#define NULL ((void *)0)
typedef unsigned long size_t; // Customize by platform.
typedef long intptr_t;
typedef unsigned long uintptr_t;
typedef long scalar_t__; // Either arithmetic or pointer type.
/* By default, we understand bool (as a convenience). */
typedef int bool;
#define false 0
#define true 1

/* Forward declarations */

/* Type definitions */

/* Variables and functions */
int /*<<< orphan*/ printf(char *, ...);
int /*<<< orphan*/ scanf(char *, char *);
int main() {
  int astrcmp(char *, char *);
  int m;
  char str1[20], str2[20];
  char *p1, *p2;
  printf("input two strings:\n");
  scanf("%s", str1);
  scanf("%s", str2);
  p1 = &str1[0];
  p2 = &str2[0];
  m = astrcmp(p1, p2);
  printf("result:%d\n", m);
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x50,%rsp
movl   $0x0,-0x4(%rbp)
lea    0xeba(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
lea    -0x20(%rbp),%rsi
lea    0xebc(%rip),%rdi
call   1050 <scanf@plt>
lea    -0x40(%rbp),%rsi
lea    0xeac(%rip),%rdi
call   1050 <scanf@plt>
lea    -0x20(%rbp),%rax
mov    %rax,-0x48(%rbp)
lea    -0x40(%rbp),%rax
mov    %rax,-0x50(%rbp)
mov    -0x48(%rbp),%rdi
mov    -0x50(%rbp),%rsi
call   1040 <astrcmp@plt>
mov    %eax,-0x8(%rbp)
mov    -0x8(%rbp),%esi
lea    0xe80(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
xor    %eax,%eax
add    $0x50,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %r15
push   %r14
push   %rbx
sub    $0x40,%rsp
lea    0xebe(%rip),%rdi
call   1030 <puts@plt>
lea    0xea4(%rip),%r15
lea    0x20(%rsp),%r14
mov    %r15,%rdi
mov    %r14,%rsi
call   1060 <scanf@plt>
mov    %rsp,%rbx
mov    %r15,%rdi
mov    %rbx,%rsi
call   1060 <scanf@plt>
mov    %r14,%rdi
mov    %rbx,%rsi
call   1050 <astrcmp@plt>
lea    0xe77(%rip),%rdi
mov    %eax,%esi
xor    %eax,%eax
call   1040 <printf@plt>
xor    %eax,%eax
add    $0x40,%rsp
pop    %rbx
pop    %r14
pop    %r15
ret

LLVM IR (-O0):
@.str = [20 x i8] c"input two strings:\0A\00"
@.str.1 = [3 x i8] c"%s\00"
@.str.2 = [11 x i8] c"result:%d\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i32
%3 = alloca [20 x i8]
%4 = alloca [20 x i8]
%5 = alloca i8*
%6 = alloca i8*
store i32 0, i32* %1
%7 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([20 x i8], [20 x i8]* @.str, i64 0, i64 0))
%8 = getelementptr inbounds [20 x i8], [20 x i8]* %3, i64 0, i64 0
%9 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i8* %8)
%10 = getelementptr inbounds [20 x i8], [20 x i8]* %4, i64 0, i64 0
%11 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i8* %10)
%12 = getelementptr inbounds [20 x i8], [20 x i8]* %3, i64 0, i64 0
store i8* %12, i8** %5
%13 = getelementptr inbounds [20 x i8], [20 x i8]* %4, i64 0, i64 0
store i8* %13, i8** %6
%14 = load i8*, i8** %5
%15 = load i8*, i8** %6
%16 = call i32 @astrcmp(i8* %14, i8* %15)
store i32 %16, i32* %2
%17 = load i32, i32* %2
%18 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([11 x i8], [11 x i8]* @.str.2, i64 0, i64 0), i32 %17)
ret i32 0
}

LLVM IR (-O2):
@.str.1 = [3 x i8] c"%s\00"
@.str.2 = [11 x i8] c"result:%d\0A\00"
@str = [19 x i8] c"input two strings:\00"
define i32 @main() {
%1 = alloca [20 x i8]
%2 = alloca [20 x i8]
%3 = getelementptr inbounds [20 x i8], [20 x i8]* %1, i64 0, i64 0
%4 = getelementptr inbounds [20 x i8], [20 x i8]* %2, i64 0, i64 0
%5 = tail call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([19 x i8], [19 x i8]* @str, i64 0, i64 0))
%6 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i8* %3)
%7 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i8* %4)
%8 = call i32 @astrcmp(i8* %3, i8* %4)
%9 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([11 x i8], [11 x i8]* @.str.2, i64 0, i64 0), i32 %8)
ret i32 0
}