#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 */
typedef struct TYPE_2__ TYPE_1__;

/* Type definitions */
struct TYPE_2__ {
  int /*<<< orphan*/ s_addr;
};
struct sockaddr_in {
  int sin_port;
  TYPE_1__ sin_addr;
  int /*<<< orphan*/ sin_family;
};
struct sockaddr {
  int dummy;
};
typedef int /*<<< orphan*/ server_address;
typedef int /*<<< orphan*/ client_address;

/* Variables and functions */
int /*<<< orphan*/ AF_INET;
int /*<<< orphan*/ SOCK_STREAM;
int accept(int, struct sockaddr *, int *);
int /*<<< orphan*/ bind(int, struct sockaddr *, int);
int /*<<< orphan*/ close(int);
int /*<<< orphan*/ inet_addr(char *);
int /*<<< orphan*/ listen(int, int);
int /*<<< orphan*/ printf(char *);
int /*<<< orphan*/ read(int, char *, int);
int socket(int /*<<< orphan*/, int /*<<< orphan*/, int /*<<< orphan*/);
int /*<<< orphan*/ write(int, char *, int);
int main() {
  int server_sockfd, client_sockfd;
  int server_len, client_len;
  struct sockaddr_in server_address;
  struct sockaddr_in client_address;
  server_sockfd = socket(AF_INET, SOCK_STREAM, 0);
  server_address.sin_family = AF_INET;
  server_address.sin_addr.s_addr = inet_addr("127.0.0.1");
  server_address.sin_port = 9734;
  server_len = sizeof(server_address);
  bind(server_sockfd, (struct sockaddr *)&server_address, server_len);
  listen(server_sockfd, 5);
  while (1) {
    char ch;
    printf("server waiting\n");
    client_len = sizeof(client_address);
    client_sockfd =
        accept(server_sockfd, (struct sockaddr *)&client_address, &client_len);
    read(client_sockfd, &ch, 1);
    ch++;
    write(client_sockfd, &ch, 1);
    close(client_sockfd);
  }
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x40,%rsp
movl   $0x0,-0x4(%rbp)
mov    0x2e42(%rip),%rax
mov    (%rax),%edi
mov    0x2e29(%rip),%rax
mov    (%rax),%esi
xor    %edx,%edx
call   10b0 <socket@plt>
mov    %eax,-0x8(%rbp)
mov    0x2e26(%rip),%rax
mov    (%rax),%eax
mov    %eax,-0x18(%rbp)
lea    0xe32(%rip),%rdi
call   1070 <inet_addr@plt>
mov    %eax,-0x1c(%rbp)
movl   $0x2606,-0x20(%rbp)
movl   $0xc,-0x10(%rbp)
mov    -0x8(%rbp),%edi
lea    -0x20(%rbp),%rsi
mov    -0x10(%rbp),%edx
call   1090 <bind@plt>
mov    -0x8(%rbp),%edi
mov    $0x5,%esi
call   1080 <listen@plt>
lea    0xe03(%rip),%rdi
call   1040 <printf@plt>
movl   $0xc,-0x14(%rbp)
mov    -0x8(%rbp),%edi
lea    -0x30(%rbp),%rsi
lea    -0x14(%rbp),%rdx
call   10a0 <accept@plt>
mov    %eax,-0xc(%rbp)
mov    -0xc(%rbp),%edi
lea    -0x31(%rbp),%rsi
mov    $0x1,%edx
call   1060 <read@plt>
mov    -0x31(%rbp),%al
add    $0x1,%al
mov    %al,-0x32(%rbp)
mov    %al,-0x31(%rbp)
mov    -0xc(%rbp),%edi
lea    -0x31(%rbp),%rsi
mov    $0x1,%edx
call   1030 <write@plt>
mov    -0xc(%rbp),%edi
call   1050 <close@plt>
jmp    1200 <main+0x70>

x86 assembly (clang, -O2):
<main>:
push   %rbp
push   %r15
push   %r14
push   %r13
push   %r12
push   %rbx
sub    $0x28,%rsp
mov    0x2e43(%rip),%rbx
mov    (%rbx),%edi
mov    0x2e2a(%rip),%rax
mov    (%rax),%esi
xor    %edx,%edx
call   10b0 <socket@plt>
mov    %eax,%r13d
mov    (%rbx),%eax
mov    %eax,0x10(%rsp)
lea    0xe39(%rip),%rdi
call   1070 <inet_addr@plt>
mov    %eax,0xc(%rsp)
movl   $0x2606,0x8(%rsp)
lea    0x8(%rsp),%rsi
mov    %r13d,%edi
mov    $0xc,%edx
call   1090 <bind@plt>
mov    %r13d,%edi
mov    $0x5,%esi
call   1080 <listen@plt>
lea    0xe0c(%rip),%r14
lea    0x18(%rsp),%r15
lea    0x4(%rsp),%r12
lea    0x3(%rsp),%rbx
nopl   (%rax)
mov    %r14,%rdi
call   1030 <puts@plt>
movl   $0xc,0x4(%rsp)
mov    %r13d,%edi
mov    %r15,%rsi
mov    %r12,%rdx
call   10a0 <accept@plt>
mov    %eax,%ebp
mov    %eax,%edi
mov    %rbx,%rsi
mov    $0x1,%edx
call   1060 <read@plt>
addb   $0x1,0x3(%rsp)
mov    %ebp,%edi
mov    %rbx,%rsi
mov    $0x1,%edx
call   1040 <write@plt>
mov    %ebp,%edi
call   1050 <close@plt>
jmp    1210 <main+0x80>

LLVM IR (-O0):
%struct.sockaddr_in = type { i32, %struct.TYPE_2__, i32 }
%struct.TYPE_2__ = type { i32 }
%struct.sockaddr = type { i32 }
@AF_INET = global i32 0
@SOCK_STREAM = global i32 0
@.str = [10 x i8] c"127.0.0.1\00"
@.str.1 = [16 x i8] c"server waiting\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i32
%3 = alloca i32
%4 = alloca i32
%5 = alloca i32
%6 = alloca %struct.sockaddr_in
%7 = alloca %struct.sockaddr_in
%8 = alloca i8
store i32 0, i32* %1
%9 = load i32, i32* @AF_INET
%10 = load i32, i32* @SOCK_STREAM
%11 = call i32 @socket(i32 %9, i32 %10, i32 0)
store i32 %11, i32* %2
%12 = load i32, i32* @AF_INET
%13 = getelementptr inbounds %struct.sockaddr_in, %struct.sockaddr_in* %6, i32 0, i32 2
store i32 %12, i32* %13
%14 = call i32 @inet_addr(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str, i64 0, i64 0))
%15 = getelementptr inbounds %struct.sockaddr_in, %struct.sockaddr_in* %6, i32 0, i32 1
%16 = getelementptr inbounds %struct.TYPE_2__, %struct.TYPE_2__* %15, i32 0, i32 0
store i32 %14, i32* %16
%17 = getelementptr inbounds %struct.sockaddr_in, %struct.sockaddr_in* %6, i32 0, i32 0
store i32 9734, i32* %17
store i32 12, i32* %4
%18 = load i32, i32* %2
%19 = bitcast %struct.sockaddr_in* %6 to %struct.sockaddr*
%20 = load i32, i32* %4
%21 = call i32 @bind(i32 %18, %struct.sockaddr* %19, i32 %20)
%22 = load i32, i32* %2
%23 = call i32 @listen(i32 %22, i32 5)
br label %24
24: ; preds = %0, %24
%25 = call i32 @printf(i8* getelementptr inbounds ([16 x i8], [16 x i8]* @.str.1, i64 0, i64 0))
store i32 12, i32* %5
%26 = load i32, i32* %2
%27 = bitcast %struct.sockaddr_in* %7 to %struct.sockaddr*
%28 = call i32 @accept(i32 %26, %struct.sockaddr* %27, i32* %5)
store i32 %28, i32* %3
%29 = load i32, i32* %3
%30 = call i32 @read(i32 %29, i8* %8, i32 1)
%31 = load i8, i8* %8
%32 = add i8 %31, 1
store i8 %32, i8* %8
%33 = load i32, i32* %3
%34 = call i32 @write(i32 %33, i8* %8, i32 1)
%35 = load i32, i32* %3
%36 = call i32 @close(i32 %35)
br label %24
}

LLVM IR (-O2):
%struct.sockaddr_in = type { i32, %struct.TYPE_2__, i32 }
%struct.TYPE_2__ = type { i32 }
%struct.sockaddr = type { i32 }
@AF_INET = global i32 0
@SOCK_STREAM = global i32 0
@.str = [10 x i8] c"127.0.0.1\00"
@str = [15 x i8] c"server waiting\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca %struct.sockaddr_in
%3 = alloca %struct.sockaddr_in
%4 = alloca i8
%5 = bitcast i32* %1 to i8*
%6 = bitcast %struct.sockaddr_in* %2 to i8*
%7 = bitcast %struct.sockaddr_in* %3 to i8*
%8 = load i32, i32* @AF_INET
%9 = load i32, i32* @SOCK_STREAM
%10 = tail call i32 @socket(i32 %8, i32 %9, i32 0)
%11 = load i32, i32* @AF_INET
%12 = getelementptr inbounds %struct.sockaddr_in, %struct.sockaddr_in* %2, i64 0, i32 2
store i32 %11, i32* %12
%13 = tail call i32 @inet_addr(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str, i64 0, i64 0))
%14 = getelementptr inbounds %struct.sockaddr_in, %struct.sockaddr_in* %2, i64 0, i32 1, i32 0
store i32 %13, i32* %14
%15 = getelementptr inbounds %struct.sockaddr_in, %struct.sockaddr_in* %2, i64 0, i32 0
store i32 9734, i32* %15
%16 = bitcast %struct.sockaddr_in* %2 to %struct.sockaddr*
%17 = call i32 @bind(i32 %10, %struct.sockaddr* %16, i32 12)
%18 = call i32 @listen(i32 %10, i32 5)
%19 = bitcast %struct.sockaddr_in* %3 to %struct.sockaddr*
br label %20
20: ; preds = %20, %0
%21 = call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([15 x i8], [15 x i8]* @str, i64 0, i64 0))
store i32 12, i32* %1
%22 = call i32 @accept(i32 %10, %struct.sockaddr* %19, i32* %1)
%23 = call i32 @read(i32 %22, i8* %4, i32 1)
%24 = load i8, i8* %4
%25 = add i8 %24, 1
store i8 %25, i8* %4
%26 = call i32 @write(i32 %22, i8* %4, i32 1)
%27 = call i32 @close(i32 %22)
br label %20
}