#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(void) {
  int digits = 0, n;
  printf("Enter a nonnegative integer: ");
  scanf("%d", &n);
  do {
    n /= 10;
    digits++;
  } while (n > 0);
  printf("The number has %d digit(s).\n", digits);
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
movl   $0x0,-0x4(%rbp)
movl   $0x0,-0x8(%rbp)
lea    0xec3(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
lea    0xed3(%rip),%rdi
lea    -0xc(%rbp),%rsi
call   1040 <scanf@plt>
mov    -0xc(%rbp),%eax
mov    $0xa,%ecx
cltd
idiv   %ecx
mov    %eax,-0xc(%rbp)
mov    -0x8(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x8(%rbp)
cmpl   $0x0,-0xc(%rbp)
jg     1154 <main+0x34>
mov    -0x8(%rbp),%esi
lea    0xea2(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
xor    %eax,%eax
add    $0x10,%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    0xee2(%rip),%rdi
lea    0xc(%rsp),%rsi
call   1040 <scanf@plt>
mov    0xc(%rsp),%eax
nopw   0x0(%rax,%rax,1)
movslq %eax,%rcx
imul   $0x66666667,%rcx,%rax
mov    %rax,%rdx
shr    $0x3f,%rdx
sar    $0x22,%rax
add    %edx,%eax
add    $0x1,%ebx
cmp    $0x9,%ecx
jg     1150 <main+0x30>
mov    %eax,0xc(%rsp)
lea    0xea7(%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 = [30 x i8] c"Enter a nonnegative integer: \00"
@.str.1 = [3 x i8] c"%d\00"
@.str.2 = [29 x i8] c"The number has %d digit(s).\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i32
%3 = alloca i32
store i32 0, i32* %1
store i32 0, i32* %2
%4 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([30 x i8], [30 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* %3)
br label %6
6: ; preds = %11, %0
%7 = load i32, i32* %3
%8 = sdiv i32 %7, 10
store i32 %8, i32* %3
%9 = load i32, i32* %2
%10 = add nsw i32 %9, 1
store i32 %10, i32* %2
br label %11
11: ; preds = %6
%12 = load i32, i32* %3
%13 = icmp sgt i32 %12, 0
br i1 %13, label %6, label %14
14: ; preds = %11
%15 = load i32, i32* %2
%16 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([29 x i8], [29 x i8]* @.str.2, i64 0, i64 0), i32 %15)
ret i32 0
}

LLVM IR (-O2):
@.str = [30 x i8] c"Enter a nonnegative integer: \00"
@.str.1 = [3 x i8] c"%d\00"
@.str.2 = [29 x i8] c"The number has %d digit(s).\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = bitcast i32* %1 to i8*
%3 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([30 x i8], [30 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
br label %6
6: ; preds = %6, %0
%7 = phi i32 [ %9, %6 ], [ %5, %0 ]
%8 = phi i32 [ %10, %6 ], [ 0, %0 ]
%9 = sdiv i32 %7, 10
%10 = add nuw nsw i32 %8, 1
%11 = icmp sgt i32 %7, 9
br i1 %11, label %6, label %12
12: ; preds = %6
store i32 %9, i32* %1
%13 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([29 x i8], [29 x i8]* @.str.2, i64 0, i64 0), i32 %10)
ret i32 0
}