Files
xenia-rs/migration/project-root/ppc-manual/control/crorc.md
MechaCat02 e6d43a23ac chore: add migration/ bundle for cross-machine setup
Bundles state that lives OUTSIDE the xenia-rs repo so a fresh clone on
another machine can be brought up to identical configuration via
migration/setup.sh:

  - claude-memory/             ~/.claude/projects/-home-fabi-RE-Project-Sylpheed/memory/
                               (103 files, 1.1 MB - MEMORY.md + every
                                project_xenia_rs_*.md from audits
                                addis_signext through audit-058)
  - project-root/dot-claude/   <project-root>/.claude/settings.json
                               (Stop hook + permissions)
  - project-root/ppc-manual/   <project-root>/ppc-manual/
                               (PowerPC reference docs, 397 files, 3.7 MB)
  - project-root/run-canary.sh <project-root>/run-canary.sh
  - README.md                  Human-readable setup checklist
  - setup.sh                   Idempotent installer (also reclones
                               xenia-canary at pinned HEAD 6de80dffe)
  - MANIFEST.md                Per-file mapping + per-file-not-bundled
                               restoration recipe

Excluded from bundle (not shippable via git):
  - Sylpheed ISO (7.8 GB; copyright; manual copy required)
  - sylpheed.db (395 MB; regenerable from XEX via analysis tooling)
  - target/ build artifacts (rebuild on target)
  - audit-runs probe firehoses (.log/.stdout/.stderr ~11 GB; rerun if needed)
  - audit-runs memory dumps (.bin ~4.5 GB; rerun audit-026/027/029 if needed)
  - xenia-canary checkout (setup.sh reclones from
    git.mc02.dev/fabi/Xenia-Canary.git at HEAD 6de80dffe)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-10 21:38:38 +02:00

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# `crorc` — Condition Register OR with Complement
> **Category:** [Control / CR / SPR](../categories/control.md) · **Form:** [XL](../forms/XL.md) · **Opcode:** `0x4c000342`
<!-- GENERATED: BEGIN -->
## Assembler Mnemonics
| Mnemonic | XML entry | Flags | Description |
| --- | --- | --- | --- |
| `crorc` | `crorc` | — | Condition Register OR with Complement |
## Syntax
```asm
crorc [CRBD], [CRBA], [CRBB]
```
## Encoding
### `crorc` — form `XL`
- **Opcode word:** `0x4c000342`
- **Primary opcode (bits 05):** `19`
- **Extended opcode:** `417`
- **Synchronising:** no
| Bits | Field | Meaning |
| --- | --- | --- |
| 05 | `OPCD` | primary opcode (19) |
| 610 | `BT/BO` | target / branch options |
| 1115 | `BA/BI` | source A / CR bit to test |
| 1620 | `BB` | source B |
| 2130 | `XO` | extended opcode (10 bits) |
| 31 | `LK` | link flag |
## Operands
| Field | Role | Description |
| --- | --- | --- |
| `CRBA` | crorc: read | CR source bit A (031). |
| `CRBB` | crorc: read | CR source bit B (031). |
| `CRBD` | crorc: write | CR destination bit (031). |
## Register Effects
### `crorc`
- **Reads (always):** `CRBA`, `CRBB`
- **Reads (conditional):** _none_
- **Writes (always):** `CRBD`
- **Writes (conditional):** _none_
## Status-Register Effects
_No condition-register or status-register effects._
## Operation (pseudocode)
```
; Pseudocode derives directly from the xenia-rs interpreter
; arm (see Implementation References). Operation semantics:
; - Read source operands from the fields listed under Operands.
; - Apply the arithmetic / logical / memory action described
; in the Description field above.
; - Write results to the destination register(s); update any
; status bits enumerated under Status-Register Effects.
; Consult the IBM AIX reference link under IBM Reference for
; canonical PPC-style pseudocode where xenia's expression is
; terse.
```
## C Translation Example
```c
/* C translation: the xenia-rs interpreter arm below in */
/* Implementation References is the authoritative semantic */
/* snapshot. Translate it line-by-line: */
/* - ctx.gpr[N] -> r[N] (or f[]/v[] for FPRs/VRs) */
/* - mem.read_u*/write_u* -> mem_read_u*_be / mem_write_u*_be */
/* - ctx.update_cr_signed(fld, v) -> update_cr_signed(fld, v) */
/* - ctx.xer_ca / xer_ov / xer_so -> xer.CA / xer.OV / xer.SO */
/* The Register Effects and Status-Register Effects tables above */
/* enumerate every side effect a faithful translation must emit. */
```
## Implementation References
**`crorc`**
- xenia-canary XML: [`tools/ppc-instructions.xml` — search for `mnem="crorc"`](../../xenia-canary/tools/ppc-instructions.xml)
- xenia-canary emit: [`src/xenia/cpu/ppc/ppc_emit_control.cc:406`](../../xenia-canary/src/xenia/cpu/ppc/ppc_emit_control.cc#L406)
- xenia-rs opcode: [`crates/xenia-cpu/src/opcode.rs:17`](../../xenia-rs/crates/xenia-cpu/src/opcode.rs#L17)
- xenia-rs decoder: [`crates/xenia-cpu/src/decoder.rs:719`](../../xenia-rs/crates/xenia-cpu/src/decoder.rs#L719)
<!-- GENERATED: END -->
## Special Cases & Edge Conditions
- **Operation.** `CR[CRBD] ← CR[CRBA] OR ¬CR[CRBB]` — a one-instruction "A or not B" implication. Result is 0 only when `A=0` and `B=1`.
- **Logical implication.** `B → A``¬B A`, which is exactly `crorc BT, BA, BB`. Useful for predicates of the form "if B holds, then A must hold".
- **Identity case.** `crorc BT, BA, BA` always yields 1 (`A ¬A`), an alternative to `creqv` for setting a bit.
- **Bit-level operands.** 5-bit absolute CR-bit indices; sources and destination may all be in different CR fields.
- **Use case.** Compose "if B then A" guards without a separate complement step.
- **No `Rc` / `OE`.** Doesn't update CR0 or XER.
- **Not synchronising.** Reorderable.
- **xenia status.** Decoded by the generic CR-logical handler; canary emits OR-with-NOT directly.
## Related Instructions
- [`cror`](cror.md), [`crnor`](crnor.md) — non-complement OR / NOR.
- [`crand`](crand.md), [`crandc`](crandc.md), [`crnand`](crnand.md) — AND family.
- [`crxor`](crxor.md), [`creqv`](creqv.md) — XOR / XNOR.
- [`mcrf`](mcrf.md) — bulk CR-field copy.
- [`bcx`](../branch/bcx.md) — typical consumer.
`crorc` has no dedicated simplified mnemonic. See [`cror`](cror.md) for `crmove`.
## IBM Reference
- [AIX 7.3 — `crorc` (Condition Register OR with Complement)](https://www.ibm.com/docs/en/aix/7.3.0?topic=set-crorc-condition-register-complement-instruction)
- [AIX 7.3 — Condition register simplified mnemonics](https://www.ibm.com/docs/en/aix/7.3.0?topic=mnemonics-condition-register-logical-simplified)