EXTRQ, INSERTQ, MOVNTSS and MOVNTSD are rewritten at relink time: same-length in-place forms
where they exist, otherwise a jmp rel32 into an appended executable section holding a
scratch-free SSE body and a jump back, so no code shifts and no RIP-relative or jump-table
operand needs adjusting. Decoder fixes for POPCNT and 0F BB (BTC), codegen and elfpatcher
tests, README and technical-debt notes. The runtime illegal-instruction trap stays as a
fallback.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0177gthrWEBBfBu5xJDXgBfo
01c4e3edf7