From c39476459bc14cd0cc95aa957d6d68f138f05f22 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Adri=C3=A0=20Franch?= Date: Thu, 8 Oct 2026 15:05:40 +0200 Subject: [PATCH] docs: record the inferred NGG merged wave info layout in TechnicalDebt Co-Authored-By: Claude --- docs/dev/TechnicalDebt.md | 1 + 1 file changed, 1 insertion(+) diff --git a/docs/dev/TechnicalDebt.md b/docs/dev/TechnicalDebt.md index d4b6a8757..29b3bf5a6 100644 --- a/docs/dev/TechnicalDebt.md +++ b/docs/dev/TechnicalDebt.md @@ -96,6 +96,7 @@ Throughout the project, every function at every stage either **does exactly what - [User data registers](../../core/libs/prx/libSceAgcDriver/Execution/src/Driver/Diagnostics.cpp) (AGC driver) - a `SPI_SHADER_USER_DATA_*` or `COMPUTE_USER_DATA_*` register the title never wrote reads as 0 when a stage's RSRC2 count covers it, as Kyty (zeroed `UserSgprInfo`) and SharpEmu (missing registers read 0) do, and as AMD PAL and Mesa initialize them; the console's value is not confirmed - [SET_PREDICATION](../../core/libs/prx/libSceAgcDriver/Execution/src/Pm4.cpp) (AGC driver) - boolean predication follows the AMD PM4 encoding [Mesa](https://gitlab.freedesktop.org/mesa/mesa/-/blob/main/src/amd/common/sid.h) uses: operation 3 reads 64 bits and 4 reads 32 bits, and bit 8 runs predicated packets when the value is non-zero (clear: when it is zero); the bit 12 hint is ignored. The address must have its low 4 bits clear, as `sceAgcDcbSetPredication` writes it. Query predication (Z-pass, primitive count), a predicated COND_EXEC, predicated command buffer chains and flips in predicated command buffers throw - [sceAgcGetGsOversubscription](../../core/libs/prx/libSceAgc/Shader/src/GsOversubscription.cpp) (libSceAgc) - signature and occupancy formula (base and expanded vertex/export capacities, budget shift, `GE_PC_ALLOC` / `SPI_SHADER_PGM_RSRC4_GS` encoding) follow KytyPS5 only, not confirmed on hardware or a title; a negative or NaN factor that gives a negative target, a missing GS context register or a zero `GE_MAX_OUTPUT_PER_SUBGROUP` throws +- [Vertex entry merged wave info](../../core/shader/recompiler/Translation/src/InstructionTranslator.cpp) (recompiler) - `s3` of every vertex-path shader is set to `waveSize | waveSize << 8` (vertex and primitive count of a full wave, wave index 0). Layout taken from the prologue Mesa's ACO emits for NGG vertex shaders (`s_bfe_u64 exec` from `s3`), not measured on hardware. The driver gives every graphics program user data from `s8`, so the condition does not tell NGG from legacy vertex shaders: they just never read `s3`. A draw whose last wave is partial still reports a full wave. - [sceAgcCbCondWrite](../../core/libs/prx/libSceAgc/Cb/src/Branch.cpp) (libSceAgc) - argument order and the 9-dword COND_WRITE layout follow the clean-room [OpenAGC](https://github.com/OpenAGC/OpenAGC/blob/main/src/game_compat.c) and [sharpemu](https://github.com/sharpemu/sharpemu/blob/main/src/SharpEmu.Libs/Agc/AgcExports.CommandPackets.cs), which agree on them; SharpProspero lists another order. The write space is accepted only as 1 (memory), the one value both encode the same way, and other values throw. - [sceAgcGetIsTrinityMode](../../core/libs/prx/libSceAgc/Misc/src/Platform.cpp) (libSceAgc) - signature from the only PPSA26344 call (a pointer to a one-byte flag, result ignored); a null pointer throws because its error code is unknown - [zARR5aCmkoY](../../core/libs/prx/libSceAgc/DcbFlow/src/Control.cpp) (libSceAgc) - unknown name, signature