Add Zcmp extension#1026
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Those registers overwrite registers other than the `rd` register. This can lead to infinite loops. This ensures that we don't use any loop registers for all registers modified by those instructions.
Since the push/pop instructions have so many side effects, test them in a dedicated instruction stream. This class builds blocks of push and pop instructions, which operate withing a given stack size. Multiple such blocks are generated and linked in a random order. To jump between these blocks, we use the popret/popretz instructions.
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This PR adds support for the Zcmp extension, which introduces
cm.push/popand double move (cm.mv) instructions.Because the push/pop instructions modify multiple registers and have significant side effects, this PR implements a specialized test class to generate valid sequences in a dedicated instruction stream. This class builds blocks of push and pop instructions that operate within a given stack size. Multiple blocks are generated and linked in a random order, using
popret/popretzinstructions to jump between them.Note: This PR depends on PRs #1024 and #1025 and should be rebased and merged after they land. New changes from this PR: review only new commits
Those tests are used in Ibex's verification: lowRISC/ibex#2324