From d259104c8de1e43619327f5d7f6a0dbb372f3f66 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Antonio=20S=C3=A1nchez?= <cantonios@google.com>
Date: Thu, 24 Feb 2022 22:16:37 +0000
Subject: [PATCH] Fix frexp packetmath tests for MSVC.

(cherry picked from commit 2ed4bee78fc44b37d5e5b9f532f5659f9c978499)
---
 test/packetmath.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/test/packetmath.cpp b/test/packetmath.cpp
index f29417b98..23aa33fc2 100644
--- a/test/packetmath.cpp
+++ b/test/packetmath.cpp
@@ -52,6 +52,12 @@ inline T REF_FREXP(const T& x, T& exp) {
   EIGEN_USING_STD(frexp)
   const T out = static_cast<T>(frexp(x, &iexp));
   exp = static_cast<T>(iexp);
+  
+  // The exponent value is unspecified if the input is inf or NaN, but MSVC
+  // seems to set it to 1.  We need to set it back to zero for consistency.
+  if (!(numext::isfinite)(x)) {
+    exp = T(0);
+  }
   return out;
 }