const char *reason_code_to_text(unsigned rc) {
  switch (rc) {
  case (0x05):
    return "SMART_DATA";
  case (0x07):
    return "UNSUPPORTED";
  case (0x08):
    return "INTERNAL_DEVICE_RESET";
  case (0x09):
    return "TASK_ABORT_INTERNAL";
  case (0x0A):
    return "ABORT_TASK_SET_INTERNAL";
  case (0x0B):
    return "CLEAR_TASK_SET_INTERNAL";
  case (0x0C):
    return "QUERY_TASK_INTERNAL";
  case (0x0D):
    return "ASYNC_NOTIFICATION";
  case (0x0E):
    return "COMPLETED_INTERNAL_DEV_RESET";
  case (0x0F):
    return "COMPLETED_TASK_ABORT_INTERNAL";
  case (0x10):
    return "SATA_INIT_FAILURE";
  case (0x11):
    return "EXPANDER_REDUCED_FUNCTIONALITY";
  case (0x12):
    return "COMPLETED_EXPANDER_REDUCED_FUNCTIONALITY";
  }
  return "UNKNOWN";
}


x86 assembly (clang, -O0):
<reason_code_to_text>:
push   %rbp
mov    %rsp,%rbp
mov    %edi,-0xc(%rbp)
mov    -0xc(%rbp),%eax
add    $0xfffffffb,%eax
mov    %eax,%ecx
mov    %rcx,-0x18(%rbp)
sub    $0xd,%eax
ja     1200 <reason_code_to_text+0x100>
mov    -0x18(%rbp),%rax
lea    0xed9(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
jmp    *%rax
lea    0xf01(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    120b <reason_code_to_text+0x10b>
lea    0xefc(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    120b <reason_code_to_text+0x10b>
lea    0xef8(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    120b <reason_code_to_text+0x10b>
lea    0xf7c(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    120b <reason_code_to_text+0x10b>
lea    0xeee(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    120b <reason_code_to_text+0x10b>
lea    0xef6(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    120b <reason_code_to_text+0x10b>
lea    0xefe(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    120b <reason_code_to_text+0x10b>
lea    0xf02(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    120b <reason_code_to_text+0x10b>
lea    0xf05(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    120b <reason_code_to_text+0x10b>
lea    0xf12(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    120b <reason_code_to_text+0x10b>
lea    0xf20(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    120b <reason_code_to_text+0x10b>
lea    0xf2c(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    120b <reason_code_to_text+0x10b>
lea    0xf12(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    120b <reason_code_to_text+0x10b>
lea    0xf2b(%rip),%rax
mov    %rax,-0x8(%rbp)
mov    -0x8(%rbp),%rax
pop    %rbp
ret

x86 assembly (clang, -O2):
<reason_code_to_text>:
add    $0xfffffffb,%edi
cmp    $0xd,%edi
ja     111a <reason_code_to_text+0x1a>
movslq %edi,%rax
lea    0xff2(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
ret
lea    0xfd9(%rip),%rax
ret

LLVM IR (-O0):
@.str = [11 x i8] c"SMART_DATA\00"
@.str.1 = [12 x i8] c"UNSUPPORTED\00"
@.str.2 = [22 x i8] c"INTERNAL_DEVICE_RESET\00"
@.str.3 = [20 x i8] c"TASK_ABORT_INTERNAL\00"
@.str.4 = [24 x i8] c"ABORT_TASK_SET_INTERNAL\00"
@.str.5 = [24 x i8] c"CLEAR_TASK_SET_INTERNAL\00"
@.str.6 = [20 x i8] c"QUERY_TASK_INTERNAL\00"
@.str.7 = [19 x i8] c"ASYNC_NOTIFICATION\00"
@.str.8 = [29 x i8] c"COMPLETED_INTERNAL_DEV_RESET\00"
@.str.9 = [30 x i8] c"COMPLETED_TASK_ABORT_INTERNAL\00"
@.str.10 = [18 x i8] c"SATA_INIT_FAILURE\00"
@.str.11 = [31 x i8] c"EXPANDER_REDUCED_FUNCTIONALITY\00"
@.str.12 = [41 x i8] c"COMPLETED_EXPANDER_REDUCED_FUNCTIONALITY\00"
@.str.13 = [8 x i8] c"UNKNOWN\00"
define i8* @reason_code_to_text(i32 %0) {
%2 = alloca i8*
%3 = alloca i32
store i32 %0, i32* %3
%4 = load i32, i32* %3
switch i32 %4, label %18 [
i32 5, label %5
i32 7, label %6
i32 8, label %7
i32 9, label %8
i32 10, label %9
i32 11, label %10
i32 12, label %11
i32 13, label %12
i32 14, label %13
i32 15, label %14
i32 16, label %15
i32 17, label %16
i32 18, label %17
]
5: ; preds = %1
store i8* getelementptr inbounds ([11 x i8], [11 x i8]* @.str, i64 0, i64 0), i8** %2
br label %19
6: ; preds = %1
store i8* getelementptr inbounds ([12 x i8], [12 x i8]* @.str.1, i64 0, i64 0), i8** %2
br label %19
7: ; preds = %1
store i8* getelementptr inbounds ([22 x i8], [22 x i8]* @.str.2, i64 0, i64 0), i8** %2
br label %19
8: ; preds = %1
store i8* getelementptr inbounds ([20 x i8], [20 x i8]* @.str.3, i64 0, i64 0), i8** %2
br label %19
9: ; preds = %1
store i8* getelementptr inbounds ([24 x i8], [24 x i8]* @.str.4, i64 0, i64 0), i8** %2
br label %19
10: ; preds = %1
store i8* getelementptr inbounds ([24 x i8], [24 x i8]* @.str.5, i64 0, i64 0), i8** %2
br label %19
11: ; preds = %1
store i8* getelementptr inbounds ([20 x i8], [20 x i8]* @.str.6, i64 0, i64 0), i8** %2
br label %19
12: ; preds = %1
store i8* getelementptr inbounds ([19 x i8], [19 x i8]* @.str.7, i64 0, i64 0), i8** %2
br label %19
13: ; preds = %1
store i8* getelementptr inbounds ([29 x i8], [29 x i8]* @.str.8, i64 0, i64 0), i8** %2
br label %19
14: ; preds = %1
store i8* getelementptr inbounds ([30 x i8], [30 x i8]* @.str.9, i64 0, i64 0), i8** %2
br label %19
15: ; preds = %1
store i8* getelementptr inbounds ([18 x i8], [18 x i8]* @.str.10, i64 0, i64 0), i8** %2
br label %19
16: ; preds = %1
store i8* getelementptr inbounds ([31 x i8], [31 x i8]* @.str.11, i64 0, i64 0), i8** %2
br label %19
17: ; preds = %1
store i8* getelementptr inbounds ([41 x i8], [41 x i8]* @.str.12, i64 0, i64 0), i8** %2
br label %19
18: ; preds = %1
store i8* getelementptr inbounds ([8 x i8], [8 x i8]* @.str.13, i64 0, i64 0), i8** %2
br label %19
19: ; preds = %18, %17, %16, %15, %14, %13, %12, %11, %10, %9, %8, %7, %6, %5
%20 = load i8*, i8** %2
ret i8* %20
}

LLVM IR (-O2):
@.str = [11 x i8] c"SMART_DATA\00"
@.str.1 = [12 x i8] c"UNSUPPORTED\00"
@.str.2 = [22 x i8] c"INTERNAL_DEVICE_RESET\00"
@.str.3 = [20 x i8] c"TASK_ABORT_INTERNAL\00"
@.str.4 = [24 x i8] c"ABORT_TASK_SET_INTERNAL\00"
@.str.5 = [24 x i8] c"CLEAR_TASK_SET_INTERNAL\00"
@.str.6 = [20 x i8] c"QUERY_TASK_INTERNAL\00"
@.str.7 = [19 x i8] c"ASYNC_NOTIFICATION\00"
@.str.8 = [29 x i8] c"COMPLETED_INTERNAL_DEV_RESET\00"
@.str.9 = [30 x i8] c"COMPLETED_TASK_ABORT_INTERNAL\00"
@.str.10 = [18 x i8] c"SATA_INIT_FAILURE\00"
@.str.11 = [31 x i8] c"EXPANDER_REDUCED_FUNCTIONALITY\00"
@.str.12 = [41 x i8] c"COMPLETED_EXPANDER_REDUCED_FUNCTIONALITY\00"
@.str.13 = [8 x i8] c"UNKNOWN\00"
@reltable.reason_code_to_text = [14 x i32] [i32 trunc (i64 sub (i64 ptrtoint ([11 x i8]* @.str to i64), i64 ptrtoint ([14 x i32]* @reltable.reason_code_to_text to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([8 x i8]* @.str.13 to i64), i64 ptrtoint ([14 x i32]* @reltable.reason_code_to_text to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([12 x i8]* @.str.1 to i64), i64 ptrtoint ([14 x i32]* @reltable.reason_code_to_text to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([22 x i8]* @.str.2 to i64), i64 ptrtoint ([14 x i32]* @reltable.reason_code_to_text to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([20 x i8]* @.str.3 to i64), i64 ptrtoint ([14 x i32]* @reltable.reason_code_to_text to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([24 x i8]* @.str.4 to i64), i64 ptrtoint ([14 x i32]* @reltable.reason_code_to_text to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([24 x i8]* @.str.5 to i64), i64 ptrtoint ([14 x i32]* @reltable.reason_code_to_text to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([20 x i8]* @.str.6 to i64), i64 ptrtoint ([14 x i32]* @reltable.reason_code_to_text to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([19 x i8]* @.str.7 to i64), i64 ptrtoint ([14 x i32]* @reltable.reason_code_to_text to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([29 x i8]* @.str.8 to i64), i64 ptrtoint ([14 x i32]* @reltable.reason_code_to_text to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([30 x i8]* @.str.9 to i64), i64 ptrtoint ([14 x i32]* @reltable.reason_code_to_text to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([18 x i8]* @.str.10 to i64), i64 ptrtoint ([14 x i32]* @reltable.reason_code_to_text to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([31 x i8]* @.str.11 to i64), i64 ptrtoint ([14 x i32]* @reltable.reason_code_to_text to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([41 x i8]* @.str.12 to i64), i64 ptrtoint ([14 x i32]* @reltable.reason_code_to_text to i64)) to i32)]
define i8* @reason_code_to_text(i32 %0) {
%2 = add i32 %0, -5
%3 = icmp ult i32 %2, 14
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 ([14 x i32]* @reltable.reason_code_to_text to i8*), i64 %6)
br label %8
8: ; preds = %1, %4
%9 = phi i8* [ %7, %4 ], [ getelementptr inbounds ([8 x i8], [8 x i8]* @.str.13, i64 0, i64 0), %1 ]
ret i8* %9
}