e6d43a23ac
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>
115 lines
4.0 KiB
Markdown
115 lines
4.0 KiB
Markdown
# `xoris` — XOR Immediate Shifted
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> **Category:** [Integer ALU](../categories/alu.md) · **Form:** [D](../forms/D.md) · **Opcode:** `0x6c000000`
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<!-- GENERATED: BEGIN -->
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## Assembler Mnemonics
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| Mnemonic | XML entry | Flags | Description |
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| --- | --- | --- | --- |
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| `xoris` | `xoris` | — | XOR Immediate Shifted |
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## Syntax
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```asm
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xoris [RA], [RS], [UIMM]
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```
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## Encoding
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### `xoris` — form `D`
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- **Opcode word:** `0x6c000000`
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- **Primary opcode (bits 0–5):** `27`
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- **Extended opcode:** —
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- **Synchronising:** no
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| Bits | Field | Meaning |
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| --- | --- | --- |
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| 0–5 | `OPCD` | primary opcode |
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| 6–10 | `RT` | destination GPR (or RS when storing) |
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| 11–15 | `RA` | source GPR (0 ⇒ literal 0 for RA0 forms) |
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| 16–31 | `D/SI/UI` | 16-bit signed or unsigned immediate |
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## Operands
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| Field | Role | Description |
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| --- | --- | --- |
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| `RS` | xoris: read | Source GPR (alias for RD in some stores). |
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| `UIMM` | xoris: read | 16-bit unsigned immediate. Zero-extended. |
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| `RA` | xoris: write | Source GPR (`r0`–`r31`). |
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## Register Effects
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### `xoris`
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- **Reads (always):** `RS`, `UIMM`
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- **Reads (conditional):** _none_
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- **Writes (always):** `RA`
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- **Writes (conditional):** _none_
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## Status-Register Effects
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_No condition-register or status-register effects._
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## Operation (pseudocode)
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```
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RA <- (RS) ^ (UIMM || 0x0000)
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```
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## C Translation Example
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```c
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/* C translation: the xenia-rs interpreter arm below in */
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/* Implementation References is the authoritative semantic */
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/* snapshot. Translate it line-by-line: */
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/* - ctx.gpr[N] -> r[N] (or f[]/v[] for FPRs/VRs) */
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/* - mem.read_u*/write_u* -> mem_read_u*_be / mem_write_u*_be */
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/* - ctx.update_cr_signed(fld, v) -> update_cr_signed(fld, v) */
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/* - ctx.xer_ca / xer_ov / xer_so -> xer.CA / xer.OV / xer.SO */
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/* The Register Effects and Status-Register Effects tables above */
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/* enumerate every side effect a faithful translation must emit. */
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```
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## Implementation References
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**`xoris`**
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- xenia-canary XML: [`tools/ppc-instructions.xml` — search for `mnem="xoris"`](../../xenia-canary/tools/ppc-instructions.xml)
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- xenia-canary emit: [`src/xenia/cpu/ppc/ppc_emit_alu.cc:846`](../../xenia-canary/src/xenia/cpu/ppc/ppc_emit_alu.cc#L846)
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- xenia-rs opcode: [`crates/xenia-cpu/src/opcode.rs:132`](../../xenia-rs/crates/xenia-cpu/src/opcode.rs#L132)
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- xenia-rs decoder: [`crates/xenia-cpu/src/decoder.rs:350`](../../xenia-rs/crates/xenia-cpu/src/decoder.rs#L350)
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- xenia-rs interpreter: [`crates/xenia-cpu/src/interpreter.rs:524-527`](../../xenia-rs/crates/xenia-cpu/src/interpreter.rs#L524-L527)
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<details><summary>xenia-rs interpreter body (frozen snapshot)</summary>
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```rust
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PpcOpcode::xoris => {
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ctx.gpr[instr.ra()] = ctx.gpr[instr.rs()] ^ ((instr.uimm16() as u64) << 16);
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ctx.pc += 4;
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}
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```
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</details>
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<!-- GENERATED: END -->
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## Special Cases & Edge Conditions
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- **No record form.** Like all immediate logicals other than `andi.`/`andis.`, `xoris` does not update CR0.
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- **Immediate is zero-extended *then* shifted left 16.** Only bits 32–47 of `RA` (PowerISA bit numbering) can be flipped; the high 32 bits and low 16 bits of `RA` come from `RS` unchanged.
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- **Common pattern with [`xori`](xori.md)** to flip arbitrary 32-bit bitmasks: `xoris RA, RS, hi16; xori RA, RA, lo16`.
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- **64-bit operation.** [`interpreter.rs:342`](../../xenia-rs/crates/xenia-cpu/src/interpreter.rs#L342).
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- **No `XER`, no `CR`.**
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- **`RA = 0` reads `r0`** (not literal zero).
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- **Used to toggle the high half of a 32-bit word**, e.g. `xoris r3, r3, 0x8000` flips bit 32 (the sign bit of the low word) — a one-instruction sign-flip on a 32-bit value.
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## Related Instructions
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- [`xori`](xori.md) — companion (immediate not shifted).
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- [`xorx`](xorx.md) — register-register XOR.
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- [`oris`](oris.md), [`andisx`](andisx.md) — sister immediate-shifted logicals.
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## IBM Reference
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- [AIX 7.3 — `xoris` (XOR Immediate Shifted)](https://www.ibm.com/docs/en/aix/7.3.0?topic=set-xoris-immediate-shifted-instruction)
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