Intrinsic Functions for SIMD Instructions

Click Nuclei DSP Feature to learn about Core DSP in Nuclei ISA Spec.

group NMSIS_Core_DSP_Intrinsic

Functions that generate RISC-V DSP SIMD instructions.

The following functions generate specified RISC-V SIMD instructions that cannot be directly accessed by compiler.

DSP ISA Extension Instruction Summary
- Shorthand Definitions
  - r.H == rH1: r[31:16], r.L == r.H0: r[15:0]
  - r.B3: r[31:24], r.B2: r[23:16], r.B1: r[15:8], r.B0: r[7:0]
  - r.B[x]: r[(x*8+7):(x*8+0)]
  - r.H[x]: r[(x*16+7):(x*16+0)]
  - r.W[x]: r[(x*32+31):(x*32+0)]
  - r[xU]: the upper 32-bit of a 64-bit number; xU represents the GPR number that contains this upper part 32-bit value.
  - r[xL]: the lower 32-bit of a 64-bit number; xL represents the GPR number that contains this lower part 32-bit value.
  - r[xU].r[xL]: a 64-bit number that is formed from a pair of GPRs.
  - s>>: signed arithmetic right shift:
  - u>>: unsigned logical right shift
  - SAT.Qn(): Saturate to the range of [-2^n, 2^n-1], if saturation happens, set PSW.OV.
  - SAT.Um(): Saturate to the range of [0, 2^m-1], if saturation happens, set PSW.OV.
  - RUND(): Indicate rounding, i.e., add 1 to the most significant discarded bit for right shift or MSW-type multiplication instructions.
  - Sign or Zero Extending functions:
    - SEm(data): Sign-Extend data to m-bit.:
    - ZEm(data): Zero-Extend data to m-bit.
  - ABS(x): Calculate the absolute value of x.
  - CONCAT(x,y): Concatinate x and y to form a value.
  - u<: Unsinged less than comparison.
  - u<=: Unsinged less than & equal comparison.
  - u>: Unsinged greater than comparison.
  - s*: Signed multiplication.
  - u*: Unsigned multiplication.