#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*/ SEEK_END;
int /*<<< orphan*/ SEEK_SET;
int /*<<< orphan*/ fclose(int /*<<< orphan*/ *);
int /*<<< orphan*/ *fopen(char const *, char *);
int /*<<< orphan*/ fread(char *, long, int, int /*<<< orphan*/ *);
int /*<<< orphan*/ fseek(int /*<<< orphan*/ *, long, int /*<<< orphan*/);
long ftell(int /*<<< orphan*/ *);
char *malloc(long);
char *config_read_file(const char *filename, int *length) {
  FILE *cfg;
  long len;
  char *buf;
  cfg = fopen(filename, "r");
  if (cfg == NULL)
    return NULL;
  fseek(cfg, 0L, SEEK_END);
  len = ftell(cfg);
  fseek(cfg, 0L, SEEK_SET);
  buf = malloc(len);
  if (buf == NULL) {
    fclose(cfg);
    return NULL;
  }
  fread(buf, len, 1, cfg);
  fclose(cfg);
  *length = len;
  return buf;
}


x86 assembly (clang, -O0):
<config_read_file>:
push   %rbp
mov    %rsp,%rbp
sub    $0x30,%rsp
mov    %rdi,-0x10(%rbp)
mov    %rsi,-0x18(%rbp)
mov    -0x10(%rbp),%rdi
lea    0xe85(%rip),%rsi
call   1080 <fopen@plt>
mov    %rax,-0x20(%rbp)
cmpq   $0x0,-0x20(%rbp)
jne    119c <config_read_file+0x3c>
movq   $0x0,-0x8(%rbp)
jmp    1236 <config_read_file+0xd6>
mov    -0x20(%rbp),%rdi
mov    0x2e41(%rip),%rax
mov    (%rax),%edx
xor    %eax,%eax
mov    %eax,%esi
call   1070 <fseek@plt>
mov    -0x20(%rbp),%rdi
call   1050 <ftell@plt>
mov    %rax,-0x28(%rbp)
mov    -0x20(%rbp),%rdi
mov    0x2e0e(%rip),%rax
mov    (%rax),%edx
xor    %eax,%eax
mov    %eax,%esi
call   1070 <fseek@plt>
mov    -0x28(%rbp),%rdi
call   1060 <malloc@plt>
mov    %rax,-0x30(%rbp)
cmpq   $0x0,-0x30(%rbp)
jne    1203 <config_read_file+0xa3>
mov    -0x20(%rbp),%rdi
call   1040 <fclose@plt>
movq   $0x0,-0x8(%rbp)
jmp    1236 <config_read_file+0xd6>
mov    -0x30(%rbp),%rdi
mov    -0x28(%rbp),%rsi
mov    -0x20(%rbp),%rcx
mov    $0x1,%edx
call   1030 <fread@plt>
mov    -0x20(%rbp),%rdi
call   1040 <fclose@plt>
mov    -0x28(%rbp),%rax
mov    %eax,%ecx
mov    -0x18(%rbp),%rax
mov    %ecx,(%rax)
mov    -0x30(%rbp),%rax
mov    %rax,-0x8(%rbp)
mov    -0x8(%rbp),%rax
add    $0x30,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<config_read_file>:
push   %r15
push   %r14
push   %r12
push   %rbx
push   %rax
mov    %rsi,%r14
lea    0xe8e(%rip),%rsi
call   1080 <fopen@plt>
test   %rax,%rax
je     11e8 <config_read_file+0x88>
mov    %rax,%rbx
mov    0x2e62(%rip),%rax
mov    (%rax),%edx
mov    %rbx,%rdi
xor    %esi,%esi
call   1070 <fseek@plt>
mov    %rbx,%rdi
call   1050 <ftell@plt>
mov    %rax,%r15
mov    0x2e34(%rip),%rax
mov    (%rax),%edx
mov    %rbx,%rdi
xor    %esi,%esi
call   1070 <fseek@plt>
mov    %r15,%rdi
call   1060 <malloc@plt>
test   %rax,%rax
je     11e0 <config_read_file+0x80>
mov    %rax,%r12
mov    %rax,%rdi
mov    %r15,%rsi
mov    $0x1,%edx
mov    %rbx,%rcx
call   1030 <fread@plt>
mov    %rbx,%rdi
call   1040 <fclose@plt>
mov    %r15d,(%r14)
jmp    11eb <config_read_file+0x8b>
mov    %rbx,%rdi
call   1040 <fclose@plt>
xor    %r12d,%r12d
mov    %r12,%rax
add    $0x8,%rsp
pop    %rbx
pop    %r12
pop    %r14
pop    %r15
ret

LLVM IR (-O0):
@.str = [2 x i8] c"r\00"
@SEEK_END = global i32 0
@SEEK_SET = global i32 0
define i8* @config_read_file(i8* %0, i32* %1) {
%3 = alloca i8*
%4 = alloca i8*
%5 = alloca i32*
%6 = alloca i32*
%7 = alloca i64
%8 = alloca i8*
store i8* %0, i8** %4
store i32* %1, i32** %5
%9 = load i8*, i8** %4
%10 = call i32* @fopen(i8* %9, i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str, i64 0, i64 0))
store i32* %10, i32** %6
%11 = load i32*, i32** %6
%12 = icmp eq i32* %11, null
br i1 %12, label %13, label %14
13: ; preds = %2
store i8* null, i8** %3
br label %41
14: ; preds = %2
%15 = load i32*, i32** %6
%16 = load i32, i32* @SEEK_END
%17 = call i32 @fseek(i32* %15, i64 0, i32 %16)
%18 = load i32*, i32** %6
%19 = call i64 @ftell(i32* %18)
store i64 %19, i64* %7
%20 = load i32*, i32** %6
%21 = load i32, i32* @SEEK_SET
%22 = call i32 @fseek(i32* %20, i64 0, i32 %21)
%23 = load i64, i64* %7
%24 = call i8* @malloc(i64 %23)
store i8* %24, i8** %8
%25 = load i8*, i8** %8
%26 = icmp eq i8* %25, null
br i1 %26, label %27, label %30
27: ; preds = %14
%28 = load i32*, i32** %6
%29 = call i32 @fclose(i32* %28)
store i8* null, i8** %3
br label %41
30: ; preds = %14
%31 = load i8*, i8** %8
%32 = load i64, i64* %7
%33 = load i32*, i32** %6
%34 = call i32 @fread(i8* %31, i64 %32, i32 1, i32* %33)
%35 = load i32*, i32** %6
%36 = call i32 @fclose(i32* %35)
%37 = load i64, i64* %7
%38 = trunc i64 %37 to i32
%39 = load i32*, i32** %5
store i32 %38, i32* %39
%40 = load i8*, i8** %8
store i8* %40, i8** %3
br label %41
41: ; preds = %30, %27, %13
%42 = load i8*, i8** %3
ret i8* %42
}

LLVM IR (-O2):
@.str = [2 x i8] c"r\00"
@SEEK_END = global i32 0
@SEEK_SET = global i32 0
define noalias i8* @config_read_file(i8* nocapture %0, i32* nocapture writeonly %1) {
%3 = tail call i32* @fopen(i8* %0, i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str, i64 0, i64 0))
%4 = icmp eq i32* %3, null
br i1 %4, label %19, label %5
5: ; preds = %2
%6 = load i32, i32* @SEEK_END
%7 = tail call i32 @fseek(i32* %3, i64 0, i32 %6)
%8 = tail call i64 @ftell(i32* %3)
%9 = load i32, i32* @SEEK_SET
%10 = tail call i32 @fseek(i32* %3, i64 0, i32 %9)
%11 = tail call i8* @malloc(i64 %8)
%12 = icmp eq i8* %11, null
br i1 %12, label %13, label %15
13: ; preds = %5
%14 = tail call i32 @fclose(i32* %3)
br label %19
15: ; preds = %5
%16 = tail call i32 @fread(i8* %11, i64 %8, i32 1, i32* %3)
%17 = tail call i32 @fclose(i32* %3)
%18 = trunc i64 %8 to i32
store i32 %18, i32* %1
br label %19
19: ; preds = %2, %15, %13
%20 = phi i8* [ null, %13 ], [ %11, %15 ], [ null, %2 ]
ret i8* %20
}