const char *read_password_error(int error) {
  if (error == -1)
    return "fopen()";
  if (error == -2)
    return "fileno()";
  if (error == -3)
    return "tcgetattr()";
  if (error == -4)
    return "tcsetattr()";
  if (error == -5)
    return "fgetc()";
  if (error == -6)
    return "password too long";
  if (error == -7)
    return "passwords don't match";
  return "No valid error code specified!!!";
}


x86 assembly (clang, -O0):
<read_password_error>:
push   %rbp
mov    %rsp,%rbp
mov    %edi,-0xc(%rbp)
cmpl   $0xffffffff,-0xc(%rbp)
jne    1121 <read_password_error+0x21>
lea    0xee8(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11c8 <read_password_error+0xc8>
cmpl   $0xfffffffe,-0xc(%rbp)
jne    113b <read_password_error+0x3b>
lea    0xed6(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11c8 <read_password_error+0xc8>
cmpl   $0xfffffffd,-0xc(%rbp)
jne    1155 <read_password_error+0x55>
lea    0xec5(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11c8 <read_password_error+0xc8>
cmpl   $0xfffffffc,-0xc(%rbp)
jne    116f <read_password_error+0x6f>
lea    0xeb7(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11c8 <read_password_error+0xc8>
cmpl   $0xfffffffb,-0xc(%rbp)
jne    1189 <read_password_error+0x89>
lea    0xea9(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11c8 <read_password_error+0xc8>
cmpl   $0xfffffffa,-0xc(%rbp)
jne    11a3 <read_password_error+0xa3>
lea    0xe97(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11c8 <read_password_error+0xc8>
cmpl   $0xfffffff9,-0xc(%rbp)
jne    11bd <read_password_error+0xbd>
lea    0xe8f(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11c8 <read_password_error+0xc8>
lea    0xe95(%rip),%rax
mov    %rax,-0x8(%rbp)
mov    -0x8(%rbp),%rax
pop    %rbp
ret

x86 assembly (clang, -O2):
<read_password_error>:
cmp    $0xfffffff9,%edi
jb     111a <read_password_error+0x1a>
add    $0x7,%edi
movslq %edi,%rax
lea    0xf6a(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
ret
lea    0xf38(%rip),%rax
ret

LLVM IR (-O0):
@.str = [8 x i8] c"fopen()\00"
@.str.1 = [9 x i8] c"fileno()\00"
@.str.2 = [12 x i8] c"tcgetattr()\00"
@.str.3 = [12 x i8] c"tcsetattr()\00"
@.str.4 = [8 x i8] c"fgetc()\00"
@.str.5 = [18 x i8] c"password too long\00"
@.str.6 = [22 x i8] c"passwords don't match\00"
@.str.7 = [33 x i8] c"No valid error code specified!!!\00"
define i8* @read_password_error(i32 %0) {
%2 = alloca i8*
%3 = alloca i32
store i32 %0, i32* %3
%4 = load i32, i32* %3
%5 = icmp eq i32 %4, -1
br i1 %5, label %6, label %7
6: ; preds = %1
store i8* getelementptr inbounds ([8 x i8], [8 x i8]* @.str, i64 0, i64 0), i8** %2
br label %32
7: ; preds = %1
%8 = load i32, i32* %3
%9 = icmp eq i32 %8, -2
br i1 %9, label %10, label %11
10: ; preds = %7
store i8* getelementptr inbounds ([9 x i8], [9 x i8]* @.str.1, i64 0, i64 0), i8** %2
br label %32
11: ; preds = %7
%12 = load i32, i32* %3
%13 = icmp eq i32 %12, -3
br i1 %13, label %14, label %15
14: ; preds = %11
store i8* getelementptr inbounds ([12 x i8], [12 x i8]* @.str.2, i64 0, i64 0), i8** %2
br label %32
15: ; preds = %11
%16 = load i32, i32* %3
%17 = icmp eq i32 %16, -4
br i1 %17, label %18, label %19
18: ; preds = %15
store i8* getelementptr inbounds ([12 x i8], [12 x i8]* @.str.3, i64 0, i64 0), i8** %2
br label %32
19: ; preds = %15
%20 = load i32, i32* %3
%21 = icmp eq i32 %20, -5
br i1 %21, label %22, label %23
22: ; preds = %19
store i8* getelementptr inbounds ([8 x i8], [8 x i8]* @.str.4, i64 0, i64 0), i8** %2
br label %32
23: ; preds = %19
%24 = load i32, i32* %3
%25 = icmp eq i32 %24, -6
br i1 %25, label %26, label %27
26: ; preds = %23
store i8* getelementptr inbounds ([18 x i8], [18 x i8]* @.str.5, i64 0, i64 0), i8** %2
br label %32
27: ; preds = %23
%28 = load i32, i32* %3
%29 = icmp eq i32 %28, -7
br i1 %29, label %30, label %31
30: ; preds = %27
store i8* getelementptr inbounds ([22 x i8], [22 x i8]* @.str.6, i64 0, i64 0), i8** %2
br label %32
31: ; preds = %27
store i8* getelementptr inbounds ([33 x i8], [33 x i8]* @.str.7, i64 0, i64 0), i8** %2
br label %32
32: ; preds = %31, %30, %26, %22, %18, %14, %10, %6
%33 = load i8*, i8** %2
ret i8* %33
}

LLVM IR (-O2):
@.str = [8 x i8] c"fopen()\00"
@.str.1 = [9 x i8] c"fileno()\00"
@.str.2 = [12 x i8] c"tcgetattr()\00"
@.str.3 = [12 x i8] c"tcsetattr()\00"
@.str.4 = [8 x i8] c"fgetc()\00"
@.str.5 = [18 x i8] c"password too long\00"
@.str.6 = [22 x i8] c"passwords don't match\00"
@.str.7 = [33 x i8] c"No valid error code specified!!!\00"
@reltable.read_password_error = [7 x i32] [i32 trunc (i64 sub (i64 ptrtoint ([22 x i8]* @.str.6 to i64), i64 ptrtoint ([7 x i32]* @reltable.read_password_error to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([18 x i8]* @.str.5 to i64), i64 ptrtoint ([7 x i32]* @reltable.read_password_error to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([8 x i8]* @.str.4 to i64), i64 ptrtoint ([7 x i32]* @reltable.read_password_error to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([12 x i8]* @.str.3 to i64), i64 ptrtoint ([7 x i32]* @reltable.read_password_error to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([12 x i8]* @.str.2 to i64), i64 ptrtoint ([7 x i32]* @reltable.read_password_error to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([9 x i8]* @.str.1 to i64), i64 ptrtoint ([7 x i32]* @reltable.read_password_error to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([8 x i8]* @.str to i64), i64 ptrtoint ([7 x i32]* @reltable.read_password_error to i64)) to i32)]
define i8* @read_password_error(i32 %0) {
%2 = icmp ugt i32 %0, -8
br i1 %2, label %3, label %8
3: ; preds = %1
%4 = add i32 %0, 7
%5 = sext i32 %4 to i64
%6 = shl i64 %5, 2
%7 = call i8* @llvm.load.relative.i64(i8* bitcast ([7 x i32]* @reltable.read_password_error to i8*), i64 %6)
br label %8
8: ; preds = %1, %3
%9 = phi i8* [ %7, %3 ], [ getelementptr inbounds ([33 x i8], [33 x i8]* @.str.7, i64 0, i64 0), %1 ]
ret i8* %9
}