#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 main(void) {
  int i = 0, n = 0;
  printf("请输入一个整数: ");
  scanf("%d", &n);
  i = 2;
  while (i <= n) {
    printf("%d ", i);
    i *= 2;
    if (i > n) {
      printf("\n");
    }
  }
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
movl   $0x0,-0x4(%rbp)
movl   $0x0,-0x8(%rbp)
movl   $0x0,-0xc(%rbp)
lea    0xebc(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
lea    0xec6(%rip),%rdi
lea    -0xc(%rbp),%rsi
call   1040 <scanf@plt>
movl   $0x2,-0x8(%rbp)
mov    -0x8(%rbp),%eax
cmp    -0xc(%rbp),%eax
jg     11a7 <main+0x87>
mov    -0x8(%rbp),%esi
lea    0xea3(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
mov    -0x8(%rbp),%eax
shl    $0x1,%eax
mov    %eax,-0x8(%rbp)
mov    -0x8(%rbp),%eax
cmp    -0xc(%rbp),%eax
jle    11a2 <main+0x82>
lea    0xe84(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
jmp    1162 <main+0x42>
xor    %eax,%eax
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %r14
push   %rbx
push   %rax
movl   $0x0,0x4(%rsp)
lea    0xebd(%rip),%rdi
xor    %eax,%eax
call   1040 <printf@plt>
lea    0xec7(%rip),%rdi
lea    0x4(%rsp),%rsi
call   1050 <scanf@plt>
cmpl   $0x2,0x4(%rsp)
jge    116c <main+0x3c>
xor    %eax,%eax
add    $0x8,%rsp
pop    %rbx
pop    %r14
ret
mov    $0x2,%ebx
lea    0xea3(%rip),%r14
jmp    1184 <main+0x54>
nopw   0x0(%rax,%rax,1)
cmp    %eax,%ebx
jg     1162 <main+0x32>
mov    %r14,%rdi
mov    %ebx,%esi
xor    %eax,%eax
call   1040 <printf@plt>
add    %ebx,%ebx
mov    0x4(%rsp),%eax
cmp    %eax,%ebx
jle    1180 <main+0x50>
mov    $0xa,%edi
call   1030 <putchar@plt>
mov    0x4(%rsp),%eax
jmp    1180 <main+0x50>

LLVM IR (-O0):
@.str = [24 x i8] c"\E8\AF\B7\E8\BE\93\E5\85\A5\E4\B8\80\E4\B8\AA\E6\95\B4\E6\95\B0: \00"
@.str.1 = [3 x i8] c"%d\00"
@.str.2 = [4 x i8] c"%d \00"
@.str.3 = [2 x i8] c"\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i32
%3 = alloca i32
store i32 0, i32* %1
store i32 0, i32* %2
store i32 0, i32* %3
%4 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([24 x i8], [24 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* %3)
store i32 2, i32* %2
br label %6
6: ; preds = %20, %0
%7 = load i32, i32* %2
%8 = load i32, i32* %3
%9 = icmp sle i32 %7, %8
br i1 %9, label %10, label %21
10: ; preds = %6
%11 = load i32, i32* %2
%12 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.2, i64 0, i64 0), i32 %11)
%13 = load i32, i32* %2
%14 = mul nsw i32 %13, 2
store i32 %14, i32* %2
%15 = load i32, i32* %2
%16 = load i32, i32* %3
%17 = icmp sgt i32 %15, %16
br i1 %17, label %18, label %20
18: ; preds = %10
%19 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str.3, i64 0, i64 0))
br label %20
20: ; preds = %18, %10
br label %6
21: ; preds = %6
ret i32 0
}

LLVM IR (-O2):
@.str = [24 x i8] c"\E8\AF\B7\E8\BE\93\E5\85\A5\E4\B8\80\E4\B8\AA\E6\95\B4\E6\95\B0: \00"
@.str.1 = [3 x i8] c"%d\00"
@.str.2 = [4 x i8] c"%d \00"
define i32 @main() {
%1 = alloca i32
%2 = bitcast i32* %1 to i8*
store i32 0, i32* %1
%3 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([24 x i8], [24 x i8]* @.str, i64 0, i64 0))
%4 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i32* %1)
%5 = load i32, i32* %1
%6 = icmp slt i32 %5, 2
br i1 %6, label %19, label %7
7: ; preds = %0, %16
%8 = phi i32 [ %10, %16 ], [ 2, %0 ]
%9 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([4 x i8], [4 x i8]* @.str.2, i64 0, i64 0), i32 %8)
%10 = shl nsw i32 %8, 1
%11 = load i32, i32* %1
%12 = icmp sgt i32 %10, %11
br i1 %12, label %13, label %16
13: ; preds = %7
%14 = call i32 @putchar(i32 10)
%15 = load i32, i32* %1
br label %16
16: ; preds = %13, %7
%17 = phi i32 [ %15, %13 ], [ %11, %7 ]
%18 = icmp sgt i32 %10, %17
br i1 %18, label %19, label %7
19: ; preds = %16, %0
ret i32 0
}