const char *memstat_strerror(int error) {
  switch (error) {
  case 1:
    return ("Cannot allocate memory");
  case 2:
    return ("Version mismatch");
  case 3:
    return ("Permission denied");
  case 5:
    return ("Data format error");
  case 6:
    return ("KVM error");
  case 7:
    return ("KVM unable to find symbol");
  case 8:
    return ("KVM short read");
  case 0:
  default:
    return ("Unknown error");
  }
}


x86 assembly (clang, -O0):
<memstat_strerror>:
push   %rbp
mov    %rsp,%rbp
mov    %edi,-0xc(%rbp)
mov    -0xc(%rbp),%eax
mov    %rax,-0x18(%rbp)
sub    $0x8,%rax
ja     11a1 <memstat_strerror+0xa1>
mov    -0x18(%rbp),%rax
lea    0xedd(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
jmp    *%rax
lea    0xef1(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11ac <memstat_strerror+0xac>
lea    0xef8(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11ac <memstat_strerror+0xac>
lea    0xef9(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11ac <memstat_strerror+0xac>
lea    0xefb(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11ac <memstat_strerror+0xac>
lea    0xefd(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11ac <memstat_strerror+0xac>
lea    0xef7(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11ac <memstat_strerror+0xac>
lea    0xf01(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11ac <memstat_strerror+0xac>
jmp    11a1 <memstat_strerror+0xa1>
lea    0xefb(%rip),%rax
mov    %rax,-0x8(%rbp)
mov    -0x8(%rbp),%rax
pop    %rbp
ret

x86 assembly (clang, -O2):
<memstat_strerror>:
add    $0xffffffff,%edi
cmp    $0x7,%edi
ja     111a <memstat_strerror+0x1a>
movslq %edi,%rax
lea    0xf7e(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
ret
lea    0xf5e(%rip),%rax
ret

LLVM IR (-O0):
@.str = [23 x i8] c"Cannot allocate memory\00"
@.str.1 = [17 x i8] c"Version mismatch\00"
@.str.2 = [18 x i8] c"Permission denied\00"
@.str.3 = [18 x i8] c"Data format error\00"
@.str.4 = [10 x i8] c"KVM error\00"
@.str.5 = [26 x i8] c"KVM unable to find symbol\00"
@.str.6 = [15 x i8] c"KVM short read\00"
@.str.7 = [14 x i8] c"Unknown error\00"
define i8* @memstat_strerror(i32 %0) {
%2 = alloca i8*
%3 = alloca i32
store i32 %0, i32* %3
%4 = load i32, i32* %3
switch i32 %4, label %13 [
i32 1, label %5
i32 2, label %6
i32 3, label %7
i32 5, label %8
i32 6, label %9
i32 7, label %10
i32 8, label %11
i32 0, label %12
]
5: ; preds = %1
store i8* getelementptr inbounds ([23 x i8], [23 x i8]* @.str, i64 0, i64 0), i8** %2
br label %14
6: ; preds = %1
store i8* getelementptr inbounds ([17 x i8], [17 x i8]* @.str.1, i64 0, i64 0), i8** %2
br label %14
7: ; preds = %1
store i8* getelementptr inbounds ([18 x i8], [18 x i8]* @.str.2, i64 0, i64 0), i8** %2
br label %14
8: ; preds = %1
store i8* getelementptr inbounds ([18 x i8], [18 x i8]* @.str.3, i64 0, i64 0), i8** %2
br label %14
9: ; preds = %1
store i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.4, i64 0, i64 0), i8** %2
br label %14
10: ; preds = %1
store i8* getelementptr inbounds ([26 x i8], [26 x i8]* @.str.5, i64 0, i64 0), i8** %2
br label %14
11: ; preds = %1
store i8* getelementptr inbounds ([15 x i8], [15 x i8]* @.str.6, i64 0, i64 0), i8** %2
br label %14
12: ; preds = %1
br label %13
13: ; preds = %1, %12
store i8* getelementptr inbounds ([14 x i8], [14 x i8]* @.str.7, i64 0, i64 0), i8** %2
br label %14
14: ; preds = %13, %11, %10, %9, %8, %7, %6, %5
%15 = load i8*, i8** %2
ret i8* %15
}

LLVM IR (-O2):
@.str = [23 x i8] c"Cannot allocate memory\00"
@.str.1 = [17 x i8] c"Version mismatch\00"
@.str.2 = [18 x i8] c"Permission denied\00"
@.str.3 = [18 x i8] c"Data format error\00"
@.str.4 = [10 x i8] c"KVM error\00"
@.str.5 = [26 x i8] c"KVM unable to find symbol\00"
@.str.6 = [15 x i8] c"KVM short read\00"
@.str.7 = [14 x i8] c"Unknown error\00"
@reltable.memstat_strerror = [8 x i32] [i32 trunc (i64 sub (i64 ptrtoint ([23 x i8]* @.str to i64), i64 ptrtoint ([8 x i32]* @reltable.memstat_strerror to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([17 x i8]* @.str.1 to i64), i64 ptrtoint ([8 x i32]* @reltable.memstat_strerror to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([18 x i8]* @.str.2 to i64), i64 ptrtoint ([8 x i32]* @reltable.memstat_strerror to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([14 x i8]* @.str.7 to i64), i64 ptrtoint ([8 x i32]* @reltable.memstat_strerror to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([18 x i8]* @.str.3 to i64), i64 ptrtoint ([8 x i32]* @reltable.memstat_strerror to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([10 x i8]* @.str.4 to i64), i64 ptrtoint ([8 x i32]* @reltable.memstat_strerror to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([26 x i8]* @.str.5 to i64), i64 ptrtoint ([8 x i32]* @reltable.memstat_strerror to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([15 x i8]* @.str.6 to i64), i64 ptrtoint ([8 x i32]* @reltable.memstat_strerror to i64)) to i32)]
define i8* @memstat_strerror(i32 %0) {
%2 = add i32 %0, -1
%3 = icmp ult i32 %2, 8
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 ([8 x i32]* @reltable.memstat_strerror to i8*), i64 %6)
br label %8
8: ; preds = %1, %4
%9 = phi i8* [ %7, %4 ], [ getelementptr inbounds ([14 x i8], [14 x i8]* @.str.7, i64 0, i64 0), %1 ]
ret i8* %9
}