From 6aad0f821b1c6bc4302dbbb7658d23121a94dbb4 Mon Sep 17 00:00:00 2001
From: Rasmus Munk Larsen <rmlarsen@google.com>
Date: Mon, 22 Aug 2022 20:19:35 +0000
Subject: [PATCH] Fix psign for unsigned integer types, such as bool.

---
 .../arch/Default/GenericPacketMathFunctions.h   | 17 ++++++++++++++++-
 Eigen/src/Core/arch/SSE/PacketMath.h            |  1 -
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/Eigen/src/Core/arch/Default/GenericPacketMathFunctions.h b/Eigen/src/Core/arch/Default/GenericPacketMathFunctions.h
index d27fbd0b6..158f31182 100644
--- a/Eigen/src/Core/arch/Default/GenericPacketMathFunctions.h
+++ b/Eigen/src/Core/arch/Default/GenericPacketMathFunctions.h
@@ -855,7 +855,7 @@ Packet psqrt_complex(const Packet& a) {
 
 /** \internal \returns -1 if a is strictly negative, 0 otherwise, +1 if a is
     strictly positive. */
-template<typename Packet> 
+template<typename Packet>
 EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS
 std::enable_if_t<(!NumTraits<typename unpacket_traits<Packet>::type>::IsComplex &&
                   !NumTraits<typename unpacket_traits<Packet>::type>::IsInteger), Packet>
@@ -877,6 +877,7 @@ psign(const Packet& a) {
 template<typename Packet> 
 EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS
 std::enable_if_t<(!NumTraits<typename unpacket_traits<Packet>::type>::IsComplex &&
+                  NumTraits<typename unpacket_traits<Packet>::type>::IsSigned &&
                   NumTraits<typename unpacket_traits<Packet>::type>::IsInteger), Packet>
 psign(const Packet& a) {
   using Scalar = typename unpacket_traits<Packet>::type;
@@ -892,6 +893,20 @@ psign(const Packet& a) {
   return por(positive, negative);
 }
 
+template<typename Packet> 
+EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS
+std::enable_if_t<(!NumTraits<typename unpacket_traits<Packet>::type>::IsComplex &&
+                  !NumTraits<typename unpacket_traits<Packet>::type>::IsSigned &&
+                  NumTraits<typename unpacket_traits<Packet>::type>::IsInteger), Packet>
+psign(const Packet& a) {
+  using Scalar = typename unpacket_traits<Packet>::type;
+  const Packet cst_one = pset1<Packet>(Scalar(1));
+  const Packet cst_zero = pzero(a);
+
+  const Packet zero_mask = pcmp_eq(cst_zero, a);
+  return pandnot(cst_one, zero_mask);
+}
+
 // \internal \returns the the sign of a complex number z, defined as z / abs(z).
 template<typename Packet>
 EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS
diff --git a/Eigen/src/Core/arch/SSE/PacketMath.h b/Eigen/src/Core/arch/SSE/PacketMath.h
index b13d65420..ee2883df3 100644
--- a/Eigen/src/Core/arch/SSE/PacketMath.h
+++ b/Eigen/src/Core/arch/SSE/PacketMath.h
@@ -218,7 +218,6 @@ template<> struct packet_traits<bool> : default_packet_traits
     HasMin       = 0,
     HasMax       = 0,
     HasConj      = 0,
-    HasSign      = 0,
     HasSqrt      = 1
   };
 };