From a5e147305b3bfc91a30eb71b6b15f61c19d88c16 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Antonio=20S=C3=A1nchez?= <cantonios@google.com>
Date: Mon, 29 Apr 2024 20:32:09 +0000
Subject: [PATCH] Fix undefined behavior for generating inputs to the
 predux_mul test.

---
 test/packetmath.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/test/packetmath.cpp b/test/packetmath.cpp
index b9a06b869..894fb4126 100644
--- a/test/packetmath.cpp
+++ b/test/packetmath.cpp
@@ -624,7 +624,8 @@ void packetmath() {
   }
 
   // Avoid overflows.
-  if (NumTraits<Scalar>::IsInteger && NumTraits<Scalar>::IsSigned) {
+  if (NumTraits<Scalar>::IsInteger && NumTraits<Scalar>::IsSigned &&
+      Eigen::internal::unpacket_traits<Packet>::size > 1) {
     Scalar limit =
         static_cast<Scalar>(std::pow(static_cast<double>(numext::real(NumTraits<Scalar>::highest())),
                                      1.0 / static_cast<double>(Eigen::internal::unpacket_traits<Packet>::size)));