#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 MAXPATHLEN;
size_t atoi(char *);
int /*<<< orphan*/ printf(char *, char *);
int /*<<< orphan*/ readlink(char *, char *, size_t);
int main(int argc, char *argv[]) {
  char b[MAXPATHLEN];
  size_t len = atoi(argv[1]);
  (void)readlink("/", b, len);
  (void)printf("%s\n", b);
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x30,%rsp
movl   $0x0,-0x4(%rbp)
mov    %edi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
mov    0x2e9b(%rip),%rax
mov    (%rax),%eax
mov    %rsp,%rcx
mov    %rcx,-0x18(%rbp)
mov    %rax,%rdx
add    $0xf,%rdx
and    $0xfffffffffffffff0,%rdx
mov    %rsp,%rcx
sub    %rdx,%rcx
mov    %rcx,-0x30(%rbp)
mov    %rcx,%rsp
mov    %rax,-0x20(%rbp)
mov    -0x10(%rbp),%rax
mov    0x8(%rax),%rdi
call   1050 <atoi@plt>
mov    -0x30(%rbp),%rsi
mov    %rax,-0x28(%rbp)
mov    -0x28(%rbp),%rdx
lea    0xe6e(%rip),%rdi
call   1030 <readlink@plt>
mov    -0x30(%rbp),%rsi
lea    0xe60(%rip),%rdi
call   1040 <printf@plt>
movl   $0x0,-0x4(%rbp)
mov    -0x18(%rbp),%rax
mov    %rax,%rsp
mov    -0x4(%rbp),%eax
mov    %rbp,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rbp
mov    %rsp,%rbp
push   %rbx
push   %rax
mov    0x2eab(%rip),%rax
mov    (%rax),%eax
mov    %rsp,%rbx
add    $0xf,%rax
and    $0xfffffffffffffff0,%rax
sub    %rax,%rbx
mov    %rbx,%rsp
mov    0x8(%rsi),%rdi
call   1050 <atoi@plt>
lea    0xea0(%rip),%rdi
mov    %rbx,%rsi
mov    %rax,%rdx
call   1030 <readlink@plt>
lea    0xe90(%rip),%rdi
mov    %rbx,%rsi
call   1040 <printf@plt>
xor    %eax,%eax
lea    -0x8(%rbp),%rsp
pop    %rbx
pop    %rbp
ret

LLVM IR (-O0):
@MAXPATHLEN = global i32 0
@.str = [2 x i8] c"/\00"
@.str.1 = [4 x i8] c"%s\0A\00"
define i32 @main(i32 %0, i8** %1) {
%3 = alloca i32
%4 = alloca i32
%5 = alloca i8**
%6 = alloca i8*
%7 = alloca i64
%8 = alloca i64
store i32 0, i32* %3
store i32 %0, i32* %4
store i8** %1, i8*** %5
%9 = load i32, i32* @MAXPATHLEN
%10 = zext i32 %9 to i64
%11 = call i8* @llvm.stacksave()
store i8* %11, i8** %6
%12 = alloca i8, i64 %10
store i64 %10, i64* %7
%13 = load i8**, i8*** %5
%14 = getelementptr inbounds i8*, i8** %13, i64 1
%15 = load i8*, i8** %14
%16 = call i64 @atoi(i8* %15)
store i64 %16, i64* %8
%17 = load i64, i64* %8
%18 = call i32 @readlink(i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str, i64 0, i64 0), i8* %12, i64 %17)
%19 = call i32 @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.1, i64 0, i64 0), i8* %12)
store i32 0, i32* %3
%20 = load i8*, i8** %6
%21 = load i32, i32* %3
ret i32 %21
}

LLVM IR (-O2):
@MAXPATHLEN = global i32 0
@.str = [2 x i8] c"/\00"
@.str.1 = [4 x i8] c"%s\0A\00"
define i32 @main(i32 %0, i8** nocapture %1) {
%3 = load i32, i32* @MAXPATHLEN
%4 = zext i32 %3 to i64
%5 = alloca i8, i64 %4
%6 = getelementptr inbounds i8*, i8** %1, i64 1
%7 = load i8*, i8** %6
%8 = tail call i64 @atoi(i8* %7)
%9 = call i32 @readlink(i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str, i64 0, i64 0), i8* %5, i64 %8)
%10 = call i32 @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.1, i64 0, i64 0), i8* %5)
ret i32 0
}