__builtin_inf() functions of GCC compiler

These functions do not need to include any header file to use them. So it provides faster usage, as these are Built-in functions of GCC compiler which is most used compiler, even in competitive programming.

Note: If the compiler shows warning of overflow, use casting before __builtin_inf() function as 

(data_type)__builtin_inf()

1. __builtin_inf(void): This function returns positive infinity which will then be converted to DBL_MAX of C language limits.h header file Macro. Its return data type is double. 

Example: 

if __builtin_inf() is used
it returns infinite

Output: inf

Here is a C++ program that shows the use of this function:

inf

2. __builtin_infd32(void): This function returns maximum value of 4-byte integer and returns data type is 32-bit integer.

Example: 

if __builtin_infd32() is used
it returns the maximum value of
the 32-bit integer

Output: 2147483647

Here is a C++ program which shows the use of this function: 

2147483647
2147483647
4294967295
4294967295

3. __builtin_infd64(void): This function returns Highest value that can be represented by 8 byte integer which is highest value of integer we can use in C++.

Example: 

if __builtin_infd64() is used
it returns the maximum value of
the 64-bit integer

Output: 9223372036854775807

Here is a C++ program which shows the use of this function: 

9223372036854775807
9223372036854775807
18446744073709551615
18446744073709551615

4. __builtin_infd128(void): As the maximum size that can be used for integer is 64-bit in C/C++, this function give the same result as __builtin_infd64().

Example: 

if __builtin_infd128() is used
it returns the maximum value of
the 64-bit integer

Output: 9223372036854775807

5. __builtin_inff(void): This function returns float maximum value means 4-byte maximum decimal point value.

Example: 

if __builtin_inff() is used
it returns the maximum value of
the 32-bit float

Output: inf

Here is a C++ program which shows the use of this function: 

inf
inf

6. __builtin_infl(void): This function returns maximum long double data type value.

Example: 

if __builtin_infl() is used
it returns the maximum value of
the long double type

Output: inf

Here is a C++ program which shows the use of this function: 

inf
inf

7. In the recent versions of GCC compiler, these are two new functions: __builtin_infn(void) & __builtin_infnx(void). One can replace n with 32 or 64 and it will return inf value respectively of 32-bit, 64-bit. 

Similar article: Builtin functions of GCC compiler