#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 */
unsigned long long atoll(char *);
int /*<<< orphan*/ fprintf(int /*<<< orphan*/, char *, char *);
int /*<<< orphan*/ nchoosek_native(unsigned long long, unsigned long long);
int /*<<< orphan*/ printf(char *, unsigned long long, ...);
int /*<<< orphan*/ stderr;
int main(int argc, char **argv) {
  if (argc < 3) {
    fprintf(stderr, "usage: %s <n> <k>\n", argv[0]);
    return 1;
  }
  unsigned long long n = atoll(argv[1]);
  unsigned long long k = atoll(argv[2]);
  printf("calculating nchoosek(%li, %li) (native)... \n", n, k);
  printf("result: %li\n", nchoosek_native(n, k));
  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)
cmpl   $0x3,-0x8(%rbp)
jge    1188 <main+0x48>
mov    0x2e79(%rip),%rax
mov    (%rax),%edi
mov    -0x10(%rbp),%rax
mov    (%rax),%rdx
lea    0xe89(%rip),%rsi
call   1060 <fprintf@plt>
movl   $0x1,-0x4(%rbp)
jmp    11e5 <main+0xa5>
mov    -0x10(%rbp),%rax
mov    0x8(%rax),%rdi
call   1040 <atoll@plt>
mov    %rax,-0x18(%rbp)
mov    -0x10(%rbp),%rax
mov    0x10(%rax),%rdi
call   1040 <atoll@plt>
mov    %rax,-0x20(%rbp)
mov    -0x18(%rbp),%rsi
mov    -0x20(%rbp),%rdx
lea    0xe5a(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
mov    -0x18(%rbp),%rdi
mov    -0x20(%rbp),%rsi
call   1050 <nchoosek_native@plt>
movslq %eax,%rsi
lea    0xe69(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
movl   $0x0,-0x4(%rbp)
mov    -0x4(%rbp),%eax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rbp
push   %r14
push   %rbx
mov    %rsi,%rbx
cmp    $0x2,%edi
jg     116b <main+0x2b>
mov    0x2e8d(%rip),%rax
mov    (%rax),%edi
mov    (%rbx),%rdx
lea    0xea1(%rip),%rsi
call   1060 <fprintf@plt>
mov    $0x1,%ebp
jmp    11b5 <main+0x75>
mov    0x8(%rbx),%rdi
call   1040 <atoll@plt>
mov    %rax,%r14
mov    0x10(%rbx),%rdi
call   1040 <atoll@plt>
mov    %rax,%rbx
lea    0xe89(%rip),%rdi
xor    %ebp,%ebp
mov    %r14,%rsi
mov    %rax,%rdx
xor    %eax,%eax
call   1030 <printf@plt>
mov    %r14,%rdi
mov    %rbx,%rsi
call   1050 <nchoosek_native@plt>
movslq %eax,%rsi
lea    0xe92(%rip),%rdi
xor    %eax,%eax
call   1030 <printf@plt>
mov    %ebp,%eax
pop    %rbx
pop    %r14
pop    %rbp
ret

LLVM IR (-O0):
@stderr = global i32 0
@.str = [19 x i8] c"usage: %s <n> <k>\0A\00"
@.str.1 = [45 x i8] c"calculating nchoosek(%li, %li) (native)... \0A\00"
@.str.2 = [13 x i8] c"result: %li\0A\00"
define i32 @main(i32 %0, i8** %1) {
%3 = alloca i32
%4 = alloca i32
%5 = alloca i8**
%6 = alloca i64
%7 = alloca i64
store i32 0, i32* %3
store i32 %0, i32* %4
store i8** %1, i8*** %5
%8 = load i32, i32* %4
%9 = icmp slt i32 %8, 3
br i1 %9, label %10, label %16
10: ; preds = %2
%11 = load i32, i32* @stderr
%12 = load i8**, i8*** %5
%13 = getelementptr inbounds i8*, i8** %12, i64 0
%14 = load i8*, i8** %13
%15 = call i32 @fprintf(i32 %11, i8* getelementptr inbounds ([19 x i8], [19 x i8]* @.str, i64 0, i64 0), i8* %14)
store i32 1, i32* %3
br label %33
16: ; preds = %2
%17 = load i8**, i8*** %5
%18 = getelementptr inbounds i8*, i8** %17, i64 1
%19 = load i8*, i8** %18
%20 = call i64 @atoll(i8* %19)
store i64 %20, i64* %6
%21 = load i8**, i8*** %5
%22 = getelementptr inbounds i8*, i8** %21, i64 2
%23 = load i8*, i8** %22
%24 = call i64 @atoll(i8* %23)
store i64 %24, i64* %7
%25 = load i64, i64* %6
%26 = load i64, i64* %7
%27 = call i32 (i8*, i64, ...) @printf(i8* getelementptr inbounds ([45 x i8], [45 x i8]* @.str.1, i64 0, i64 0), i64 %25, i64 %26)
%28 = load i64, i64* %6
%29 = load i64, i64* %7
%30 = call i32 @nchoosek_native(i64 %28, i64 %29)
%31 = sext i32 %30 to i64
%32 = call i32 (i8*, i64, ...) @printf(i8* getelementptr inbounds ([13 x i8], [13 x i8]* @.str.2, i64 0, i64 0), i64 %31)
store i32 0, i32* %3
br label %33
33: ; preds = %16, %10
%34 = load i32, i32* %3
ret i32 %34
}

LLVM IR (-O2):
@stderr = global i32 0
@.str = [19 x i8] c"usage: %s <n> <k>\0A\00"
@.str.1 = [45 x i8] c"calculating nchoosek(%li, %li) (native)... \0A\00"
@.str.2 = [13 x i8] c"result: %li\0A\00"
define i32 @main(i32 %0, i8** nocapture %1) {
%3 = icmp slt i32 %0, 3
br i1 %3, label %4, label %8
4: ; preds = %2
%5 = load i32, i32* @stderr
%6 = load i8*, i8** %1
%7 = tail call i32 @fprintf(i32 %5, i8* getelementptr inbounds ([19 x i8], [19 x i8]* @.str, i64 0, i64 0), i8* %6)
br label %19
8: ; preds = %2
%9 = getelementptr inbounds i8*, i8** %1, i64 1
%10 = load i8*, i8** %9
%11 = tail call i64 @atoll(i8* %10)
%12 = getelementptr inbounds i8*, i8** %1, i64 2
%13 = load i8*, i8** %12
%14 = tail call i64 @atoll(i8* %13)
%15 = tail call i32 (i8*, i64, ...) @printf(i8* getelementptr inbounds ([45 x i8], [45 x i8]* @.str.1, i64 0, i64 0), i64 %11, i64 %14)
%16 = tail call i32 @nchoosek_native(i64 %11, i64 %14)
%17 = sext i32 %16 to i64
%18 = tail call i32 (i8*, i64, ...) @printf(i8* getelementptr inbounds ([13 x i8], [13 x i8]* @.str.2, i64 0, i64 0), i64 %17)
br label %19
19: ; preds = %8, %4
%20 = phi i32 [ 1, %4 ], [ 0, %8 ]
ret i32 %20
}