#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*/ printf(char *);
int /*<<< orphan*/ scanf(char *, int *);
int main() {
  int n;
  int i;
  int k;
  do {
    printf("Inserisci lato tra 2 e 20: ");
    scanf("%d", &n);
  } while ((n < 2) || (n > 20));
  for (i = 0; i < n; i++) {
    for (k = 0; k < n; k++) {
      printf("*");
    }
    printf("\n");
  }
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
movl   $0x0,-0x4(%rbp)
lea    0xeca(%rip),%rdi
call   1030 <printf@plt>
lea    0xeda(%rip),%rdi
lea    -0x8(%rbp),%rsi
call   1040 <scanf@plt>
mov    $0x1,%al
cmpl   $0x2,-0x8(%rbp)
mov    %al,-0x11(%rbp)
jl     1164 <main+0x44>
cmpl   $0x14,-0x8(%rbp)
setg   %al
mov    %al,-0x11(%rbp)
mov    -0x11(%rbp),%al
test   $0x1,%al
jne    112f <main+0xf>
movl   $0x0,-0xc(%rbp)
mov    -0xc(%rbp),%eax
cmp    -0x8(%rbp),%eax
jge    11c9 <main+0xa9>
movl   $0x0,-0x10(%rbp)
mov    -0x10(%rbp),%eax
cmp    -0x8(%rbp),%eax
jge    11af <main+0x8f>
lea    0xe83(%rip),%rdi
call   1030 <printf@plt>
mov    -0x10(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x10(%rbp)
jmp    1189 <main+0x69>
lea    0xe6b(%rip),%rdi
call   1030 <printf@plt>
mov    -0xc(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0xc(%rbp)
jmp    1176 <main+0x56>
mov    -0x4(%rbp),%eax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rbp
push   %r15
push   %r14
push   %rbx
push   %rax
lea    0xec2(%rip),%r14
lea    0xed7(%rip),%r15
lea    0x4(%rsp),%rbx
nopw   0x0(%rax,%rax,1)
mov    %r14,%rdi
call   1040 <printf@plt>
mov    %r15,%rdi
mov    %rbx,%rsi
call   1050 <scanf@plt>
mov    0x4(%rsp),%eax
lea    -0x15(%rax),%ecx
cmp    $0xffffffed,%ecx
jb     1150 <main+0x20>
xor    %ebx,%ebx
jmp    1195 <main+0x65>
cs nopw 0x0(%rax,%rax,1)
nopl   (%rax)
mov    $0xa,%edi
call   1030 <putchar@plt>
add    $0x1,%ebx
mov    0x4(%rsp),%eax
cmp    %eax,%ebx
jge    11b5 <main+0x85>
test   %eax,%eax
jle    1180 <main+0x50>
xor    %ebp,%ebp
nopl   0x0(%rax,%rax,1)
mov    $0x2a,%edi
call   1030 <putchar@plt>
add    $0x1,%ebp
cmp    0x4(%rsp),%ebp
jl     11a0 <main+0x70>
jmp    1180 <main+0x50>
xor    %eax,%eax
add    $0x8,%rsp
pop    %rbx
pop    %r14
pop    %r15
pop    %rbp
ret

LLVM IR (-O0):
@.str = [28 x i8] c"Inserisci lato tra 2 e 20: \00"
@.str.1 = [3 x i8] c"%d\00"
@.str.2 = [2 x i8] c"*\00"
@.str.3 = [2 x i8] c"\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i32
%3 = alloca i32
%4 = alloca i32
store i32 0, i32* %1
br label %5
5: ; preds = %14, %0
%6 = call i32 @printf(i8* getelementptr inbounds ([28 x i8], [28 x i8]* @.str, i64 0, i64 0))
%7 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i32* %2)
br label %8
8: ; preds = %5
%9 = load i32, i32* %2
%10 = icmp slt i32 %9, 2
br i1 %10, label %14, label %11
11: ; preds = %8
%12 = load i32, i32* %2
%13 = icmp sgt i32 %12, 20
br label %14
14: ; preds = %11, %8
%15 = phi i1 [ true, %8 ], [ %13, %11 ]
br i1 %15, label %5, label %16
16: ; preds = %14
store i32 0, i32* %3
br label %17
17: ; preds = %33, %16
%18 = load i32, i32* %3
%19 = load i32, i32* %2
%20 = icmp slt i32 %18, %19
br i1 %20, label %21, label %36
21: ; preds = %17
store i32 0, i32* %4
br label %22
22: ; preds = %28, %21
%23 = load i32, i32* %4
%24 = load i32, i32* %2
%25 = icmp slt i32 %23, %24
br i1 %25, label %26, label %31
26: ; preds = %22
%27 = call i32 @printf(i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str.2, i64 0, i64 0))
br label %28
28: ; preds = %26
%29 = load i32, i32* %4
%30 = add nsw i32 %29, 1
store i32 %30, i32* %4
br label %22
31: ; preds = %22
%32 = call i32 @printf(i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str.3, i64 0, i64 0))
br label %33
33: ; preds = %31
%34 = load i32, i32* %3
%35 = add nsw i32 %34, 1
store i32 %35, i32* %3
br label %17
36: ; preds = %17
%37 = load i32, i32* %1
ret i32 %37
}

LLVM IR (-O2):
@.str = [28 x i8] c"Inserisci lato tra 2 e 20: \00"
@.str.1 = [3 x i8] c"%d\00"
define i32 @main() {
%1 = alloca i32
%2 = bitcast i32* %1 to i8*
br label %3
3: ; preds = %3, %0
%4 = call i32 @printf(i8* dereferenceable(1) getelementptr inbounds ([28 x i8], [28 x i8]* @.str, i64 0, i64 0))
%5 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i32* %1)
%6 = load i32, i32* %1
%7 = add i32 %6, -21
%8 = icmp ult i32 %7, -19
br i1 %8, label %3, label %9
9: ; preds = %3, %19
%10 = phi i32 [ %22, %19 ], [ %6, %3 ]
%11 = phi i32 [ %21, %19 ], [ 0, %3 ]
%12 = icmp sgt i32 %10, 0
br i1 %12, label %13, label %19
13: ; preds = %9, %13
%14 = phi i32 [ %16, %13 ], [ 0, %9 ]
%15 = call i32 @putchar(i32 42)
%16 = add nuw nsw i32 %14, 1
%17 = load i32, i32* %1
%18 = icmp slt i32 %16, %17
br i1 %18, label %13, label %19
19: ; preds = %13, %9
%20 = call i32 @putchar(i32 10)
%21 = add nuw nsw i32 %11, 1
%22 = load i32, i32* %1
%23 = icmp slt i32 %21, %22
br i1 %23, label %9, label %24
24: ; preds = %19
ret i32 0
}