Lui指令的立即数范围 [英] Range of immediates in lui instruction

问题描述

我不确定lui指令中立即数的范围是什么.

I'm not sure what is the range bound for the immediate in lui instruction.

我组装时:

lui $t0,32768

它成功运行，没有错误.

It successfully went without errors.

但是，

lui $t0,-32768 

通知-32768超出范围.

notified that -32768 out of range.

推荐答案

在MIPS中，I型指令的立即数始终为16位长.这意味着如果汇编器将其视为未签名，则范围将为[0，65535]，对于已签名的情况将范围为[-32768，32767]

In MIPS the immediate in I-type instructions is always 16-bit long. That means the range will be [0, 65535] if the assembler treats it as unsigned, and [-32768, 32767] for the signed case

但是您可以在汇编中使用什么取决于汇编器

However what you can use in the assembly depends on the assembler

例如，某些汇编程序，例如 shell-storm 和 WeMips 接受[-32768，65535]中的常量，这是两个16-位签名和未签名， MIPS转换器仅接受十六进制值，但 WebMIPSASM 甚至接受9223372036854775807之类的巨大值并将结果截断为16位

For example some assemblers like shell-storm and WeMips accept constants in [-32768, 65535] which is a mix of both 16-bit signed and unsigned, MIPS Converter only accepts hexadecimal values but WebMIPSASM accepts even huge values like 9223372036854775807 and truncate the result to 16 bits

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