char *pdkim_verify_ext_status_str(int ext_status) {
  switch (ext_status) {
  case 1:
    return "PDKIM_VERIFY_FAIL_BODY";
  case 2:
    return "PDKIM_VERIFY_FAIL_MESSAGE";
  case 3:
    return "PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE";
  case 4:
    return "PDKIM_VERIFY_INVALID_BUFFER_SIZE";
  case 5:
    return "PDKIM_VERIFY_INVALID_PUBKEY_PARSING";
  default:
    return "PDKIM_VERIFY_UNKNOWN";
  }
}


x86 assembly (clang, -O0):
<pdkim_verify_ext_status_str>:
push   %rbp
mov    %rsp,%rbp
mov    %edi,-0xc(%rbp)
mov    -0xc(%rbp),%eax
add    $0xffffffff,%eax
mov    %eax,%ecx
mov    %rcx,-0x18(%rbp)
sub    $0x4,%eax
ja     1180 <pdkim_verify_ext_status_str+0x80>
mov    -0x18(%rbp),%rax
lea    0xed9(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
jmp    *%rax
lea    0xedd(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    118b <pdkim_verify_ext_status_str+0x8b>
lea    0xee4(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    118b <pdkim_verify_ext_status_str+0x8b>
lea    0xeee(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    118b <pdkim_verify_ext_status_str+0x8b>
lea    0xf06(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    118b <pdkim_verify_ext_status_str+0x8b>
lea    0xf17(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    118b <pdkim_verify_ext_status_str+0x8b>
lea    0xf2b(%rip),%rax
mov    %rax,-0x8(%rbp)
mov    -0x8(%rbp),%rax
pop    %rbp
ret

x86 assembly (clang, -O2):
<pdkim_verify_ext_status_str>:
add    $0xffffffff,%edi
cmp    $0x4,%edi
ja     111a <pdkim_verify_ext_status_str+0x1a>
movslq %edi,%rax
lea    0xfa2(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
ret
lea    0xf7d(%rip),%rax
ret

LLVM IR (-O0):
@.str = [23 x i8] c"PDKIM_VERIFY_FAIL_BODY\00"
@.str.1 = [26 x i8] c"PDKIM_VERIFY_FAIL_MESSAGE\00"
@.str.2 = [40 x i8] c"PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE\00"
@.str.3 = [33 x i8] c"PDKIM_VERIFY_INVALID_BUFFER_SIZE\00"
@.str.4 = [36 x i8] c"PDKIM_VERIFY_INVALID_PUBKEY_PARSING\00"
@.str.5 = [21 x i8] c"PDKIM_VERIFY_UNKNOWN\00"
define i8* @pdkim_verify_ext_status_str(i32 %0) {
%2 = alloca i8*
%3 = alloca i32
store i32 %0, i32* %3
%4 = load i32, i32* %3
switch i32 %4, label %10 [
i32 1, label %5
i32 2, label %6
i32 3, label %7
i32 4, label %8
i32 5, label %9
]
5: ; preds = %1
store i8* getelementptr inbounds ([23 x i8], [23 x i8]* @.str, i64 0, i64 0), i8** %2
br label %11
6: ; preds = %1
store i8* getelementptr inbounds ([26 x i8], [26 x i8]* @.str.1, i64 0, i64 0), i8** %2
br label %11
7: ; preds = %1
store i8* getelementptr inbounds ([40 x i8], [40 x i8]* @.str.2, i64 0, i64 0), i8** %2
br label %11
8: ; preds = %1
store i8* getelementptr inbounds ([33 x i8], [33 x i8]* @.str.3, i64 0, i64 0), i8** %2
br label %11
9: ; preds = %1
store i8* getelementptr inbounds ([36 x i8], [36 x i8]* @.str.4, i64 0, i64 0), i8** %2
br label %11
10: ; preds = %1
store i8* getelementptr inbounds ([21 x i8], [21 x i8]* @.str.5, i64 0, i64 0), i8** %2
br label %11
11: ; preds = %10, %9, %8, %7, %6, %5
%12 = load i8*, i8** %2
ret i8* %12
}

LLVM IR (-O2):
@.str = [23 x i8] c"PDKIM_VERIFY_FAIL_BODY\00"
@.str.1 = [26 x i8] c"PDKIM_VERIFY_FAIL_MESSAGE\00"
@.str.2 = [40 x i8] c"PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE\00"
@.str.3 = [33 x i8] c"PDKIM_VERIFY_INVALID_BUFFER_SIZE\00"
@.str.4 = [36 x i8] c"PDKIM_VERIFY_INVALID_PUBKEY_PARSING\00"
@.str.5 = [21 x i8] c"PDKIM_VERIFY_UNKNOWN\00"
@reltable.pdkim_verify_ext_status_str = [5 x i32] [i32 trunc (i64 sub (i64 ptrtoint ([23 x i8]* @.str to i64), i64 ptrtoint ([5 x i32]* @reltable.pdkim_verify_ext_status_str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([26 x i8]* @.str.1 to i64), i64 ptrtoint ([5 x i32]* @reltable.pdkim_verify_ext_status_str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([40 x i8]* @.str.2 to i64), i64 ptrtoint ([5 x i32]* @reltable.pdkim_verify_ext_status_str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([33 x i8]* @.str.3 to i64), i64 ptrtoint ([5 x i32]* @reltable.pdkim_verify_ext_status_str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([36 x i8]* @.str.4 to i64), i64 ptrtoint ([5 x i32]* @reltable.pdkim_verify_ext_status_str to i64)) to i32)]
define i8* @pdkim_verify_ext_status_str(i32 %0) {
%2 = add i32 %0, -1
%3 = icmp ult i32 %2, 5
br i1 %3, label %4, label %8
4: ; preds = %1
%5 = sext i32 %2 to i64
%6 = shl i64 %5, 2
%7 = call i8* @llvm.load.relative.i64(i8* bitcast ([5 x i32]* @reltable.pdkim_verify_ext_status_str to i8*), i64 %6)
br label %8
8: ; preds = %1, %4
%9 = phi i8* [ %7, %4 ], [ getelementptr inbounds ([21 x i8], [21 x i8]* @.str.5, i64 0, i64 0), %1 ]
ret i8* %9
}