D927 - A stencil plane a draw loads binds as its values' bits

Status: decided Date: 2026-10-20

A pixel shader may load the stencil plane of a depth target as a texture. Its descriptor is 8_UINT under a depth swizzle, flat, at the base the submission's stencil tests read or write (DB_STENCIL_READ_BASE, DB_STENCIL_WRITE_BASE). That slot binds the target's stencil as the host attachment holds it. Each value is widened to a word and fetched through an R32_SFLOAT view.

A load of an 8_UINT texel answers the value as an unsigned integer in the register. A fetch from a 32-bit float format neither filters nor converts, so it hands those same bits to the module. The module declares a float image, as every draw module does, and needs no integer image type and no second translation.

This is assumed for a filtered sample, where the hardware's answer for an integer format is not established. Only an unfiltered load is grounded. A slot compared, sampled as a cube or a volume, or loaded by layer is refused as before.

Why: Grand Theft Auto V's loading-screen lighting tests the scene's stencil and also loads it through its descriptor table at the stencil read base. That one descriptor was the last of the segment's unbound slots, and the segment, with every submission behind it, never ran.

Rejected:

• Declaring an unsigned integer image in the module and translating it again for the draws whose slot binds one. A dispatch does this (D916), but a draw's module is shared by draws whose tables differ, and one uber-shader would be translated per table.
• An R8_UINT view. Its fetch is an unsigned integer, which a float image type cannot declare.