Clean up macro in GetLogicalProcessorCacheSizeFromOS to include cache…

…Size as a parameter via a new argument CURRENT_CACHE_SIZE (#100596)

* Clean up macro

* Addressed feedback.

* Removed redundant print

* Update src/coreclr/gc/unix/gcenv.unix.cpp

Co-authored-by: Jan Kotas <jkotas@microsoft.com>

* Inlined function call

* Update src/coreclr/gc/unix/gcenv.unix.cpp

Co-authored-by: Jan Kotas <jkotas@microsoft.com>

* Update src/coreclr/gc/unix/gcenv.unix.cpp

Co-authored-by: Jan Kotas <jkotas@microsoft.com>

* Update src/coreclr/gc/unix/gcenv.unix.cpp

Co-authored-by: Jan Kotas <jkotas@microsoft.com>

* Update src/coreclr/gc/unix/gcenv.unix.cpp

Co-authored-by: Jan Kotas <jkotas@microsoft.com>

* Update src/coreclr/gc/unix/gcenv.unix.cpp

---------

Co-authored-by: Jan Kotas <jkotas@microsoft.com>

src/coreclr/gc/unix/gcenv.unix.cpp

@@ -862,31 +862,30 @@ bool ReadMemoryValueFromFile(const char* filename, uint64_t* val)
     return result;
 }
 
-#define UPDATE_CACHE_SIZE_AND_LEVEL(NEW_CACHE_SIZE, NEW_CACHE_LEVEL) if (NEW_CACHE_SIZE > ((long)cacheSize)) { cacheSize = NEW_CACHE_SIZE; cacheLevel = NEW_CACHE_LEVEL; }
-
 static size_t GetLogicalProcessorCacheSizeFromOS()
 {
     size_t cacheLevel = 0;
     size_t cacheSize = 0;
-    long size;
 
-    // sysconf can return -1 if the cache size is unavailable in some distributions and 0 in others.
-    // UPDATE_CACHE_SIZE_AND_LEVEL should handle both the cases by not updating cacheSize if either of cases are met.
-#ifdef _SC_LEVEL1_DCACHE_SIZE
-    size = sysconf(_SC_LEVEL1_DCACHE_SIZE);
-    UPDATE_CACHE_SIZE_AND_LEVEL(size, 1)
-#endif
-#ifdef _SC_LEVEL2_CACHE_SIZE
-    size = sysconf(_SC_LEVEL2_CACHE_SIZE);
-    UPDATE_CACHE_SIZE_AND_LEVEL(size, 2)
-#endif
-#ifdef _SC_LEVEL3_CACHE_SIZE
-    size = sysconf(_SC_LEVEL3_CACHE_SIZE);
-    UPDATE_CACHE_SIZE_AND_LEVEL(size, 3)
-#endif
-#ifdef _SC_LEVEL4_CACHE_SIZE
-    size = sysconf(_SC_LEVEL4_CACHE_SIZE);
-    UPDATE_CACHE_SIZE_AND_LEVEL(size, 4)
+#if defined(_SC_LEVEL1_DCACHE_SIZE) || defined(_SC_LEVEL2_CACHE_SIZE) || defined(_SC_LEVEL3_CACHE_SIZE) || defined(_SC_LEVEL4_CACHE_SIZE)
+    const int cacheLevelNames[] =
+    {
+        _SC_LEVEL1_DCACHE_SIZE,
+        _SC_LEVEL2_CACHE_SIZE,
+        _SC_LEVEL3_CACHE_SIZE,
+        _SC_LEVEL4_CACHE_SIZE,
+    };
+
+    for (int i = ARRAY_SIZE(cacheLevelNames) - 1; i >= 0; i--)
+    {
+        long size = sysconf(cacheLevelNames[i]);
+        if (size > 0)
+        {
+            cacheSize = (size_t)size;
+            cacheLevel = i + 1;
+            break;
+        }
+    }
 #endif
 
 #if defined(TARGET_LINUX) && !defined(HOST_ARM) && !defined(HOST_X86)
@@ -912,18 +911,12 @@ static size_t GetLogicalProcessorCacheSizeFromOS()
 
             if (ReadMemoryValueFromFile(path_to_size_file, &cache_size_from_sys_file))
             {
-                // uint64_t to long conversion as ReadMemoryValueFromFile takes a uint64_t* as an argument for the val argument.
-                size = (long)cache_size_from_sys_file;
-                path_to_level_file[index] = (char)(48 + i);
+                cacheSize = std::max(cacheSize, (size_t)cache_size_from_sys_file);
 
+                path_to_level_file[index] = (char)(48 + i);
                 if (ReadMemoryValueFromFile(path_to_level_file, &level))
                 {
-                    UPDATE_CACHE_SIZE_AND_LEVEL(size, level)
-                }
-
-                else
-                {
-                    cacheSize = std::max((long)cacheSize, size);
+                    cacheLevel = level;
                 }
             }
         }
@@ -975,7 +968,7 @@ static size_t GetLogicalProcessorCacheSizeFromOS()
         if (success)
         {
             assert(cacheSizeFromSysctl > 0);
-            cacheSize = ( size_t) cacheSizeFromSysctl;
+            cacheSize = (size_t) cacheSizeFromSysctl;
         }
     }
 #endif