riscv_zfa

Draft Extension: Zfa

• Status: WITHDRAWN
  (Christoph Müllner et al. upstreamed the support; my work is partially used)
• Branch: riscv-zfa
• Tracking PR: #56 (view Pull Request and Diff)
• Mailing List:
  • REVIEW ONLY v1 (2022-09-18)

Based On

• Draft Extension: Zfb

Feature Description

This patchset implements the draft implementation of the Zfa extension (formerly the Zfb extension).

To implement FLI instructions, it requires new operand type ('i'), which accepts either:

• Values: 0...29 (inclusive)
  Unlike draft specification, it does allow not only decimal numbers but complex expressions. However, they are not tested (intentionally).
• min (encoded as 1, equivalent to value 1)
• inf (encoded as 30, decimal representation is invalid)
• nan (encoded as 31, decimal representation is invalid)