We use g++ compiler to turn provided C code into assembly language. To see the assembly code generated by the C compiler, we can use the “-S” option on the command line: 

Syntax:  

$ gcc -S filename.c

This will cause gcc to run the compiler, generating an assembly file. Suppose we write a C code and store it in a file name “geeks.c” .  

// C code stored in geeks.c file
#include 

// global string
char s[] = "GeeksforGeeks";

// Driver Code
int main()
{
	// Declaring variables
	int a = 2000, b =17;
	
	// Printing statement
	printf("%s %d \n", s, a+b);
}

Running the command: 

$ gcc -S geeks.c

This will cause gcc to run the compiler, generating an assembly file geeks.s, and go no further. (Normally it would then invoke the assembler to generate an object- code file.)
The assembly-code file contains various declarations including the set of lines: 

	.section __TEXT, __text, regular, pure_instructions
	.macosx_version_min 10, 12
	.global _main
	.align 4, 0x90
_main:								 ## @main
	.cfi_startproc
## BB#0:
	pushq %rbp
Ltmp0:
	.cfi_def_cfa_offset 16
Ltmp1:
	.cfi_offset %rbp, -16
	movq %rsp, %rbp
Ltmp2:
	.cfi_def_cfa_register %rbp
	subq $16, %rsp
	leaq L_.str(%rip), %rdi
	leaq _s(%rip), %rsi
	movl $2000, -4(%rbp)		 ## imm = 0x7D0
	movl $17, -8(%rbp)
	movl -4(%rbp), %eax
	addl -8(%rbp), %eax
	movl %eax, %edx
	movb $0, %al
	callq _printf
	xorl %edx, %edx
	movl %eax, -12(%rbp)		 ## 4-byte Spill
	movl %edx, %eax
	addq $16, %rsp
	popq %rbp
	retq
	.cfi_endproc

	.section __DATA, __data
	.global _s					 ## @s
_s:
	.asciz "GeeksforGeeks"

	.section __TEXT, __cstring, cstring_literals
L_.str:								 ## @.str
	.asciz "%s %d \n"


.subsections_via_symbols

Each indented line in the above code corresponds to a single machine instruction. For example, the pushq instruction indicates that the contents of register %rbp should be pushed onto the program stack. All information about local variable names or data types has been stripped away. We still see a reference to the global 
variable s[]= “GeeksforGeeks”, since the compiler has not yet determined where in memory this variable will be stored.