#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*/ fgets(char *, int, int /*<<< orphan*/);
int /*<<< orphan*/ printf(char *, ...);
int /*<<< orphan*/ reverse_string(char *);
int /*<<< orphan*/ stdin;
int main(int argc, char const *argv[]) {
  char string[256];
  printf("Input test string: ");
  fgets(string, 256, stdin);
  reverse_string(string);
  printf("Result: %s\n", string);
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x110,%rsp
movl   $0x0,-0x4(%rbp)
mov    %edi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
lea    0xeb0(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
lea    -0x110(%rbp),%rdi
mov    0x2e83(%rip),%rax
mov    (%rax),%edx
mov    $0x100,%esi
call   1050 <fgets@plt>
lea    -0x110(%rbp),%rdi
call   1030 <reverse_string@plt>
lea    -0x110(%rbp),%rsi
lea    0xe89(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
xor    %eax,%eax
add    $0x110,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rbx
sub    $0x100,%rsp
lea    0xec1(%rip),%rdi
xor    %eax,%eax
call   1040 <printf@plt>
mov    0x2e9b(%rip),%rax
mov    (%rax),%edx
mov    %rsp,%rbx
mov    %rbx,%rdi
mov    $0x100,%esi
call   1050 <fgets@plt>
mov    %rbx,%rdi
call   1030 <reverse_string@plt>
lea    0xea6(%rip),%rdi
mov    %rbx,%rsi
xor    %eax,%eax
call   1040 <printf@plt>
xor    %eax,%eax
add    $0x100,%rsp
pop    %rbx
ret

LLVM IR (-O0):
@.str = [20 x i8] c"Input test string: \00"
@stdin = global i32 0
@.str.1 = [12 x i8] c"Result: %s\0A\00"
define i32 @main(i32 %0, i8** %1) {
%3 = alloca i32
%4 = alloca i32
%5 = alloca i8**
%6 = alloca [256 x i8]
store i32 0, i32* %3
store i32 %0, i32* %4
store i8** %1, i8*** %5
%7 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([20 x i8], [20 x i8]* @.str, i64 0, i64 0))
%8 = getelementptr inbounds [256 x i8], [256 x i8]* %6, i64 0, i64 0
%9 = load i32, i32* @stdin
%10 = call i32 @fgets(i8* %8, i32 256, i32 %9)
%11 = getelementptr inbounds [256 x i8], [256 x i8]* %6, i64 0, i64 0
%12 = call i32 @reverse_string(i8* %11)
%13 = getelementptr inbounds [256 x i8], [256 x i8]* %6, i64 0, i64 0
%14 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([12 x i8], [12 x i8]* @.str.1, i64 0, i64 0), i8* %13)
ret i32 0
}

LLVM IR (-O2):
@.str = [20 x i8] c"Input test string: \00"
@stdin = global i32 0
@.str.1 = [12 x i8] c"Result: %s\0A\00"
define i32 @main(i32 %0, i8** nocapture readnone %1) {
%3 = alloca [256 x i8]
%4 = getelementptr inbounds [256 x i8], [256 x i8]* %3, i64 0, i64 0
%5 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([20 x i8], [20 x i8]* @.str, i64 0, i64 0))
%6 = load i32, i32* @stdin
%7 = call i32 @fgets(i8* %4, i32 256, i32 %6)
%8 = call i32 @reverse_string(i8* %4)
%9 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([12 x i8], [12 x i8]* @.str.1, i64 0, i64 0), i8* %4)
ret i32 0
}