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uxmal / reko

Reko is a binary decompiler.
https://uxmal.github.io/reko
GNU General Public License v2.0
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AEON: Add bt.lwst instruction #1321

Closed throwaway96 closed 5 months ago

throwaway96 commented 5 months ago

The encoding for bt.lwst is almost the same as that of bt.swst except that it has the LSB set. This means the value for the immediate starts at bit 1, is 4 bits long, and is shifted left by 2 bits to calculate the offset. These instructions seem to be intended to provide more efficient stack access, using only 16 bits rather than the 24 bits of bn.sw/bn.lwz.

The bt.lwst and bt.swst mnemonics are both entirely made up. I would love to know what the official mnemonics are or if these are actually just special cases of other load/store word instructions.

uxmal commented 5 months ago

Until we know for sure what the mnemonic should be, bt.lwst is perfectly adequate. Thanks for the contribution.