c to assembly Ref

c to assembly
complied with gcc
gcc -S hello2.c
cc -o helly2 hello2.s
./helly2
http://www.classes.cs.uchicago.edu/archive/2009/spring/22620-1/docs/handout-03.pdf
http://en.wikipedia.org/wiki/X86_assembly_language
http://en.wikipedia.org/wiki/File:Table_of_x86_Registers.png
https://www.hackerschool.com/blog/7-understanding-c-by-learning-assembly
http://docs.oracle.com/cd/E19205-01/820-4220/
http://cs.nyu.edu/courses/fall11/CSCI-GA.2130-001/x64-intro.pdf
https://gist.github.com/mikesmullin/6330894
http://cseweb.ucsd.edu/classes/sp10/cse141/pdf/02/S01_x86_64.key.pdf


1) Blank c program

test.c
===START===

====END====

Assembly

.section	__TEXT,__text,regular,pure_instructions

.subsections_via_symbols


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2) 2 line c program

test.c
===START===

int main (void) {

	
}

====END====

Assembly

	.section	__TEXT,__text,regular,pure_instructions
	.globl	_main
	.align	4, 0x90
_main:                                  ## @main
	.cfi_startproc
## BB#0:
	pushq	%rbp
Ltmp2:
	.cfi_def_cfa_offset 16
Ltmp3:
	.cfi_offset %rbp, -16
	movq	%rsp, %rbp
Ltmp4:
	.cfi_def_cfa_register %rbp
	movl	$0, %eax
	popq	%rbp
	ret
	.cfi_endproc


.subsections_via_symbols




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3) basic printf c program

test.c
===START===

#include <stdio.h>

int main (void) {
	
	printf("hello");
		
	return 0;
}

====END====

Assembly

	.section	__TEXT,__text,regular,pure_instructions
	.globl	_main
	.align	4, 0x90
_main:                                  ## @main
	.cfi_startproc
## BB#0:
	pushq	%rbp
Ltmp2:
	.cfi_def_cfa_offset 16
Ltmp3:
	.cfi_offset %rbp, -16
	movq	%rsp, %rbp
Ltmp4:
	.cfi_def_cfa_register %rbp
	subq	$16, %rsp
	leaq	L_.str(%rip), %rdi
	movl	$0, -4(%rbp)
	movb	$0, %al
	callq	_printf
	movl	$0, %ecx
	movl	%eax, -8(%rbp)          ## 4-byte Spill
	movl	%ecx, %eax
	addq	$16, %rsp
	popq	%rbp
	ret
	.cfi_endproc

	.section	__TEXT,__cstring,cstring_literals
L_.str:                                 ## @.str
	.asciz	 "hello"


.subsections_via_symbols





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4) multiple printf c program

test.c
===START===

#include <stdio.h>

int main (void) {
	
	printf("hello \n");
	printf("assembly \n");
	printf("meet \n");
	printf("aakash \n");
	printf("apoorv \n");
	return 0;
}

====END====

Assembly

	.section	__TEXT,__text,regular,pure_instructions
	.globl	_main
	.align	4, 0x90
_main:                                  ## @main
	.cfi_startproc
## BB#0:
	pushq	%rbp
Ltmp2:
	.cfi_def_cfa_offset 16
Ltmp3:
	.cfi_offset %rbp, -16
	movq	%rsp, %rbp
Ltmp4:
	.cfi_def_cfa_register %rbp
	subq	$32, %rsp
	
	#####################
	
	leaq	AAKASH_STRING_1(%rip), %rdi
	movl	$0, -4(%rbp)
	movb	$0, %al
	callq	_printf
	
	leaq	AAKASH_STRING_2(%rip), %rdi
	movl	%eax, -8(%rbp)          ## 4-byte Spill
	movb	$0, %al
	callq	_printf
	
	leaq	AAKASH_STRING_3(%rip), %rdi
	movl	%eax, -12(%rbp)         ## 4-byte Spill
	movb	$0, %al
	callq	_printf
	
	leaq	AAKASH_STRING_4(%rip), %rdi
	movl	%eax, -16(%rbp)         ## 4-byte Spill
	movb	$0, %al
	callq	_printf
	
	leaq	AAKASH_STRING_5(%rip), %rdi
	movl	%eax, -20(%rbp)         ## 4-byte Spill
	movb	$0, %al
	callq	_printf
	
	####################
	
	movl	$0, %ecx
	movl	%eax, -24(%rbp)         ## 4-byte Spill
	movl	%ecx, %eax
	addq	$32, %rsp
	popq	%rbp
	ret
	.cfi_endproc

	.section	__TEXT,__cstring,cstring_literals
AAKASH_STRING_1:                                 ## @STRING_1
	.asciz	 "hello \n"

AAKASH_STRING_2:                                ## @STRING_2
	.asciz	 "assembly \n"

AAKASH_STRING_3:                                ## @STRING_3
	.asciz	 "meet \n"

AAKASH_STRING_4:                                ## @STRING_4
	.asciz	 "aakash \n"

AAKASH_STRING_5:                                ## @STRING_5
	.asciz	 "apoorv \n"


.subsections_via_symbols





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5) simple int c program

test.c
===START===

#include <stdio.h>

int main (void) {
	int as = 5;
	return 0;
}

====END====

Assembly

	.section	__TEXT,__text,regular,pure_instructions
	.globl	_main
	.align	4, 0x90
_main:                                  ## @main
	.cfi_startproc
## BB#0:
	pushq	%rbp
Ltmp2:
	.cfi_def_cfa_offset 16
Ltmp3:
	.cfi_offset %rbp, -16
	movq	%rsp, %rbp
Ltmp4:
	.cfi_def_cfa_register %rbp
	movl	$0, %eax
	movl	$0, -4(%rbp)
	movl	$5, -8(%rbp)
	popq	%rbp
	ret
	.cfi_endproc


.subsections_via_symbols





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6) multiple int c program

test.c
===START===

#include <stdio.h>

int main (void) {
	int as = 5;
	int bs = 6;
	int cs = 7;
	int ds = 8;
	int es = 9;
	int fs = 10;
	int gs = 11;

	return 0;
}

====END====

Assembly

	.section	__TEXT,__text,regular,pure_instructions
	.globl	_main
	.align	4, 0x90
_main:                                  ## @main
	.cfi_startproc
## BB#0:
	pushq	%rbp
Ltmp2:
	.cfi_def_cfa_offset 16
Ltmp3:
	.cfi_offset %rbp, -16
	movq	%rsp, %rbp
Ltmp4:
	.cfi_def_cfa_register %rbp
	movl	$0, %eax
	movl	$0, -4(%rbp)
	movl	$5, -8(%rbp)
	movl	$6, -12(%rbp)
	movl	$7, -16(%rbp)
	movl	$8, -20(%rbp)
	movl	$9, -24(%rbp)
	movl	$10, -28(%rbp)
	movl	$11, -32(%rbp)
	popq	%rbp
	ret
	.cfi_endproc


.subsections_via_symbols





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7) basic math c program

test.c
===START===

#include <stdio.h>

int main (void) {
	int as = 5;
	int bs = 6;
	int cs = 7;
	int ds = 8;
	int es = 9;
	int fs = 10;
	
	int gs = as + bs;
	int hs = as - bs;
	int is = as * bs;
	int js = as / bs;
	int ks = as;

	return 0;
}

====END====

Assembly

		.section	__TEXT,__text,regular,pure_instructions
	.globl	_main
	.align	4, 0x90
_main:                                  ## @main
	.cfi_startproc
## BB#0:
	pushq	%rbp
Ltmp2:
	.cfi_def_cfa_offset 16
Ltmp3:
	.cfi_offset %rbp, -16
	movq	%rsp, %rbp
Ltmp4:
	.cfi_def_cfa_register %rbp
	movl	$0, %eax
	movl	$0, -4(%rbp)
	movl	$5, -8(%rbp)
	movl	$6, -12(%rbp)
	movl	$7, -16(%rbp)
	movl	$8, -20(%rbp)
	movl	$9, -24(%rbp)
	movl	$10, -28(%rbp)
	
	movl	-8(%rbp), %ecx
	movl	-12(%rbp), %edx
	addl	%edx, %ecx
	movl	%ecx, -32(%rbp)
	
	movl	-8(%rbp), %ecx
	movl	-12(%rbp), %edx
	subl	%edx, %ecx
	movl	%ecx, -36(%rbp)
	
	movl	-8(%rbp), %ecx
	movl	-12(%rbp), %edx
	imull	%edx, %ecx
	movl	%ecx, -40(%rbp)
	
	movl	-8(%rbp), %ecx
	movl	-12(%rbp), %edx
	movl	%eax, -52(%rbp)         ## 4-byte Spill
	movl	%ecx, %eax
	movl	%edx, -56(%rbp)         ## 4-byte Spill
	cltd
	movl	-56(%rbp), %ecx         ## 4-byte Reload
	idivl	%ecx
	movl	%eax, -44(%rbp)
	
	movl	-8(%rbp), %eax
	movl	%eax, -48(%rbp)
	
	movl	-52(%rbp), %eax         ## 4-byte Reload
	popq	%rbp
	ret
	.cfi_endproc


.subsections_via_symbols





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8) basic math with print c program

test.c
===START===

#include <stdio.h>

int main (void) {
	int as = 5;
	printf("= %d /n" , as);
	int bs = 6;
	printf("= %d /n" , bs);
	int cs = 7;
	printf("= %d /n" , cs);
	int ds = 8;
	printf("= %d /n" , ds);
	int es = 9;
	printf("= %d /n" , es);
	int fs = 10;
	printf("= %d /n" , fs);
	
	int gs = as + bs;
	printf("= %d /n" , gs);
	int hs = as - bs;
	printf("= %d /n" , hs);
	int is = as * bs;
	printf("= %d /n" , is);
	int js = as / bs;
	printf("= %d /n" , js);
	int ks = as;
	printf("= %d /n" , ks);
	return 0;
}

====END====

Assembly

	.section	__TEXT,__text,regular,pure_instructions
	.globl	_main
	.align	4, 0x90
_main:                                  ## @main
	.cfi_startproc
## BB#0:
	pushq	%rbp
Ltmp2:
	.cfi_def_cfa_offset 16
Ltmp3:
	.cfi_offset %rbp, -16
	movq	%rsp, %rbp
Ltmp4:
	.cfi_def_cfa_register %rbp
	subq	$128, %rsp
	leaq	L_.str(%rip), %rdi
	movl	$0, -4(%rbp)
	
	
	movl	$5, -8(%rbp)
	
	movl	$5, %esi
	xorb	%al, %al
	leaq	L_.str(%rip), %rcx
	movq	%rdi, -56(%rbp)         ## 8-byte Spill
	movq	%rcx, %rdi
	movb	%al, -57(%rbp)          ## 1-byte Spill
	movq	%rcx, -72(%rbp)         ## 8-byte Spill
	callq	_printf
	
	
	movl	$6, -12(%rbp)
	
	movl	$6, %esi
	movq	-72(%rbp), %rdi         ## 8-byte Reload
	movb	-57(%rbp), %dl          ## 1-byte Reload
	movl	%eax, -76(%rbp)         ## 4-byte Spill
	movb	%dl, %al
	callq	_printf
	
	
	movl	$7, -16(%rbp)
	
	movl	$7, %esi
	movq	-72(%rbp), %rdi         ## 8-byte Reload
	movb	-57(%rbp), %dl          ## 1-byte Reload
	movl	%eax, -80(%rbp)         ## 4-byte Spill
	movb	%dl, %al
	callq	_printf
	
	
	movl	$8, -20(%rbp)
	
	movl	$8, %esi
	movq	-72(%rbp), %rdi         ## 8-byte Reload
	movb	-57(%rbp), %dl          ## 1-byte Reload
	movl	%eax, -84(%rbp)         ## 4-byte Spill
	movb	%dl, %al
	callq	_printf
	
	
	movl	$9, -24(%rbp)
	
	movl	$9, %esi
	movq	-72(%rbp), %rdi         ## 8-byte Reload
	movb	-57(%rbp), %dl          ## 1-byte Reload
	movl	%eax, -88(%rbp)         ## 4-byte Spill
	movb	%dl, %al
	callq	_printf
	
	
	movl	$10, -28(%rbp)
	
	movl	$10, %esi
	movq	-72(%rbp), %rdi         ## 8-byte Reload
	movb	-57(%rbp), %dl          ## 1-byte Reload
	movl	%eax, -92(%rbp)         ## 4-byte Spill
	movb	%dl, %al
	callq	_printf
	
	
	movl	-8(%rbp), %esi
	
	movl	-12(%rbp), %r8d
	addl	%r8d, %esi
	movl	%esi, -32(%rbp)
	movq	-72(%rbp), %rdi         ## 8-byte Reload
	movb	-57(%rbp), %dl          ## 1-byte Reload
	movl	%eax, -96(%rbp)         ## 4-byte Spill
	movb	%dl, %al
	callq	_printf
	
	
	movl	-8(%rbp), %esi
	
	movl	-12(%rbp), %r8d
	subl	%r8d, %esi
	movl	%esi, -36(%rbp)
	movq	-72(%rbp), %rdi         ## 8-byte Reload
	movb	-57(%rbp), %dl          ## 1-byte Reload
	movl	%eax, -100(%rbp)        ## 4-byte Spill
	movb	%dl, %al
	callq	_printf
	
	
	movl	-8(%rbp), %esi
	
	movl	-12(%rbp), %r8d
	imull	%r8d, %esi
	movl	%esi, -40(%rbp)
	movq	-72(%rbp), %rdi         ## 8-byte Reload
	movb	-57(%rbp), %dl          ## 1-byte Reload
	movl	%eax, -104(%rbp)        ## 4-byte Spill
	movb	%dl, %al
	callq	_printf
	
	
	movl	-8(%rbp), %esi
	
	movl	-12(%rbp), %r8d
	movl	%eax, -108(%rbp)        ## 4-byte Spill
	movl	%esi, %eax
	cltd
	idivl	%r8d
	movl	%eax, -44(%rbp)
	movl	-44(%rbp), %esi
	movq	-56(%rbp), %rdi         ## 8-byte Reload
	movb	$0, %al
	callq	_printf
	
	
	leaq	L_.str(%rip), %rdi
	
	movl	-8(%rbp), %edx
	movl	%edx, -48(%rbp)
	movl	-48(%rbp), %esi
	movl	%eax, -112(%rbp)        ## 4-byte Spill
	movb	$0, %al
	callq	_printf
	
	
	movl	$0, %edx
	movl	%eax, -116(%rbp)        ## 4-byte Spill
	movl	%edx, %eax
	addq	$128, %rsp
	popq	%rbp
	ret
	.cfi_endproc

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


.subsections_via_symbols





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