I am trying to write a simulator for a RISC-V CPU and can not find a definitve answer to my question.
Let's say I want to use
ANDI rs1, rd, 0xFFF
with rs1 containing 0xFFFFFFFF and the immediate value being 0xFFF.
Does the ANDI operate on the full register and just fill the remaining 20 bit of the immediate with zeros so the result in rd will be 0x000000FFF?
Or are the higher 20 bits ignored and the result in rd will still be 0xFFFFFFFF?
Same question for XORI and ORI commands.
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