pub unsafe fn xperm4(rs1: usize, rs2: usize) -> usize🔬This is a nightly-only experimental API. (
stdsimd #48556)Available on RISC-V RV32 and target feature
zbkx only.Expand description
Nibble-wise lookup of indicies into a vector.
The xperm4 instruction operates on nibbles. The rs1 register contains a vector of XLEN/4 4-bit elements. The rs2 register contains a vector of XLEN/4 4-bit indexes. The result is each element in rs2 replaced by the indexed element in rs1, or zero if the index into rs2 is out of bounds.
Source: RISC-V Cryptography Extensions Volume I: Scalar & Entropy Source Instructions
Version: v1.0.1
Section: 3.48
§Safety
This function is safe to use if the zbkx target feature is present.