#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*/ flushall();
int /*<<< orphan*/ getchar();
int /*<<< orphan*/ printf(char *);
int /*<<< orphan*/ scanf(char *, int *);
main() {
  int year;
  printf("Please enter a 4 digit year: \n");
  scanf("%d", &year);
  flushall();
  if (year != 100)
    if (year % 4 == 0)
      printf("This is a leap year");
    else if (year % 400 == 0)
      printf("This is a leap year");
    else
      printf("This is not a leap year");
  else
    printf("This is not a leap year");
  getchar();
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
movl   $0x0,-0x4(%rbp)
lea    0xeaa(%rip),%rdi
call   1030 <printf@plt>
lea    0xebd(%rip),%rdi
lea    -0x8(%rbp),%rsi
call   1060 <scanf@plt>
mov    $0x0,%al
call   1040 <flushall@plt>
cmpl   $0x64,-0x8(%rbp)
je     11dc <main+0x9c>
mov    -0x8(%rbp),%eax
mov    $0x4,%ecx
cltd
idiv   %ecx
cmp    $0x0,%edx
jne    11a1 <main+0x61>
lea    0xe8b(%rip),%rdi
call   1030 <printf@plt>
jmp    11d7 <main+0x97>
mov    -0x8(%rbp),%eax
mov    $0x190,%ecx
cltd
idiv   %ecx
cmp    $0x0,%edx
jne    11c6 <main+0x86>
lea    0xe66(%rip),%rdi
call   1030 <printf@plt>
jmp    11d2 <main+0x92>
lea    0xe69(%rip),%rdi
call   1030 <printf@plt>
jmp    11d7 <main+0x97>
jmp    11e8 <main+0xa8>
lea    0xe53(%rip),%rdi
call   1030 <printf@plt>
mov    $0x0,%al
call   1050 <getchar@plt>
mov    -0x4(%rbp),%eax
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rax
lea    0xed7(%rip),%rdi
call   1030 <puts@plt>
lea    0xe9c(%rip),%rdi
lea    0x4(%rsp),%rsi
call   1070 <scanf@plt>
xor    %eax,%eax
call   1050 <flushall@plt>
mov    0x4(%rsp),%eax
cmp    $0x64,%eax
jne    1187 <main+0x37>
lea    0xe92(%rip),%rdi
jmp    11b9 <main+0x69>
test   $0x3,%al
je     11b2 <main+0x62>
imul   $0xc28f5c29,%eax,%eax
add    $0x51eb850,%eax
ror    $0x4,%eax
cmp    $0xa3d70b,%eax
lea    0xe5e(%rip),%rax
lea    0xe6b(%rip),%rdi
cmovb  %rax,%rdi
jmp    11b9 <main+0x69>
lea    0xe4a(%rip),%rdi
call   1040 <printf@plt>
xor    %eax,%eax
call   1060 <getchar@plt>
xor    %eax,%eax
pop    %rcx
ret

LLVM IR (-O0):
@.str = [31 x i8] c"Please enter a 4 digit year: \0A\00"
@.str.1 = [3 x i8] c"%d\00"
@.str.2 = [20 x i8] c"This is a leap year\00"
@.str.3 = [24 x i8] c"This is not a leap year\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i32
store i32 0, i32* %1
%3 = call i32 @printf(i8* getelementptr inbounds ([31 x i8], [31 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* %2)
%5 = call i32 (...) @flushall()
%6 = load i32, i32* %2
%7 = icmp ne i32 %6, 100
br i1 %7, label %8, label %24
8: ; preds = %0
%9 = load i32, i32* %2
%10 = srem i32 %9, 4
%11 = icmp eq i32 %10, 0
br i1 %11, label %12, label %14
12: ; preds = %8
%13 = call i32 @printf(i8* getelementptr inbounds ([20 x i8], [20 x i8]* @.str.2, i64 0, i64 0))
br label %23
14: ; preds = %8
%15 = load i32, i32* %2
%16 = srem i32 %15, 400
%17 = icmp eq i32 %16, 0
br i1 %17, label %18, label %20
18: ; preds = %14
%19 = call i32 @printf(i8* getelementptr inbounds ([20 x i8], [20 x i8]* @.str.2, i64 0, i64 0))
br label %22
20: ; preds = %14
%21 = call i32 @printf(i8* getelementptr inbounds ([24 x i8], [24 x i8]* @.str.3, i64 0, i64 0))
br label %22
22: ; preds = %20, %18
br label %23
23: ; preds = %22, %12
br label %26
24: ; preds = %0
%25 = call i32 @printf(i8* getelementptr inbounds ([24 x i8], [24 x i8]* @.str.3, i64 0, i64 0))
br label %26
26: ; preds = %24, %23
%27 = call i32 (...) @getchar()
%28 = load i32, i32* %1
ret i32 %28
}

LLVM IR (-O2):
@.str.1 = [3 x i8] c"%d\00"
@.str.2 = [20 x i8] c"This is a leap year\00"
@.str.3 = [24 x i8] c"This is not a leap year\00"
@str = [30 x i8] c"Please enter a 4 digit year: \00"
define i32 @main() {
%1 = alloca i32
%2 = bitcast i32* %1 to i8*
%3 = tail call i32 @puts(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 = call i32 (...) @flushall()
%6 = load i32, i32* %1
%7 = icmp eq i32 %6, 100
br i1 %7, label %15, label %8
8: ; preds = %0
%9 = and i32 %6, 3
%10 = icmp eq i32 %9, 0
br i1 %10, label %15, label %11
11: ; preds = %8
%12 = srem i32 %6, 400
%13 = icmp eq i32 %12, 0
%14 = select i1 %13, i8* getelementptr inbounds ([20 x i8], [20 x i8]* @.str.2, i64 0, i64 0), i8* getelementptr inbounds ([24 x i8], [24 x i8]* @.str.3, i64 0, i64 0)
br label %15
15: ; preds = %0, %11, %8
%16 = phi i8* [ getelementptr inbounds ([20 x i8], [20 x i8]* @.str.2, i64 0, i64 0), %8 ], [ %14, %11 ], [ getelementptr inbounds ([24 x i8], [24 x i8]* @.str.3, i64 0, i64 0), %0 ]
%17 = call i32 @printf(i8* dereferenceable(1) %16)
%18 = call i32 (...) @getchar()
ret i32 0
}