Merge pull request godotengine#100145 from Ivorforce/memory-offset-func

Add `mem_aligned_address` to simplify data offset constants.

Author: Repiteo

core/os/memory.h

@@ -50,9 +50,9 @@ class Memory {
 	//             └─────────────────┴──┴────────────────┴──┴───────────...
 	// Offset:     ↑ SIZE_OFFSET        ↑ ELEMENT_OFFSET    ↑ DATA_OFFSET
 
-	static constexpr size_t SIZE_OFFSET = 0;
-	static constexpr size_t ELEMENT_OFFSET = ((SIZE_OFFSET + sizeof(uint64_t)) % alignof(uint64_t) == 0) ? (SIZE_OFFSET + sizeof(uint64_t)) : ((SIZE_OFFSET + sizeof(uint64_t)) + alignof(uint64_t) - ((SIZE_OFFSET + sizeof(uint64_t)) % alignof(uint64_t)));
-	static constexpr size_t DATA_OFFSET = ((ELEMENT_OFFSET + sizeof(uint64_t)) % alignof(max_align_t) == 0) ? (ELEMENT_OFFSET + sizeof(uint64_t)) : ((ELEMENT_OFFSET + sizeof(uint64_t)) + alignof(max_align_t) - ((ELEMENT_OFFSET + sizeof(uint64_t)) % alignof(max_align_t)));
+	static const size_t SIZE_OFFSET;
+	static const size_t ELEMENT_OFFSET;
+	static const size_t DATA_OFFSET;
 
 	template <bool p_ensure_zero = false>
 	static void *alloc_static(size_t p_bytes, bool p_pad_align = false);
@@ -87,8 +87,19 @@ class Memory {
 	static uint64_t get_mem_available();
 	static uint64_t get_mem_usage();
 	static uint64_t get_mem_max_usage();
+
+	static constexpr size_t get_aligned_address(size_t p_address, size_t p_alignment);
 };
 
+constexpr size_t Memory::get_aligned_address(size_t p_address, size_t p_alignment) {
+	const size_t n_bytes_unaligned = p_address % p_alignment;
+	return (n_bytes_unaligned == 0) ? p_address : (p_address + p_alignment - n_bytes_unaligned);
+}
+
+inline constexpr size_t Memory::SIZE_OFFSET = 0;
+inline constexpr size_t Memory::ELEMENT_OFFSET = get_aligned_address(SIZE_OFFSET + sizeof(uint64_t), alignof(uint64_t));
+inline constexpr size_t Memory::DATA_OFFSET = get_aligned_address(ELEMENT_OFFSET + sizeof(uint64_t), alignof(max_align_t));
+
 class DefaultAllocator {
 public:
 	_FORCE_INLINE_ static void *alloc(size_t p_memory) { return Memory::alloc_static(p_memory, false); }

core/templates/cowdata.h

@@ -60,8 +60,8 @@ class CowData {
 	// Offset:     ↑ REF_COUNT_OFFSET      ↑ SIZE_OFFSET    ↑ DATA_OFFSET
 
 	static constexpr size_t REF_COUNT_OFFSET = 0;
-	static constexpr size_t SIZE_OFFSET = ((REF_COUNT_OFFSET + sizeof(SafeNumeric<USize>)) % alignof(USize) == 0) ? (REF_COUNT_OFFSET + sizeof(SafeNumeric<USize>)) : ((REF_COUNT_OFFSET + sizeof(SafeNumeric<USize>)) + alignof(USize) - ((REF_COUNT_OFFSET + sizeof(SafeNumeric<USize>)) % alignof(USize)));
-	static constexpr size_t DATA_OFFSET = ((SIZE_OFFSET + sizeof(USize)) % alignof(max_align_t) == 0) ? (SIZE_OFFSET + sizeof(USize)) : ((SIZE_OFFSET + sizeof(USize)) + alignof(max_align_t) - ((SIZE_OFFSET + sizeof(USize)) % alignof(max_align_t)));
+	static constexpr size_t SIZE_OFFSET = Memory::get_aligned_address(REF_COUNT_OFFSET + sizeof(SafeNumeric<USize>), alignof(USize));
+	static constexpr size_t DATA_OFFSET = Memory::get_aligned_address(SIZE_OFFSET + sizeof(USize), alignof(max_align_t));
 
 	mutable T *_ptr = nullptr;