gcc undeclared identifier “_asm”

Question

I'm trying to understand how memory works, and how every instruction allocates memory. I'm also trying to understand the concept of offset, and base pointers. I am doing this for intel processors and MIPS. I am able to access memory windows in Visual Studio, however when i use gcc and gdb on UNIX, i get the this error on my code ![after compilation code][1]

error: use of undeclared identifier "_asm" _asm

I do not get this error in VISUAL STUDIO Here's what I'm trying to run (Very simple code)

 void main() { int quizint = 0x01000080; int n = 0xfffffff; int MIPSzint = 0x80000001; register int m = 3; register int p = 256; static int q = 0x7fffffff; static int r = 0x10000000; static int R = 0x8000000; _asm { start_loop: mov ebx, MIPSzint add ebx, -2 mov ecx, quizint mov eax, n sub eax, q add eax, R mov edx, 1 add edx, q add edx, 1 add edx, n add R, -1 } } 

====>>> _asm gives me the error. Question is, do I need to add something in order to make it work in gcc?

Answer 1

GCC calls it asm instead of _asm and the syntax is a little different. See https://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html and http://www.ibiblio.org/gferg/ldp/GCC-Inline-Assembly-HOWTO.html

Answer 2

Use __asm__ if you are compiling with GNU extensions disabled. With GNU extensions you can also use asm but _asm is not supported by gcc .