From 745046ca43c7e8717f2f8eb1f6d11216952e35a2 Mon Sep 17 00:00:00 2001
From: Matthew Stanley <1379tech@gmail.com>
Date: Tue, 28 Apr 2026 21:52:32 -0700
Subject: [PATCH] analysis: don't extend max_reached past last visited code in
 jtbl handling
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discover_function_bounds was extending max_reached to cover the jump
table's bytes themselves (jtbl_end - 4). This was wrong: jtbl entries
are DATA, not code. Including their bytes in the function's words
range made recompile_function try to interpret intervening data words
as MIPS instructions, which usually fails (encountering 'pref',
'INVALID', branches to outside the function, etc.).

The fix: stop extending max_reached for jtbl_end. The recompiler's
analyze_function reads jtbl entries directly from context.rom — they
don't need to be part of func.words. Function bounds = max-reached-
instruction + 4 (delay slot), nothing more.

Effect on Stadium's 0x8FF00000 pattern activation:

  Before this fix: 1 recompile error (`func_8FF00020__rom_FE000020`
  at instr 8243 — 'pref' instruction emitted at vram 0x8FF080B8,
  followed by INVALID instructions). The function had been sized
  large enough to contain unrelated data after the case-arms region.

  After this fix: 0 errors. All 219 pattern-synthesized sections
  recompile cleanly.

Stadium boot impact (pattern activated, 30-second run):
  - 1048 audio hits (15x improvement; was ~70 with static fragment78).
  - 31 fragments registered (3.4x improvement; was ~9).
  - 17 different fragment78-family variants streamed through link
    vram 0x8FF00000, each correctly content-hash-dispatched.
  - Stadium reaches a NEW failure mode much later: `lookup miss
    at 0x810001D0` — a different fragment slot (link bucket 0x10)
    needs similar treatment. Tracked separately.

The pattern is now ACTIVE in Stadium's game.toml. game.toml updated
to document the active configuration.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
---
 src/analysis.cpp | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/src/analysis.cpp b/src/analysis.cpp
index d7bbe23..333ba8f 100644
--- a/src/analysis.cpp
+++ b/src/analysis.cpp
@@ -526,21 +526,22 @@ bool N64Recomp::discover_function_bounds(
                         cursor, jtbl.vram);
                     return false;
                 }
-                // Add each target to BFS. Also extend max_reached past
-                // the table itself so we count its bytes as part of
-                // the function.
+                // Add each target to BFS so its arm gets walked and
+                // its instructions count toward max_reached. Do NOT
+                // extend max_reached to cover the jump table's bytes
+                // themselves: jtbl entries are DATA, not code, and
+                // including them in the function's `words` makes
+                // recompile_function try to interpret intervening
+                // data words as MIPS instructions (which usually
+                // fails because the data isn't valid code). The
+                // recompiler's analyze_function reads jtbl entries
+                // directly from context.rom — they don't need to
+                // be inside func.words.
                 for (size_t t : jtbl_targets) {
                     if (!visited.contains(t)) {
                         worklist.push_back(t);
                     }
                 }
-                size_t jtbl_end = (jtbl.vram - vram_base) +
-                                  collected * 4;
-                if (jtbl_end > 0) {
-                    if (jtbl_end - 4 > max_reached) {
-                        max_reached = jtbl_end - 4;
-                    }
-                }
                 break;  // block ends after the jr's delay slot
             }