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ac0589daa1
Precompute each encoding form into a flat Form_Recipe -- prefix byte, escape+
opcode blob, role->operand-index slots, ext, imm size, flags -- so the encoder
replays common forms straight-line instead of re-interpreting enc.ops/enc.enc
on every instruction (the resolve scan, escape ladder, prefix/REX selection).
encode() takes the fast path when the form is hinted, eligible, has a register
r/m and a literal immediate; everything else falls through to the existing
interpreter, which stays the byte-exact source of truth. First cut:
- reg-direct ModR/M only (memory r/m falls back)
- hint path only (matcher / generic builders fall back)
- ~33% of forms eligible (VEX/EVEX, 16-bit operand-size, x87 fixed-ModR/M,
moffs/far/rel/implicit operands are marked ineligible)
Recipes are built at startup into static storage (no heap); this moves into the
table generator (#loaded like every other table) once the shape settles.
Realistic immediate-heavy mix: ~19.0 -> ~16.3 ns/inst (52.7 -> 61.3 M/s).
Byte-exact across 2282 cases + idempotent.
Next: memory r/m addressing in the fast path, then the matcher path, then the
gen-time port.