const char *swim_error_name(int code) {
  switch (-code) {
  case -1:
    return "READ_BIT_TIMEOUT";
  case -2:
    return "INVALID_TARGET_ID";
  case -3:
    return "PARITY";
  case -4:
    return "NACK";
  case -5:
    return "SYNC_TIMEOUT_1";
  case -6:
    return "SYNC_TIMEOUT_2";
  default:
    return "unknown (invalid)";
  }
}


x86 assembly (clang, -O0):
<swim_error_name>:
push   %rbp
mov    %rsp,%rbp
mov    %edi,-0xc(%rbp)
mov    -0xc(%rbp),%ecx
mov    $0x6,%eax
sub    %ecx,%eax
mov    %eax,%ecx
mov    %rcx,-0x18(%rbp)
sub    $0x5,%eax
ja     1194 <swim_error_name+0x94>
mov    -0x18(%rbp),%rax
lea    0xed5(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
jmp    *%rax
lea    0xedd(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    119f <swim_error_name+0x9f>
lea    0xede(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    119f <swim_error_name+0x9f>
lea    0xee0(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    119f <swim_error_name+0x9f>
lea    0xed7(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    119f <swim_error_name+0x9f>
lea    0xecc(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    119f <swim_error_name+0x9f>
lea    0xecb(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    119f <swim_error_name+0x9f>
lea    0xeca(%rip),%rax
mov    %rax,-0x8(%rbp)
mov    -0x8(%rbp),%rax
pop    %rbp
ret

x86 assembly (clang, -O2):
<swim_error_name>:
mov    $0x6,%eax
sub    %edi,%eax
cmp    $0x5,%eax
ja     111d <swim_error_name+0x1d>
cltq
lea    0xf4b(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
ret
lea    0xf29(%rip),%rax
ret

LLVM IR (-O0):
@.str = [17 x i8] c"READ_BIT_TIMEOUT\00"
@.str.1 = [18 x i8] c"INVALID_TARGET_ID\00"
@.str.2 = [7 x i8] c"PARITY\00"
@.str.3 = [5 x i8] c"NACK\00"
@.str.4 = [15 x i8] c"SYNC_TIMEOUT_1\00"
@.str.5 = [15 x i8] c"SYNC_TIMEOUT_2\00"
@.str.6 = [18 x i8] c"unknown (invalid)\00"
define i8* @swim_error_name(i32 %0) {
%2 = alloca i8*
%3 = alloca i32
store i32 %0, i32* %3
%4 = load i32, i32* %3
%5 = sub nsw i32 0, %4
switch i32 %5, label %12 [
i32 -1, label %6
i32 -2, label %7
i32 -3, label %8
i32 -4, label %9
i32 -5, label %10
i32 -6, label %11
]
6: ; preds = %1
store i8* getelementptr inbounds ([17 x i8], [17 x i8]* @.str, i64 0, i64 0), i8** %2
br label %13
7: ; preds = %1
store i8* getelementptr inbounds ([18 x i8], [18 x i8]* @.str.1, i64 0, i64 0), i8** %2
br label %13
8: ; preds = %1
store i8* getelementptr inbounds ([7 x i8], [7 x i8]* @.str.2, i64 0, i64 0), i8** %2
br label %13
9: ; preds = %1
store i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str.3, i64 0, i64 0), i8** %2
br label %13
10: ; preds = %1
store i8* getelementptr inbounds ([15 x i8], [15 x i8]* @.str.4, i64 0, i64 0), i8** %2
br label %13
11: ; preds = %1
store i8* getelementptr inbounds ([15 x i8], [15 x i8]* @.str.5, i64 0, i64 0), i8** %2
br label %13
12: ; preds = %1
store i8* getelementptr inbounds ([18 x i8], [18 x i8]* @.str.6, i64 0, i64 0), i8** %2
br label %13
13: ; preds = %12, %11, %10, %9, %8, %7, %6
%14 = load i8*, i8** %2
ret i8* %14
}

LLVM IR (-O2):
@.str = [17 x i8] c"READ_BIT_TIMEOUT\00"
@.str.1 = [18 x i8] c"INVALID_TARGET_ID\00"
@.str.2 = [7 x i8] c"PARITY\00"
@.str.3 = [5 x i8] c"NACK\00"
@.str.4 = [15 x i8] c"SYNC_TIMEOUT_1\00"
@.str.5 = [15 x i8] c"SYNC_TIMEOUT_2\00"
@.str.6 = [18 x i8] c"unknown (invalid)\00"
@reltable.swim_error_name = [6 x i32] [i32 trunc (i64 sub (i64 ptrtoint ([15 x i8]* @.str.5 to i64), i64 ptrtoint ([6 x i32]* @reltable.swim_error_name to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([15 x i8]* @.str.4 to i64), i64 ptrtoint ([6 x i32]* @reltable.swim_error_name to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([5 x i8]* @.str.3 to i64), i64 ptrtoint ([6 x i32]* @reltable.swim_error_name to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([7 x i8]* @.str.2 to i64), i64 ptrtoint ([6 x i32]* @reltable.swim_error_name to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([18 x i8]* @.str.1 to i64), i64 ptrtoint ([6 x i32]* @reltable.swim_error_name to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([17 x i8]* @.str to i64), i64 ptrtoint ([6 x i32]* @reltable.swim_error_name to i64)) to i32)]
define i8* @swim_error_name(i32 %0) {
%2 = sub i32 6, %0
%3 = icmp ult i32 %2, 6
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 ([6 x i32]* @reltable.swim_error_name to i8*), i64 %6)
br label %8
8: ; preds = %1, %4
%9 = phi i8* [ %7, %4 ], [ getelementptr inbounds ([18 x i8], [18 x i8]* @.str.6, i64 0, i64 0), %1 ]
ret i8* %9
}