#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 /*<<< orphan*/ swap(int *, int *);
int main() {
  int r1, r2;
  printf("Enter reference integer 1: ");
  scanf("%d", &r1);
  printf("Enter reference integer 2: ");
  scanf("%d", &r2);
  printf("Prior to swap by reference: r1:%d, r2:%d\n", r1, r2);
  swap(&r1, &r2);
  printf("Post to swap by reference: r1:%d, r2:%d\n", r1, r2);
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
movl   $0x0,-0x4(%rbp)
lea    0xeba(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
lea    0xec8(%rip),%rdi
lea    -0x8(%rbp),%rsi
call   1040 <scanf@plt>
lea    0xebb(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
lea    0xeaa(%rip),%rdi
lea    -0xc(%rbp),%rsi
call   1040 <scanf@plt>
mov    -0x8(%rbp),%esi
mov    -0xc(%rbp),%edx
lea    0xeb3(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
lea    -0x8(%rbp),%rdi
lea    -0xc(%rbp),%rsi
call   1050 <swap@plt>
mov    -0x8(%rbp),%esi
mov    -0xc(%rbp),%edx
lea    0xebc(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
xor    %eax,%eax
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %r15
push   %r14
push   %rbx
sub    $0x10,%rsp
lea    0xec0(%rip),%rdi
xor    %eax,%eax
call   1030 <printf@plt>
lea    0xece(%rip),%rbx
lea    0xc(%rsp),%r14
mov    %rbx,%rdi
mov    %r14,%rsi
call   1040 <scanf@plt>
lea    0xeba(%rip),%rdi
xor    %eax,%eax
call   1030 <printf@plt>
lea    0x8(%rsp),%r15
mov    %rbx,%rdi
mov    %r15,%rsi
call   1040 <scanf@plt>
mov    0xc(%rsp),%esi
mov    0x8(%rsp),%edx
lea    0xeb0(%rip),%rdi
xor    %eax,%eax
call   1030 <printf@plt>
mov    %r14,%rdi
mov    %r15,%rsi
call   1050 <swap@plt>
mov    0xc(%rsp),%esi
mov    0x8(%rsp),%edx
lea    0xeb9(%rip),%rdi
xor    %eax,%eax
call   1030 <printf@plt>
xor    %eax,%eax
add    $0x10,%rsp
pop    %rbx
pop    %r14
pop    %r15
ret

LLVM IR (-O0):
@.str = [28 x i8] c"Enter reference integer 1: \00"
@.str.1 = [3 x i8] c"%d\00"
@.str.2 = [28 x i8] c"Enter reference integer 2: \00"
@.str.3 = [42 x i8] c"Prior to swap by reference: r1:%d, r2:%d\0A\00"
@.str.4 = [41 x i8] c"Post to swap by reference: r1:%d, r2:%d\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i32
%3 = alloca i32
store i32 0, i32* %1
%4 = call i32 (i8*, ...) @printf(i8* 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* %2)
%6 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([28 x i8], [28 x i8]* @.str.2, i64 0, i64 0))
%7 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i32* %3)
%8 = load i32, i32* %2
%9 = load i32, i32* %3
%10 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([42 x i8], [42 x i8]* @.str.3, i64 0, i64 0), i32 %8, i32 %9)
%11 = call i32 @swap(i32* %2, i32* %3)
%12 = load i32, i32* %2
%13 = load i32, i32* %3
%14 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([41 x i8], [41 x i8]* @.str.4, i64 0, i64 0), i32 %12, i32 %13)
ret i32 0
}

LLVM IR (-O2):
@.str = [28 x i8] c"Enter reference integer 1: \00"
@.str.1 = [3 x i8] c"%d\00"
@.str.2 = [28 x i8] c"Enter reference integer 2: \00"
@.str.3 = [42 x i8] c"Prior to swap by reference: r1:%d, r2:%d\0A\00"
@.str.4 = [41 x i8] c"Post to swap by reference: r1:%d, r2:%d\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i32
%3 = bitcast i32* %1 to i8*
%4 = bitcast i32* %2 to i8*
%5 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([28 x i8], [28 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* %1)
%7 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([28 x i8], [28 x i8]* @.str.2, i64 0, i64 0))
%8 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i32* %2)
%9 = load i32, i32* %1
%10 = load i32, i32* %2
%11 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([42 x i8], [42 x i8]* @.str.3, i64 0, i64 0), i32 %9, i32 %10)
%12 = call i32 @swap(i32* %1, i32* %2)
%13 = load i32, i32* %1
%14 = load i32, i32* %2
%15 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([41 x i8], [41 x i8]* @.str.4, i64 0, i64 0), i32 %13, i32 %14)
ret i32 0
}