From 32b0f386bcb20b7a2fae6351683aeb59b99cdd8d Mon Sep 17 00:00:00 2001
From: Sergiu Deitsch <sergiu.deitsch@gmail.com>
Date: Sat, 4 Oct 2025 00:03:03 +0200
Subject: [PATCH] Eliminate possible -Wstringop-overflow warning in .setZero()

---
 Eigen/src/Core/Fill.h | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/Eigen/src/Core/Fill.h b/Eigen/src/Core/Fill.h
index f40d56db6..779ef26ab 100644
--- a/Eigen/src/Core/Fill.h
+++ b/Eigen/src/Core/Fill.h
@@ -115,17 +115,15 @@ struct eigen_zero_impl<Xpr, /*use_memset*/ false> {
 template <typename Xpr>
 struct eigen_zero_impl<Xpr, /*use_memset*/ true> {
   using Scalar = typename Xpr::Scalar;
-  static constexpr size_t max_bytes = (std::numeric_limits<std::ptrdiff_t>::max)();
   static EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void run(Xpr& dst) {
-    const size_t num_bytes = dst.size() * sizeof(Scalar);
-    if (num_bytes == 0) return;
+    const std::ptrdiff_t num_bytes = dst.size() * static_cast<std::ptrdiff_t>(sizeof(Scalar));
+    if (num_bytes <= 0) return;
     void* dst_ptr = static_cast<void*>(dst.data());
 #ifndef EIGEN_NO_DEBUG
-    if (num_bytes > max_bytes) throw_std_bad_alloc();
     eigen_assert((dst_ptr != nullptr) && "null pointer dereference error!");
 #endif
     EIGEN_USING_STD(memset);
-    memset(dst_ptr, 0, num_bytes);
+    memset(dst_ptr, 0, static_cast<std::size_t>(num_bytes));
   }
   template <typename SrcXpr>
   static EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void run(Xpr& dst, const SrcXpr& src) {