#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 */

/* Variables and functions */
int /*<<< orphan*/ exit(int);
int /*<<< orphan*/ free(int *);
int *malloc(int);
int /*<<< orphan*/ merge_sort(int *, int);
int /*<<< orphan*/ perror(char *);
int /*<<< orphan*/ printf(char *, ...);
int /*<<< orphan*/ scanf(char *, int *);
int main() {
  int length;
  for (;;) {
    printf("Enter a positive length: ");
    scanf("%d", &length);
    if (length > 1) {
      break;
    } else {
      printf("You entered length = %d\n\n", length);
    }
  }
  int *arr = malloc(sizeof(int) * length);
  if (arr == NULL) {
    perror("The following error occurred");
    exit(-1);
  }
  for (int i = 0; i < length; i++) {
    scanf("%d", &arr[i]);
  }
  merge_sort(arr, length);
  for (int i = 0; i < length; i++) {
    printf("%d ", arr[i]);
  }
  free(arr);
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
movl   $0x0,-0x4(%rbp)
lea    0xe7a(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
lea    0xe86(%rip),%rdi
lea    -0x8(%rbp),%rsi
call   1070 <scanf@plt>
cmpl   $0x1,-0x8(%rbp)
jle    11ac <main+0x3c>
jmp    11c2 <main+0x52>
mov    -0x8(%rbp),%esi
lea    0xe67(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
jmp    117f <main+0xf>
movslq -0x8(%rbp),%rax
shl    $0x2,%rax
mov    %eax,%edi
call   1050 <malloc@plt>
mov    %rax,-0x10(%rbp)
cmpq   $0x0,-0x10(%rbp)
jne    11f6 <main+0x86>
lea    0xe50(%rip),%rdi
call   1080 <perror@plt>
mov    $0xffffffff,%edi
call   1090 <exit@plt>
movl   $0x0,-0x14(%rbp)
mov    -0x14(%rbp),%eax
cmp    -0x8(%rbp),%eax
jge    1232 <main+0xc2>
mov    -0x10(%rbp),%rsi
movslq -0x14(%rbp),%rax
shl    $0x2,%rax
add    %rax,%rsi
lea    0xdfb(%rip),%rdi
call   1070 <scanf@plt>
mov    -0x14(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x14(%rbp)
jmp    11fd <main+0x8d>
mov    -0x10(%rbp),%rdi
mov    -0x8(%rbp),%esi
call   1060 <merge_sort@plt>
movl   $0x0,-0x18(%rbp)
mov    -0x18(%rbp),%eax
cmp    -0x8(%rbp),%eax
jge    1278 <main+0x108>
mov    -0x10(%rbp),%rax
movslq -0x18(%rbp),%rcx
mov    (%rax,%rcx,4),%esi
lea    0xdf1(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
mov    -0x18(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x18(%rbp)
jmp    1245 <main+0xd5>
mov    -0x10(%rbp),%rdi
call   1030 <free@plt>
xor    %eax,%eax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %r15
push   %r14
push   %r12
push   %rbx
push   %rax
lea    0xe81(%rip),%rdi
xor    %eax,%eax
call   1040 <printf@plt>
lea    0xe8d(%rip),%rdi
lea    0x4(%rsp),%rsi
call   1070 <scanf@plt>
mov    0x4(%rsp),%esi
cmp    $0x1,%esi
jg     11e8 <main+0x78>
lea    0xe76(%rip),%r14
lea    0xe52(%rip),%r15
lea    0xe65(%rip),%r12
lea    0x4(%rsp),%rbx
nopw   0x0(%rax,%rax,1)
mov    %r14,%rdi
xor    %eax,%eax
call   1040 <printf@plt>
mov    %r15,%rdi
xor    %eax,%eax
call   1040 <printf@plt>
mov    %r12,%rdi
mov    %rbx,%rsi
call   1070 <scanf@plt>
mov    0x4(%rsp),%esi
cmp    $0x2,%esi
jl     11c0 <main+0x50>
shl    $0x2,%esi
mov    %esi,%edi
call   1050 <malloc@plt>
test   %rax,%rax
je     1282 <main+0x112>
mov    %rax,%r14
xor    %r12d,%r12d
lea    0xe12(%rip),%r15
mov    %rax,%rbx
nopl   0x0(%rax,%rax,1)
mov    %r15,%rdi
mov    %rbx,%rsi
call   1070 <scanf@plt>
add    $0x1,%r12
movslq 0x4(%rsp),%rsi
add    $0x4,%rbx
cmp    %rsi,%r12
jl     1210 <main+0xa0>
mov    %r14,%rdi
call   1060 <merge_sort@plt>
cmpl   $0x0,0x4(%rsp)
jle    126c <main+0xfc>
lea    0xe11(%rip),%r15
xor    %ebx,%ebx
cs nopw 0x0(%rax,%rax,1)
nop
mov    (%r14,%rbx,4),%esi
mov    %r15,%rdi
xor    %eax,%eax
call   1040 <printf@plt>
add    $0x1,%rbx
movslq 0x4(%rsp),%rax
cmp    %rax,%rbx
jl     1250 <main+0xe0>
mov    %r14,%rdi
call   1030 <free@plt>
xor    %eax,%eax
add    $0x8,%rsp
pop    %rbx
pop    %r12
pop    %r14
pop    %r15
ret
lea    0xdae(%rip),%rdi
call   1080 <perror@plt>
mov    $0xffffffff,%edi
call   1090 <exit@plt>

LLVM IR (-O0):
@.str = [26 x i8] c"Enter a positive length: \00"
@.str.1 = [3 x i8] c"%d\00"
@.str.2 = [26 x i8] c"You entered length = %d\0A\0A\00"
@.str.3 = [29 x i8] c"The following error occurred\00"
@.str.4 = [4 x i8] c"%d \00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i32
%3 = alloca i32*
%4 = alloca i32
%5 = alloca i32
store i32 0, i32* %1
br label %6
6: ; preds = %15, %0
%7 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([26 x i8], [26 x i8]* @.str, i64 0, i64 0))
%8 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i32* %2)
%9 = load i32, i32* %2
%10 = icmp sgt i32 %9, 1
br i1 %10, label %11, label %12
11: ; preds = %6
br label %16
12: ; preds = %6
%13 = load i32, i32* %2
%14 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([26 x i8], [26 x i8]* @.str.2, i64 0, i64 0), i32 %13)
br label %15
15: ; preds = %12
br label %6
16: ; preds = %11
%17 = load i32, i32* %2
%18 = sext i32 %17 to i64
%19 = mul i64 4, %18
%20 = trunc i64 %19 to i32
%21 = call i32* @malloc(i32 %20)
store i32* %21, i32** %3
%22 = load i32*, i32** %3
%23 = icmp eq i32* %22, null
br i1 %23, label %24, label %27
24: ; preds = %16
%25 = call i32 @perror(i8* getelementptr inbounds ([29 x i8], [29 x i8]* @.str.3, i64 0, i64 0))
%26 = call i32 @exit(i32 -1)
unreachable
27: ; preds = %16
store i32 0, i32* %4
br label %28
28: ; preds = %38, %27
%29 = load i32, i32* %4
%30 = load i32, i32* %2
%31 = icmp slt i32 %29, %30
br i1 %31, label %32, label %41
32: ; preds = %28
%33 = load i32*, i32** %3
%34 = load i32, i32* %4
%35 = sext i32 %34 to i64
%36 = getelementptr inbounds i32, i32* %33, i64 %35
%37 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i32* %36)
br label %38
38: ; preds = %32
%39 = load i32, i32* %4
%40 = add nsw i32 %39, 1
store i32 %40, i32* %4
br label %28
41: ; preds = %28
%42 = load i32*, i32** %3
%43 = load i32, i32* %2
%44 = call i32 @merge_sort(i32* %42, i32 %43)
store i32 0, i32* %5
br label %45
45: ; preds = %56, %41
%46 = load i32, i32* %5
%47 = load i32, i32* %2
%48 = icmp slt i32 %46, %47
br i1 %48, label %49, label %59
49: ; preds = %45
%50 = load i32*, i32** %3
%51 = load i32, i32* %5
%52 = sext i32 %51 to i64
%53 = getelementptr inbounds i32, i32* %50, i64 %52
%54 = load i32, i32* %53
%55 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.4, i64 0, i64 0), i32 %54)
br label %56
56: ; preds = %49
%57 = load i32, i32* %5
%58 = add nsw i32 %57, 1
store i32 %58, i32* %5
br label %45
59: ; preds = %45
%60 = load i32*, i32** %3
%61 = call i32 @free(i32* %60)
ret i32 0
}

LLVM IR (-O2):
@.str = [26 x i8] c"Enter a positive length: \00"
@.str.1 = [3 x i8] c"%d\00"
@.str.2 = [26 x i8] c"You entered length = %d\0A\0A\00"
@.str.3 = [29 x i8] c"The following error occurred\00"
@.str.4 = [4 x i8] c"%d \00"
define i32 @main() {
%1 = alloca i32
%2 = bitcast i32* %1 to i8*
%3 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([26 x i8], [26 x i8]* @.str, i64 0, i64 0))
%4 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i32* %1)
%5 = load i32, i32* %1
%6 = icmp sgt i32 %5, 1
br i1 %6, label %14, label %7
7: ; preds = %0, %7
%8 = phi i32 [ %12, %7 ], [ %5, %0 ]
%9 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([26 x i8], [26 x i8]* @.str.2, i64 0, i64 0), i32 %8)
%10 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([26 x i8], [26 x i8]* @.str, i64 0, i64 0))
%11 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i32* %1)
%12 = load i32, i32* %1
%13 = icmp sgt i32 %12, 1
br i1 %13, label %14, label %7
14: ; preds = %7, %0
%15 = phi i32 [ %5, %0 ], [ %12, %7 ]
%16 = shl i32 %15, 2
%17 = call i32* @malloc(i32 %16)
%18 = icmp eq i32* %17, null
br i1 %18, label %19, label %26
19: ; preds = %14
%20 = call i32 @perror(i8* getelementptr inbounds ([29 x i8], [29 x i8]* @.str.3, i64 0, i64 0))
%21 = call i32 @exit(i32 -1)
unreachable
22: ; preds = %26
%23 = call i32 @merge_sort(i32* %17, i32 %31)
%24 = load i32, i32* %1
%25 = icmp sgt i32 %24, 0
br i1 %25, label %36, label %34
26: ; preds = %14, %26
%27 = phi i64 [ %30, %26 ], [ 0, %14 ]
%28 = getelementptr inbounds i32, i32* %17, i64 %27
%29 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i32* %28)
%30 = add nuw nsw i64 %27, 1
%31 = load i32, i32* %1
%32 = sext i32 %31 to i64
%33 = icmp slt i64 %30, %32
br i1 %33, label %26, label %22
34: ; preds = %36, %22
%35 = call i32 @free(i32* %17)
ret i32 0
36: ; preds = %22, %36
%37 = phi i64 [ %41, %36 ], [ 0, %22 ]
%38 = getelementptr inbounds i32, i32* %17, i64 %37
%39 = load i32, i32* %38
%40 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([4 x i8], [4 x i8]* @.str.4, i64 0, i64 0), i32 %39)
%41 = add nuw nsw i64 %37, 1
%42 = load i32, i32* %1
%43 = sext i32 %42 to i64
%44 = icmp slt i64 %41, %43
br i1 %44, label %36, label %34
}