[SOL] Use mov32 to load and zero extend immediate in V2+
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LucasSte
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mov32 to load an zero extend immediate in V2+mov32 to load and zero extend immediate in V2+
Lichtso
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Jul 25, 2025
LucasSte
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anza-xyz:solana-rustc/19.1-2024-12-03
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LucasSte
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Aug 12, 2025
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Problem
For SBPFv2 onwards, we can use
mov32 reg, immto load and sign extend immediate values, without the pair hor64/mo32. This is particularly useful for numbers betweenu32::MAX >> 1andu32::MAX.Solution
Create a new instruction to represent a load with zero extend. Since it has the same opcode as all the other use cases for mov32, it needs a new decoder namespace, so that LLVM knows which instruction the opcode refers to when disassembling a file.
PS: In the disassembler, we do not care which of the defined
mov32 reg, immthe instruction we are reading is assigned to. All of them have the same syntax and semantic.