Cycles: Disable lossless MTLTexture compression & render up to 2% faster

Disallow lossless texture compression in MetalDevice. Path-tracing texture access patterns are very random, and cache reuse gains are typically too low to offset the decompression overheads. This change doesn't increase memory usage for any of the benchmark scenes (https://projects.blender.org/blender/blender-benchmarks/src/branch/main/cycles) as most textures are high entropy and don't compress well using lossless methods.

Pull Request: https://projects.blender.org/blender/blender/pulls/143074

intern/cycles/device/metal/device_impl.mm

@@ -1072,6 +1072,11 @@ void MetalDevice::tex_alloc(device_texture &mem)
       desc.storageMode = MTLStorageModeShared;
       desc.usage = MTLTextureUsageShaderRead;
 
+      /* Disallow lossless texture compression. Path-tracing texture access patterns are very
+       * random, and cache reuse gains are typically too low to offset the decompression overheads.
+       */
+      desc.allowGPUOptimizedContents = false;
+
       LOG_WORK << "Texture 2D allocate: " << mem.name << ", "
                << string_human_readable_number(mem.memory_size()) << " bytes. ("
                << string_human_readable_size(mem.memory_size()) << ")";
@@ -1124,13 +1129,6 @@ void MetalDevice::tex_alloc(device_texture &mem)
       }
     }
 
-    /* Optimize the texture for GPU access. */
-    id<MTLCommandBuffer> commandBuffer = [mtlGeneralCommandQueue commandBuffer];
-    id<MTLBlitCommandEncoder> blitCommandEncoder = [commandBuffer blitCommandEncoder];
-    [blitCommandEncoder optimizeContentsForGPUAccess:mtlTexture];
-    [blitCommandEncoder endEncoding];
-    [commandBuffer commit];
-
     /* Set Mapping. */
     texture_slot_map[slot] = mtlTexture;
     texture_info[slot] = mem.info;