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xenia-rs/migration/project-root/ppc-manual/vmx/vor.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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# `vor` — Vector Logical OR
> **Category:** [VMX (Altivec)](../categories/vmx.md) · **Form:** [VX](../forms/VX.md) · **Opcode:** `0x10000484`
<!-- GENERATED: BEGIN -->
## Assembler Mnemonics
| Mnemonic | XML entry | Flags | Description |
| --- | --- | --- | --- |
| `vor` | `vor` | — | Vector Logical OR |
| `vor128` | `vor128` | — | Vector128 Logical OR |
## Syntax
```asm
vor [VD], [VA], [VB]
vor128 [VD], [VA], [VB]
```
## Encoding
### `vor` — form `VX`
- **Opcode word:** `0x10000484`
- **Primary opcode (bits 0–5):** `4`
- **Extended opcode:** `1156`
- **Synchronising:** no
| Bits | Field | Meaning |
| --- | --- | --- |
| 0–5 | `OPCD` | primary opcode (4) |
| 6–10 | `VRT/VD` | destination vector register |
| 11–15 | `VRA/VA` | source A vector register |
| 16–20 | `VRB/VB` | source B vector register |
| 21–31 | `XO` | extended opcode (11 bits) |
### `vor128` — form `VX128`
- **Opcode word:** `0x140002d0`
- **Primary opcode (bits 0–5):** `5`
- **Extended opcode:** `720`
- **Synchronising:** no
| Bits | Field | Meaning |
| --- | --- | --- |
| 0–5 | `OPCD` | primary opcode (4 or 5) |
| 6–10 | `VD128l` | destination low 5 bits |
| 11–15 | `VA128l` | source A low 5 bits |
| 16–20 | `VB128l` | source B low 5 bits |
| 21 | `VA128H` | source A high bit |
| 22 | `—` | reserved |
| 23–25 | `VC` | optional VC / XO sub-field |
| 26 | `VA128h` | source A middle bit |
| 27 | `—` | reserved |
| 28–29 | `VD128h` | destination high 2 bits |
| 30–31 | `VB128h` | source B high 2 bits |
## Operands
| Field | Role | Description |
| --- | --- | --- |
| `VA` | vor: read; vor128: read | Source A vector register. |
| `VB` | vor: read; vor128: read | Source B vector register. |
| `VD` | vor: write; vor128: write | Destination vector register. |
## Register Effects
### `vor`
- **Reads (always):** `VA`, `VB`
- **Reads (conditional):** _none_
- **Writes (always):** `VD`
- **Writes (conditional):** _none_
### `vor128`
- **Reads (always):** `VA`, `VB`
- **Reads (conditional):** _none_
- **Writes (always):** `VD`
- **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
**`vor`**
- xenia-canary XML: [`tools/ppc-instructions.xml` — search for `mnem="vor"`](../../xenia-canary/tools/ppc-instructions.xml)
- xenia-canary emit: [`src/xenia/cpu/ppc/ppc_emit_altivec.cc:1186`](../../xenia-canary/src/xenia/cpu/ppc/ppc_emit_altivec.cc#L1186)
- xenia-rs opcode: [`crates/xenia-cpu/src/opcode.rs:111`](../../xenia-rs/crates/xenia-cpu/src/opcode.rs#L111)
- xenia-rs decoder: [`crates/xenia-cpu/src/decoder.rs:531`](../../xenia-rs/crates/xenia-cpu/src/decoder.rs#L531)
- xenia-rs interpreter: [`crates/xenia-cpu/src/interpreter.rs:2226-2234`](../../xenia-rs/crates/xenia-cpu/src/interpreter.rs#L2226-L2234)
<details><summary>xenia-rs interpreter body (frozen snapshot)</summary>
```rust
PpcOpcode::vor | PpcOpcode::vor128 => {
let (va, vb, vd) = vmx_reg_triple(instr);
let a = ctx.vr[va].as_u32x4();
let b = ctx.vr[vb].as_u32x4();
let mut r = [0u32; 4];
for i in 0..4 { r[i] = a[i] | b[i]; }
ctx.vr[vd] = xenia_types::Vec128::from_u32x4_array(r);
ctx.pc += 4;
}
```
</details>
**`vor128`**
- xenia-canary XML: [`tools/ppc-instructions.xml` — search for `mnem="vor128"`](../../xenia-canary/tools/ppc-instructions.xml)
- xenia-canary emit: [`src/xenia/cpu/ppc/ppc_emit_altivec.cc:1189`](../../xenia-canary/src/xenia/cpu/ppc/ppc_emit_altivec.cc#L1189)
- xenia-rs opcode: [`crates/xenia-cpu/src/opcode.rs:111`](../../xenia-rs/crates/xenia-cpu/src/opcode.rs#L111)
- xenia-rs decoder: [`crates/xenia-cpu/src/decoder.rs:625`](../../xenia-rs/crates/xenia-cpu/src/decoder.rs#L625)
- xenia-rs interpreter: [`crates/xenia-cpu/src/interpreter.rs:2226-2234`](../../xenia-rs/crates/xenia-cpu/src/interpreter.rs#L2226-L2234)
<details><summary>xenia-rs interpreter body (frozen snapshot)</summary>
```rust
PpcOpcode::vor | PpcOpcode::vor128 => {
let (va, vb, vd) = vmx_reg_triple(instr);
let a = ctx.vr[va].as_u32x4();
let b = ctx.vr[vb].as_u32x4();
let mut r = [0u32; 4];
for i in 0..4 { r[i] = a[i] | b[i]; }
ctx.vr[vd] = xenia_types::Vec128::from_u32x4_array(r);
ctx.pc += 4;
}
```
</details>
<!-- GENERATED: END -->
## Special Cases & Edge Conditions
- **Bitwise OR across the full 128-bit register.** Lane-agnostic; xenia implements it as four 32-bit lanes but the result is identical at any granularity.
- **`vor VD, VA, VA` is the idiomatic register move.** No dedicated "vmr" exists in base Altivec; compilers recognise the `vor v3, v4, v4` pattern as a move and schedule accordingly.
- **Aliasing is legal.** `vor v3, v3, v4` merges the mask in `v4` into `v3`.
- **No flags, no VSCR effect.**
- **VMX128 sibling [`vor128`](vor128.md).** Same operation, wider register file.
- **Common pattern: ORing a compare mask with a data vector** to force specific lanes to all-ones without needing a select.
## Related Instructions
- [`vand`](vand.md), [`vandc`](vandc.md) — AND / AND-with-complement.
- [`vnor`](vnor.md) — NOR, includes the idiom for bitwise NOT.
- [`vxor`](vxor.md) — XOR; also a common "zero register" via `vxor vD, vD, vD`.
- [`vsel`](vsel.md) — three-operand bit-select, often combined with OR of masks.
## IBM Reference
- [AIX 7.3 — `vor` (Vector Logical OR)](https://www.ibm.com/docs/en/aix/7.3.0?topic=set-vor-vector-logical-or-instruction)
- [IBM AltiVec Technology Programmer's Interface Manual, Chapter 3 — Logical Operations](https://www.nxp.com/docs/en/reference-manual/ALTIVECPIM.pdf)
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