#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*/ r;

/* Variables and functions */
int /*<<< orphan*/ O_RDONLY;
int /*<<< orphan*/ close(int);
int /*<<< orphan*/ exit(int /*<<< orphan*/);
int open(char *, int /*<<< orphan*/);
int /*<<< orphan*/ perror(char *);
int /*<<< orphan*/ read(int, int *, int);
int getseed(void) {
  int fd = open("/dev/urandom", O_RDONLY);
  int r;
  if (fd < 0) {
    perror("open");
    exit(0);
  }
  read(fd, &r, sizeof(r));
  close(fd);
  return (r);
}


x86 assembly (clang, -O0):
<getseed>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
mov    0x2e89(%rip),%rax
mov    (%rax),%esi
lea    0xe98(%rip),%rdi
call   1050 <open@plt>
mov    %eax,-0x4(%rbp)
cmpl   $0x0,-0x4(%rbp)
jge    118d <getseed+0x3d>
lea    0xe8c(%rip),%rdi
call   1060 <perror@plt>
xor    %edi,%edi
call   1070 <exit@plt>
mov    -0x4(%rbp),%edi
lea    -0x8(%rbp),%rsi
mov    $0x4,%edx
call   1040 <read@plt>
mov    -0x4(%rbp),%edi
call   1030 <close@plt>
mov    -0x8(%rbp),%eax
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<getseed>:
push   %rbx
sub    $0x10,%rsp
mov    0x2e8c(%rip),%rax
mov    (%rax),%esi
lea    0xe9b(%rip),%rdi
call   1050 <open@plt>
test   %eax,%eax
js     1192 <getseed+0x42>
mov    %eax,%ebx
lea    0xc(%rsp),%rsi
mov    %eax,%edi
mov    $0x4,%edx
call   1040 <read@plt>
mov    %ebx,%edi
call   1030 <close@plt>
mov    0xc(%rsp),%eax
add    $0x10,%rsp
pop    %rbx
ret
lea    0xe74(%rip),%rdi
call   1060 <perror@plt>
xor    %edi,%edi
call   1070 <exit@plt>

LLVM IR (-O0):
@.str = [13 x i8] c"/dev/urandom\00"
@O_RDONLY = global i32 0
@.str.1 = [5 x i8] c"open\00"
define i32 @getseed() {
%1 = alloca i32
%2 = alloca i32
%3 = load i32, i32* @O_RDONLY
%4 = call i32 @open(i8* getelementptr inbounds ([13 x i8], [13 x i8]* @.str, i64 0, i64 0), i32 %3)
store i32 %4, i32* %1
%5 = load i32, i32* %1
%6 = icmp slt i32 %5, 0
br i1 %6, label %7, label %10
7: ; preds = %0
%8 = call i32 @perror(i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str.1, i64 0, i64 0))
%9 = call i32 @exit(i32 0)
unreachable
10: ; preds = %0
%11 = load i32, i32* %1
%12 = call i32 @read(i32 %11, i32* %2, i32 4)
%13 = load i32, i32* %1
%14 = call i32 @close(i32 %13)
%15 = load i32, i32* %2
ret i32 %15
}

LLVM IR (-O2):
@.str = [13 x i8] c"/dev/urandom\00"
@O_RDONLY = global i32 0
@.str.1 = [5 x i8] c"open\00"
define i32 @getseed() {
%1 = alloca i32
%2 = load i32, i32* @O_RDONLY
%3 = tail call i32 @open(i8* getelementptr inbounds ([13 x i8], [13 x i8]* @.str, i64 0, i64 0), i32 %2)
%4 = bitcast i32* %1 to i8*
%5 = icmp slt i32 %3, 0
br i1 %5, label %6, label %9
6: ; preds = %0
%7 = tail call i32 @perror(i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str.1, i64 0, i64 0))
%8 = tail call i32 @exit(i32 0)
unreachable
9: ; preds = %0
%10 = call i32 @read(i32 %3, i32* %1, i32 4)
%11 = tail call i32 @close(i32 %3)
%12 = load i32, i32* %1
ret i32 %12
}