PPCBUG-561: Add DecodedInstr::mb_md() to decoder.rs — the correct MD-form
6-bit mask-begin reconstruction (MB[4:0] at PPC bits 21-25, MB[5] at PPC
bit 26). The disassembler already had the correct local formula; this
promotes it to a single source of truth on DecodedInstr.
PPCBUG-046: All 6 doubleword-rotate arms (rldicl, rldicr, rldic, rldimi,
rldcl, rldcr) inlined "(instr.mb() << 1) | ((instr.raw >> 1) & 1)" which
reads SH5 (host bit 1) instead of MB5 (host bit 5). For the canonical
"clrldi r3, r4, 32" zero-extend idiom (mb=32 → MB5=1, MB[4:0]=0), the
wrong formula produced mb=0, making the instruction a no-op and leaving
upper 32 bits of the GPR polluted. Replace all 6 sites with instr.mb_md().
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
PPCBUG-040: decoder.rs sh64() assembled the XS-form shift amount as
(SH[4:0] << 1) | SH[5] instead of (SH[5] << 5) | SH[4:0]. Every
`sradi` with shift N ∈ 1..=62 executed with a completely wrong shift
count (e.g. shift=32 executed as shift=1).
PPCBUG-560: disasm_goldens.rs rldicl() test helper was encoding sh[5:1]
at PPC bits 16-20 and sh[0] at PPC bit 30 — exactly backwards. The wrong
encoder and wrong decoder cancelled out, hiding PPCBUG-040 from tests.
Fix both together so tests validate ISA-correct encodings.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
PPCBUG-160 partial: stswi's single invalidate_for_write(ea) only covered
the first cache line; with nb up to 32, the write span can cross a 128-byte
line boundary. Replace with two-call guard:
first_line = ea & !RESERVATION_MASK
last_line = ea.wrapping_add(nb - 1) & !RESERVATION_MASK
invalidate first; if last != first, invalidate last.
PPCBUG-160 partial: stswx had the same single-call gap; nb from XER[0:6]
can be up to 127 bytes. Same two-call guard applied; wrapped in `if nb > 0`
to guard against nb==0 underflow (XER TBC field is 0 when no bytes to store).
dcbz: zeroes 32 bytes at a 32-byte-aligned EA — touches exactly one 128-byte
cache line; add canonical single-call invalidate guard (was entirely missing).
dcbz128: zeroes 128 bytes at a 128-byte-aligned EA — one full reservation
line; add canonical single-call invalidate guard (was entirely missing).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Adds doc comments above lwarx/ldarx/stwcx./stdcx. clarifying that the
legacy per-ctx reservation path is only correct in strict lockstep
(single host thread); under --parallel the M3 scheduler must enable
the cross-thread ReservationTable before spawning a second host thread.
A debug_assert fires in the legacy stwcx./stdcx. branch if a
non-primary HW slot (hw_id != 0) takes that path — surfacing
ReservationTable-disabled misconfiguration early in debug builds.
Note: the primary slot (hw_id==0) racing other parallel slots is
not caught by the assert; that case requires the table to be enabled.
Affected:
PPCBUG-108 legacy per-ctx reservation path cannot invalidate
cross-thread; informational — no behavioral change
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Track lwarx vs ldarx reservation width in PpcContext as a u8 (4 = word,
8 = doubleword, 0 = none). stwcx. requires width==4; stdcx. requires
width==8. Cross-width pairs (lwarx + stdcx., ldarx + stwcx.) now fail
deterministically with CR0.EQ=0 instead of spuriously succeeding.
The width is held per-thread; the cross-thread reservation table keeps
its existing slot encoding because each host thread consults its own
ctx.reservation_width before committing.
Affected:
PPCBUG-151 stwcx./stdcx. shared the same reservation slot without
width discriminator; cross-width commits silently succeeded
Tests: lwarx_then_stdcx_cross_width_fails,
ldarx_then_stwcx_cross_width_fails
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Continuation of the PPCBUG-107 cascade sweep. All 16 VMX store opcodes
(stvx/stvxl, stvebx/stvehx/stvewx, stvlx/stvrx and 128 variants of each)
now invalidate the reservation table before writing.
stvlx/stvrx partial-vector stores can write at non-16-byte-aligned EAs;
they invalidate both potentially-touched cache lines.
stvewx128 currently writes 16 bytes at the wrong EA scope (PPCBUG-510);
the invalidate guard fires at that over-wide EA today and will narrow
automatically when PPCBUG-510 is fixed in P3.
Affected:
PPCBUG-511 stvx, stvx128, stvxl, stvxl128
PPCBUG-512 stvebx, stvehx, stvewx, stvewx128
PPCBUG-513 stvlx, stvlx128, stvlxl, stvlxl128
PPCBUG-514 stvrx, stvrx128, stvrxl, stvrxl128
Tests: lwarx_then_plain_stvx_invalidates_reservation,
lwarx_then_plain_stvlx_invalidates_reservation
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Continuation of the PPCBUG-107 cascade sweep. stmw/stswi/stswx (multiple
and string stores) and the 9 floating-point stores now invalidate the
reservation table before writing.
stmw can span two cache lines when the writeback range crosses a line
boundary; the guard iterates over all touched lines so multi-line atomic
holds the same guarantee as single-line stores.
Affected:
PPCBUG-160 3 multiple/string stores: stmw, stswi, stswx
PPCBUG-167 9 FP stores: stfs, stfsu, stfsx, stfsux,
stfd, stfdu, stfdx, stfdux, stfiwx
Tests: lwarx_then_plain_stmw_spans_two_lines_and_invalidates,
lwarx_then_plain_stfd_invalidates_reservation
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Continuation of the PPCBUG-107 cascade sweep (batch 1: word stores landed
in 4538fa9). Plain stb/stbu/stbx/stbux, sth/sthu/sthx/sthux/sthbrx, and
std/stdu/stdx/stdux/stdbrx now invalidate the reservation table before
writing, so cross-thread lwarx/stwcx. atomicity holds when these widths
are written by another host thread.
Affected:
PPCBUG-130 9 byte/halfword stores missing invalidate_for_write
stb, stbu, stbx, stbux, sth, sthu, sthx, sthux, sthbrx
PPCBUG-150 5 doubleword stores missing invalidate_for_write
std, stdu, stdx, stdux, stdbrx
Tests: lwarx_then_plain_stb_invalidates_reservation,
lwarx_then_plain_std_invalidates_reservation
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Word stores (stw, stwu, stwx, stwux, stwbrx) now invalidate the
reservation table for the target line before writing. Without this,
plain stores by other host threads silently fail to clear reservations
held by lwarx, causing stwcx. to spuriously succeed under --parallel.
Affected:
PPCBUG-107 ReservationTable::invalidate_for_write never called from any store
PPCBUG-140 stw missing invalidate_for_write (interpreter.rs:1183)
PPCBUG-141 stwu missing invalidate_for_write (interpreter.rs:1189)
PPCBUG-142 stwx missing invalidate_for_write (interpreter.rs:1195)
PPCBUG-143 stwux missing invalidate_for_write (interpreter.rs:1201)
PPCBUG-144 stwbrx missing invalidate_for_write (interpreter.rs:1568)
Tests: lwarx_then_plain_stw_invalidates_reservation,
lwarx_then_stwcx_succeeds_without_intervening_store
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Split the monolithic interpreter into cohesive modules: dedicated
decoder (decoder.rs) producing 8-byte DecodedInstr; opcode tables
(opcode.rs); explicit traps (trap.rs); FPSCR helpers (fpscr.rs);
overflow/carry helpers (overflow.rs); a 4 KiB-page-versioned decode
cache and basic-block cache (block_cache.rs); and a full VMX/VMX128
implementation (vmx.rs) covering AltiVec + Xenon's 128-bit extensions.
Add the parallel-execution substrate behind --parallel: a 7-party
phaser (phaser.rs) for round-based barrier sync, ReservationTable
(reservation.rs) for guest LL/SC, and the per-HW-thread scheduler
core (scheduler.rs) that owns ThreadRefs, runqueues, and pending IRQs.
Disassembler is now the single source of truth: disasm.rs gains the
full base + extended + VMX128 mnemonic set, with golden JSON fixtures
and a disasm_goldens test suite. Add a criterion-style interpreter
bench. context.rs grows the per-thread state the new modules need
(reservation slot, FPSCR, vector regs).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Rust reimplementation of the xenia Xbox 360 emulator targeting reverse-
engineering and preservation, initially scoped to Project Sylpheed.
Includes:
- XEX2 loader (LZX decompression, AES decryption, PE parsing)
- XISO / XGD2 disc image VFS
- PPC interpreter with 200+ opcodes and VMX128 decoding
- Static analyzer: functions, cross-references, labels, asm + SQLite output
- HLE kernel covering the xboxkrnl/xam subset used by Sylpheed init
- Debugger with in-memory and SQLite-backed execution tracing
- `xenia-rs` CLI with extract/dis/exec commands that produce cumulative,
superset SQLite databases and opt-in instruction/import/branch traces
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
