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>
123 lines
5.3 KiB
Markdown
123 lines
5.3 KiB
Markdown
# `andx` — AND
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> **Category:** [Integer ALU](../categories/alu.md) · **Form:** [X](../forms/X.md) · **Opcode:** `0x7c000038`
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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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| `and` | `andx` | — | AND |
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| `and.` | `andx` | Rc=1 | AND |
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## Syntax
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```asm
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and[Rc] [RA], [RS], [RB]
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```
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## Encoding
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### `andx` — form `X`
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- **Opcode word:** `0x7c000038`
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- **Primary opcode (bits 0–5):** `31`
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- **Extended opcode:** `28`
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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/FRT/VRT` | destination |
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| 11–15 | `RA/FRA/VRA` | source A |
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| 16–20 | `RB/FRB/VRB` | source B |
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| 21–30 | `XO` | extended opcode (10 bits) |
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| 31 | `Rc` | record-form flag |
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## Operands
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| Field | Role | Description |
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| --- | --- | --- |
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| `RS` | andx: read | Source GPR (alias for RD in some stores). |
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| `RB` | andx: read | Source GPR. |
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| `RA` | andx: write | Source GPR (`r0`–`r31`). |
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| `CR` | andx: write (conditional) | Condition-register update. When `Rc=1`, CR field 0 (or CR6 for vector compares, CR1 for FPU) is updated from the result. |
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## Register Effects
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### `andx`
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- **Reads (always):** `RS`, `RB`
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- **Reads (conditional):** _none_
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- **Writes (always):** `RA`
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- **Writes (conditional):** `CR`
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## Status-Register Effects
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- `andx`: **CR0** ← signed-compare(result, 0) with `SO ← XER[SO]`, when `Rc=1`.
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## Operation (pseudocode)
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```
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RA <- (RS) & (RB)
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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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**`andx`**
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- xenia-canary XML: [`tools/ppc-instructions.xml` — search for `mnem="andx"`](../../xenia-canary/tools/ppc-instructions.xml)
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- xenia-canary emit: [`src/xenia/cpu/ppc/ppc_emit_alu.cc:637`](../../xenia-canary/src/xenia/cpu/ppc/ppc_emit_alu.cc#L637)
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- xenia-rs opcode: [`crates/xenia-cpu/src/opcode.rs:9`](../../xenia-rs/crates/xenia-cpu/src/opcode.rs#L9)
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- xenia-rs decoder: [`crates/xenia-cpu/src/decoder.rs:760`](../../xenia-rs/crates/xenia-cpu/src/decoder.rs#L760)
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- xenia-rs interpreter: [`crates/xenia-cpu/src/interpreter.rs:528-533`](../../xenia-rs/crates/xenia-cpu/src/interpreter.rs#L528-L533)
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<details><summary>xenia-rs interpreter body (frozen snapshot)</summary>
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```rust
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PpcOpcode::andx => {
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// PPCBUG-032+020: 32-bit ABI CR0 view (latent under clean inputs).
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ctx.gpr[instr.ra()] = ctx.gpr[instr.rs()] & ctx.gpr[instr.rb()];
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if instr.rc_bit() { ctx.update_cr_signed(0, ctx.gpr[instr.ra()] as u32 as i32 as i64); }
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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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- **Operand convention is reversed.** Unlike the arithmetic XO-form (`add RT, RA, RB`), the logical X-form writes `RA` and reads `RS`/`RB`: `and RA, RS, RB`. The destination is the **second** operand encoded. This convention applies to the entire and/or/xor family; mixing them up is a frequent disassembly error.
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- **No `OE`, no `XER[CA]`, no `XER[OV]`.** Logical operations never affect XER. Only `Rc=1` updates `CR0` (signed compare against zero, with `SO ← XER[SO]`).
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- **64-bit AND on Xenon.** Both inputs are 64-bit GPRs; the result is the bitwise AND of all 64 bits.
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- **64-bit CR update on Xenon, 32-bit in xenia-rs.** The interpreter's `Rc=1` path in [`interpreter.rs:347`](../../xenia-rs/crates/xenia-cpu/src/interpreter.rs#L347) compares `result as i32 as i64`. For an AND whose high 32 bits are non-zero but low 32 bits are zero (e.g. `r3 = 0x1_0000_0000`, `and. r4, r3, r3`), spec sets CR0 to GT but xenia would set EQ. Flag this if reproducing CR-sensitive behaviour.
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- **Operand aliasing.** `and RA, RA, RA` is a no-op except for the optional CR0 update — this is the canonical "test register against zero" pattern when no `cmpwi` is desired (though `cmpwi` is more typical).
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- **No simplified mnemonic for AND-immediate.** Use [`andix`](andix.md) (`andi.`) or [`andisx`](andisx.md) (`andis.`) for immediate operands; both are *always* record forms (no plain `andi`).
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## Related Instructions
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- [`andcx`](andcx.md) — AND with complement: `RA ← RS & ~RB`.
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- [`andix`](andix.md), [`andisx`](andisx.md) — D-form AND immediate (always `Rc=1`).
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- [`nandx`](nandx.md) — NAND.
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- [`orx`](orx.md), [`orcx`](orcx.md), [`xorx`](xorx.md), [`eqvx`](eqvx.md), [`norx`](norx.md) — sister logical instructions.
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- [`cmp`](cmp.md), [`cmpi`](cmpi.md) — explicit zero/value test when CR-only effect is wanted without overwriting `RA`.
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## IBM Reference
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- [AIX 7.3 — `and` (AND)](https://www.ibm.com/docs/en/aix/7.3.0?topic=set-instruction)
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- [AIX 7.3 — Reference: PowerPC instruction set](https://www.ibm.com/docs/en/aix/7.3.0?topic=reference-instruction-set)
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