#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 EOF;
int /*<<< orphan*/ printf(char *, int, ...);
int scanf(char *, int *, int *);
int main() {
  int a, b, c;
  while ((c = scanf("%d %d", &a, &b)) == 2) {
    printf("%d\n", a + b);
  }
  printf("scanf return %d EOF=%d\n", c, EOF);
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
movl   $0x0,-0x4(%rbp)
lea    0xeca(%rip),%rdi
lea    -0x8(%rbp),%rsi
lea    -0xc(%rbp),%rdx
call   1040 <scanf@plt>
mov    %eax,-0x10(%rbp)
cmp    $0x2,%eax
jne    1168 <main+0x48>
mov    -0x8(%rbp),%esi
add    -0xc(%rbp),%esi
lea    0xebe(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
jmp    112f <main+0xf>
mov    -0x10(%rbp),%esi
mov    0x2e76(%rip),%rax
mov    (%rax),%edx
lea    0xe8b(%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   %r12
push   %rbx
push   %rax
lea    0xed1(%rip),%rdi
lea    0x4(%rsp),%rsi
mov    %rsp,%rdx
call   1040 <scanf@plt>
cmp    $0x2,%eax
jne    1184 <main+0x64>
lea    0xed2(%rip),%r14
lea    0xeb1(%rip),%r15
lea    0x4(%rsp),%r12
mov    %rsp,%rbx
nopw   0x0(%rax,%rax,1)
mov    (%rsp),%esi
add    0x4(%rsp),%esi
mov    %r14,%rdi
xor    %eax,%eax
call   1030 <printf@plt>
mov    %r15,%rdi
mov    %r12,%rsi
mov    %rbx,%rdx
call   1040 <scanf@plt>
cmp    $0x2,%eax
je     1160 <main+0x40>
mov    0x2e5d(%rip),%rcx
mov    (%rcx),%edx
lea    0xe72(%rip),%rdi
mov    %eax,%esi
xor    %eax,%eax
call   1030 <printf@plt>
xor    %eax,%eax
add    $0x8,%rsp
pop    %rbx
pop    %r12
pop    %r14
pop    %r15
ret

LLVM IR (-O0):
@.str = [6 x i8] c"%d %d\00"
@.str.1 = [4 x i8] c"%d\0A\00"
@.str.2 = [24 x i8] c"scanf return %d EOF=%d\0A\00"
@EOF = global i32 0
define i32 @main() {
%1 = alloca i32
%2 = alloca i32
%3 = alloca i32
%4 = alloca i32
store i32 0, i32* %1
br label %5
5: ; preds = %8, %0
%6 = call i32 @scanf(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str, i64 0, i64 0), i32* %2, i32* %3)
store i32 %6, i32* %4
%7 = icmp eq i32 %6, 2
br i1 %7, label %8, label %13
8: ; preds = %5
%9 = load i32, i32* %2
%10 = load i32, i32* %3
%11 = add nsw i32 %9, %10
%12 = call i32 (i8*, i32, ...) @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.1, i64 0, i64 0), i32 %11)
br label %5
13: ; preds = %5
%14 = load i32, i32* %4
%15 = load i32, i32* @EOF
%16 = call i32 (i8*, i32, ...) @printf(i8* getelementptr inbounds ([24 x i8], [24 x i8]* @.str.2, i64 0, i64 0), i32 %14, i32 %15)
ret i32 0
}

LLVM IR (-O2):
@.str = [6 x i8] c"%d %d\00"
@.str.1 = [4 x i8] c"%d\0A\00"
@.str.2 = [24 x i8] c"scanf return %d EOF=%d\0A\00"
@EOF = global i32 0
define i32 @main() {
%1 = alloca i32
%2 = alloca i32
%3 = bitcast i32* %1 to i8*
%4 = bitcast i32* %2 to i8*
%5 = call i32 @scanf(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str, i64 0, i64 0), i32* %1, i32* %2)
%6 = icmp eq i32 %5, 2
br i1 %6, label %7, label %14
7: ; preds = %0, %7
%8 = load i32, i32* %1
%9 = load i32, i32* %2
%10 = add nsw i32 %9, %8
%11 = call i32 (i8*, i32, ...) @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.1, i64 0, i64 0), i32 %10)
%12 = call i32 @scanf(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str, i64 0, i64 0), i32* %1, i32* %2)
%13 = icmp eq i32 %12, 2
br i1 %13, label %7, label %14
14: ; preds = %7, %0
%15 = phi i32 [ %5, %0 ], [ %12, %7 ]
%16 = load i32, i32* @EOF
%17 = call i32 (i8*, i32, ...) @printf(i8* getelementptr inbounds ([24 x i8], [24 x i8]* @.str.2, i64 0, i64 0), i32 %15, i32 %16)
ret i32 0
}