#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 mntent {
  int dummy;
};
typedef int /*<<< orphan*/ FILE;

/* Variables and functions */
int /*<<< orphan*/ addmntent(int /*<<< orphan*/ *, struct mntent *);
int /*<<< orphan*/ endmntent(int /*<<< orphan*/ *);
int /*<<< orphan*/ exit(int);
int /*<<< orphan*/ perror(char *);
int /*<<< orphan*/ *setmntent(char *, char *);
void add2mtab(struct mntent *mnt) {
  FILE *f;
  f = setmntent("/etc/mtab", "a");
  if (f == NULL) {
    perror("/etc/mtab");
    exit(1);
  }
  addmntent(f, mnt);
  endmntent(f);
}


x86 assembly (clang, -O0):
<add2mtab>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
mov    %rdi,-0x8(%rbp)
lea    0xe9d(%rip),%rdi
lea    0xea0(%rip),%rsi
call   1050 <setmntent@plt>
mov    %rax,-0x10(%rbp)
cmpq   $0x0,-0x10(%rbp)
jne    1194 <add2mtab+0x44>
lea    0xe7b(%rip),%rdi
call   1060 <perror@plt>
mov    $0x1,%edi
call   1070 <exit@plt>
mov    -0x10(%rbp),%rdi
mov    -0x8(%rbp),%rsi
call   1040 <addmntent@plt>
mov    -0x10(%rbp),%rdi
call   1030 <endmntent@plt>
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<add2mtab>:
push   %r14
push   %rbx
push   %rax
mov    %rdi,%r14
lea    0xea2(%rip),%rdi
lea    0xea5(%rip),%rsi
call   1050 <setmntent@plt>
test   %rax,%rax
je     118c <add2mtab+0x3c>
mov    %rax,%rbx
mov    %rax,%rdi
mov    %r14,%rsi
call   1040 <addmntent@plt>
mov    %rbx,%rdi
add    $0x8,%rsp
pop    %rbx
pop    %r14
jmp    1030 <endmntent@plt>
lea    0xe6d(%rip),%rdi
call   1060 <perror@plt>
mov    $0x1,%edi
call   1070 <exit@plt>

LLVM IR (-O0):
%struct.mntent = type { i32 }
@.str = [10 x i8] c"/etc/mtab\00"
@.str.1 = [2 x i8] c"a\00"
define void @add2mtab(%struct.mntent* %0) {
%2 = alloca %struct.mntent*
%3 = alloca i32*
store %struct.mntent* %0, %struct.mntent** %2
%4 = call i32* @setmntent(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str, i64 0, i64 0), i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str.1, i64 0, i64 0))
store i32* %4, i32** %3
%5 = load i32*, i32** %3
%6 = icmp eq i32* %5, null
br i1 %6, label %7, label %10
7: ; preds = %1
%8 = call i32 @perror(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str, i64 0, i64 0))
%9 = call i32 @exit(i32 1)
unreachable
10: ; preds = %1
%11 = load i32*, i32** %3
%12 = load %struct.mntent*, %struct.mntent** %2
%13 = call i32 @addmntent(i32* %11, %struct.mntent* %12)
%14 = load i32*, i32** %3
%15 = call i32 @endmntent(i32* %14)
ret void
}

LLVM IR (-O2):
%struct.mntent = type { i32 }
@.str = [10 x i8] c"/etc/mtab\00"
@.str.1 = [2 x i8] c"a\00"
define void @add2mtab(%struct.mntent* %0) {
%2 = tail call i32* @setmntent(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str, i64 0, i64 0), i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str.1, i64 0, i64 0))
%3 = icmp eq i32* %2, null
br i1 %3, label %4, label %7
4: ; preds = %1
%5 = tail call i32 @perror(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str, i64 0, i64 0))
%6 = tail call i32 @exit(i32 1)
unreachable
7: ; preds = %1
%8 = tail call i32 @addmntent(i32* %2, %struct.mntent* %0)
%9 = tail call i32 @endmntent(i32* %2)
ret void
}