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
The table had the R6 unsigned mul, both muh, and mod/modu, but not the R6
SIGNED low multiply (SPECIAL funct 0x18, sa=2 → 0x98) or the R6 signed/unsigned
divide (funct 0x1A, sa=2/3 → 0x9A/0x9B). Add MUL_R6, DIV_R6, DIVU_R6 to the
Mnemonic enum + the encoding table (all SPECIAL, RD/RS/RT, mask 0xFC0007FF,
MIPS32_R6) and regenerate the tables. Verified against llvm-mc -mcpu=mips32r6
(mul/div/divu $rd,$rs,$rt). All existing mips tests pass (166/39/65/14).
The MIPS decode tables are universal — every variant (MIPS I..64/R6, the PS1
GTE, PS2 MMI/VU, PSP VFPU) shares one table. Some primary opcodes collide
across variants: most visibly 0x37 is `LD` on 64-bit MIPS but `vfim.s` on the
PSP Allegrex VFPU. The decoder took the first table match, so `LD $ra, 0($sp)`
(0xdfbf0000) mis-decoded as `vfim.s $31, 0`.
Each Decode_Entry already carries a `feature`; the decoder just ignored it.
`decode` now takes a `features: Feature_Set` (a bit_set over `Feature`),
defaulting to `FEATURES_ALL` so existing callers are unchanged, and skips an
entry whose feature isn't enabled — the first ENABLED match wins, preserving
the most-specific-mask-first order. Added `FEATURES_MIPS_III` (MIPS I/II/III +
COP0 + FPU — the VR4300 / classic 64-bit baseline) for N64/MIPS-III consumers.
decode_smoke: opcode 0x37 decodes as LD under FEATURES_MIPS_III and (still)
as the PSP VFPU entry under FEATURES_ALL. 65 decoder checks pass.
