#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_addr;
  int /*<<< orphan*/ sin_port;
  int /*<<< orphan*/ sin_family;
};
struct sockaddr {
  int dummy;
};
struct iovec {
  char *iov_base;
  void *iov_len;
};
typedef int /*<<< orphan*/ iovec;
typedef int /*<<< orphan*/ addr;

/* Variables and functions */
int /*<<< orphan*/ AF_INET;
int EXIT_FAILURE;
int EXIT_SUCCESS;
int /*<<< orphan*/ IPPROTO_UDP;
int /*<<< orphan*/ SOCK_DGRAM;
scalar_t__ connect(int, struct sockaddr *, int);
int /*<<< orphan*/ errno;
int /*<<< orphan*/ fprintf(int /*<<< orphan*/, char *, char *);
int /*<<< orphan*/ htons(int);
int /*<<< orphan*/ inet_aton(char *, int /*<<< orphan*/ *);
int socket(int /*<<< orphan*/, int /*<<< orphan*/, int /*<<< orphan*/);
int /*<<< orphan*/ stderr;
char *strerror(int /*<<< orphan*/);
void *strlen(char *);
scalar_t__ writev(int, struct iovec *, int);
int main(void) {
  int sock;
  if ((sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
    fprintf(stderr, "socket() failed: %s\n.", strerror(errno));
    return (EXIT_FAILURE);
  }
  struct sockaddr_in addr;
  addr.sin_family = AF_INET;
  addr.sin_port = htons(8000);
  inet_aton("127.0.0.1", &addr.sin_addr);
  if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
    fprintf(stderr, "connect() failed: %s\n.", strerror(errno));
    return (EXIT_FAILURE);
  }
  char *iovec_buf0 = "short string\n";
  char *iovec_buf1 = "This is a longer string\n";
  char *iovec_buf2 = "This is the longest string in this example\n";
  struct iovec iovec[3];
  iovec[0].iov_base = iovec_buf0;
  iovec[0].iov_len = strlen(iovec_buf0);
  iovec[1].iov_base = iovec_buf1;
  iovec[1].iov_len = strlen(iovec_buf1);
  iovec[2].iov_base = iovec_buf2;
  iovec[2].iov_len = strlen(iovec_buf2);
  if (writev(sock, iovec, sizeof(iovec) / sizeof(struct iovec)) < 0) {
    fprintf(stderr, "writev() failed: %s\n.", strerror(errno));
    return (EXIT_FAILURE);
  }
  return (EXIT_SUCCESS);
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x70,%rsp
movl   $0x0,-0x4(%rbp)
mov    0x2e52(%rip),%rax
mov    (%rax),%edi
mov    0x2e41(%rip),%rax
mov    (%rax),%esi
mov    0x2e00(%rip),%rax
mov    (%rax),%edx
call   10a0 <socket@plt>
mov    %eax,-0x8(%rbp)
cmp    $0x0,%eax
jge    11f8 <main+0x78>
mov    0x2e0e(%rip),%rax
mov    (%rax),%eax
mov    %eax,-0x64(%rbp)
mov    0x2dfa(%rip),%rax
mov    (%rax),%edi
call   1090 <strerror@plt>
mov    -0x64(%rbp),%edi
mov    %rax,%rdx
lea    0xe1e(%rip),%rsi
call   1060 <fprintf@plt>
mov    0x2dd2(%rip),%rax
mov    (%rax),%eax
mov    %eax,-0x4(%rbp)
jmp    133d <main+0x1bd>
mov    0x2de9(%rip),%rax
mov    (%rax),%eax
mov    %eax,-0x10(%rbp)
mov    $0x1f40,%edi
call   1050 <htons@plt>
mov    %eax,-0x14(%rbp)
lea    -0x18(%rbp),%rsi
lea    0xdfa(%rip),%rdi
call   1070 <inet_aton@plt>
mov    -0x8(%rbp),%edi
lea    -0x18(%rbp),%rsi
mov    $0xc,%edx
call   1080 <connect@plt>
cmp    $0x0,%rax
jge    1279 <main+0xf9>
mov    0x2d8d(%rip),%rax
mov    (%rax),%eax
mov    %eax,-0x68(%rbp)
mov    0x2d79(%rip),%rax
mov    (%rax),%edi
call   1090 <strerror@plt>
mov    -0x68(%rbp),%edi
mov    %rax,%rdx
lea    0xdbd(%rip),%rsi
call   1060 <fprintf@plt>
mov    0x2d51(%rip),%rax
mov    (%rax),%eax
mov    %eax,-0x4(%rbp)
jmp    133d <main+0x1bd>
lea    0xdb7(%rip),%rax
mov    %rax,-0x20(%rbp)
lea    0xdba(%rip),%rax
mov    %rax,-0x28(%rbp)
lea    0xdc8(%rip),%rax
mov    %rax,-0x30(%rbp)
mov    -0x20(%rbp),%rax
mov    %rax,-0x60(%rbp)
mov    -0x20(%rbp),%rdi
call   1040 <strlen@plt>
mov    %rax,-0x58(%rbp)
mov    -0x28(%rbp),%rax
mov    %rax,-0x50(%rbp)
mov    -0x28(%rbp),%rdi
call   1040 <strlen@plt>
mov    %rax,-0x48(%rbp)
mov    -0x30(%rbp),%rax
mov    %rax,-0x40(%rbp)
mov    -0x30(%rbp),%rdi
call   1040 <strlen@plt>
mov    %rax,-0x38(%rbp)
mov    -0x8(%rbp),%edi
lea    -0x60(%rbp),%rsi
mov    $0x3,%edx
call   1030 <writev@plt>
cmp    $0x0,%rax
jge    1331 <main+0x1b1>
mov    0x2cd5(%rip),%rax
mov    (%rax),%eax
mov    %eax,-0x6c(%rbp)
mov    0x2cc1(%rip),%rax
mov    (%rax),%edi
call   1090 <strerror@plt>
mov    -0x6c(%rbp),%edi
mov    %rax,%rdx
lea    0xd6f(%rip),%rsi
call   1060 <fprintf@plt>
mov    0x2c99(%rip),%rax
mov    (%rax),%eax
mov    %eax,-0x4(%rbp)
jmp    133d <main+0x1bd>
mov    0x2c80(%rip),%rax
mov    (%rax),%eax
mov    %eax,-0x4(%rbp)
mov    -0x4(%rbp),%eax
add    $0x70,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %r14
push   %rbx
sub    $0x48,%rsp
mov    0x2e5a(%rip),%r14
mov    (%r14),%edi
mov    0x2e48(%rip),%rax
mov    (%rax),%esi
mov    0x2e07(%rip),%rax
mov    (%rax),%edx
call   10a0 <socket@plt>
test   %eax,%eax
js     1252 <main+0xd2>
mov    %eax,%ebx
mov    (%r14),%eax
mov    %eax,0x8(%rsp)
mov    $0x1f40,%edi
call   1050 <htons@plt>
mov    %eax,0x4(%rsp)
lea    0xe48(%rip),%rdi
mov    %rsp,%r14
mov    %r14,%rsi
call   1070 <inet_aton@plt>
mov    %ebx,%edi
mov    %r14,%rsi
mov    $0xc,%edx
call   1080 <connect@plt>
test   %rax,%rax
js     1272 <main+0xf2>
lea    0xe3f(%rip),%rdi
mov    %rdi,0x10(%rsp)
call   1040 <strlen@plt>
mov    %rax,0x18(%rsp)
lea    0xe37(%rip),%rdi
mov    %rdi,0x20(%rsp)
call   1040 <strlen@plt>
mov    %rax,0x28(%rsp)
lea    0xe3a(%rip),%rdi
mov    %rdi,0x30(%rsp)
call   1040 <strlen@plt>
mov    %rax,0x38(%rsp)
lea    0x10(%rsp),%rsi
mov    %ebx,%edi
mov    $0x3,%edx
call   1030 <writev@plt>
test   %rax,%rax
js     1292 <main+0x112>
mov    0x2d68(%rip),%rax
jmp    12c1 <main+0x141>
mov    0x2d77(%rip),%rax
mov    (%rax),%ebx
mov    0x2d66(%rip),%rax
mov    (%rax),%edi
call   1090 <strerror@plt>
lea    0xd90(%rip),%rsi
jmp    12b0 <main+0x130>
mov    0x2d57(%rip),%rax
mov    (%rax),%ebx
mov    0x2d46(%rip),%rax
mov    (%rax),%edi
call   1090 <strerror@plt>
lea    0xd90(%rip),%rsi
jmp    12b0 <main+0x130>
mov    0x2d37(%rip),%rax
mov    (%rax),%ebx
mov    0x2d26(%rip),%rax
mov    (%rax),%edi
call   1090 <strerror@plt>
lea    0xdda(%rip),%rsi
mov    %ebx,%edi
mov    %rax,%rdx
call   1060 <fprintf@plt>
mov    0x2cff(%rip),%rax
mov    (%rax),%eax
add    $0x48,%rsp
pop    %rbx
pop    %r14
ret

LLVM IR (-O0):
%struct.sockaddr_in = type { i32, i32, i32 }
%struct.iovec = type { i8*, i8* }
%struct.sockaddr = type { i32 }
@AF_INET = global i32 0
@SOCK_DGRAM = global i32 0
@IPPROTO_UDP = global i32 0
@stderr = global i32 0
@.str = [22 x i8] c"socket() failed: %s\0A.\00"
@errno = global i32 0
@EXIT_FAILURE = global i32 0
@.str.1 = [10 x i8] c"127.0.0.1\00"
@.str.2 = [23 x i8] c"connect() failed: %s\0A.\00"
@.str.3 = [14 x i8] c"short string\0A\00"
@.str.4 = [25 x i8] c"This is a longer string\0A\00"
@.str.5 = [44 x i8] c"This is the longest string in this example\0A\00"
@.str.6 = [22 x i8] c"writev() failed: %s\0A.\00"
@EXIT_SUCCESS = global i32 0
define i32 @main() {
%1 = alloca i32
%2 = alloca i32
%3 = alloca %struct.sockaddr_in
%4 = alloca i8*
%5 = alloca i8*
%6 = alloca i8*
%7 = alloca [3 x %struct.iovec]
store i32 0, i32* %1
%8 = load i32, i32* @AF_INET
%9 = load i32, i32* @SOCK_DGRAM
%10 = load i32, i32* @IPPROTO_UDP
%11 = call i32 @socket(i32 %8, i32 %9, i32 %10)
store i32 %11, i32* %2
%12 = icmp slt i32 %11, 0
br i1 %12, label %13, label %19
13: ; preds = %0
%14 = load i32, i32* @stderr
%15 = load i32, i32* @errno
%16 = call i8* @strerror(i32 %15)
%17 = call i32 @fprintf(i32 %14, i8* getelementptr inbounds ([22 x i8], [22 x i8]* @.str, i64 0, i64 0), i8* %16)
%18 = load i32, i32* @EXIT_FAILURE
store i32 %18, i32* %1
br label %70
19: ; preds = %0
%20 = load i32, i32* @AF_INET
%21 = getelementptr inbounds %struct.sockaddr_in, %struct.sockaddr_in* %3, i32 0, i32 2
store i32 %20, i32* %21
%22 = call i32 @htons(i32 8000)
%23 = getelementptr inbounds %struct.sockaddr_in, %struct.sockaddr_in* %3, i32 0, i32 1
store i32 %22, i32* %23
%24 = getelementptr inbounds %struct.sockaddr_in, %struct.sockaddr_in* %3, i32 0, i32 0
%25 = call i32 @inet_aton(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.1, i64 0, i64 0), i32* %24)
%26 = load i32, i32* %2
%27 = bitcast %struct.sockaddr_in* %3 to %struct.sockaddr*
%28 = call i64 @connect(i32 %26, %struct.sockaddr* %27, i32 12)
%29 = icmp slt i64 %28, 0
br i1 %29, label %30, label %36
30: ; preds = %19
%31 = load i32, i32* @stderr
%32 = load i32, i32* @errno
%33 = call i8* @strerror(i32 %32)
%34 = call i32 @fprintf(i32 %31, i8* getelementptr inbounds ([23 x i8], [23 x i8]* @.str.2, i64 0, i64 0), i8* %33)
%35 = load i32, i32* @EXIT_FAILURE
store i32 %35, i32* %1
br label %70
36: ; preds = %19
store i8* getelementptr inbounds ([14 x i8], [14 x i8]* @.str.3, i64 0, i64 0), i8** %4
store i8* getelementptr inbounds ([25 x i8], [25 x i8]* @.str.4, i64 0, i64 0), i8** %5
store i8* getelementptr inbounds ([44 x i8], [44 x i8]* @.str.5, i64 0, i64 0), i8** %6
%37 = load i8*, i8** %4
%38 = getelementptr inbounds [3 x %struct.iovec], [3 x %struct.iovec]* %7, i64 0, i64 0
%39 = getelementptr inbounds %struct.iovec, %struct.iovec* %38, i32 0, i32 0
store i8* %37, i8** %39
%40 = load i8*, i8** %4
%41 = call i8* @strlen(i8* %40)
%42 = getelementptr inbounds [3 x %struct.iovec], [3 x %struct.iovec]* %7, i64 0, i64 0
%43 = getelementptr inbounds %struct.iovec, %struct.iovec* %42, i32 0, i32 1
store i8* %41, i8** %43
%44 = load i8*, i8** %5
%45 = getelementptr inbounds [3 x %struct.iovec], [3 x %struct.iovec]* %7, i64 0, i64 1
%46 = getelementptr inbounds %struct.iovec, %struct.iovec* %45, i32 0, i32 0
store i8* %44, i8** %46
%47 = load i8*, i8** %5
%48 = call i8* @strlen(i8* %47)
%49 = getelementptr inbounds [3 x %struct.iovec], [3 x %struct.iovec]* %7, i64 0, i64 1
%50 = getelementptr inbounds %struct.iovec, %struct.iovec* %49, i32 0, i32 1
store i8* %48, i8** %50
%51 = load i8*, i8** %6
%52 = getelementptr inbounds [3 x %struct.iovec], [3 x %struct.iovec]* %7, i64 0, i64 2
%53 = getelementptr inbounds %struct.iovec, %struct.iovec* %52, i32 0, i32 0
store i8* %51, i8** %53
%54 = load i8*, i8** %6
%55 = call i8* @strlen(i8* %54)
%56 = getelementptr inbounds [3 x %struct.iovec], [3 x %struct.iovec]* %7, i64 0, i64 2
%57 = getelementptr inbounds %struct.iovec, %struct.iovec* %56, i32 0, i32 1
store i8* %55, i8** %57
%58 = load i32, i32* %2
%59 = getelementptr inbounds [3 x %struct.iovec], [3 x %struct.iovec]* %7, i64 0, i64 0
%60 = call i64 @writev(i32 %58, %struct.iovec* %59, i32 3)
%61 = icmp slt i64 %60, 0
br i1 %61, label %62, label %68
62: ; preds = %36
%63 = load i32, i32* @stderr
%64 = load i32, i32* @errno
%65 = call i8* @strerror(i32 %64)
%66 = call i32 @fprintf(i32 %63, i8* getelementptr inbounds ([22 x i8], [22 x i8]* @.str.6, i64 0, i64 0), i8* %65)
%67 = load i32, i32* @EXIT_FAILURE
store i32 %67, i32* %1
br label %70
68: ; preds = %36
%69 = load i32, i32* @EXIT_SUCCESS
store i32 %69, i32* %1
br label %70
70: ; preds = %68, %62, %30, %13
%71 = load i32, i32* %1
ret i32 %71
}

LLVM IR (-O2):
%struct.sockaddr_in = type { i32, i32, i32 }
%struct.iovec = type { i8*, i8* }
%struct.sockaddr = type { i32 }
@AF_INET = global i32 0
@SOCK_DGRAM = global i32 0
@IPPROTO_UDP = global i32 0
@stderr = global i32 0
@.str = [22 x i8] c"socket() failed: %s\0A.\00"
@errno = global i32 0
@EXIT_FAILURE = global i32 0
@.str.1 = [10 x i8] c"127.0.0.1\00"
@.str.2 = [23 x i8] c"connect() failed: %s\0A.\00"
@.str.3 = [14 x i8] c"short string\0A\00"
@.str.4 = [25 x i8] c"This is a longer string\0A\00"
@.str.5 = [44 x i8] c"This is the longest string in this example\0A\00"
@.str.6 = [22 x i8] c"writev() failed: %s\0A.\00"
@EXIT_SUCCESS = global i32 0
define i32 @main() {
%1 = alloca %struct.sockaddr_in
%2 = alloca [3 x %struct.iovec]
%3 = load i32, i32* @AF_INET
%4 = load i32, i32* @SOCK_DGRAM
%5 = load i32, i32* @IPPROTO_UDP
%6 = tail call i32 @socket(i32 %3, i32 %4, i32 %5)
%7 = icmp slt i32 %6, 0
br i1 %7, label %8, label %14
8: ; preds = %0
%9 = load i32, i32* @stderr
%10 = load i32, i32* @errno
%11 = tail call i8* @strerror(i32 %10)
%12 = tail call i32 @fprintf(i32 %9, i8* getelementptr inbounds ([22 x i8], [22 x i8]* @.str, i64 0, i64 0), i8* %11)
%13 = load i32, i32* @EXIT_FAILURE
br label %55
14: ; preds = %0
%15 = bitcast %struct.sockaddr_in* %1 to i8*
%16 = load i32, i32* @AF_INET
%17 = getelementptr inbounds %struct.sockaddr_in, %struct.sockaddr_in* %1, i64 0, i32 2
store i32 %16, i32* %17
%18 = tail call i32 @htons(i32 8000)
%19 = getelementptr inbounds %struct.sockaddr_in, %struct.sockaddr_in* %1, i64 0, i32 1
store i32 %18, i32* %19
%20 = getelementptr inbounds %struct.sockaddr_in, %struct.sockaddr_in* %1, i64 0, i32 0
%21 = call i32 @inet_aton(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.1, i64 0, i64 0), i32* %20)
%22 = bitcast %struct.sockaddr_in* %1 to %struct.sockaddr*
%23 = call i64 @connect(i32 %6, %struct.sockaddr* %22, i32 12)
%24 = icmp slt i64 %23, 0
br i1 %24, label %25, label %31
25: ; preds = %14
%26 = load i32, i32* @stderr
%27 = load i32, i32* @errno
%28 = call i8* @strerror(i32 %27)
%29 = call i32 @fprintf(i32 %26, i8* getelementptr inbounds ([23 x i8], [23 x i8]* @.str.2, i64 0, i64 0), i8* %28)
%30 = load i32, i32* @EXIT_FAILURE
br label %53
31: ; preds = %14
%32 = bitcast [3 x %struct.iovec]* %2 to i8*
%33 = getelementptr inbounds [3 x %struct.iovec], [3 x %struct.iovec]* %2, i64 0, i64 0
%34 = getelementptr inbounds [3 x %struct.iovec], [3 x %struct.iovec]* %2, i64 0, i64 0, i32 0
store i8* getelementptr inbounds ([14 x i8], [14 x i8]* @.str.3, i64 0, i64 0), i8** %34
%35 = call i8* @strlen(i8* getelementptr inbounds ([14 x i8], [14 x i8]* @.str.3, i64 0, i64 0))
%36 = getelementptr inbounds [3 x %struct.iovec], [3 x %struct.iovec]* %2, i64 0, i64 0, i32 1
store i8* %35, i8** %36
%37 = getelementptr inbounds [3 x %struct.iovec], [3 x %struct.iovec]* %2, i64 0, i64 1, i32 0
store i8* getelementptr inbounds ([25 x i8], [25 x i8]* @.str.4, i64 0, i64 0), i8** %37
%38 = call i8* @strlen(i8* getelementptr inbounds ([25 x i8], [25 x i8]* @.str.4, i64 0, i64 0))
%39 = getelementptr inbounds [3 x %struct.iovec], [3 x %struct.iovec]* %2, i64 0, i64 1, i32 1
store i8* %38, i8** %39
%40 = getelementptr inbounds [3 x %struct.iovec], [3 x %struct.iovec]* %2, i64 0, i64 2, i32 0
store i8* getelementptr inbounds ([44 x i8], [44 x i8]* @.str.5, i64 0, i64 0), i8** %40
%41 = call i8* @strlen(i8* getelementptr inbounds ([44 x i8], [44 x i8]* @.str.5, i64 0, i64 0))
%42 = getelementptr inbounds [3 x %struct.iovec], [3 x %struct.iovec]* %2, i64 0, i64 2, i32 1
store i8* %41, i8** %42
%43 = call i64 @writev(i32 %6, %struct.iovec* %33, i32 3)
%44 = icmp slt i64 %43, 0
br i1 %44, label %45, label %50
45: ; preds = %31
%46 = load i32, i32* @stderr
%47 = load i32, i32* @errno
%48 = call i8* @strerror(i32 %47)
%49 = call i32 @fprintf(i32 %46, i8* getelementptr inbounds ([22 x i8], [22 x i8]* @.str.6, i64 0, i64 0), i8* %48)
br label %50
50: ; preds = %31, %45
%51 = phi i32* [ @EXIT_FAILURE, %45 ], [ @EXIT_SUCCESS, %31 ]
%52 = load i32, i32* %51
br label %53
53: ; preds = %50, %25
%54 = phi i32 [ %30, %25 ], [ %52, %50 ]
br label %55
55: ; preds = %53, %8
%56 = phi i32 [ %13, %8 ], [ %54, %53 ]
ret i32 %56
}