From 6b079a4e12ea6e40680215190f88483548717e2b Mon Sep 17 00:00:00 2001
From: Brian Degenhardt <bmd@bmdhacks.com>
Date: Wed, 22 Jul 2026 09:39:53 -0700
Subject: [PATCH] GS: add texture-cache hit/miss perfmon counters

There were no texture-cache hit/miss counters at all. Hit/miss was visible only
as GL_CACHE strings, which are compiled out unless ENABLE_OGL_DEBUG is set and
are further gated on UseDebugDevice at emit time -- so on a shipped build the
texture cache is completely opaque. For a tiler-bound title, source misses
(upload + swizzle) are a prime suspect we could not see.

Adds TCSourceHit/Miss, TCTargetHit/Miss and HashCacheHit/Miss, incremented at
the existing hit/miss forks in LookupSource and the hash cache lookup. The new
entries are appended after the ROV counters so the aliased slots
(TextureCopies = Fillrate, TextureUploads = SyncPoint) keep their indices.

Also fills in the three missing HW counter names. names_hw was declared
[CounterLastHW] but had only 10 initialisers, leaving TextureCopiesROV,
DrawCallsROV and BarriersROV as null pointers -- GSPerfMon::Dump iterates to
CounterLastHW and passed them straight to fprintf %s.
---
 pcsx2/GS/GSPerfMon.h                     | 10 ++++++++++
 pcsx2/GS/GSUtil.cpp                      | 11 ++++++++++-
 pcsx2/GS/Renderers/HW/GSTextureCache.cpp |  8 ++++++++
 3 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/pcsx2/GS/GSPerfMon.h b/pcsx2/GS/GSPerfMon.h
index d4defa8125..a0bb0595c9 100644
--- a/pcsx2/GS/GSPerfMon.h
+++ b/pcsx2/GS/GSPerfMon.h
@@ -26,6 +26,16 @@ public:
 		TextureCopiesROV, // Overlaps with regular texture copies.
 		DrawCallsROV, // Overlaps with regular draw calls.
 		BarriersROV, // Overlaps with regular barriers.
+
+		// Texture cache lookup outcomes (HW only). Appended last so the aliased
+		// slots below keep their existing indices.
+		TCTargetHit,
+		TCTargetMiss,
+		TCSourceHit,
+		TCSourceMiss,
+		HashCacheHit,
+		HashCacheMiss,
+
 		CounterLast,
 
 		// Reused counters for HW.
diff --git a/pcsx2/GS/GSUtil.cpp b/pcsx2/GS/GSUtil.cpp
index d98a00d9b0..e050a53543 100644
--- a/pcsx2/GS/GSUtil.cpp
+++ b/pcsx2/GS/GSUtil.cpp
@@ -190,7 +190,16 @@ const char* GSUtil::GetPerfMonCounterName(GSPerfMon::counter_t counter, bool hw)
 			"TextureCopies",
 			"TextureUploads",
 			"Barriers",
-			"RenderPasses"
+			"RenderPasses",
+			"TextureCopiesROV",
+			"DrawCallsROV",
+			"BarriersROV",
+			"TCTargetHit",
+			"TCTargetMiss",
+			"TCSourceHit",
+			"TCSourceMiss",
+			"HashCacheHit",
+			"HashCacheMiss"
 		};
 		return counter < std::size(names_hw) ? names_hw[counter] : "";
 	}
diff --git a/pcsx2/GS/Renderers/HW/GSTextureCache.cpp b/pcsx2/GS/Renderers/HW/GSTextureCache.cpp
index 05b7472b3e..ca54b8e5a5 100644
--- a/pcsx2/GS/Renderers/HW/GSTextureCache.cpp
+++ b/pcsx2/GS/Renderers/HW/GSTextureCache.cpp
@@ -2150,6 +2150,10 @@ GSTextureCache::Source* GSTextureCache::LookupSource(const bool is_color, const
 
 	if (!src)
 	{
+		// A Source has to be built: upload + swizzle. This is the expensive outcome.
+		g_perfmon.Put(GSPerfMon::TCSourceMiss, 1);
+		g_perfmon.Put(dst ? GSPerfMon::TCTargetHit : GSPerfMon::TCTargetMiss, 1);
+
 #ifdef ENABLE_OGL_DEBUG
 		if (dst)
 		{
@@ -2225,6 +2229,8 @@ GSTextureCache::Source* GSTextureCache::LookupSource(const bool is_color, const
 	}
 	else
 	{
+		g_perfmon.Put(GSPerfMon::TCSourceHit, 1);
+
 		GL_CACHE("TC: src hit: (0x%x, 0x%x, %s)",
 			TEX0.TBP0, psm_s.pal > 0 ? TEX0.CBP : 0,
 			GSUtil::GetPSMName(TEX0.PSM));
@@ -7036,6 +7042,7 @@ GSTextureCache::HashCacheEntry* GSTextureCache::LookupHashCache(const GIFRegTEX0
 	if (it != m_hash_cache.end())
 	{
 		// super easy, cache hit. remove paltex if it's a replacement texture.
+		g_perfmon.Put(GSPerfMon::HashCacheHit, 1);
 		GL_CACHE("TC: HC Hit: %" PRIx64 " %" PRIx64 " R-%ux%u", key.TEX0Hash, key.CLUTHash, key.region_width, key.region_height);
 		HashCacheEntry* entry = &it->second;
 		paltex &= (entry->texture->GetFormat() == GSTexture::Format::UNorm8);
@@ -7044,6 +7051,7 @@ GSTextureCache::HashCacheEntry* GSTextureCache::LookupHashCache(const GIFRegTEX0
 	}
 
 	// cache miss.
+	g_perfmon.Put(GSPerfMon::HashCacheMiss, 1);
 	GL_CACHE("TC: HC Miss: %" PRIx64 " %" PRIx64 " R-%ux%u", key.TEX0Hash, key.CLUTHash, key.region_width, key.region_height);
 
 	// check for a replacement texture with the full clut key