Internal label ids are allocation-order handles: the encoder's creation
order, or the decoder's branch-DISCOVERY order (a loop's latch names the
header before an earlier forward target). Printing labels by raw id leaked
that accident into listings — label numbers appeared out of order down the
page — and the printers' `label_names: ^map[u32]string` keyed the caller's
names by those synthesized ids, which a decode consumer cannot know without
re-deriving them (the practical result: naming "label 0" could caption a
random interior branch target).
Naming is now derived at the presentation seam, shared by every ISA
(`isa.Label_Display` in isa/print.odin):
- display numbers are assigned in ASCENDING ADDRESS order, so a listing
reads L0, L1, L2 … top to bottom regardless of id allocation;
- caller names are keyed by BYTE OFFSET (`isa.Label_Names`, with a
`distinct` Label_Offset key so an id-keyed map from the old contract
fails to compile instead of silently mis-naming);
- a named offset is guaranteed a label row even when no Label_Definition
points at it — `names[0] = "factorial"` heads a function's listing.
All ten ISA printers (x86, mips, rsp, arm32, arm64, riscv, ppc, ppc_vle,
mos6502, mos65816) drop their per-printer offset_to_label maps and
write_label helpers for the shared display; each arch re-exports
Label_Offset/Label_Names beside Label_Definition. En route this fixes an
arm32/ppc/ppc_vle bug where passing ANY names map suppressed the default
L<n> label rows for unnamed labels. Decode-side id assignment is untouched:
the reloc round-trip contract (encoder ids surviving decode) and the
sparse-id padding it relies on stay exactly as they were.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Riok9vMpkLmo78wsVKJHhz
Move all ten ISA packages (x86, arm32, arm64, mips, riscv, ppc, ppc_vle,
rsp, mos6502, mos65816) from core/rexcode/<arch> to core/rexcode/isa/<arch>,
so the import pattern is now `import "core:rexcode/isa/x86"`. The shared
core stays at core:rexcode/isa.
Mechanical: relative `import "../isa"` / "../../isa" -> absolute
"core:rexcode/isa" (the only path that survives the move; the "../" and
"../.." self/generated imports move with their packages). build.lua now
builds paths as <root>/isa/<name>; stale `cd <arch>` hints in the verify
tools and the doc.odin paths updated.
WASM stays at core/rexcode/wasm for now -- it is an IR, not an ISA, and
will move under the forthcoming core:rexcode/ir once that layer lands.
All 10 arches gen/builders/check/test green; import core:rexcode/isa/x86
verified working; wasm still compiles.
