const char *get_implementor(unsigned vendor_id) {
  switch (vendor_id) {
  case 0x41:
    return "ARM Ltd";
  case 0x44:
    return "DEC";
  case 0x4d:
    return "Motorola - Freescale";
  case 0x56:
    return "Marvell Semiconductor";
  case 0x69:
    return "Intel";
  default:
    return "Unknown vendor";
  }
}


x86 assembly (clang, -O0):
<get_implementor>:
push   %rbp
mov    %rsp,%rbp
mov    %edi,-0xc(%rbp)
mov    -0xc(%rbp),%eax
add    $0xffffffbf,%eax
mov    %eax,%ecx
mov    %rcx,-0x18(%rbp)
sub    $0x28,%eax
ja     1180 <get_implementor+0x80>
mov    -0x18(%rbp),%rax
lea    0xed9(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
jmp    *%rax
lea    0xf6d(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    118b <get_implementor+0x8b>
lea    0xf65(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    118b <get_implementor+0x8b>
lea    0xf59(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    118b <get_implementor+0x8b>
lea    0xf5e(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    118b <get_implementor+0x8b>
lea    0xf64(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    118b <get_implementor+0x8b>
lea    0xf5a(%rip),%rax
mov    %rax,-0x8(%rbp)
mov    -0x8(%rbp),%rax
pop    %rbp
ret

x86 assembly (clang, -O2):
<get_implementor>:
add    $0xffffffbf,%edi
cmp    $0x28,%edi
ja     1127 <get_implementor+0x27>
lea    0xf95(%rip),%rax
lea    0xeea(%rip),%rcx
movslq (%rcx,%rdi,4),%rdx
add    %rcx,%rdx
jmp    *%rdx
lea    0xf86(%rip),%rax
ret
lea    0xfb3(%rip),%rax
ret
lea    0xf7a(%rip),%rax
ret
lea    0xf87(%rip),%rax
ret
lea    0xf95(%rip),%rax
ret

LLVM IR (-O0):
@.str = [8 x i8] c"ARM Ltd\00"
@.str.1 = [4 x i8] c"DEC\00"
@.str.2 = [21 x i8] c"Motorola - Freescale\00"
@.str.3 = [22 x i8] c"Marvell Semiconductor\00"
@.str.4 = [6 x i8] c"Intel\00"
@.str.5 = [15 x i8] c"Unknown vendor\00"
define i8* @get_implementor(i32 %0) {
%2 = alloca i8*
%3 = alloca i32
store i32 %0, i32* %3
%4 = load i32, i32* %3
switch i32 %4, label %10 [
i32 65, label %5
i32 68, label %6
i32 77, label %7
i32 86, label %8
i32 105, label %9
]
5: ; preds = %1
store i8* getelementptr inbounds ([8 x i8], [8 x i8]* @.str, i64 0, i64 0), i8** %2
br label %11
6: ; preds = %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.1, i64 0, i64 0), i8** %2
br label %11
7: ; preds = %1
store i8* getelementptr inbounds ([21 x i8], [21 x i8]* @.str.2, i64 0, i64 0), i8** %2
br label %11
8: ; preds = %1
store i8* getelementptr inbounds ([22 x i8], [22 x i8]* @.str.3, i64 0, i64 0), i8** %2
br label %11
9: ; preds = %1
store i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str.4, i64 0, i64 0), i8** %2
br label %11
10: ; preds = %1
store i8* getelementptr inbounds ([15 x i8], [15 x i8]* @.str.5, i64 0, i64 0), i8** %2
br label %11
11: ; preds = %10, %9, %8, %7, %6, %5
%12 = load i8*, i8** %2
ret i8* %12
}

LLVM IR (-O2):
@.str = [8 x i8] c"ARM Ltd\00"
@.str.1 = [4 x i8] c"DEC\00"
@.str.2 = [21 x i8] c"Motorola - Freescale\00"
@.str.3 = [22 x i8] c"Marvell Semiconductor\00"
@.str.4 = [6 x i8] c"Intel\00"
@.str.5 = [15 x i8] c"Unknown vendor\00"
define i8* @get_implementor(i32 %0) {
switch i32 %0, label %6 [
i32 65, label %7
i32 68, label %2
i32 77, label %3
i32 86, label %4
i32 105, label %5
]
2: ; preds = %1
br label %7
3: ; preds = %1
br label %7
4: ; preds = %1
br label %7
5: ; preds = %1
br label %7
6: ; preds = %1
br label %7
7: ; preds = %1, %6, %5, %4, %3, %2
%8 = phi i8* [ getelementptr inbounds ([15 x i8], [15 x i8]* @.str.5, i64 0, i64 0), %6 ], [ getelementptr inbounds ([6 x i8], [6 x i8]* @.str.4, i64 0, i64 0), %5 ], [ getelementptr inbounds ([22 x i8], [22 x i8]* @.str.3, i64 0, i64 0), %4 ], [ getelementptr inbounds ([21 x i8], [21 x i8]* @.str.2, i64 0, i64 0), %3 ], [ getelementptr inbounds ([4 x i8], [4 x i8]* @.str.1, i64 0, i64 0), %2 ], [ getelementptr inbounds ([8 x i8], [8 x i8]* @.str, i64 0, i64 0), %1 ]
ret i8* %8
}