#define NULL ((void *)0)
typedef unsigned long size_t; // Customize by platform.
typedef long intptr_t;
typedef unsigned long uintptr_t;
typedef long scalar_t__; // Either arithmetic or pointer type.
/* By default, we understand bool (as a convenience). */
typedef int bool;
#define false 0
#define true 1

/* Forward declarations */

/* Type definitions */
typedef int u_short;
typedef int /*<<< orphan*/ protoName;

/* Variables and functions */
#define IPPROTO_GRE 131
#define IPPROTO_ICMP 130
#define IPPROTO_TCP 129
#define IPPROTO_UDP 128
int /*<<< orphan*/ snprintf(char *, int, char *, int);
char *proto2str(u_short proto) {
  static char protoName[8];
  switch (proto) {
  case IPPROTO_TCP:
    return ("TCP");
  case IPPROTO_UDP:
    return ("UDP");
  case IPPROTO_ICMP:
    return ("ICMP");
  case IPPROTO_GRE:
    return ("GRE");
  default:
    snprintf(protoName, sizeof(protoName), "%d", proto);
    return (protoName);
  }
}


x86 assembly (clang, -O0):
<proto2str>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
mov    %edi,-0xc(%rbp)
mov    -0xc(%rbp),%eax
add    $0xffffff80,%eax
mov    %eax,%ecx
mov    %rcx,-0x18(%rbp)
sub    $0x3,%eax
ja     1184 <proto2str+0x74>
mov    -0x18(%rbp),%rax
lea    0xec5(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
jmp    *%rax
lea    0xec5(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11aa <proto2str+0x9a>
lea    0xeb9(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11aa <proto2str+0x9a>
lea    0xead(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11aa <proto2str+0x9a>
lea    0xea2(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11aa <proto2str+0x9a>
mov    -0xc(%rbp),%ecx
lea    0x2e9b(%rip),%rdi
mov    $0x8,%esi
lea    0xe87(%rip),%rdx
call   1030 <snprintf@plt>
lea    0x2e83(%rip),%rax
mov    %rax,-0x8(%rbp)
mov    -0x8(%rbp),%rax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<proto2str>:
push   %rbx
mov    %edi,%ecx
lea    -0x80(%rcx),%eax
cmp    $0x4,%eax
jae    112d <proto2str+0x1d>
cltq
lea    0xef0(%rip),%rcx
movslq (%rcx,%rax,4),%rbx
add    %rcx,%rbx
jmp    1148 <proto2str+0x38>
lea    0x2ef5(%rip),%rbx
lea    0xed6(%rip),%rdx
mov    %rbx,%rdi
mov    $0x8,%esi
call   1030 <snprintf@plt>
mov    %rbx,%rax
pop    %rbx
ret

LLVM IR (-O0):
@proto2str.protoName = internal global [8 x i8] zeroinitializer
@.str = [4 x i8] c"TCP\00"
@.str.1 = [4 x i8] c"UDP\00"
@.str.2 = [5 x i8] c"ICMP\00"
@.str.3 = [4 x i8] c"GRE\00"
@.str.4 = [3 x i8] c"%d\00"
define i8* @proto2str(i32 %0) {
%2 = alloca i8*
%3 = alloca i32
store i32 %0, i32* %3
%4 = load i32, i32* %3
switch i32 %4, label %9 [
i32 129, label %5
i32 128, label %6
i32 130, label %7
i32 131, label %8
]
5: ; preds = %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str, i64 0, i64 0), i8** %2
br label %12
6: ; preds = %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.1, i64 0, i64 0), i8** %2
br label %12
7: ; preds = %1
store i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str.2, i64 0, i64 0), i8** %2
br label %12
8: ; preds = %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.3, i64 0, i64 0), i8** %2
br label %12
9: ; preds = %1
%10 = load i32, i32* %3
%11 = call i32 @snprintf(i8* getelementptr inbounds ([8 x i8], [8 x i8]* @proto2str.protoName, i64 0, i64 0), i32 8, i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.4, i64 0, i64 0), i32 %10)
store i8* getelementptr inbounds ([8 x i8], [8 x i8]* @proto2str.protoName, i64 0, i64 0), i8** %2
br label %12
12: ; preds = %9, %8, %7, %6, %5
%13 = load i8*, i8** %2
ret i8* %13
}

LLVM IR (-O2):
@proto2str.protoName = internal global [8 x i8] zeroinitializer
@.str = [4 x i8] c"TCP\00"
@.str.1 = [4 x i8] c"UDP\00"
@.str.2 = [5 x i8] c"ICMP\00"
@.str.3 = [4 x i8] c"GRE\00"
@.str.4 = [3 x i8] c"%d\00"
@reltable.proto2str = [4 x i32] [i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.1 to i64), i64 ptrtoint ([4 x i32]* @reltable.proto2str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str to i64), i64 ptrtoint ([4 x i32]* @reltable.proto2str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([5 x i8]* @.str.2 to i64), i64 ptrtoint ([4 x i32]* @reltable.proto2str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.3 to i64), i64 ptrtoint ([4 x i32]* @reltable.proto2str to i64)) to i32)]
define i8* @proto2str(i32 %0) {
%2 = add i32 %0, -128
%3 = icmp ult i32 %2, 4
br i1 %3, label %6, label %4
4: ; preds = %1
%5 = tail call i32 @snprintf(i8* getelementptr inbounds ([8 x i8], [8 x i8]* @proto2str.protoName, i64 0, i64 0), i32 8, i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.4, i64 0, i64 0), i32 %0)
br label %10
6: ; preds = %1
%7 = sext i32 %2 to i64
%8 = shl i64 %7, 2
%9 = call i8* @llvm.load.relative.i64(i8* bitcast ([4 x i32]* @reltable.proto2str to i8*), i64 %8)
br label %10
10: ; preds = %6, %4
%11 = phi i8* [ getelementptr inbounds ([8 x i8], [8 x i8]* @proto2str.protoName, i64 0, i64 0), %4 ], [ %9, %6 ]
ret i8* %11
}