#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*/ FILE;

/* Variables and functions */
int /*<<< orphan*/ fclose(int /*<<< orphan*/ *);
int /*<<< orphan*/ *fopen(char *, char *);
int /*<<< orphan*/ fputs(char *, int /*<<< orphan*/ *);
int /*<<< orphan*/ perror(char *);
int elog(char *msg) {
  FILE *fp = fopen("debug.log", "a+");
  if (fp == NULL) {
    perror("In elog:fopen debug.log error!");
    return 1;
  }
  fputs(msg, fp);
  fclose(fp);
  return 0;
}


x86 assembly (clang, -O0):
<elog>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
mov    %rdi,-0x10(%rbp)
lea    0xead(%rip),%rdi
lea    0xeb0(%rip),%rsi
call   1050 <fopen@plt>
mov    %rax,-0x18(%rbp)
cmpq   $0x0,-0x18(%rbp)
jne    1186 <elog+0x46>
lea    0xe98(%rip),%rdi
call   1060 <perror@plt>
movl   $0x1,-0x4(%rbp)
jmp    11a3 <elog+0x63>
mov    -0x10(%rbp),%rdi
mov    -0x18(%rbp),%rsi
call   1040 <fputs@plt>
mov    -0x18(%rbp),%rdi
call   1030 <fclose@plt>
movl   $0x0,-0x4(%rbp)
mov    -0x4(%rbp),%eax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<elog>:
push   %r14
push   %rbx
push   %rax
mov    %rdi,%r14
lea    0xeb2(%rip),%rdi
lea    0xeb5(%rip),%rsi
call   1050 <fopen@plt>
test   %rax,%rax
je     117f <elog+0x3f>
mov    %rax,%rbx
mov    %r14,%rdi
mov    %rax,%rsi
call   1040 <fputs@plt>
mov    %rbx,%rdi
call   1030 <fclose@plt>
xor    %eax,%eax
add    $0x8,%rsp
pop    %rbx
pop    %r14
ret
lea    0xe87(%rip),%rdi
call   1060 <perror@plt>
mov    $0x1,%eax
jmp    1177 <elog+0x37>

LLVM IR (-O0):
@.str = [10 x i8] c"debug.log\00"
@.str.1 = [3 x i8] c"a+\00"
@.str.2 = [31 x i8] c"In elog:fopen debug.log error!\00"
define i32 @elog(i8* %0) {
%2 = alloca i32
%3 = alloca i8*
%4 = alloca i32*
store i8* %0, i8** %3
%5 = call i32* @fopen(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str, i64 0, i64 0), i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0))
store i32* %5, i32** %4
%6 = load i32*, i32** %4
%7 = icmp eq i32* %6, null
br i1 %7, label %8, label %10
8: ; preds = %1
%9 = call i32 @perror(i8* getelementptr inbounds ([31 x i8], [31 x i8]* @.str.2, i64 0, i64 0))
store i32 1, i32* %2
br label %16
10: ; preds = %1
%11 = load i8*, i8** %3
%12 = load i32*, i32** %4
%13 = call i32 @fputs(i8* %11, i32* %12)
%14 = load i32*, i32** %4
%15 = call i32 @fclose(i32* %14)
store i32 0, i32* %2
br label %16
16: ; preds = %10, %8
%17 = load i32, i32* %2
ret i32 %17
}

LLVM IR (-O2):
@.str = [10 x i8] c"debug.log\00"
@.str.1 = [3 x i8] c"a+\00"
@.str.2 = [31 x i8] c"In elog:fopen debug.log error!\00"
define i32 @elog(i8* nocapture %0) {
%2 = tail call i32* @fopen(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str, i64 0, i64 0), i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0))
%3 = icmp eq i32* %2, null
br i1 %3, label %4, label %6
4: ; preds = %1
%5 = tail call i32 @perror(i8* getelementptr inbounds ([31 x i8], [31 x i8]* @.str.2, i64 0, i64 0))
br label %9
6: ; preds = %1
%7 = tail call i32 @fputs(i8* %0, i32* %2)
%8 = tail call i32 @fclose(i32* %2)
br label %9
9: ; preds = %6, %4
%10 = phi i32 [ 1, %4 ], [ 0, %6 ]
ret i32 %10
}