What is the difference between a = a * (2^3) and a = a << 3?
2011-07-26 22:14
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What is the difference between a = a * (2^3) and a = a <<3?
在面试题中，经常会问，如何高效的实现某个数值乘以2的n次方，标准答案一般是向左移位n位。
其实，这个跟编译器有关系的。当编译器看到常数2的n次方后，可能会直接优化成左移位操作。大家可以自己调试跟踪一下汇编代码。
在面试题中，经常会问，如何高效的实现某个数值乘以2的n次方，标准答案一般是向左移位n位。
其实，这个跟编译器有关系的。当编译器看到常数2的n次方后，可能会直接优化成左移位操作。大家可以自己调试跟踪一下汇编代码。
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