void f1(void) {
  int i, j;
#pragma omp for
  for (i = 0; i < 3; i++) {
#pragma omp for
    for (j = 0; j < 3; j++)
      ;
#pragma omp sections
    {
      ;
#pragma omp section
      ;
    }
#pragma omp single
    ;
#pragma omp master
    ;
#pragma omp barrier
  }
#pragma omp sections
  {
#pragma omp for
    for (j = 0; j < 3; j++)
      ;
#pragma omp sections
    {
      ;
#pragma omp section
      ;
    }
#pragma omp single
    ;
#pragma omp master
    ;
#pragma omp section
    ;
  }
#pragma omp single
  {
#pragma omp for
    for (j = 0; j < 3; j++)
      ;
#pragma omp sections
    {
      ;
#pragma omp section
      ;
    }
#pragma omp single
    ;
#pragma omp master
    ;
#pragma omp barrier
  }
#pragma omp master
  {
#pragma omp for
    for (j = 0; j < 3; j++)
      ;
#pragma omp sections
    {
      ;
#pragma omp section
      ;
    }
#pragma omp single
    ;
#pragma omp master
    ;
#pragma omp barrier
  }
#pragma omp task
  {
#pragma omp for
    for (j = 0; j < 3; j++)
      ;
#pragma omp sections
    {
      ;
#pragma omp section
      ;
    }
#pragma omp single
    ;
#pragma omp master
    ;
#pragma omp barrier
  }
#pragma omp parallel
  {
#pragma omp for
    for (j = 0; j < 3; j++)
      ;
#pragma omp sections
    {
      ;
#pragma omp section
      ;
    }
#pragma omp single
    ;
#pragma omp master
    ;
#pragma omp barrier
  }
}


x86 assembly (clang, -O0):
<f1>:
push   %rbp
mov    %rsp,%rbp
movl   $0x0,-0x4(%rbp)
cmpl   $0x3,-0x4(%rbp)
jge    114c <f1+0x4c>
movl   $0x0,-0x8(%rbp)
cmpl   $0x3,-0x8(%rbp)
jge    1139 <f1+0x39>
jmp    112b <f1+0x2b>
mov    -0x8(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x8(%rbp)
jmp    111c <f1+0x1c>
jmp    113e <f1+0x3e>
mov    -0x4(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x4(%rbp)
jmp    110b <f1+0xb>
movl   $0x0,-0x8(%rbp)
cmpl   $0x3,-0x8(%rbp)
jge    1170 <f1+0x70>
jmp    1162 <f1+0x62>
mov    -0x8(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x8(%rbp)
jmp    1153 <f1+0x53>
movl   $0x0,-0x8(%rbp)
cmpl   $0x3,-0x8(%rbp)
jge    1194 <f1+0x94>
jmp    1186 <f1+0x86>
mov    -0x8(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x8(%rbp)
jmp    1177 <f1+0x77>
movl   $0x0,-0x8(%rbp)
cmpl   $0x3,-0x8(%rbp)
jge    11b8 <f1+0xb8>
jmp    11aa <f1+0xaa>
mov    -0x8(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x8(%rbp)
jmp    119b <f1+0x9b>
movl   $0x0,-0x8(%rbp)
cmpl   $0x3,-0x8(%rbp)
jge    11dc <f1+0xdc>
jmp    11ce <f1+0xce>
mov    -0x8(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x8(%rbp)
jmp    11bf <f1+0xbf>
movl   $0x0,-0x8(%rbp)
cmpl   $0x3,-0x8(%rbp)
jge    1200 <f1+0x100>
jmp    11f2 <f1+0xf2>
mov    -0x8(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x8(%rbp)
jmp    11e3 <f1+0xe3>
pop    %rbp
ret

x86 assembly (clang, -O2):
<f1>:
ret

LLVM IR (-O0):
define void @f1() {
%1 = alloca i32
%2 = alloca i32
store i32 0, i32* %1
br label %3
3: ; preds = %15, %0
%4 = load i32, i32* %1
%5 = icmp slt i32 %4, 3
br i1 %5, label %6, label %18
6: ; preds = %3
store i32 0, i32* %2
br label %7
7: ; preds = %11, %6
%8 = load i32, i32* %2
%9 = icmp slt i32 %8, 3
br i1 %9, label %10, label %14
10: ; preds = %7
br label %11
11: ; preds = %10
%12 = load i32, i32* %2
%13 = add nsw i32 %12, 1
store i32 %13, i32* %2
br label %7
14: ; preds = %7
br label %15
15: ; preds = %14
%16 = load i32, i32* %1
%17 = add nsw i32 %16, 1
store i32 %17, i32* %1
br label %3
18: ; preds = %3
store i32 0, i32* %2
br label %19
19: ; preds = %23, %18
%20 = load i32, i32* %2
%21 = icmp slt i32 %20, 3
br i1 %21, label %22, label %26
22: ; preds = %19
br label %23
23: ; preds = %22
%24 = load i32, i32* %2
%25 = add nsw i32 %24, 1
store i32 %25, i32* %2
br label %19
26: ; preds = %19
store i32 0, i32* %2
br label %27
27: ; preds = %31, %26
%28 = load i32, i32* %2
%29 = icmp slt i32 %28, 3
br i1 %29, label %30, label %34
30: ; preds = %27
br label %31
31: ; preds = %30
%32 = load i32, i32* %2
%33 = add nsw i32 %32, 1
store i32 %33, i32* %2
br label %27
34: ; preds = %27
store i32 0, i32* %2
br label %35
35: ; preds = %39, %34
%36 = load i32, i32* %2
%37 = icmp slt i32 %36, 3
br i1 %37, label %38, label %42
38: ; preds = %35
br label %39
39: ; preds = %38
%40 = load i32, i32* %2
%41 = add nsw i32 %40, 1
store i32 %41, i32* %2
br label %35
42: ; preds = %35
store i32 0, i32* %2
br label %43
43: ; preds = %47, %42
%44 = load i32, i32* %2
%45 = icmp slt i32 %44, 3
br i1 %45, label %46, label %50
46: ; preds = %43
br label %47
47: ; preds = %46
%48 = load i32, i32* %2
%49 = add nsw i32 %48, 1
store i32 %49, i32* %2
br label %43
50: ; preds = %43
store i32 0, i32* %2
br label %51
51: ; preds = %55, %50
%52 = load i32, i32* %2
%53 = icmp slt i32 %52, 3
br i1 %53, label %54, label %58
54: ; preds = %51
br label %55
55: ; preds = %54
%56 = load i32, i32* %2
%57 = add nsw i32 %56, 1
store i32 %57, i32* %2
br label %51
58: ; preds = %51
ret void
}

LLVM IR (-O2):
define void @f1() {
ret void
}