Fix BC alias writes and GC

src/graphics/host_gpu/renderer/cache/textureCache.cpp

@@ -633,6 +633,9 @@ void TextureCache::CopyImage(ImageId destination_id, ImageId source_id) {
 void TextureCache::CopyImageMip(ImageId destination_id, ImageId source_id, uint32_t mip,
                                 uint32_t layer) {
 	RefreshCopySource(source_id);
+	if (m_slot_images[destination_id].IsBufferModified()) {
+		RefreshImage(destination_id);
+	}
 	auto& destination = m_slot_images[destination_id];
 	auto& source      = m_slot_images[source_id];
 	TrackImage(destination_id);
@@ -753,11 +756,63 @@ ImageId TextureCache::ResolveDepthOverlap(const ImageInfo& requested, BindingTyp
 	return replacement_id;
 }
 
+namespace BcAlias {
+
+bool Matches(const ImageInfo& requested, const ImageInfo& cached) {
+	return requested.guest_format != cached.guest_format &&
+	       requested.IsBlock() != cached.IsBlock() &&
+	       requested.tile_mode == cached.tile_mode &&
+	       requested.bytes_per_block == cached.bytes_per_block &&
+	       requested.samples == 1 && cached.samples == 1 &&
+	       (requested.data != cached.data || requested.resources != cached.resources ||
+	        requested.BlockExtent() != cached.BlockExtent()) &&
+	       !TextureCache::SameBacking(cached, requested, false);
+}
+
+bool Publish(TextureCache& cache, Image& image) {
+	if (!cache.CanDownload(image)) {
+		return false;
+	}
+	// ObtainBuffer preserves padding and records ownership before the GPU-only transfer.
+	auto [buffer, offset] =
+	    cache.m_buffer_cache.ObtainBuffer(image.info.data.address, image.info.data.size, true);
+	cache.DownloadImage(image, *buffer, offset, image.info.data.size, image.info.resources.levels);
+	image.ClearGpuModified();
+	image.MarkBufferModified();
+	return true;
+}
+
+void Resolve(TextureCache& cache, ImageId cached_id, ImageId merged_id) {
+	auto& cached = cache.m_slot_images[cached_id];
+	auto* merged = merged_id ? &cache.m_slot_images[merged_id] : nullptr;
+	// PS5 raw block images can span several packed BC mips. Transfer their complete
+	// guest bytes, including tail padding, before retiring the incompatible backing.
+	if (cached.SafeToDownload()) {
+		if (merged && merged->SafeToDownload() && !Publish(cache, *merged)) {
+			return;
+		}
+		if (!Publish(cache, cached)) {
+			return;
+		}
+		if (merged) {
+			merged->MarkBufferModified();
+		}
+	}
+	cached.binding.needs_rebind |= cached.binding.is_bound || cached.binding.is_target;
+	cache.FreeImage(cached_id);
+}
+
+} // namespace BcAlias
+
 TextureCache::OverlapResult TextureCache::ResolveOverlap(const ImageInfo& requested,
                                                          BindingType binding, ImageId cached_id,
                                                          ImageId merged_id) {
 	auto owner = m_slot_images.try_get(cached_id);
-	if (owner == nullptr) {
+	if (owner == nullptr || !owner->registered) {
+		return {merged_id};
+	}
+	if (BcAlias::Matches(requested, owner->info) && !owner->IsCpuDirty()) {
+		BcAlias::Resolve(*this, cached_id, merged_id);
 		return {merged_id};
 	}
 	auto&      cached       = *owner;
@@ -1175,6 +1230,7 @@ ImageId TextureCache::FindImage(ImageDesc& desc, bool exact_format) {
 		std::scoped_lock lock {m_lock};
 		const auto       candidates =
 		    FindImagesInRegion(desc.info.data.address, desc.info.data.size, false);
+		bool block_alias = false;
 
 		for (const auto id: candidates) {
 			const auto& image = m_slot_images[id];
@@ -1193,6 +1249,9 @@ ImageId TextureCache::FindImage(ImageDesc& desc, bool exact_format) {
 			}
 			if (SameBacking(image.info, desc.info, exact_format)) {
 				result = id;
+			} else if (image.SafeToDownload() &&
+			           BcAlias::Matches(desc.info, image.info)) {
+				block_alias = true;
 			}
 		}
 
@@ -1210,6 +1269,15 @@ ImageId TextureCache::FindImage(ImageDesc& desc, bool exact_format) {
 					view_layer = overlap.layer;
 				}
 			}
+		} else if (block_alias) {
+			for (const auto candidate: candidates) {
+				const auto* owner = m_slot_images.try_get(candidate);
+				if (candidate != result && owner != nullptr && owner->registered &&
+				    !owner->IsCpuDirty() &&
+				    BcAlias::Matches(m_slot_images[result].info, owner->info)) {
+					BcAlias::Resolve(*this, candidate, result);
+				}
+			}
 		}
 
 		if (result && !m_slot_images[result].depth_id) {