char *parse_socks_status(unsigned char status) {
  switch (status) {
  case 90:
    return "Request granted";
  case 91:
    return "Request rejected/failed - unknown reason";
  case 92:
    return "Request rejected: SOCKS server cannot connect to identd on the "
           "client";
  case 93:
    return "Request rejected: the client program and identd report different "
           "user-ids";
  default:
    return "Unknown status";
  }
}


x86 assembly (clang, -O0):
<parse_socks_status>:
push   %rbp
mov    %rsp,%rbp
mov    %dil,%al
mov    %al,-0x9(%rbp)
movzbl -0x9(%rbp),%eax
add    $0xffffffa6,%eax
mov    %eax,%ecx
mov    %rcx,-0x18(%rbp)
sub    $0x3,%eax
ja     1174 <parse_socks_status+0x74>
mov    -0x18(%rbp),%rax
lea    0xed5(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
jmp    *%rax
lea    0xed5(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    117f <parse_socks_status+0x7f>
lea    0xed5(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    117f <parse_socks_status+0x7f>
lea    0xeee(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    117f <parse_socks_status+0x7f>
lea    0xf24(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    117f <parse_socks_status+0x7f>
lea    0xf5e(%rip),%rax
mov    %rax,-0x8(%rbp)
mov    -0x8(%rbp),%rax
pop    %rbp
ret

x86 assembly (clang, -O2):
<parse_socks_status>:
add    $0xa6,%dil
cmp    $0x3,%dil
ja     111d <parse_socks_status+0x1d>
movsbq %dil,%rax
lea    0xfc3(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
ret
lea    0xfa5(%rip),%rax
ret

LLVM IR (-O0):
@.str = [16 x i8] c"Request granted\00"
@.str.1 = [41 x i8] c"Request rejected/failed - unknown reason\00"
@.str.2 = [70 x i8] c"Request rejected: SOCKS server cannot connect to identd on the client\00"
@.str.3 = [74 x i8] c"Request rejected: the client program and identd report different user-ids\00"
@.str.4 = [15 x i8] c"Unknown status\00"
define i8* @parse_socks_status(i8 zeroext %0) {
%2 = alloca i8*
%3 = alloca i8
store i8 %0, i8* %3
%4 = load i8, i8* %3
%5 = zext i8 %4 to i32
switch i32 %5, label %10 [
i32 90, label %6
i32 91, label %7
i32 92, label %8
i32 93, label %9
]
6: ; preds = %1
store i8* getelementptr inbounds ([16 x i8], [16 x i8]* @.str, i64 0, i64 0), i8** %2
br label %11
7: ; preds = %1
store i8* getelementptr inbounds ([41 x i8], [41 x i8]* @.str.1, i64 0, i64 0), i8** %2
br label %11
8: ; preds = %1
store i8* getelementptr inbounds ([70 x i8], [70 x i8]* @.str.2, i64 0, i64 0), i8** %2
br label %11
9: ; preds = %1
store i8* getelementptr inbounds ([74 x i8], [74 x i8]* @.str.3, i64 0, i64 0), i8** %2
br label %11
10: ; preds = %1
store i8* getelementptr inbounds ([15 x i8], [15 x i8]* @.str.4, i64 0, i64 0), i8** %2
br label %11
11: ; preds = %10, %9, %8, %7, %6
%12 = load i8*, i8** %2
ret i8* %12
}

LLVM IR (-O2):
@.str = [16 x i8] c"Request granted\00"
@.str.1 = [41 x i8] c"Request rejected/failed - unknown reason\00"
@.str.2 = [70 x i8] c"Request rejected: SOCKS server cannot connect to identd on the client\00"
@.str.3 = [74 x i8] c"Request rejected: the client program and identd report different user-ids\00"
@.str.4 = [15 x i8] c"Unknown status\00"
@reltable.parse_socks_status = [4 x i32] [i32 trunc (i64 sub (i64 ptrtoint ([16 x i8]* @.str to i64), i64 ptrtoint ([4 x i32]* @reltable.parse_socks_status to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([41 x i8]* @.str.1 to i64), i64 ptrtoint ([4 x i32]* @reltable.parse_socks_status to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([70 x i8]* @.str.2 to i64), i64 ptrtoint ([4 x i32]* @reltable.parse_socks_status to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([74 x i8]* @.str.3 to i64), i64 ptrtoint ([4 x i32]* @reltable.parse_socks_status to i64)) to i32)]
define i8* @parse_socks_status(i8 zeroext %0) {
%2 = add i8 %0, -90
%3 = icmp ult i8 %2, 4
br i1 %3, label %4, label %8
4: ; preds = %1
%5 = sext i8 %2 to i64
%6 = shl i64 %5, 2
%7 = call i8* @llvm.load.relative.i64(i8* bitcast ([4 x i32]* @reltable.parse_socks_status to i8*), i64 %6)
br label %8
8: ; preds = %1, %4
%9 = phi i8* [ %7, %4 ], [ getelementptr inbounds ([15 x i8], [15 x i8]* @.str.4, i64 0, i64 0), %1 ]
ret i8* %9
}