#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 */
struct sockaddr_in {
  int /*<<< orphan*/ sin_port;
  int /*<<< orphan*/ sin_addr;
  int /*<<< orphan*/ sin_family;
};
struct hostent {
  int /*<<< orphan*/ h_length;
  scalar_t__ h_addr;
};

/* Variables and functions */
int /*<<< orphan*/ AF_INET;
int /*<<< orphan*/ SOCK_DGRAM;
int /*<<< orphan*/ atoi(char *);
int /*<<< orphan*/ bcopy(char *, char *, int /*<<< orphan*/);
int /*<<< orphan*/ bzero(char *, int);
int /*<<< orphan*/ error(char *);
int /*<<< orphan*/ exit(int);
int /*<<< orphan*/ fgets(char *, int, int /*<<< orphan*/);
struct hostent *gethostbyname(char *);
int /*<<< orphan*/ htons(int /*<<< orphan*/);
int /*<<< orphan*/ printf(char *);
int recvfrom(int, char *, int, int /*<<< orphan*/, struct sockaddr_in *, int *);
int sendto(int, char *, int /*<<< orphan*/, int /*<<< orphan*/,
           struct sockaddr_in *, int);
int socket(int /*<<< orphan*/, int /*<<< orphan*/, int /*<<< orphan*/);
int /*<<< orphan*/ stdin;
int /*<<< orphan*/ strlen(char *);
int /*<<< orphan*/ write(int, char *, int);
int main(int argc, char *argv[]) {
  int sock, length, n;
  struct sockaddr_in server, from;
  struct hostent *hp;
  char buffer[256];
  if (argc != 3) {
    printf("Usage: server port\n");
    exit(1);
  }
  sock = socket(AF_INET, SOCK_DGRAM, 0);
  if (sock < 0)
    error("socket");
  server.sin_family = AF_INET;
  hp = gethostbyname(argv[1]);
  if (hp == 0)
    error("Unknown host");
  bcopy((char *)hp->h_addr, (char *)&server.sin_addr, hp->h_length);
  server.sin_port = htons(atoi(argv[2]));
  length = sizeof(struct sockaddr_in);
  printf("Please enter the message: ");
  bzero(buffer, 256);
  fgets(buffer, 255, stdin);
  n = sendto(sock, buffer, strlen(buffer), 0, &server, length);
  if (n < 0)
    error("Sendto");
  n = recvfrom(sock, buffer, 256, 0, &from, &length);
  if (n < 0)
    error("recvfrom");
  write(1, "Got an ack: ", 12);
  write(1, buffer, n);
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x150,%rsp
movl   $0x0,-0x4(%rbp)
mov    %edi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
cmpl   $0x3,-0x8(%rbp)
je     1219 <main+0x39>
lea    0xdf6(%rip),%rdi
call   1060 <printf@plt>
mov    $0x1,%edi
call   10f0 <exit@plt>
mov    0x2dc8(%rip),%rax
mov    (%rax),%edi
mov    0x2daf(%rip),%rax
mov    (%rax),%esi
xor    %edx,%edx
call   1100 <socket@plt>
mov    %eax,-0x14(%rbp)
cmpl   $0x0,-0x14(%rbp)
jge    124b <main+0x6b>
lea    0xdce(%rip),%rdi
call   10c0 <error@plt>
mov    0x2d96(%rip),%rax
mov    (%rax),%eax
mov    %eax,-0x20(%rbp)
mov    -0x10(%rbp),%rax
mov    0x8(%rax),%rdi
call   1090 <gethostbyname@plt>
mov    %rax,-0x40(%rbp)
cmpq   $0x0,-0x40(%rbp)
jne    127f <main+0x9f>
lea    0xda1(%rip),%rdi
call   10c0 <error@plt>
mov    -0x40(%rbp),%rax
mov    0x8(%rax),%rdi
lea    -0x28(%rbp),%rsi
add    $0x4,%rsi
mov    -0x40(%rbp),%rax
mov    (%rax),%edx
call   10b0 <bcopy@plt>
mov    -0x10(%rbp),%rax
mov    0x10(%rax),%rdi
call   10e0 <atoi@plt>
mov    %eax,%edi
call   1050 <htons@plt>
mov    %eax,-0x28(%rbp)
movl   $0xc,-0x18(%rbp)
lea    0xd69(%rip),%rdi
call   1060 <printf@plt>
lea    -0x140(%rbp),%rdi
mov    $0x100,%esi
call   10d0 <bzero@plt>
lea    -0x140(%rbp),%rdi
mov    0x2cfd(%rip),%rax
mov    (%rax),%edx
mov    $0xff,%esi
call   1080 <fgets@plt>
mov    -0x14(%rbp),%eax
mov    %eax,-0x14c(%rbp)
lea    -0x140(%rbp),%rax
mov    %rax,-0x148(%rbp)
lea    -0x140(%rbp),%rdi
call   1040 <strlen@plt>
mov    -0x14c(%rbp),%edi
mov    -0x148(%rbp),%rsi
mov    %eax,%edx
mov    -0x18(%rbp),%r9d
xor    %ecx,%ecx
lea    -0x28(%rbp),%r8
call   1070 <sendto@plt>
mov    %eax,-0x1c(%rbp)
cmpl   $0x0,-0x1c(%rbp)
jge    1349 <main+0x169>
lea    0xcff(%rip),%rdi
call   10c0 <error@plt>
mov    -0x14(%rbp),%edi
lea    -0x140(%rbp),%rsi
mov    $0x100,%edx
xor    %ecx,%ecx
lea    -0x38(%rbp),%r8
lea    -0x18(%rbp),%r9
call   10a0 <recvfrom@plt>
mov    %eax,-0x1c(%rbp)
cmpl   $0x0,-0x1c(%rbp)
jge    1380 <main+0x1a0>
lea    0xccf(%rip),%rdi
call   10c0 <error@plt>
mov    $0x1,%edi
lea    0xcc7(%rip),%rsi
mov    $0xc,%edx
call   1030 <write@plt>
lea    -0x140(%rbp),%rsi
mov    -0x1c(%rbp),%edx
mov    $0x1,%edi
call   1030 <write@plt>
mov    -0x4(%rbp),%eax
add    $0x150,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rbp
push   %r14
push   %rbx
sub    $0x130,%rsp
cmp    $0x3,%edi
jne    1350 <main+0x160>
mov    %rsi,%rbx
mov    0x2dda(%rip),%rbp
mov    0x0(%rbp),%edi
mov    0x2dc0(%rip),%rax
mov    (%rax),%esi
xor    %edx,%edx
call   1110 <socket@plt>
mov    %eax,%r14d
test   %eax,%eax
jns    1234 <main+0x44>
lea    0xdd1(%rip),%rdi
call   10d0 <error@plt>
mov    0x0(%rbp),%eax
mov    %eax,0x18(%rsp)
mov    0x8(%rbx),%rdi
call   10a0 <gethostbyname@plt>
mov    %rax,%rbp
test   %rax,%rax
jne    1258 <main+0x68>
lea    0xdb4(%rip),%rdi
call   10d0 <error@plt>
mov    0x8(%rbp),%rsi
lea    0x14(%rsp),%rdi
mov    0x0(%rbp),%edx
call   10c0 <memmove@plt>
mov    0x10(%rbx),%rdi
call   10f0 <atoi@plt>
mov    %eax,%edi
call   1060 <htons@plt>
mov    %eax,0x10(%rsp)
movl   $0xc,0xc(%rsp)
lea    0xd88(%rip),%rdi
call   1070 <printf@plt>
lea    0x30(%rsp),%rbx
mov    %rbx,%rdi
mov    $0x100,%esi
call   10e0 <bzero@plt>
mov    0x2d36(%rip),%rax
mov    (%rax),%edx
mov    %rbx,%rdi
mov    $0xff,%esi
call   1090 <fgets@plt>
mov    %rbx,%rdi
call   1050 <strlen@plt>
lea    0x10(%rsp),%r8
mov    %r14d,%edi
mov    %rbx,%rsi
mov    %eax,%edx
xor    %ecx,%ecx
mov    $0xc,%r9d
call   1080 <sendto@plt>
test   %eax,%eax
jns    12eb <main+0xfb>
lea    0xd49(%rip),%rdi
call   10d0 <error@plt>
lea    0x30(%rsp),%rsi
lea    0x20(%rsp),%r8
lea    0xc(%rsp),%r9
mov    %r14d,%edi
mov    $0x100,%edx
xor    %ecx,%ecx
call   10b0 <recvfrom@plt>
mov    %eax,%ebx
test   %eax,%eax
jns    131b <main+0x12b>
lea    0xd20(%rip),%rdi
call   10d0 <error@plt>
lea    0xd1d(%rip),%rsi
mov    $0x1,%edi
mov    $0xc,%edx
call   1040 <write@plt>
lea    0x30(%rsp),%rsi
mov    $0x1,%edi
mov    %ebx,%edx
call   1040 <write@plt>
xor    %eax,%eax
add    $0x130,%rsp
pop    %rbx
pop    %r14
pop    %rbp
ret
lea    0xcf5(%rip),%rdi
call   1030 <puts@plt>
mov    $0x1,%edi
call   1100 <exit@plt>

LLVM IR (-O0):
%struct.sockaddr_in = type { i32, i32, i32 }
%struct.hostent = type { i32, i64 }
@.str = [20 x i8] c"Usage: server port\0A\00"
@AF_INET = global i32 0
@SOCK_DGRAM = global i32 0
@.str.1 = [7 x i8] c"socket\00"
@.str.2 = [13 x i8] c"Unknown host\00"
@.str.3 = [27 x i8] c"Please enter the message: \00"
@stdin = global i32 0
@.str.4 = [7 x i8] c"Sendto\00"
@.str.5 = [9 x i8] c"recvfrom\00"
@.str.6 = [13 x i8] c"Got an ack: \00"
define i32 @main(i32 %0, i8** %1) {
%3 = alloca i32
%4 = alloca i32
%5 = alloca i8**
%6 = alloca i32
%7 = alloca i32
%8 = alloca i32
%9 = alloca %struct.sockaddr_in
%10 = alloca %struct.sockaddr_in
%11 = alloca %struct.hostent*
%12 = alloca [256 x i8]
store i32 0, i32* %3
store i32 %0, i32* %4
store i8** %1, i8*** %5
%13 = load i32, i32* %4
%14 = icmp ne i32 %13, 3
br i1 %14, label %15, label %18
15: ; preds = %2
%16 = call i32 @printf(i8* getelementptr inbounds ([20 x i8], [20 x i8]* @.str, i64 0, i64 0))
%17 = call i32 @exit(i32 1)
unreachable
18: ; preds = %2
%19 = load i32, i32* @AF_INET
%20 = load i32, i32* @SOCK_DGRAM
%21 = call i32 @socket(i32 %19, i32 %20, i32 0)
store i32 %21, i32* %6
%22 = load i32, i32* %6
%23 = icmp slt i32 %22, 0
br i1 %23, label %24, label %26
24: ; preds = %18
%25 = call i32 @error(i8* getelementptr inbounds ([7 x i8], [7 x i8]* @.str.1, i64 0, i64 0))
br label %26
26: ; preds = %24, %18
%27 = load i32, i32* @AF_INET
%28 = getelementptr inbounds %struct.sockaddr_in, %struct.sockaddr_in* %9, i32 0, i32 2
store i32 %27, i32* %28
%29 = load i8**, i8*** %5
%30 = getelementptr inbounds i8*, i8** %29, i64 1
%31 = load i8*, i8** %30
%32 = call %struct.hostent* @gethostbyname(i8* %31)
store %struct.hostent* %32, %struct.hostent** %11
%33 = load %struct.hostent*, %struct.hostent** %11
%34 = icmp eq %struct.hostent* %33, null
br i1 %34, label %35, label %37
35: ; preds = %26
%36 = call i32 @error(i8* getelementptr inbounds ([13 x i8], [13 x i8]* @.str.2, i64 0, i64 0))
br label %37
37: ; preds = %35, %26
%38 = load %struct.hostent*, %struct.hostent** %11
%39 = getelementptr inbounds %struct.hostent, %struct.hostent* %38, i32 0, i32 1
%40 = load i64, i64* %39
%41 = inttoptr i64 %40 to i8*
%42 = getelementptr inbounds %struct.sockaddr_in, %struct.sockaddr_in* %9, i32 0, i32 1
%43 = bitcast i32* %42 to i8*
%44 = load %struct.hostent*, %struct.hostent** %11
%45 = getelementptr inbounds %struct.hostent, %struct.hostent* %44, i32 0, i32 0
%46 = load i32, i32* %45
%47 = call i32 @bcopy(i8* %41, i8* %43, i32 %46)
%48 = load i8**, i8*** %5
%49 = getelementptr inbounds i8*, i8** %48, i64 2
%50 = load i8*, i8** %49
%51 = call i32 @atoi(i8* %50)
%52 = call i32 @htons(i32 %51)
%53 = getelementptr inbounds %struct.sockaddr_in, %struct.sockaddr_in* %9, i32 0, i32 0
store i32 %52, i32* %53
store i32 12, i32* %7
%54 = call i32 @printf(i8* getelementptr inbounds ([27 x i8], [27 x i8]* @.str.3, i64 0, i64 0))
%55 = getelementptr inbounds [256 x i8], [256 x i8]* %12, i64 0, i64 0
%56 = call i32 @bzero(i8* %55, i32 256)
%57 = getelementptr inbounds [256 x i8], [256 x i8]* %12, i64 0, i64 0
%58 = load i32, i32* @stdin
%59 = call i32 @fgets(i8* %57, i32 255, i32 %58)
%60 = load i32, i32* %6
%61 = getelementptr inbounds [256 x i8], [256 x i8]* %12, i64 0, i64 0
%62 = getelementptr inbounds [256 x i8], [256 x i8]* %12, i64 0, i64 0
%63 = call i32 @strlen(i8* %62)
%64 = load i32, i32* %7
%65 = call i32 @sendto(i32 %60, i8* %61, i32 %63, i32 0, %struct.sockaddr_in* %9, i32 %64)
store i32 %65, i32* %8
%66 = load i32, i32* %8
%67 = icmp slt i32 %66, 0
br i1 %67, label %68, label %70
68: ; preds = %37
%69 = call i32 @error(i8* getelementptr inbounds ([7 x i8], [7 x i8]* @.str.4, i64 0, i64 0))
br label %70
70: ; preds = %68, %37
%71 = load i32, i32* %6
%72 = getelementptr inbounds [256 x i8], [256 x i8]* %12, i64 0, i64 0
%73 = call i32 @recvfrom(i32 %71, i8* %72, i32 256, i32 0, %struct.sockaddr_in* %10, i32* %7)
store i32 %73, i32* %8
%74 = load i32, i32* %8
%75 = icmp slt i32 %74, 0
br i1 %75, label %76, label %78
76: ; preds = %70
%77 = call i32 @error(i8* getelementptr inbounds ([9 x i8], [9 x i8]* @.str.5, i64 0, i64 0))
br label %78
78: ; preds = %76, %70
%79 = call i32 @write(i32 1, i8* getelementptr inbounds ([13 x i8], [13 x i8]* @.str.6, i64 0, i64 0), i32 12)
%80 = getelementptr inbounds [256 x i8], [256 x i8]* %12, i64 0, i64 0
%81 = load i32, i32* %8
%82 = call i32 @write(i32 1, i8* %80, i32 %81)
%83 = load i32, i32* %3
ret i32 %83
}

LLVM IR (-O2):
%struct.sockaddr_in = type { i32, i32, i32 }
%struct.hostent = type { i32, i64 }
@AF_INET = global i32 0
@SOCK_DGRAM = global i32 0
@.str.1 = [7 x i8] c"socket\00"
@.str.2 = [13 x i8] c"Unknown host\00"
@.str.3 = [27 x i8] c"Please enter the message: \00"
@stdin = global i32 0
@.str.4 = [7 x i8] c"Sendto\00"
@.str.5 = [9 x i8] c"recvfrom\00"
@.str.6 = [13 x i8] c"Got an ack: \00"
@str = [19 x i8] c"Usage: server port\00"
define i32 @main(i32 %0, i8** nocapture %1) {
%3 = alloca i32
%4 = alloca %struct.sockaddr_in
%5 = alloca %struct.sockaddr_in
%6 = alloca [256 x i8]
%7 = bitcast i32* %3 to i8*
%8 = bitcast %struct.sockaddr_in* %4 to i8*
%9 = bitcast %struct.sockaddr_in* %5 to i8*
%10 = getelementptr inbounds [256 x i8], [256 x i8]* %6, i64 0, i64 0
%11 = icmp eq i32 %0, 3
br i1 %11, label %15, label %12
12: ; preds = %2
%13 = tail call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([19 x i8], [19 x i8]* @str, i64 0, i64 0))
%14 = tail call i32 @exit(i32 1)
unreachable
15: ; preds = %2
%16 = load i32, i32* @AF_INET
%17 = load i32, i32* @SOCK_DGRAM
%18 = tail call i32 @socket(i32 %16, i32 %17, i32 0)
%19 = icmp slt i32 %18, 0
br i1 %19, label %20, label %22
20: ; preds = %15
%21 = tail call i32 @error(i8* getelementptr inbounds ([7 x i8], [7 x i8]* @.str.1, i64 0, i64 0))
br label %22
22: ; preds = %20, %15
%23 = load i32, i32* @AF_INET
%24 = getelementptr inbounds %struct.sockaddr_in, %struct.sockaddr_in* %4, i64 0, i32 2
store i32 %23, i32* %24
%25 = getelementptr inbounds i8*, i8** %1, i64 1
%26 = load i8*, i8** %25
%27 = tail call %struct.hostent* @gethostbyname(i8* %26)
%28 = icmp eq %struct.hostent* %27, null
br i1 %28, label %29, label %31
29: ; preds = %22
%30 = tail call i32 @error(i8* getelementptr inbounds ([13 x i8], [13 x i8]* @.str.2, i64 0, i64 0))
br label %31
31: ; preds = %29, %22
%32 = getelementptr inbounds %struct.hostent, %struct.hostent* %27, i64 0, i32 1
%33 = load i64, i64* %32
%34 = inttoptr i64 %33 to i8*
%35 = getelementptr inbounds %struct.sockaddr_in, %struct.sockaddr_in* %4, i64 0, i32 1
%36 = bitcast i32* %35 to i8*
%37 = getelementptr inbounds %struct.hostent, %struct.hostent* %27, i64 0, i32 0
%38 = load i32, i32* %37
%39 = getelementptr inbounds i8*, i8** %1, i64 2
%40 = load i8*, i8** %39
%41 = tail call i32 @atoi(i8* %40)
%42 = tail call i32 @htons(i32 %41)
%43 = getelementptr inbounds %struct.sockaddr_in, %struct.sockaddr_in* %4, i64 0, i32 0
store i32 %42, i32* %43
store i32 12, i32* %3
%44 = tail call i32 @printf(i8* dereferenceable(1) getelementptr inbounds ([27 x i8], [27 x i8]* @.str.3, i64 0, i64 0))
%45 = call i32 @bzero(i8* %10, i32 256)
%46 = load i32, i32* @stdin
%47 = call i32 @fgets(i8* %10, i32 255, i32 %46)
%48 = call i32 @strlen(i8* %10)
%49 = call i32 @sendto(i32 %18, i8* %10, i32 %48, i32 0, %struct.sockaddr_in* %4, i32 12)
%50 = icmp slt i32 %49, 0
br i1 %50, label %51, label %53
51: ; preds = %31
%52 = call i32 @error(i8* getelementptr inbounds ([7 x i8], [7 x i8]* @.str.4, i64 0, i64 0))
br label %53
53: ; preds = %51, %31
%54 = call i32 @recvfrom(i32 %18, i8* %10, i32 256, i32 0, %struct.sockaddr_in* %5, i32* %3)
%55 = icmp slt i32 %54, 0
br i1 %55, label %56, label %58
56: ; preds = %53
%57 = call i32 @error(i8* getelementptr inbounds ([9 x i8], [9 x i8]* @.str.5, i64 0, i64 0))
br label %58
58: ; preds = %56, %53
%59 = call i32 @write(i32 1, i8* getelementptr inbounds ([13 x i8], [13 x i8]* @.str.6, i64 0, i64 0), i32 12)
%60 = call i32 @write(i32 1, i8* %10, i32 %54)
ret i32 0
}