A renderer that keeps a screen X as SX << 16 tests the right edge against
a lui-held W << 16 and the left edge with bltz on the shifted value. No
explicit [widescreen.cull] kind fits either: bltz_sites compares the whole
register with -margin, and a lui at a screen_x site was a build error.
screen_x_sites now also takes
lui rt, W -> rt = (W + margin) << 16
bltz x, outside -> taken while SX < -margin (x = SX << 16)
Both are the identity at 4:3. The helpers are defined for native code and
for overlay shards; their math is in ws_cull_edge.h. The two prototypes are
written only for a config that lists screen_x_sites, so the generated code
of every other title is unchanged.
Two generic explicit cull-site kinds for native-wide titles whose screen-X
rejects the existing keys cannot express exactly:
- bgez_sites: `bgez SX, keep` in a signed per-vertex left-edge chain
(`bgez x0,keep; ...; bltz xN,reject`). Emitted through psx_ws_cull_bgez
(keep while SX >= -margin). bltz_sites alone still rejects a primitive
whose first vertices sit in the revealed band; with both kinds the chain
rejects exactly when every vertex is left of -margin.
- clip_edge_x_load_sites (+ clip_edge_width, default screen_w_imms[0]):
lh/lhu/lw of a clip-rectangle X bound. psx_ws_clip_edge_x moves a loaded 0
to -margin and a loaded width to width+margin and leaves interior bounds
(mirrors, split-screen halves) unchanged. xclip_load_sites is lw-only and
upper-bound-only, so it cannot express this.
Both are identity at 4:3, emit nothing when empty, and fail main-EXE
generation on an opcode mismatch (overlay variants stay vanilla). They enter
the overlay-cache hash only when non-empty, so every existing title keeps
its hash (pinned in the test against the previous layout).
Interpreter parity: the dirty-RAM interpreter now also honours explicit
bltz_sites, bgez_sites, branch_keep_sites and clip_edge_x_load_sites. Its
explicit site lists are stored sorted (binary-search lookup), the cap rises
from 64 to 256 per key, and an over-long list is logged instead of being
silently truncated.
Shared math lives in runtime/include/ws_cull_edge.h. New ctest
ws_cull_edge_codegen_test covers parsing, hash identity, emitted code,
the opcode guards and the helper math.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Alexandros Mandravillis