在"asm"中不可能的约束 [英] impossible constraint in 'asm'

问题描述

我正在使用一周前编译的第三方库.
今天，我再次坐在办公桌前，再次推动建筑，然后脑袋爆裂.
我被枪杀了这个错误:

I'm using third party library which compiled one week ago.
Today I sat down at the desk again, i pushed build again, then my head blown out.
I've been shot with this error:

"asm"中的不可能约束

impossible constraint in 'asm'

代码是:

static inline unsigned ROLc(unsigned word, const int i)
{
   asm ("roll %2,%0"
      :"=r" (word)
      :"0" (word),"I" (i));
   return word;
}

一些神秘的事情发生了...我现在唯一想的是'WTF?'
平台上装有W32 XP的Intel CoreDuo.

Some mystery things happens...only thing which I'm thinking right now is 'WTF?'
Platform Intel CoreDuo with W32 XP on board.

另外两个问题:

1. 什么会破坏我的建筑?
2. 我想asm语法不正确，那么我该如何解决?
3. 在哪里可以找到'cool'asm参考(我的意思是一些cpp参考，例如通过纯处理器命令列表数据手册/手册)

致谢

更新:
哈哈，我觉得自己像个dump-ass，上周我安装了strawberry perl ...它会在路径上安装并抛出gcc，并且我的构建系统使用默认"编译器....:D
但是我已经使用:

UPDATE:
Haha I feel like dump-ass, last week i've installed strawberry perl...which installs and throws gcc on path and my build system takes 'default' compiler....:D
However i've fixed that using :

return (word << i) | (word >> (32 - i));

推荐答案

1. 您可能已自动升级到新的编译器，从而改变了语法
2. 这建议使用Ic而不是比我;我没有测试
3. 不知道您的意思是，对于汇编程序的C ++参考对我而言没有多大意义. 这是(旧的)HOWTO gcc和内联汇编，这可能就是您想要的吗?

1. You might have auto-upgraded to a new compiler, that has changed the syntax
2. This suggests using Ic rather than I; I didn't test this
3. Not sure what you mean, a C++ reference for assembly doesn't make a lot of sense to me. This is an (old) HOWTO on gcc and inline assembly, it might be what you're after?

这篇关于在"asm"中不可能的约束的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！