#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 increment(int);
int main(void) {
  int val = 1;
  int j;
  for (j = 0; j < 20; j++)
    val = increment(val);
  return val == 20;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
movl   $0x0,-0x4(%rbp)
movl   $0x1,-0x8(%rbp)
movl   $0x0,-0xc(%rbp)
cmpl   $0x14,-0xc(%rbp)
jge    1150 <main+0x40>
mov    -0x8(%rbp),%edi
call   1030 <increment@plt>
mov    %eax,-0x8(%rbp)
mov    -0xc(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0xc(%rbp)
jmp    112d <main+0x1d>
cmpl   $0x14,-0x8(%rbp)
sete   %al
and    $0x1,%al
movzbl %al,%eax
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rax
mov    $0x1,%edi
call   1030 <increment@plt>
mov    %eax,%edi
call   1030 <increment@plt>
mov    %eax,%edi
call   1030 <increment@plt>
mov    %eax,%edi
call   1030 <increment@plt>
mov    %eax,%edi
call   1030 <increment@plt>
mov    %eax,%edi
call   1030 <increment@plt>
mov    %eax,%edi
call   1030 <increment@plt>
mov    %eax,%edi
call   1030 <increment@plt>
mov    %eax,%edi
call   1030 <increment@plt>
mov    %eax,%edi
call   1030 <increment@plt>
mov    %eax,%edi
call   1030 <increment@plt>
mov    %eax,%edi
call   1030 <increment@plt>
mov    %eax,%edi
call   1030 <increment@plt>
mov    %eax,%edi
call   1030 <increment@plt>
mov    %eax,%edi
call   1030 <increment@plt>
mov    %eax,%edi
call   1030 <increment@plt>
mov    %eax,%edi
call   1030 <increment@plt>
mov    %eax,%edi
call   1030 <increment@plt>
mov    %eax,%edi
call   1030 <increment@plt>
mov    %eax,%edi
call   1030 <increment@plt>
xor    %ecx,%ecx
cmp    $0x14,%eax
sete   %cl
mov    %ecx,%eax
pop    %rcx
ret

LLVM IR (-O0):
define i32 @main() {
%1 = alloca i32
%2 = alloca i32
%3 = alloca i32
store i32 0, i32* %1
store i32 1, i32* %2
store i32 0, i32* %3
br label %4
4: ; preds = %10, %0
%5 = load i32, i32* %3
%6 = icmp slt i32 %5, 20
br i1 %6, label %7, label %13
7: ; preds = %4
%8 = load i32, i32* %2
%9 = call i32 @increment(i32 %8)
store i32 %9, i32* %2
br label %10
10: ; preds = %7
%11 = load i32, i32* %3
%12 = add nsw i32 %11, 1
store i32 %12, i32* %3
br label %4
13: ; preds = %4
%14 = load i32, i32* %2
%15 = icmp eq i32 %14, 20
%16 = zext i1 %15 to i32
ret i32 %16
}

LLVM IR (-O2):
define i32 @main() {
%1 = tail call i32 @increment(i32 1)
%2 = tail call i32 @increment(i32 %1)
%3 = tail call i32 @increment(i32 %2)
%4 = tail call i32 @increment(i32 %3)
%5 = tail call i32 @increment(i32 %4)
%6 = tail call i32 @increment(i32 %5)
%7 = tail call i32 @increment(i32 %6)
%8 = tail call i32 @increment(i32 %7)
%9 = tail call i32 @increment(i32 %8)
%10 = tail call i32 @increment(i32 %9)
%11 = tail call i32 @increment(i32 %10)
%12 = tail call i32 @increment(i32 %11)
%13 = tail call i32 @increment(i32 %12)
%14 = tail call i32 @increment(i32 %13)
%15 = tail call i32 @increment(i32 %14)
%16 = tail call i32 @increment(i32 %15)
%17 = tail call i32 @increment(i32 %16)
%18 = tail call i32 @increment(i32 %17)
%19 = tail call i32 @increment(i32 %18)
%20 = tail call i32 @increment(i32 %19)
%21 = icmp eq i32 %20, 20
%22 = zext i1 %21 to i32
ret i32 %22
}