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v0.17.0: Zba + Zbb Bit-Manipulation Extensions

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@quantumnic quantumnic released this 19 Feb 07:34
· 73 commits to main since this release
v0.17.0
1512595

What's New

Zba Extension (Address Generation)

  • SH1ADD, SH2ADD, SH3ADD — shifted-add for array indexing patterns
  • SH1ADD.UW, SH2ADD.UW, SH3ADD.UW — unsigned word variants
  • ADD.UW — add with zero-extended 32-bit source
  • SLLI.UW — shift-left with zero-extended 32-bit source

Zbb Extension (Basic Bit Manipulation)

  • Logical: ANDN, ORN, XNOR
  • Counting: CLZ/CLZW, CTZ/CTZW, CPOP/CPOPW
  • Min/Max: MIN, MINU, MAX, MAXU (signed + unsigned)
  • Sign/Zero extend: SEXT.B, SEXT.H, ZEXT.H
  • Rotate: ROL/ROLW, ROR/RORW, RORI/RORIW
  • Byte operations: REV8 (byte-reverse), ORC.B (or-combine bytes)

Other

  • DTB ISA string updated with zba, zbb extensions
  • 16 new tests (123 total, all passing)

These extensions are part of the ratified RISC-V B (bit-manipulation) standard and are used by modern Linux kernels for optimized string operations, memory copying, and address calculations.

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