如何做ADD / SUB符号或无符号整数是否正确？ [英] How to do ADD/SUB signed or unsigned integer correctly?

问题描述

我看到有基于ARM的添加指令，它对于签署和<$ C $工作C> unsigned int类型？一些状态标志应该是不同的，当用取值后缀指定的指令，对不对？如设置溢出（ V ）标志。我想知道有没有ADD / SUB的另一个版本来处理整数之一。

I saw there is an ADD instruction on ARM, does it work for both signed and unsigned int? Some status flags should be different when the instruction is specified with S suffix, right? Such as setting overflow (V) flag. I am wondering is there another version of ADD/SUB to handle one of the integer.

推荐答案

二进制补码表示有符号和无符号除了没有区别。在S位决定任何标志是否修改或不修改IF，然后再进行的是无符号的溢/借贷和v是符号溢出/借。这是武器的所有文档描述。

Twos complement means there is no difference between signed and unsigned addition. The s bit determines whether any flags are modified or not IF modified, then carry is the unsigned overflow/borrow and v is the signed overflow/borrow. This is all described in ARMs documentation.

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