#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 */
typedef scalar_t__ pid_t;

/* Variables and functions */
int /*<<< orphan*/ execlp(char *, char *, int /*<<< orphan*/ *);
scalar_t__ fork();
int /*<<< orphan*/ fprintf(int /*<<< orphan*/, char *);
int /*<<< orphan*/ printf(char *, ...);
int /*<<< orphan*/ stderr;
int /*<<< orphan*/ wait(int /*<<< orphan*/ *);
int main() {
  pid_t pid;
  pid = fork();
  if (pid < 0) {
    fprintf(stderr, "Fork Failed\n");
    return 1;
  } else if (pid == 0) {
    printf("I am the child %d\n", pid);
    execlp("/bin/ls", "ls", NULL);
  } else {
    printf("I am the parent %d\n", pid);
    wait(NULL);
    printf("Child Complete\n");
  }
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
movl   $0x0,-0x4(%rbp)
mov    $0x0,%al
call   1070 <fork@plt>
mov    %rax,-0x10(%rbp)
cmpq   $0x0,-0x10(%rbp)
jge    1196 <main+0x46>
mov    0x2e64(%rip),%rax
mov    (%rax),%edi
lea    0xe7b(%rip),%rsi
call   1040 <fprintf@plt>
movl   $0x1,-0x4(%rbp)
jmp    1204 <main+0xb4>
cmpq   $0x0,-0x10(%rbp)
jne    11cf <main+0x7f>
mov    -0x10(%rbp),%rsi
lea    0xe61(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
lea    0xe66(%rip),%rdi
lea    0xe64(%rip),%rsi
xor    %eax,%eax
mov    %eax,%edx
call   1050 <execlp@plt>
jmp    11f8 <main+0xa8>
mov    -0x10(%rbp),%rsi
lea    0xe4e(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
xor    %eax,%eax
mov    %eax,%edi
call   1060 <wait@plt>
lea    0xe4b(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
jmp    11fd <main+0xad>
movl   $0x0,-0x4(%rbp)
mov    -0x4(%rbp),%eax
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rbx
xor    %eax,%eax
call   1080 <fork@plt>
test   %rax,%rax
js     1197 <main+0x37>
je     11b3 <main+0x53>
lea    0xeb2(%rip),%rdi
xor    %ebx,%ebx
mov    %rax,%rsi
xor    %eax,%eax
call   1040 <printf@plt>
xor    %edi,%edi
call   1070 <wait@plt>
lea    0xeac(%rip),%rdi
call   1030 <puts@plt>
jmp    11da <main+0x7a>
mov    0x2e42(%rip),%rax
mov    (%rax),%edi
lea    0xe59(%rip),%rsi
call   1050 <fprintf@plt>
mov    $0x1,%ebx
jmp    11da <main+0x7a>
lea    0xe53(%rip),%rdi
xor    %ebx,%ebx
xor    %esi,%esi
xor    %eax,%eax
call   1040 <printf@plt>
lea    0xe54(%rip),%rdi
lea    0xe52(%rip),%rsi
xor    %edx,%edx
call   1060 <execlp@plt>
mov    %ebx,%eax
pop    %rbx
ret

LLVM IR (-O0):
@stderr = global i32 0
@.str = [13 x i8] c"Fork Failed\0A\00"
@.str.1 = [19 x i8] c"I am the child %d\0A\00"
@.str.2 = [8 x i8] c"/bin/ls\00"
@.str.3 = [3 x i8] c"ls\00"
@.str.4 = [20 x i8] c"I am the parent %d\0A\00"
@.str.5 = [16 x i8] c"Child Complete\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i64
store i32 0, i32* %1
%3 = call i64 (...) @fork()
store i64 %3, i64* %2
%4 = load i64, i64* %2
%5 = icmp slt i64 %4, 0
br i1 %5, label %6, label %9
6: ; preds = %0
%7 = load i32, i32* @stderr
%8 = call i32 @fprintf(i32 %7, i8* getelementptr inbounds ([13 x i8], [13 x i8]* @.str, i64 0, i64 0))
store i32 1, i32* %1
br label %23
9: ; preds = %0
%10 = load i64, i64* %2
%11 = icmp eq i64 %10, 0
br i1 %11, label %12, label %16
12: ; preds = %9
%13 = load i64, i64* %2
%14 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([19 x i8], [19 x i8]* @.str.1, i64 0, i64 0), i64 %13)
%15 = call i32 @execlp(i8* getelementptr inbounds ([8 x i8], [8 x i8]* @.str.2, i64 0, i64 0), i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.3, i64 0, i64 0), i32* null)
br label %21
16: ; preds = %9
%17 = load i64, i64* %2
%18 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([20 x i8], [20 x i8]* @.str.4, i64 0, i64 0), i64 %17)
%19 = call i32 @wait(i32* null)
%20 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([16 x i8], [16 x i8]* @.str.5, i64 0, i64 0))
br label %21
21: ; preds = %16, %12
br label %22
22: ; preds = %21
store i32 0, i32* %1
br label %23
23: ; preds = %22, %6
%24 = load i32, i32* %1
ret i32 %24
}

LLVM IR (-O2):
@stderr = global i32 0
@.str = [13 x i8] c"Fork Failed\0A\00"
@.str.1 = [19 x i8] c"I am the child %d\0A\00"
@.str.2 = [8 x i8] c"/bin/ls\00"
@.str.3 = [3 x i8] c"ls\00"
@.str.4 = [20 x i8] c"I am the parent %d\0A\00"
@str = [15 x i8] c"Child Complete\00"
define i32 @main() {
%1 = tail call i64 (...) @fork()
%2 = icmp slt i64 %1, 0
br i1 %2, label %3, label %6
3: ; preds = %0
%4 = load i32, i32* @stderr
%5 = tail call i32 @fprintf(i32 %4, i8* getelementptr inbounds ([13 x i8], [13 x i8]* @.str, i64 0, i64 0))
br label %15
6: ; preds = %0
%7 = icmp eq i64 %1, 0
br i1 %7, label %8, label %11
8: ; preds = %6
%9 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([19 x i8], [19 x i8]* @.str.1, i64 0, i64 0), i64 0)
%10 = tail call i32 @execlp(i8* getelementptr inbounds ([8 x i8], [8 x i8]* @.str.2, i64 0, i64 0), i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.3, i64 0, i64 0), i32* null)
br label %15
11: ; preds = %6
%12 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([20 x i8], [20 x i8]* @.str.4, i64 0, i64 0), i64 %1)
%13 = tail call i32 @wait(i32* null)
%14 = tail call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([15 x i8], [15 x i8]* @str, i64 0, i64 0))
br label %15
15: ; preds = %11, %8, %3
%16 = phi i32 [ 1, %3 ], [ 0, %8 ], [ 0, %11 ]
ret i32 %16
}