FA-52650 / Raster memory layout / Member archive

Xor Bank Swizzle: Banked tile x resolves bank group instead of tile · case 05

The returned physical layout descriptor disagrees with the declared buffer mapping at tile_x.

Member previewVariant 5 · 3 implementations · 6 checks per implementation

Case contract

A stipulated 8x4 tile has four banks. Bank = (local x modulo 4) XOR (local y modulo 4); each bank stores two columns per row and begins with a one-byte tag. Tile rows include a seven-byte trailer. Return the named intermediate layout descriptor and final address fields; all quantities are integer byte offsets unless explicitly stated.

Why this case matters

Offline raster resource, upload, readback, and storage-layout regression model.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
layout fixture 3	`{"address": 969, "bank": 2, "bank_local": 4, "bank_pitch": 49, "tile_columns": 2, "tile_origin": 846, "tile_pitch": 196, "tile_row_pitch": 399, "tile_x": 2, "tile_y": 1}`	`{"address": 773, "bank": 2, "bank_local": 4, "bank_pitch": 49, "tile_columns": 2, "tile_origin": 650, "tile_pitch": 196, "tile_row_pitch": 399, "tile_x": 1, "tile_y": 1}`	Failed

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This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

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