From 77ac41708b5933cb81b5bd42eed00f199060532e Mon Sep 17 00:00:00 2001
From: Evgenii Kliuchnikov <eustas.ru@gmail.com>
Date: Fri, 8 May 2026 13:42:13 +0000
Subject: [PATCH] Update Safe{Add,Mul} to match libjxl

---
 lib/base/common.h | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/lib/base/common.h b/lib/base/common.h
index f5a7a283..34fdfd43 100644
--- a/lib/base/common.h
+++ b/lib/base/common.h
@@ -13,6 +13,7 @@
 #include <cstddef>
 #include <cstdint>
 #include <cstdio>
+#include <limits>
 #include <memory>
 #include <string>
 #include <type_traits>
@@ -33,13 +34,23 @@ constexpr inline size_t RoundUpToBlockDim(size_t dim) {
   return (dim + 7) & ~static_cast<size_t>(7);
 }
 
-static inline bool JPEGLI_MAYBE_UNUSED SafeAdd(const uint64_t a,
-                                               const uint64_t b,
-                                               uint64_t& sum) {
+template <typename U,
+          class = typename std::enable_if<std::is_unsigned<U>::value>::type>
+static inline bool SafeAdd(const U a, const U b, U& sum) {
   sum = a + b;
   return sum >= a;  // no need to check b - either sum >= both or < both.
 }
 
+template <typename U,
+          class = typename std::enable_if<std::is_unsigned<U>::value>::type>
+static inline bool SafeMul(const U a, const U b, U& product) {
+  product = 0;
+  if (a == 0 || b == 0) return true;
+  if (b > (std::numeric_limits<U>::max() / a)) return false;
+  product = a * b;
+  return true;
+}
+
 template <typename T1, typename T2>
 constexpr inline T1 DivCeil(T1 a, T2 b) {
   return (a + b - 1) / b;