#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*/ atoi(char *);
int /*<<< orphan*/ exit(int);
int /*<<< orphan*/ fprintf(int /*<<< orphan*/, char *);
int /*<<< orphan*/ printf(char *, int);
int reverseBits(int /*<<< orphan*/);
int /*<<< orphan*/ stderr;
int main(int argc, char **argv) {
  if (argc != 2) {
    fprintf(stderr, "Usage: ./test n\n");
    exit(-1);
  }
  printf("%u\n", reverseBits(atoi(argv[1])));
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
movl   $0x0,-0x4(%rbp)
mov    %edi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
cmpl   $0x2,-0x8(%rbp)
je     118f <main+0x3f>
mov    0x2e69(%rip),%rax
mov    (%rax),%edi
lea    0xe80(%rip),%rsi
call   1040 <fprintf@plt>
mov    $0xffffffff,%edi
call   1070 <exit@plt>
mov    -0x10(%rbp),%rax
mov    0x8(%rax),%rdi
call   1060 <atoi@plt>
mov    %eax,%edi
call   1050 <reverseBits@plt>
mov    %eax,%esi
lea    0xe65(%rip),%rdi
call   1030 <printf@plt>
xor    %eax,%eax
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rax
cmp    $0x2,%edi
jne    1178 <main+0x28>
mov    0x8(%rsi),%rdi
call   1060 <atoi@plt>
mov    %eax,%edi
call   1050 <reverseBits@plt>
lea    0xea4(%rip),%rdi
mov    %eax,%esi
call   1030 <printf@plt>
xor    %eax,%eax
pop    %rcx
ret
mov    0x2e61(%rip),%rax
mov    (%rax),%edi
lea    0xe78(%rip),%rsi
call   1040 <fprintf@plt>
mov    $0xffffffff,%edi
call   1070 <exit@plt>

LLVM IR (-O0):
@stderr = global i32 0
@.str = [17 x i8] c"Usage: ./test n\0A\00"
@.str.1 = [4 x i8] c"%u\0A\00"
define i32 @main(i32 %0, i8** %1) {
%3 = alloca i32
%4 = alloca i32
%5 = alloca i8**
store i32 0, i32* %3
store i32 %0, i32* %4
store i8** %1, i8*** %5
%6 = load i32, i32* %4
%7 = icmp ne i32 %6, 2
br i1 %7, label %8, label %12
8: ; preds = %2
%9 = load i32, i32* @stderr
%10 = call i32 @fprintf(i32 %9, i8* getelementptr inbounds ([17 x i8], [17 x i8]* @.str, i64 0, i64 0))
%11 = call i32 @exit(i32 -1)
unreachable
12: ; preds = %2
%13 = load i8**, i8*** %5
%14 = getelementptr inbounds i8*, i8** %13, i64 1
%15 = load i8*, i8** %14
%16 = call i32 @atoi(i8* %15)
%17 = call i32 @reverseBits(i32 %16)
%18 = call i32 @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.1, i64 0, i64 0), i32 %17)
ret i32 0
}

LLVM IR (-O2):
@stderr = global i32 0
@.str = [17 x i8] c"Usage: ./test n\0A\00"
@.str.1 = [4 x i8] c"%u\0A\00"
define i32 @main(i32 %0, i8** nocapture %1) {
%3 = icmp eq i32 %0, 2
br i1 %3, label %8, label %4
4: ; preds = %2
%5 = load i32, i32* @stderr
%6 = tail call i32 @fprintf(i32 %5, i8* getelementptr inbounds ([17 x i8], [17 x i8]* @.str, i64 0, i64 0))
%7 = tail call i32 @exit(i32 -1)
unreachable
8: ; preds = %2
%9 = getelementptr inbounds i8*, i8** %1, i64 1
%10 = load i8*, i8** %9
%11 = tail call i32 @atoi(i8* %10)
%12 = tail call i32 @reverseBits(i32 %11)
%13 = tail call i32 @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.1, i64 0, i64 0), i32 %12)
ret i32 0
}