MechaCat02 d4f6ea787b fix(disasm): PPCBUG-640+650 fmt_bc spurious condition suffix on bdnz/bdz ...

PPCBUG-640: For BO=16 (bdnz: decrement CTR, branch if non-zero, ignore CR)
and BO=18 (bdz: same with branch-if-zero), `fmt_bc` fell through to the
`if decr` block and computed `cond_name_opt` from the don't-care BI=0 /
cond_true=false pair, yielding `Some("ge")`. The output was therefore
`bdnzge` / `bdzge` — a CTR-only branch with a spurious CR-derived suffix.

PPCBUG-650 (companion): the golden fixture pinned the wrong output, so
the regression had no detection signal until now.

`fmt_bclr` already had the correct `if decr && uncond` guard at line 872
producing `bdnzlr` / `bdzlr`. `fmt_bc` lacked the equivalent.

Fix: gate the condition string on `!uncond` inside the `if decr` block.
For BO=16/18 (uncond bit set), the condition suffix is now empty.

Tests: extended_mnemonics.json fixture rows for bdnz/bdz now expect the
correct `ext_mnemonic: "bdnz"` / `"bdz"`.

Impact: every analysis-DB query for `bdnz` loops (common in pixel-shader
and vertex processing) was returning zero rows; matches stored as `bdnzge`.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

2026-05-02 10:40:45 +02:00

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