#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;
char *calloc(long, int);
int /*<<< orphan*/ fclose(int /*<<< orphan*/ *);
int /*<<< orphan*/ *fopen(char const *, char *);
int /*<<< orphan*/ fread(char *, int, long, int /*<<< orphan*/ *);
int /*<<< orphan*/ fseek(int /*<<< orphan*/ *, int /*<<< orphan*/,
                         int /*<<< orphan*/);
int ftell(int /*<<< orphan*/ *);
char *file_read(const char *filename) {
  FILE *fp;
  char *buffer;
  long fsize;
  int fres;
  fp = fopen(filename, "r");
  if (fp == NULL) {
    return NULL;
  }
  fseek(fp, 0, SEEK_END);
  fsize = ftell(fp) + 1;
  fseek(fp, 0, SEEK_SET);
  buffer = calloc(fsize, sizeof(char));
  if (buffer == NULL) {
    fclose(fp);
    return NULL;
  }
  fread(buffer, sizeof(char), fsize, fp);
  fclose(fp);
  return buffer;
}


x86 assembly (clang, -O0):
<file_read>:
push   %rbp
mov    %rsp,%rbp
sub    $0x30,%rsp
mov    %rdi,-0x10(%rbp)
mov    -0x10(%rbp),%rdi
lea    0xe89(%rip),%rsi
call   1080 <fopen@plt>
mov    %rax,-0x18(%rbp)
cmpq   $0x0,-0x18(%rbp)
jne    1198 <file_read+0x38>
movq   $0x0,-0x8(%rbp)
jmp    122c <file_read+0xcc>
mov    -0x18(%rbp),%rdi
mov    0x2e45(%rip),%rax
mov    (%rax),%edx
xor    %esi,%esi
call   1070 <fseek@plt>
mov    -0x18(%rbp),%rdi
call   1060 <ftell@plt>
add    $0x1,%eax
cltq
mov    %rax,-0x28(%rbp)
mov    -0x18(%rbp),%rdi
mov    0x2e0f(%rip),%rax
mov    (%rax),%edx
xor    %esi,%esi
call   1070 <fseek@plt>
mov    -0x28(%rbp),%rdi
mov    $0x1,%esi
call   1050 <calloc@plt>
mov    %rax,-0x20(%rbp)
cmpq   $0x0,-0x20(%rbp)
jne    1205 <file_read+0xa5>
mov    -0x18(%rbp),%rdi
call   1040 <fclose@plt>
movq   $0x0,-0x8(%rbp)
jmp    122c <file_read+0xcc>
mov    -0x20(%rbp),%rdi
mov    -0x28(%rbp),%rdx
mov    -0x18(%rbp),%rcx
mov    $0x1,%esi
call   1030 <fread@plt>
mov    -0x18(%rbp),%rdi
call   1040 <fclose@plt>
mov    -0x20(%rbp),%rax
mov    %rax,-0x8(%rbp)
mov    -0x8(%rbp),%rax
add    $0x30,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<file_read>:
push   %r15
push   %r14
push   %r12
push   %rbx
push   %rax
lea    0xe91(%rip),%rsi
call   1080 <fopen@plt>
test   %rax,%rax
je     11e8 <file_read+0x88>
mov    %rax,%rbx
mov    0x2e65(%rip),%rax
mov    (%rax),%edx
xor    %r14d,%r14d
mov    %rbx,%rdi
xor    %esi,%esi
call   1070 <fseek@plt>
mov    %rbx,%rdi
call   1060 <ftell@plt>
add    $0x1,%eax
movslq %eax,%r15
mov    0x2e31(%rip),%rax
mov    (%rax),%edx
mov    %rbx,%rdi
xor    %esi,%esi
call   1070 <fseek@plt>
mov    %r15,%rdi
mov    $0x1,%esi
call   1050 <calloc@plt>
test   %rax,%rax
je     11de <file_read+0x7e>
mov    %rax,%r12
mov    %rax,%rdi
mov    $0x1,%esi
mov    %r15,%rdx
mov    %rbx,%rcx
call   1030 <fread@plt>
mov    %r12,%r14
mov    %rbx,%rdi
call   1040 <fclose@plt>
jmp    11eb <file_read+0x8b>
xor    %r14d,%r14d
mov    %r14,%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* @file_read(i8* %0) {
%2 = alloca i8*
%3 = alloca i8*
%4 = alloca i32*
%5 = alloca i8*
%6 = alloca i64
%7 = alloca i32
store i8* %0, i8** %3
%8 = load i8*, i8** %3
%9 = call i32* @fopen(i8* %8, i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str, i64 0, i64 0))
store i32* %9, i32** %4
%10 = load i32*, i32** %4
%11 = icmp eq i32* %10, null
br i1 %11, label %12, label %13
12: ; preds = %1
store i8* null, i8** %2
br label %39
13: ; preds = %1
%14 = load i32*, i32** %4
%15 = load i32, i32* @SEEK_END
%16 = call i32 @fseek(i32* %14, i32 0, i32 %15)
%17 = load i32*, i32** %4
%18 = call i32 @ftell(i32* %17)
%19 = add nsw i32 %18, 1
%20 = sext i32 %19 to i64
store i64 %20, i64* %6
%21 = load i32*, i32** %4
%22 = load i32, i32* @SEEK_SET
%23 = call i32 @fseek(i32* %21, i32 0, i32 %22)
%24 = load i64, i64* %6
%25 = call i8* @calloc(i64 %24, i32 1)
store i8* %25, i8** %5
%26 = load i8*, i8** %5
%27 = icmp eq i8* %26, null
br i1 %27, label %28, label %31
28: ; preds = %13
%29 = load i32*, i32** %4
%30 = call i32 @fclose(i32* %29)
store i8* null, i8** %2
br label %39
31: ; preds = %13
%32 = load i8*, i8** %5
%33 = load i64, i64* %6
%34 = load i32*, i32** %4
%35 = call i32 @fread(i8* %32, i32 1, i64 %33, i32* %34)
%36 = load i32*, i32** %4
%37 = call i32 @fclose(i32* %36)
%38 = load i8*, i8** %5
store i8* %38, i8** %2
br label %39
39: ; preds = %31, %28, %12
%40 = load i8*, i8** %2
ret i8* %40
}

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