Add support for Zcmt extension #757
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Timmmm
requested changes
Feb 26, 2025
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| type target_address = bits(xlen) | ||
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| union FJT_Result = { |
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Probably just use result(target_address, unit)
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Could you explain a bit more about this and how I should modify the code?
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| function clause execute (CM_JALT(index)) = { | ||
| let base : bits(xlen) = jvt.bits & ~(zero_extend(0x3F)); | ||
| let index : bits(xlen) = zero_extend(index); |
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I believe you can delete this line.
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This wont compile, I get:
Failed to prove constraint: 8 == 32
But I think it makes sense, imagine shifting bits to the left. Since the bit width of index remains the same (without extending), the two (or three) most significant bits would be lost.
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Hi @Timmmm, thanks for the suggestions! I've incorporated them and left some comments about a few small issues I ran into. |
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Hi everyone,
This pull request adds support for the Zcmt extension.
I’ve also included some simple tests, which can be found here.
Reading from the jump table vector requires Execute permission and supports both little and big endian formats. The current RISC-V Sail model only allows little-endian access, but I will add big-endian support after #751 is merged.
One observation: at some point, it might make sense to introduce a more general interface for
loadandstore. Since the Zcmp (#730) extension also requires these operations, a shared implementation could help reduce code duplication.