const char *socks5_err2str(int e) {
  switch (e) {
  case 0:
    return "succeeded";
  case 1:
    return "general SOCKS server failure";
  case 2:
    return "connection not allowed by ruleset";
  case 3:
    return "network unreachable";
  case 4:
    return "host unreachable";
  case 5:
    return "connection refused";
  case 6:
    return "TTL expired";
  case 7:
    return "command not supported";
  case 8:
    return "address type not supported";
  case 9:
    return "to X'FF' unassigned";
  }
  return "XXX";
}


x86 assembly (clang, -O0):
<socks5_err2str>:
push   %rbp
mov    %rsp,%rbp
mov    %edi,-0xc(%rbp)
mov    -0xc(%rbp),%eax
mov    %rax,-0x18(%rbp)
sub    $0x9,%rax
ja     11cc <socks5_err2str+0xcc>
mov    -0x18(%rbp),%rax
lea    0xedd(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
jmp    *%rax
lea    0xef5(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11d7 <socks5_err2str+0xd7>
lea    0xeef(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11d7 <socks5_err2str+0xd7>
lea    0xefc(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11d7 <socks5_err2str+0xd7>
lea    0xf0e(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11d7 <socks5_err2str+0xd7>
lea    0xf12(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11d7 <socks5_err2str+0xd7>
lea    0xf13(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11d7 <socks5_err2str+0xd7>
lea    0xf16(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11d7 <socks5_err2str+0xd7>
lea    0xf12(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11d7 <socks5_err2str+0xd7>
lea    0xf18(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11d7 <socks5_err2str+0xd7>
lea    0xf23(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11d7 <socks5_err2str+0xd7>
lea    0xf27(%rip),%rax
mov    %rax,-0x8(%rbp)
mov    -0x8(%rbp),%rax
pop    %rbp
ret

x86 assembly (clang, -O2):
<socks5_err2str>:
cmp    $0x9,%edi
ja     1117 <socks5_err2str+0x17>
movslq %edi,%rax
lea    0xfc9(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
ret
lea    0xfb4(%rip),%rax
ret

LLVM IR (-O0):
@.str = [10 x i8] c"succeeded\00"
@.str.1 = [29 x i8] c"general SOCKS server failure\00"
@.str.2 = [34 x i8] c"connection not allowed by ruleset\00"
@.str.3 = [20 x i8] c"network unreachable\00"
@.str.4 = [17 x i8] c"host unreachable\00"
@.str.5 = [19 x i8] c"connection refused\00"
@.str.6 = [12 x i8] c"TTL expired\00"
@.str.7 = [22 x i8] c"command not supported\00"
@.str.8 = [27 x i8] c"address type not supported\00"
@.str.9 = [20 x i8] c"to X'FF' unassigned\00"
@.str.10 = [4 x i8] c"XXX\00"
define i8* @socks5_err2str(i32 %0) {
%2 = alloca i8*
%3 = alloca i32
store i32 %0, i32* %3
%4 = load i32, i32* %3
switch i32 %4, label %15 [
i32 0, label %5
i32 1, label %6
i32 2, label %7
i32 3, label %8
i32 4, label %9
i32 5, label %10
i32 6, label %11
i32 7, label %12
i32 8, label %13
i32 9, label %14
]
5: ; preds = %1
store i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str, i64 0, i64 0), i8** %2
br label %16
6: ; preds = %1
store i8* getelementptr inbounds ([29 x i8], [29 x i8]* @.str.1, i64 0, i64 0), i8** %2
br label %16
7: ; preds = %1
store i8* getelementptr inbounds ([34 x i8], [34 x i8]* @.str.2, i64 0, i64 0), i8** %2
br label %16
8: ; preds = %1
store i8* getelementptr inbounds ([20 x i8], [20 x i8]* @.str.3, i64 0, i64 0), i8** %2
br label %16
9: ; preds = %1
store i8* getelementptr inbounds ([17 x i8], [17 x i8]* @.str.4, i64 0, i64 0), i8** %2
br label %16
10: ; preds = %1
store i8* getelementptr inbounds ([19 x i8], [19 x i8]* @.str.5, i64 0, i64 0), i8** %2
br label %16
11: ; preds = %1
store i8* getelementptr inbounds ([12 x i8], [12 x i8]* @.str.6, i64 0, i64 0), i8** %2
br label %16
12: ; preds = %1
store i8* getelementptr inbounds ([22 x i8], [22 x i8]* @.str.7, i64 0, i64 0), i8** %2
br label %16
13: ; preds = %1
store i8* getelementptr inbounds ([27 x i8], [27 x i8]* @.str.8, i64 0, i64 0), i8** %2
br label %16
14: ; preds = %1
store i8* getelementptr inbounds ([20 x i8], [20 x i8]* @.str.9, i64 0, i64 0), i8** %2
br label %16
15: ; preds = %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.10, i64 0, i64 0), i8** %2
br label %16
16: ; preds = %15, %14, %13, %12, %11, %10, %9, %8, %7, %6, %5
%17 = load i8*, i8** %2
ret i8* %17
}

LLVM IR (-O2):
@.str = [10 x i8] c"succeeded\00"
@.str.1 = [29 x i8] c"general SOCKS server failure\00"
@.str.2 = [34 x i8] c"connection not allowed by ruleset\00"
@.str.3 = [20 x i8] c"network unreachable\00"
@.str.4 = [17 x i8] c"host unreachable\00"
@.str.5 = [19 x i8] c"connection refused\00"
@.str.6 = [12 x i8] c"TTL expired\00"
@.str.7 = [22 x i8] c"command not supported\00"
@.str.8 = [27 x i8] c"address type not supported\00"
@.str.9 = [20 x i8] c"to X'FF' unassigned\00"
@.str.10 = [4 x i8] c"XXX\00"
@reltable.socks5_err2str = [10 x i32] [i32 trunc (i64 sub (i64 ptrtoint ([10 x i8]* @.str to i64), i64 ptrtoint ([10 x i32]* @reltable.socks5_err2str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([29 x i8]* @.str.1 to i64), i64 ptrtoint ([10 x i32]* @reltable.socks5_err2str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([34 x i8]* @.str.2 to i64), i64 ptrtoint ([10 x i32]* @reltable.socks5_err2str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([20 x i8]* @.str.3 to i64), i64 ptrtoint ([10 x i32]* @reltable.socks5_err2str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([17 x i8]* @.str.4 to i64), i64 ptrtoint ([10 x i32]* @reltable.socks5_err2str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([19 x i8]* @.str.5 to i64), i64 ptrtoint ([10 x i32]* @reltable.socks5_err2str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([12 x i8]* @.str.6 to i64), i64 ptrtoint ([10 x i32]* @reltable.socks5_err2str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([22 x i8]* @.str.7 to i64), i64 ptrtoint ([10 x i32]* @reltable.socks5_err2str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([27 x i8]* @.str.8 to i64), i64 ptrtoint ([10 x i32]* @reltable.socks5_err2str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([20 x i8]* @.str.9 to i64), i64 ptrtoint ([10 x i32]* @reltable.socks5_err2str to i64)) to i32)]
define i8* @socks5_err2str(i32 %0) {
%2 = icmp ult i32 %0, 10
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 ([10 x i32]* @reltable.socks5_err2str 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.10, i64 0, i64 0), %1 ]
ret i8* %8
}