preserve-emulation/ppsspp
1
0 Fork 0
mirror of https://github.com/hrydgard/ppsspp.git synced 2026-11-12 17:19:28 +01:00
Code Issues Packages Projects Releases Wiki Activity

Merge pull request #16118 from hrydgard/vertex-cache-hash-improvement

Browse Source 
Better bit scrambling when computing draw call IDs for vertex cache.
This commit is contained in:
Henrik Rydgård authored and GitHub committed 2022-09-27 10:28:16 +02:00
2 parents 29d8f40c28 e538f5a441
commit afe3ba01fc
1 file changed
+14 -4
Download Patch File Download Diff File Expand all files Collapse all files
GPU/Common/DrawEngineCommon.cpp
+14 -4
View File
@@ -717,6 +717,16 @@ uint64_t DrawEngineCommon::ComputeHash() {
return fullhash;
}
// Cheap bit scrambler from https://nullprogram.com/blog/2018/07/31/
inline uint32_t lowbias32_r(uint32_t x) {
x ^= x >> 16;
x *= 0x43021123U;
x ^= x >> 15 ^ x >> 30;
x *= 0x1d69e2a5U;
x ^= x >> 16;
return x;
}
// vertTypeID is the vertex type but with the UVGen mode smashed into the top bits.
void DrawEngineCommon::SubmitPrim(const void *verts, const void *inds, GEPrimitiveType prim, int vertexCount, u32 vertTypeID, int cullMode, int *bytesRead) {
if (!indexGen.PrimCompatible(prevPrim_, prim) || numDrawCalls >= MAX_DEFERRED_DRAW_CALLS || vertexCountInDrawCalls_ + vertexCount > VERTEX_BUFFER_MAX) {
@@ -745,10 +755,10 @@ void DrawEngineCommon::SubmitPrim(const void *verts, const void *inds, GEPrimiti
if (g_Config.bVertexCache) {
u32 dhash = dcid_;
dhash = __rotl(dhash ^ (u32)(uintptr_t)verts, 13);
dhash = __rotl(dhash ^ (u32)(uintptr_t)inds, 13);
dhash = __rotl(dhash ^ (u32)vertTypeID, 13);
dhash = __rotl(dhash ^ (u32)vertexCount, 13);
dcid_ = dhash ^ (u32)prim;
dhash = __rotl(dhash ^ (u32)(uintptr_t)inds, 19);
dhash = __rotl(dhash ^ (u32)vertTypeID, 7);
dhash = __rotl(dhash ^ (u32)vertexCount, 11);
dcid_ = lowbias32_r(dhash ^ (u32)prim);
}
DeferredDrawCall &dc = drawCalls[numDrawCalls];