From 24da16703dd2a9f883d80f3c5c0280d12767b5ea Mon Sep 17 00:00:00 2001
From: snowstormxd <214507868+snowstormxd@users.noreply.github.com>
Date: Sun, 1 Nov 2026 22:04:01 +0000
Subject: texture_cache: clear only exposed descriptor bitmap words

Avoid zeroing unused preallocation during invalidation and pool refresh. Clear newly exposed words whenever limits grow, bound clearing to allocated storage, and test word/allocation boundaries, shrink/regrowth and malformed large limits.

Assisted-by: Codex (implementation, review, commit text and automated validation)
(cherry picked from commit 4bc1ae01f79cef43be016504c850ca8a6998457a)
---
 src/tests/video_core/descriptor_table.cpp | 36 +++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

(limited to 'src/tests')

diff --git a/src/tests/video_core/descriptor_table.cpp b/src/tests/video_core/descriptor_table.cpp
index b4c226241d..8b20564949 100644
--- a/src/tests/video_core/descriptor_table.cpp
+++ b/src/tests/video_core/descriptor_table.cpp
@@ -4,6 +4,7 @@
 #include <chrono>
 #include <cstring>
 #include <iostream>
+#include <limits>
 #include <random>
 #include <catch2/catch_test_macros.hpp>
 #include "video_core/texture_cache/descriptor_table.h"
@@ -97,6 +98,41 @@ TEST_CASE("Repeated image deletion cannot reuse stale descriptor view IDs", "[de
     }
 }
 
+TEST_CASE("Descriptor limits clear exposed slots after shrink and growth", "[descriptor_table]") {
+    struct AddressMemory {
+        void ReadBlockUnsafe(GPUVAddr address, void* output, size_t size) const {
+            std::memcpy(output, &address, size);
+        }
+    } memory;
+    constexpr std::array<u32, 9> limits{0, 63, 64, 127, 128, 0x7ffff, 0x80000, 0x80001, 0x100000};
+    for (const u32 limit : limits) {
+        VideoCommon::DescriptorTable<u64> table;
+        REQUIRE(table.Synchronize(0x1000, limit));
+        CHECK(table.Read(memory, limit).second);
+        CHECK_FALSE(table.Read(memory, limit).second);
+        table.Refresh(0x1000, 0);
+        table.Invalidate();
+        CHECK(table.Read(memory, 0).second);
+        CHECK_FALSE(table.Read(memory, 0).second);
+        table.Refresh(0x1000, limit);
+        CHECK(table.Read(memory, limit).second);
+        CHECK_FALSE(table.Read(memory, limit).second);
+        table.Invalidate();
+        table.Invalidate();
+        CHECK(table.Read(memory, limit).second);
+        CHECK_FALSE(table.Read(memory, limit).second);
+    }
+    for (const u32 limit :
+         {std::numeric_limits<u32>::max(), std::numeric_limits<u32>::max() - 0x1000}) {
+        VideoCommon::DescriptorTable<u64> table;
+        table.Refresh(0x1000, limit);
+        CHECK(table.Read(memory, 0).second);
+        table.Invalidate();
+        CHECK(table.Read(memory, 0).second);
+        CHECK_FALSE(table.Read(memory, 0).second);
+    }
+}
+
 TEST_CASE("Descriptor invalidation CPU benchmark", "[.][cache_bench]") {
     DescriptorMemory memory;
     const auto measure = [&](bool deferred) {
-- 
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