#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*/ *fopen(char *, char *);
int /*<<< orphan*/ fread(unsigned char *, int, size_t, int /*<<< orphan*/ *);
int /*<<< orphan*/ fseek(int /*<<< orphan*/ *, int /*<<< orphan*/,
                         int /*<<< orphan*/);
size_t ftell(int /*<<< orphan*/ *);
unsigned char *malloc(size_t);
unsigned char *read_buffer(char *file_name, size_t *size_ptr) {
  FILE *f;
  unsigned char *buf;
  size_t size;
  f = fopen(file_name, "rb");
  if (!f)
    return NULL;
  fseek(f, 0, SEEK_END);
  size = ftell(f);
  fseek(f, 0, SEEK_SET);
  buf = malloc(size + 1);
  fread(buf, 1, size, f);
  buf[size] = '\0';
  if (size_ptr)
    *size_ptr = size;
  return buf;
}


x86 assembly (clang, -O0):
<read_buffer>:
push   %rbp
mov    %rsp,%rbp
sub    $0x30,%rsp
mov    %rdi,-0x10(%rbp)
mov    %rsi,-0x18(%rbp)
mov    -0x10(%rbp),%rdi
lea    0xe95(%rip),%rsi
call   1070 <fopen@plt>
mov    %rax,-0x20(%rbp)
cmpq   $0x0,-0x20(%rbp)
jne    118c <read_buffer+0x3c>
movq   $0x0,-0x8(%rbp)
jmp    1212 <read_buffer+0xc2>
mov    -0x20(%rbp),%rdi
mov    0x2e51(%rip),%rax
mov    (%rax),%edx
xor    %esi,%esi
call   1060 <fseek@plt>
mov    -0x20(%rbp),%rdi
call   1040 <ftell@plt>
mov    %rax,-0x30(%rbp)
mov    -0x20(%rbp),%rdi
mov    0x2e20(%rip),%rax
mov    (%rax),%edx
xor    %esi,%esi
call   1060 <fseek@plt>
mov    -0x30(%rbp),%rdi
add    $0x1,%rdi
call   1050 <malloc@plt>
mov    %rax,-0x28(%rbp)
mov    -0x28(%rbp),%rdi
mov    -0x30(%rbp),%rdx
mov    -0x20(%rbp),%rcx
mov    $0x1,%esi
call   1030 <fread@plt>
mov    -0x28(%rbp),%rax
mov    -0x30(%rbp),%rcx
movb   $0x0,(%rax,%rcx,1)
cmpq   $0x0,-0x18(%rbp)
je     120a <read_buffer+0xba>
mov    -0x30(%rbp),%rcx
mov    -0x18(%rbp),%rax
mov    %rcx,(%rax)
mov    -0x28(%rbp),%rax
mov    %rax,-0x8(%rbp)
mov    -0x8(%rbp),%rax
add    $0x30,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<read_buffer>:
push   %r15
push   %r14
push   %r12
push   %rbx
push   %rax
mov    %rsi,%r14
lea    0xe9e(%rip),%rsi
call   1070 <fopen@plt>
test   %rax,%rax
je     11ce <read_buffer+0x7e>
mov    %rax,%rbx
mov    0x2e72(%rip),%rax
mov    (%rax),%edx
mov    %rbx,%rdi
xor    %esi,%esi
call   1060 <fseek@plt>
mov    %rbx,%rdi
call   1040 <ftell@plt>
mov    %rax,%r15
mov    0x2e44(%rip),%rax
mov    (%rax),%edx
mov    %rbx,%rdi
xor    %esi,%esi
call   1060 <fseek@plt>
lea    0x1(%r15),%rdi
call   1050 <malloc@plt>
mov    %rax,%r12
mov    %rax,%rdi
mov    $0x1,%esi
mov    %r15,%rdx
mov    %rbx,%rcx
call   1030 <fread@plt>
movb   $0x0,(%r12,%r15,1)
test   %r14,%r14
je     11d1 <read_buffer+0x81>
mov    %r15,(%r14)
jmp    11d1 <read_buffer+0x81>
xor    %r12d,%r12d
mov    %r12,%rax
add    $0x8,%rsp
pop    %rbx
pop    %r12
pop    %r14
pop    %r15
ret

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

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