const char *foo(int i) {
  const char *p;
  switch (i) {
  case 0:
  case 6:
    p = "";
    break;
  case 1:
  case 7:
    p = "abc";
    break;
  case 2:
  case 8:
    p = "def";
    break;
  default:
    p = "ghi";
    break;
  }
  return p;
}


x86 assembly (clang, -O0):
<foo>:
push   %rbp
mov    %rsp,%rbp
mov    %edi,-0x4(%rbp)
mov    -0x4(%rbp),%eax
mov    %eax,-0x14(%rbp)
test   %eax,%eax
je     116f <foo+0x6f>
jmp    111a <foo+0x1a>
mov    -0x14(%rbp),%eax
sub    $0x1,%eax
je     117f <foo+0x7f>
jmp    112b <foo+0x2b>
mov    -0x14(%rbp),%eax
sub    $0x2,%eax
je     118f <foo+0x8f>
jmp    113c <foo+0x3c>
mov    -0x14(%rbp),%eax
sub    $0x6,%eax
je     116f <foo+0x6f>
jmp    114d <foo+0x4d>
mov    -0x14(%rbp),%eax
sub    $0x7,%eax
je     117f <foo+0x7f>
jmp    115e <foo+0x5e>
mov    -0x14(%rbp),%eax
sub    $0x8,%eax
je     118f <foo+0x8f>
jmp    119f <foo+0x9f>
lea    0xe8d(%rip),%rax
mov    %rax,-0x10(%rbp)
jmp    11aa <foo+0xaa>
lea    0xe7a(%rip),%rax
mov    %rax,-0x10(%rbp)
jmp    11aa <foo+0xaa>
lea    0xe6e(%rip),%rax
mov    %rax,-0x10(%rbp)
jmp    11aa <foo+0xaa>
lea    0xe62(%rip),%rax
mov    %rax,-0x10(%rbp)
mov    -0x10(%rbp),%rax
pop    %rbp
ret

x86 assembly (clang, -O2):
<foo>:
cmp    $0x8,%edi
ja     1117 <foo+0x17>
movslq %edi,%rax
lea    0xefd(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
ret
lea    0xeea(%rip),%rax
ret

LLVM IR (-O0):
@.str = [1 x i8] zeroinitializer
@.str.1 = [4 x i8] c"abc\00"
@.str.2 = [4 x i8] c"def\00"
@.str.3 = [4 x i8] c"ghi\00"
define i8* @foo(i32 %0) {
%2 = alloca i32
%3 = alloca i8*
store i32 %0, i32* %2
%4 = load i32, i32* %2
switch i32 %4, label %8 [
i32 0, label %5
i32 6, label %5
i32 1, label %6
i32 7, label %6
i32 2, label %7
i32 8, label %7
]
5: ; preds = %1, %1
store i8* getelementptr inbounds ([1 x i8], [1 x i8]* @.str, i64 0, i64 0), i8** %3
br label %9
6: ; preds = %1, %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.1, i64 0, i64 0), i8** %3
br label %9
7: ; preds = %1, %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.2, i64 0, i64 0), i8** %3
br label %9
8: ; preds = %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.3, i64 0, i64 0), i8** %3
br label %9
9: ; preds = %8, %7, %6, %5
%10 = load i8*, i8** %3
ret i8* %10
}

LLVM IR (-O2):
@.str = [1 x i8] zeroinitializer
@.str.1 = [4 x i8] c"abc\00"
@.str.2 = [4 x i8] c"def\00"
@.str.3 = [4 x i8] c"ghi\00"
@reltable.foo = [9 x i32] [i32 trunc (i64 sub (i64 ptrtoint ([1 x i8]* @.str to i64), i64 ptrtoint ([9 x i32]* @reltable.foo to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.1 to i64), i64 ptrtoint ([9 x i32]* @reltable.foo to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.2 to i64), i64 ptrtoint ([9 x i32]* @reltable.foo to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.3 to i64), i64 ptrtoint ([9 x i32]* @reltable.foo to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.3 to i64), i64 ptrtoint ([9 x i32]* @reltable.foo to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.3 to i64), i64 ptrtoint ([9 x i32]* @reltable.foo to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([1 x i8]* @.str to i64), i64 ptrtoint ([9 x i32]* @reltable.foo to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.1 to i64), i64 ptrtoint ([9 x i32]* @reltable.foo to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.2 to i64), i64 ptrtoint ([9 x i32]* @reltable.foo to i64)) to i32)]
define i8* @foo(i32 %0) {
%2 = icmp ult i32 %0, 9
br i1 %2, label %3, label %7
3: ; preds = %1
%4 = sext i32 %0 to i64
%5 = shl i64 %4, 2
%6 = call i8* @llvm.load.relative.i64(i8* bitcast ([9 x i32]* @reltable.foo to i8*), i64 %5)
br label %7
7: ; preds = %1, %3
%8 = phi i8* [ %6, %3 ], [ getelementptr inbounds ([4 x i8], [4 x i8]* @.str.3, i64 0, i64 0), %1 ]
ret i8* %8
}