Available on RISC-V RV32 only.
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P0 transformation function as is used in the SM3 hash algorithm
This function is included in Zksh extension. It’s defined as:
P0(X) = X ⊕ (X ≪ 9) ⊕ (X ≪ 17)where ⊕ represents 32-bit xor, and ≪ k represents rotate left by k bits.
In the SM3 algorithm, the P0 transformation is used as E ← P0(TT2) when the
compression function CF uses the intermediate value TT2 to calculate
the variable E in one iteration for subsequent processes.
According to RISC-V Cryptography Extensions, Volume I, the execution latency of this instruction must always be independent from the data it operates on.