int main(int argc, const char *argv[]) {
  struct nested_struct {
    int c;
    signed char d;
  };
  struct my_struct {
    int a;
    struct nested_struct b[2];
  };
  struct my_struct array[2];
  array[0].a = 14;
  array[0].b[0].c = 20;
  array[0].b[1].c = 21;
  array[0].b[0].d = 126;
  array[0].b[1].d = 127;
  array[1].a = 15;
  array[1].b[0].c = 23;
  array[1].b[1].c = 24;
  array[1].b[0].d = 100;
  array[1].b[1].d = 99;
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
movl   $0x0,-0x4(%rbp)
mov    %edi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
movl   $0xe,-0x40(%rbp)
movl   $0x14,-0x3c(%rbp)
movl   $0x15,-0x34(%rbp)
movb   $0x7e,-0x38(%rbp)
movb   $0x7f,-0x30(%rbp)
movl   $0xf,-0x2c(%rbp)
movl   $0x17,-0x28(%rbp)
movl   $0x18,-0x20(%rbp)
movb   $0x64,-0x24(%rbp)
movb   $0x63,-0x1c(%rbp)
xor    %eax,%eax
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
xor    %eax,%eax
ret

LLVM IR (-O0):
%struct.my_struct = type { i32, [2 x %struct.nested_struct] }
%struct.nested_struct = type { i32, i8 }
define i32 @main(i32 %0, i8** %1) {
%3 = alloca i32
%4 = alloca i32
%5 = alloca i8**
%6 = alloca [2 x %struct.my_struct]
store i32 0, i32* %3
store i32 %0, i32* %4
store i8** %1, i8*** %5
%7 = getelementptr inbounds [2 x %struct.my_struct], [2 x %struct.my_struct]* %6, i64 0, i64 0
%8 = getelementptr inbounds %struct.my_struct, %struct.my_struct* %7, i32 0, i32 0
store i32 14, i32* %8
%9 = getelementptr inbounds [2 x %struct.my_struct], [2 x %struct.my_struct]* %6, i64 0, i64 0
%10 = getelementptr inbounds %struct.my_struct, %struct.my_struct* %9, i32 0, i32 1
%11 = getelementptr inbounds [2 x %struct.nested_struct], [2 x %struct.nested_struct]* %10, i64 0, i64 0
%12 = getelementptr inbounds %struct.nested_struct, %struct.nested_struct* %11, i32 0, i32 0
store i32 20, i32* %12
%13 = getelementptr inbounds [2 x %struct.my_struct], [2 x %struct.my_struct]* %6, i64 0, i64 0
%14 = getelementptr inbounds %struct.my_struct, %struct.my_struct* %13, i32 0, i32 1
%15 = getelementptr inbounds [2 x %struct.nested_struct], [2 x %struct.nested_struct]* %14, i64 0, i64 1
%16 = getelementptr inbounds %struct.nested_struct, %struct.nested_struct* %15, i32 0, i32 0
store i32 21, i32* %16
%17 = getelementptr inbounds [2 x %struct.my_struct], [2 x %struct.my_struct]* %6, i64 0, i64 0
%18 = getelementptr inbounds %struct.my_struct, %struct.my_struct* %17, i32 0, i32 1
%19 = getelementptr inbounds [2 x %struct.nested_struct], [2 x %struct.nested_struct]* %18, i64 0, i64 0
%20 = getelementptr inbounds %struct.nested_struct, %struct.nested_struct* %19, i32 0, i32 1
store i8 126, i8* %20
%21 = getelementptr inbounds [2 x %struct.my_struct], [2 x %struct.my_struct]* %6, i64 0, i64 0
%22 = getelementptr inbounds %struct.my_struct, %struct.my_struct* %21, i32 0, i32 1
%23 = getelementptr inbounds [2 x %struct.nested_struct], [2 x %struct.nested_struct]* %22, i64 0, i64 1
%24 = getelementptr inbounds %struct.nested_struct, %struct.nested_struct* %23, i32 0, i32 1
store i8 127, i8* %24
%25 = getelementptr inbounds [2 x %struct.my_struct], [2 x %struct.my_struct]* %6, i64 0, i64 1
%26 = getelementptr inbounds %struct.my_struct, %struct.my_struct* %25, i32 0, i32 0
store i32 15, i32* %26
%27 = getelementptr inbounds [2 x %struct.my_struct], [2 x %struct.my_struct]* %6, i64 0, i64 1
%28 = getelementptr inbounds %struct.my_struct, %struct.my_struct* %27, i32 0, i32 1
%29 = getelementptr inbounds [2 x %struct.nested_struct], [2 x %struct.nested_struct]* %28, i64 0, i64 0
%30 = getelementptr inbounds %struct.nested_struct, %struct.nested_struct* %29, i32 0, i32 0
store i32 23, i32* %30
%31 = getelementptr inbounds [2 x %struct.my_struct], [2 x %struct.my_struct]* %6, i64 0, i64 1
%32 = getelementptr inbounds %struct.my_struct, %struct.my_struct* %31, i32 0, i32 1
%33 = getelementptr inbounds [2 x %struct.nested_struct], [2 x %struct.nested_struct]* %32, i64 0, i64 1
%34 = getelementptr inbounds %struct.nested_struct, %struct.nested_struct* %33, i32 0, i32 0
store i32 24, i32* %34
%35 = getelementptr inbounds [2 x %struct.my_struct], [2 x %struct.my_struct]* %6, i64 0, i64 1
%36 = getelementptr inbounds %struct.my_struct, %struct.my_struct* %35, i32 0, i32 1
%37 = getelementptr inbounds [2 x %struct.nested_struct], [2 x %struct.nested_struct]* %36, i64 0, i64 0
%38 = getelementptr inbounds %struct.nested_struct, %struct.nested_struct* %37, i32 0, i32 1
store i8 100, i8* %38
%39 = getelementptr inbounds [2 x %struct.my_struct], [2 x %struct.my_struct]* %6, i64 0, i64 1
%40 = getelementptr inbounds %struct.my_struct, %struct.my_struct* %39, i32 0, i32 1
%41 = getelementptr inbounds [2 x %struct.nested_struct], [2 x %struct.nested_struct]* %40, i64 0, i64 1
%42 = getelementptr inbounds %struct.nested_struct, %struct.nested_struct* %41, i32 0, i32 1
store i8 99, i8* %42
ret i32 0
}

LLVM IR (-O2):
define i32 @main(i32 %0, i8** nocapture readnone %1) {
ret i32 0
}