 #define __GNUC_PATCHLEVEL__ 2 #define __LDBL_HAS_INFINITY__ 1 #define __INTMAX_MAX__ 9223372036854775807L #define __FLT_DENORM_MIN__ 1.40129846e-45F #define __FLT_MAX__ 3.40282347e+38F #define __SSE2__ 1 #define __FLT_MIN_10_EXP__ (-37) #define __INTMAX_TYPE__ long int #define __GNUC_MINOR__ 1 #define __DBL_MAX_10_EXP__ 308 #define __LDBL_DENORM_MIN__ 3.64519953188247460253e-4951L #define __STDC__ 1 #define __PTRDIFF_TYPE__ long int #define __LDBL_MIN_10_EXP__ (-4931) #define __GNUC_GNU_INLINE__ 1
时间： 2024-10-23 15:55:19