#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 *, long long *);
int main() {
  long long n;
  int count = 0;
  printf("Enter an integer: ");
  scanf("%lld", &n);
  while (n != 0) {
    n /= 10;
    ++count;
  }
  printf("Number of digits: %d", count);
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
movl   $0x0,-0x4(%rbp)
movl   $0x0,-0x14(%rbp)
lea    0xec3(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
lea    0xec8(%rip),%rdi
lea    -0x10(%rbp),%rsi
call   1040 <scanf@plt>
cmpq   $0x0,-0x10(%rbp)
je     117f <main+0x5f>
mov    -0x10(%rbp),%rax
mov    $0xa,%ecx
cqto
idiv   %rcx
mov    %rax,-0x10(%rbp)
mov    -0x14(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x14(%rbp)
jmp    1154 <main+0x34>
mov    -0x14(%rbp),%esi
lea    0xe8f(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
mov    -0x4(%rbp),%eax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rbx
sub    $0x10,%rsp
lea    0xed4(%rip),%rdi
xor    %ebx,%ebx
xor    %eax,%eax
call   1030 <printf@plt>
lea    0xed7(%rip),%rdi
lea    0x8(%rsp),%rsi
call   1040 <scanf@plt>
mov    0x8(%rsp),%rdx
test   %rdx,%rdx
je     1189 <main+0x69>
xor    %ebx,%ebx
movabs $0x6666666666666667,%rsi
66 66 66
nopl   0x0(%rax)
mov    %rdx,%rcx
mov    %rdx,%rax
imul   %rsi
mov    %rdx,%rax
shr    $0x3f,%rax
sar    $0x2,%rdx
add    %rax,%rdx
add    $0x1,%ebx
add    $0x9,%rcx
cmp    $0x12,%rcx
ja     1160 <main+0x40>
mov    %rdx,0x8(%rsp)
lea    0xe88(%rip),%rdi
mov    %ebx,%esi
xor    %eax,%eax
call   1030 <printf@plt>
xor    %eax,%eax
add    $0x10,%rsp
pop    %rbx
ret

LLVM IR (-O0):
@.str = [19 x i8] c"Enter an integer: \00"
@.str.1 = [5 x i8] c"%lld\00"
@.str.2 = [21 x i8] c"Number of digits: %d\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i64
%3 = alloca i32
store i32 0, i32* %1
store i32 0, i32* %3
%4 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([19 x i8], [19 x i8]* @.str, i64 0, i64 0))
%5 = call i32 @scanf(i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str.1, i64 0, i64 0), i64* %2)
br label %6
6: ; preds = %9, %0
%7 = load i64, i64* %2
%8 = icmp ne i64 %7, 0
br i1 %8, label %9, label %14
9: ; preds = %6
%10 = load i64, i64* %2
%11 = sdiv i64 %10, 10
store i64 %11, i64* %2
%12 = load i32, i32* %3
%13 = add nsw i32 %12, 1
store i32 %13, i32* %3
br label %6
14: ; preds = %6
%15 = load i32, i32* %3
%16 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([21 x i8], [21 x i8]* @.str.2, i64 0, i64 0), i32 %15)
%17 = load i32, i32* %1
ret i32 %17
}

LLVM IR (-O2):
@.str = [19 x i8] c"Enter an integer: \00"
@.str.1 = [5 x i8] c"%lld\00"
@.str.2 = [21 x i8] c"Number of digits: %d\00"
define i32 @main() {
%1 = alloca i64
%2 = bitcast i64* %1 to i8*
%3 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([19 x i8], [19 x i8]* @.str, i64 0, i64 0))
%4 = call i32 @scanf(i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str.1, i64 0, i64 0), i64* %1)
%5 = load i64, i64* %1
%6 = icmp eq i64 %5, 0
br i1 %6, label %15, label %7
7: ; preds = %0, %7
%8 = phi i32 [ %11, %7 ], [ 0, %0 ]
%9 = phi i64 [ %10, %7 ], [ %5, %0 ]
%10 = sdiv i64 %9, 10
%11 = add nuw nsw i32 %8, 1
%12 = add i64 %9, 9
%13 = icmp ult i64 %12, 19
br i1 %13, label %14, label %7
14: ; preds = %7
store i64 %10, i64* %1
br label %15
15: ; preds = %14, %0
%16 = phi i32 [ %11, %14 ], [ 0, %0 ]
%17 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([21 x i8], [21 x i8]* @.str.2, i64 0, i64 0), i32 %16)
ret i32 0
}