MIPS 立即指令 ori/addi/lui 等需要寄存器写入吗？
我正在学习 MIPS 中的流水线技术。我对即时指示及其指示流程有疑问。我一直在阅读 ori/addi/lui，并且是即时指令或 I 型。我还不断发现 I 型指令只需要 MIPS 5 阶段过程的前三个阶段。如下所示
|instruction memory|register read|ALU op|DataMemory|Register Write|
|------------------------------------------------------------------
addi| X | X | X | | |
-----------------------------------------------------------------------
ori | X | X | X | | |
-----------------------------------------------------------------------
lui | X | X | X | | |
-----------------------------------------------------------------------
我的问题是第一，这个表正确吗？我觉得奇怪的是，这些指令不需要写入寄存器来更改寄存器的内容。如果这张桌子不合适，有人可以帮我看看正确的桌子是什么样子吗？
I am learning about pipelining in MIPS. I had a question about immediate instructions and their instruction process. I keep reading that ori/addi/lui and are immediate instructions or I-type. I also keep finding that I-type instructions only require the first three stages of the of a MIPS 5-stage process. Like shown below
|instruction memory|register read|ALU op|DataMemory|Register Write|
|------------------------------------------------------------------
addi| X | X | X | | |
-----------------------------------------------------------------------
ori | X | X | X | | |
-----------------------------------------------------------------------
lui | X | X | X | | |
-----------------------------------------------------------------------
My question is first, is this table correct? I find it weird that these instructions do not require a register write to change the contents of the register. If this table is not right can someone help me with what the right table would look like?
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addi/ori/lui等立即指令确实需要将其结果写入寄存器文件。例如：addi $dest、$src、immd_val。对于该指令，操作数之一是立即数。因此计算结果为：$dest = $src + immd_val。正如您所看到的，结果必须写回寄存器$dest。您走在正确的轨道上，您需要适当修改您的表格。有些指令不需要将结果写回寄存器文件，如分支、存储、比较等。
The immediate instructions of
addi/ori/luiand so on do need to write their results to the register file. For example:addi $dest, $src, immd_val. For this instruction, one of the operands is an immediate value. So the computation will be,$dest = $src + immd_val. As you can see the result has to be written back to register$dest. You are on the right track, you need to modify your table suitably.There are some instructions that do not need to write-back the result to the register file like the branch, store, compare etc.