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


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
movl   $0x0,-0x4(%rbp)
mov    %edi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
movl   $0x0,-0x14(%rbp)
lea    0xebc(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
lea    0xecc(%rip),%rdi
lea    -0x18(%rbp),%rsi
call   1040 <scanf@plt>
mov    -0x18(%rbp),%eax
mov    $0xa,%ecx
cltd
idiv   %ecx
mov    %eax,-0x18(%rbp)
mov    -0x14(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x14(%rbp)
cmpl   $0x0,-0x18(%rbp)
jg     115b <main+0x3b>
mov    -0x14(%rbp),%esi
lea    0xe9b(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
xor    %eax,%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    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 = [30 x i8] c"The number has %d digtit(s).\0A\00"
define i32 @main(i32 %0, i8** %1) {
%3 = alloca i32
%4 = alloca i32
%5 = alloca i8**
%6 = alloca i32
%7 = alloca i32
store i32 0, i32* %3
store i32 %0, i32* %4
store i8** %1, i8*** %5
store i32 0, i32* %6
%8 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([30 x i8], [30 x i8]* @.str, i64 0, i64 0))
%9 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i32* %7)
br label %10
10: ; preds = %15, %2
%11 = load i32, i32* %7
%12 = sdiv i32 %11, 10
store i32 %12, i32* %7
%13 = load i32, i32* %6
%14 = add nsw i32 %13, 1
store i32 %14, i32* %6
br label %15
15: ; preds = %10
%16 = load i32, i32* %7
%17 = icmp sgt i32 %16, 0
br i1 %17, label %10, label %18
18: ; preds = %15
%19 = load i32, i32* %6
%20 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([30 x i8], [30 x i8]* @.str.2, i64 0, i64 0), i32 %19)
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 = [30 x i8] c"The number has %d digtit(s).\0A\00"
define i32 @main(i32 %0, i8** nocapture readnone %1) {
%3 = alloca i32
%4 = bitcast i32* %3 to i8*
%5 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([30 x i8], [30 x i8]* @.str, i64 0, i64 0))
%6 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i32* %3)
%7 = load i32, i32* %3
br label %8
8: ; preds = %8, %2
%9 = phi i32 [ %11, %8 ], [ %7, %2 ]
%10 = phi i32 [ %12, %8 ], [ 0, %2 ]
%11 = sdiv i32 %9, 10
%12 = add nuw nsw i32 %10, 1
%13 = icmp sgt i32 %9, 9
br i1 %13, label %8, label %14
14: ; preds = %8
store i32 %11, i32* %3
%15 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([30 x i8], [30 x i8]* @.str.2, i64 0, i64 0), i32 %12)
ret i32 0
}