#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 */

/* Variables and functions */
int /*<<< orphan*/ STDIN_FILENO;
int /*<<< orphan*/ STDOUT_FILENO;
int /*<<< orphan*/ exit(int /*<<< orphan*/);
int /*<<< orphan*/ perror(char *);
int read(int /*<<< orphan*/, char *, int);
int write(int /*<<< orphan*/, char *, int);
int main() {
  char buff[4096];
  int n;
  while ((n = read(STDIN_FILENO, buff, 4096)) > 0)
    if (write(STDOUT_FILENO, buff, n) < n) {
      perror("write");
      exit(0);
    }
  if (n < 0) {
    perror("read");
    exit(0);
  }
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x1020,%rsp
movl   $0x0,-0x4(%rbp)
mov    0x2e7f(%rip),%rax
mov    (%rax),%edi
lea    -0x1010(%rbp),%rsi
mov    $0x1000,%edx
call   1040 <read@plt>
mov    %eax,-0x1014(%rbp)
cmp    $0x0,%eax
jle    11ba <main+0x7a>
mov    0x2e6e(%rip),%rax
mov    (%rax),%edi
lea    -0x1010(%rbp),%rsi
mov    -0x1014(%rbp),%edx
call   1030 <write@plt>
cmp    -0x1014(%rbp),%eax
jge    11b5 <main+0x75>
lea    0xe57(%rip),%rdi
call   1050 <perror@plt>
xor    %edi,%edi
call   1060 <exit@plt>
jmp    1152 <main+0x12>
cmpl   $0x0,-0x1014(%rbp)
jge    11da <main+0x9a>
lea    0xe38(%rip),%rdi
call   1050 <perror@plt>
xor    %edi,%edi
call   1060 <exit@plt>
xor    %eax,%eax
add    $0x1020,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rbp
push   %r15
push   %r14
push   %rbx
sub    $0x1008,%rsp
mov    0x2e84(%rip),%r14
mov    %rsp,%rbx
mov    0x2e92(%rip),%r15
xchg   %ax,%ax
mov    (%r14),%edi
mov    %rbx,%rsi
mov    $0x1000,%edx
call   1040 <read@plt>
test   %eax,%eax
jle    119a <main+0x5a>
mov    %eax,%ebp
mov    (%r15),%edi
mov    %rbx,%rsi
mov    %eax,%edx
call   1030 <write@plt>
cmp    %ebp,%eax
jge    1160 <main+0x20>
lea    0xe72(%rip),%rdi
call   1050 <perror@plt>
xor    %edi,%edi
call   1060 <exit@plt>
js     11ac <main+0x6c>
xor    %eax,%eax
add    $0x1008,%rsp
pop    %rbx
pop    %r14
pop    %r15
pop    %rbp
ret
lea    0xe53(%rip),%rdi
jmp    118e <main+0x4e>

LLVM IR (-O0):
@STDIN_FILENO = global i32 0
@STDOUT_FILENO = global i32 0
@.str = [6 x i8] c"write\00"
@.str.1 = [5 x i8] c"read\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca [4096 x i8]
%3 = alloca i32
store i32 0, i32* %1
br label %4
4: ; preds = %19, %0
%5 = load i32, i32* @STDIN_FILENO
%6 = getelementptr inbounds [4096 x i8], [4096 x i8]* %2, i64 0, i64 0
%7 = call i32 @read(i32 %5, i8* %6, i32 4096)
store i32 %7, i32* %3
%8 = icmp sgt i32 %7, 0
br i1 %8, label %9, label %20
9: ; preds = %4
%10 = load i32, i32* @STDOUT_FILENO
%11 = getelementptr inbounds [4096 x i8], [4096 x i8]* %2, i64 0, i64 0
%12 = load i32, i32* %3
%13 = call i32 @write(i32 %10, i8* %11, i32 %12)
%14 = load i32, i32* %3
%15 = icmp slt i32 %13, %14
br i1 %15, label %16, label %19
16: ; preds = %9
%17 = call i32 @perror(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str, i64 0, i64 0))
%18 = call i32 @exit(i32 0)
unreachable
19: ; preds = %9
br label %4
20: ; preds = %4
%21 = load i32, i32* %3
%22 = icmp slt i32 %21, 0
br i1 %22, label %23, label %26
23: ; preds = %20
%24 = call i32 @perror(i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str.1, i64 0, i64 0))
%25 = call i32 @exit(i32 0)
unreachable
26: ; preds = %20
ret i32 0
}

LLVM IR (-O2):
@STDIN_FILENO = global i32 0
@STDOUT_FILENO = global i32 0
@.str = [6 x i8] c"write\00"
@.str.1 = [5 x i8] c"read\00"
define i32 @main() {
%1 = alloca [4096 x i8]
%2 = getelementptr inbounds [4096 x i8], [4096 x i8]* %1, i64 0, i64 0
br label %3
3: ; preds = %7, %0
%4 = load i32, i32* @STDIN_FILENO
%5 = call i32 @read(i32 %4, i8* %2, i32 4096)
%6 = icmp sgt i32 %5, 0
br i1 %6, label %7, label %14
7: ; preds = %3
%8 = load i32, i32* @STDOUT_FILENO
%9 = call i32 @write(i32 %8, i8* %2, i32 %5)
%10 = icmp slt i32 %9, %5
br i1 %10, label %11, label %3
11: ; preds = %7
%12 = tail call i32 @perror(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str, i64 0, i64 0))
%13 = tail call i32 @exit(i32 0)
unreachable
14: ; preds = %3
%15 = icmp slt i32 %5, 0
br i1 %15, label %16, label %19
16: ; preds = %14
%17 = tail call i32 @perror(i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str.1, i64 0, i64 0))
%18 = tail call i32 @exit(i32 0)
unreachable
19: ; preds = %14
ret i32 0
}