#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 /*<<< orphan*/ uint8_t;

/* Variables and functions */
int /*<<< orphan*/ exit(int);
int /*<<< orphan*/ fprintf(int /*<<< orphan*/, char *);
int /*<<< orphan*/ perror(char *);
int read(int, int /*<<< orphan*/ *, int);
int /*<<< orphan*/ stderr;
int _read(int fd, uint8_t *buf, int len) {
  int n;
  n = read(fd, buf, len);
  if (n < 0) {
    perror("read");
    exit(1);
  }
  if (n == 0) {
    fprintf(stderr, "premature EOF on read\n");
    exit(1);
  }
  return n;
}


x86 assembly (clang, -O0):
<_read>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
mov    %edi,-0x4(%rbp)
mov    %rsi,-0x10(%rbp)
mov    %edx,-0x14(%rbp)
mov    -0x4(%rbp),%edi
mov    -0x10(%rbp),%rsi
mov    -0x14(%rbp),%edx
call   1030 <read@plt>
mov    %eax,-0x18(%rbp)
cmpl   $0x0,-0x18(%rbp)
jge    1184 <_read+0x44>
lea    0xe8b(%rip),%rdi
call   1050 <perror@plt>
mov    $0x1,%edi
call   1060 <exit@plt>
cmpl   $0x0,-0x18(%rbp)
jne    11ad <_read+0x6d>
mov    0x2e4b(%rip),%rax
mov    (%rax),%edi
lea    0xe67(%rip),%rsi
call   1040 <fprintf@plt>
mov    $0x1,%edi
call   1060 <exit@plt>
mov    -0x18(%rbp),%eax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<_read>:
push   %rax
call   1030 <read@plt>
test   %eax,%eax
js     114e <_read+0xe>
je     1164 <_read+0x24>
pop    %rcx
ret
lea    0xeab(%rip),%rdi
call   1050 <perror@plt>
mov    $0x1,%edi
call   1060 <exit@plt>
mov    0x2e75(%rip),%rax
mov    (%rax),%edi
lea    0xe91(%rip),%rsi
call   1040 <fprintf@plt>
mov    $0x1,%edi
call   1060 <exit@plt>

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

LLVM IR (-O2):
@.str = [5 x i8] c"read\00"
@stderr = global i32 0
@.str.1 = [23 x i8] c"premature EOF on read\0A\00"
define i32 @_read(i32 %0, i32* nocapture %1, i32 %2) {
%4 = tail call i32 @read(i32 %0, i32* %1, i32 %2)
%5 = icmp slt i32 %4, 0
br i1 %5, label %6, label %9
6: ; preds = %3
%7 = tail call i32 @perror(i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str, i64 0, i64 0))
%8 = tail call i32 @exit(i32 1)
unreachable
9: ; preds = %3
%10 = icmp eq i32 %4, 0
br i1 %10, label %11, label %15
11: ; preds = %9
%12 = load i32, i32* @stderr
%13 = tail call i32 @fprintf(i32 %12, i8* getelementptr inbounds ([23 x i8], [23 x i8]* @.str.1, i64 0, i64 0))
%14 = tail call i32 @exit(i32 1)
unreachable
15: ; preds = %9
ret i32 %4
}