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cmingw-w64size-t

Maximum size of size_t on Windows 10/ mingw-w64 compiler

I am using mingw-w64 compiler (gcc 8.1.0) on Windows 10 (64 bit installation). My expectation is to get the maximum value of size_t equal to (2^64 - 1). But my programs always return the value of SIZE_MAX as (2^32 - 1 only). What could be the reason? How can i achieve the a maximum value of (2^64 - 1) in my C programs?

I am learning C language and wanted to check out the statement made in the book that on modern computers max size of size_t can be (2^64 - 1). The piece of code I tried for checking this is as below:

#include <stdio.h>
#include <stdint.h>

int main(){
    printf("%d\n", sizeof(size_t));
    printf("%zu\n", SIZE_MAX); 
    return 0;
}

Output:

4
4294967295

I am using only one flag -std=c11 during compiling and gcc --version returns:

gcc.exe (i686-posix-dwarf-rev0, Built by MinGW-W64 project) 8.1.0
Solution

  • When checking gcc --version you state that you get

    gcc.exe (i686-posix-dwarf-rev0, Built by MinGW-W64 project) 8.1.0

    The important part of the output is this: i686-posix-dwarf-rev0, more specifically the i686 part.

    This tells us that GCC is built as a 32-bit application (i686 is a 32-bit system), and will default to creating 32-bit executables.

    To build a 64-bit executable you need to add the -m64 flag.