CODEWITHSUNDEEP
c++cunixgccgdb
cdcrazy2292
cdcrazy2292

Reputation: 49

gcc undeclared identifier "_asm"

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?

Upvotes: 1

Views: 7194

Answers (2)

ouah
ouah

Reputation: 145829

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.

Upvotes: 1

John Zwinck
John Zwinck

Reputation: 249153

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

Upvotes: 4

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