FillClearColor refused half and B10G11R11 patterns with a denormal code,
since an implementation may flush them in a clear, so such fills over a
resident image took the CPU path: PPSA01325 fast-clears its 3840x2160
R16G16_SFLOAT target 0x515390000 with a denormal half every frame, a
33 MiB guest write and re-upload (about 85 ms).
ClearKeepsDenormals probes the device once per format: a 1x1 image
cleared with denormal codes (half 0x0001, 0x83ff, 0x0200, 0x8001;
11/10-bit 0x001) and read back. When the bits survive, FillClear takes
the refused pattern again with SmallFloat decoding denormals exactly.
NaNs, float32 denormals and the SNORM minimum stay refused.
agc_driver_recorder_tests clears an R16G16_SFLOAT resident image with a
normal, a denormal and a NaN pattern: the denormal is cleared exactly
when the probe says the device keeps it, and the NaN is refused.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UTjpbMX7BUFMZZaxJE98zV
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