void foo() {
  long maplength;
  int type;
  {
    const long nibbles = 8;
    char buf1[nibbles + 1];
    char buf2[nibbles + 1];
    char buf3[nibbles + 1];
    buf1[nibbles] = '\0';
    buf2[nibbles] = '\0';
    buf3[nibbles] = '\0';
    ((nibbles) <= 16 ? (({
      void *__s = (buf1);
      union {
        unsigned int __ui;
        unsigned short int __usi;
        unsigned char __uc;
      } *__u = __s;
      unsigned char __c = (unsigned char)('0');
      switch ((unsigned int)(nibbles)) {
      case 16:
        __u->__ui = __c * 0x01010101;
        __u = __extension__((void *)__u + 4);
      case 12:
        __u->__ui = __c * 0x01010101;
        __u = __extension__((void *)__u + 4);
      case 0:
        break;
      }
      __s;
    }))
                     : 0);
    ((nibbles) <= 16 ? (({
      void *__s = (buf2);
      union {
        unsigned int __ui;
        unsigned short int __usi;
        unsigned char __uc;
      } *__u = __s;
      unsigned char __c = (unsigned char)('0');
      switch ((unsigned int)(nibbles)) {
      case 16:
        __u->__ui = __c * 0x01010101;
        __u = __extension__((void *)__u + 4);
      case 12:
        __u->__ui = __c * 0x01010101;
        __u = __extension__((void *)__u + 4);
      case 8:
        __u->__ui = __c * 0x01010101;
        __u = __extension__((void *)__u + 4);
      case 4:
        __u->__ui = __c * 0x01010101;
      case 0:
        break;
      }
      __s;
    }))
                     : 0);
  }
}


x86 assembly (clang, -O0):
<foo>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
movq   $0x8,-0x18(%rbp)
mov    %rsp,%rax
mov    %rax,-0x20(%rbp)
movb   $0x0,-0x68(%rbp)
movb   $0x0,-0x78(%rbp)
movb   $0x0,-0x88(%rbp)
lea    -0x70(%rbp),%rax
mov    %rax,-0x28(%rbp)
mov    -0x28(%rbp),%rax
mov    %rax,-0x30(%rbp)
movb   $0x30,-0x31(%rbp)
mov    -0x28(%rbp),%rax
mov    %rax,-0x40(%rbp)
lea    -0x80(%rbp),%rax
mov    %rax,-0x48(%rbp)
mov    -0x48(%rbp),%rax
mov    %rax,-0x50(%rbp)
movb   $0x30,-0x51(%rbp)
movzbl -0x51(%rbp),%eax
imul   $0x1010101,%eax,%ecx
mov    -0x50(%rbp),%rax
mov    %ecx,(%rax)
mov    -0x50(%rbp),%rax
add    $0x4,%rax
mov    %rax,-0x50(%rbp)
movzbl -0x51(%rbp),%eax
imul   $0x1010101,%eax,%ecx
mov    -0x50(%rbp),%rax
mov    %ecx,(%rax)
mov    -0x48(%rbp),%rax
mov    %rax,-0x60(%rbp)
mov    -0x20(%rbp),%rax
mov    %rax,%rsp
add    $0x10,%rsp
pop    %rbp
ret

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

LLVM IR (-O0):
%union.anon = type { i32 }
%union.anon.0 = type { i32 }
define void @foo() {
%1 = alloca i64
%2 = alloca i32
%3 = alloca i64
%4 = alloca i8*
%5 = alloca i8*
%6 = alloca %union.anon*
%7 = alloca i8
%8 = alloca i8*
%9 = alloca i8*
%10 = alloca %union.anon.0*
%11 = alloca i8
%12 = alloca i8*
store i64 8, i64* %3
%13 = call i8* @llvm.stacksave()
store i8* %13, i8** %4
%14 = alloca i8, i64 9
%15 = alloca i8, i64 9
%16 = alloca i8, i64 9
%17 = getelementptr inbounds i8, i8* %14, i64 8
store i8 0, i8* %17
%18 = getelementptr inbounds i8, i8* %15, i64 8
store i8 0, i8* %18
%19 = getelementptr inbounds i8, i8* %16, i64 8
store i8 0, i8* %19
store i8* %14, i8** %5
%20 = load i8*, i8** %5
%21 = bitcast i8* %20 to %union.anon*
store %union.anon* %21, %union.anon** %6
store i8 48, i8* %7
%22 = load i8*, i8** %5
store i8* %22, i8** %8
%23 = load i8*, i8** %8
store i8* %15, i8** %9
%24 = load i8*, i8** %9
%25 = bitcast i8* %24 to %union.anon.0*
store %union.anon.0* %25, %union.anon.0** %10
store i8 48, i8* %11
%26 = load i8, i8* %11
%27 = zext i8 %26 to i32
%28 = mul nsw i32 %27, 16843009
%29 = load %union.anon.0*, %union.anon.0** %10
%30 = bitcast %union.anon.0* %29 to i32*
store i32 %28, i32* %30
%31 = load %union.anon.0*, %union.anon.0** %10
%32 = bitcast %union.anon.0* %31 to i8*
%33 = getelementptr i8, i8* %32, i64 4
%34 = bitcast i8* %33 to %union.anon.0*
store %union.anon.0* %34, %union.anon.0** %10
%35 = load i8, i8* %11
%36 = zext i8 %35 to i32
%37 = mul nsw i32 %36, 16843009
%38 = load %union.anon.0*, %union.anon.0** %10
%39 = bitcast %union.anon.0* %38 to i32*
store i32 %37, i32* %39
%40 = load i8*, i8** %9
store i8* %40, i8** %12
%41 = load i8*, i8** %12
%42 = load i8*, i8** %4
ret void
}

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