diff --git a/Eigen/src/Core/GenericPacketMath.h b/Eigen/src/Core/GenericPacketMath.h
index 4ae3edd..d65c63a 100644
--- a/Eigen/src/Core/GenericPacketMath.h
+++ b/Eigen/src/Core/GenericPacketMath.h
@@ -1233,12 +1233,6 @@
   // See https://en.cppreference.com/w/cpp/numeric/math/atan2
   // for how corner cases are supposed to be handled according to the
   // IEEE floating-point standard (IEC 60559).
-
-  // bend two rules:
-  // 1) inf / inf == 1
-  // 2) 0 / 0 == 0
-  // otherwise, evaluate atan(y/x) as usual and shift to the appropriate quadrant
-
   const Packet kSignMask = pset1<Packet>(-Scalar(0));
   const Packet kZero = pzero(x);
   const Packet kOne = pset1<Packet>(Scalar(1));
@@ -1246,21 +1240,16 @@
 
   const Packet x_has_signbit = psignbit(x);
   const Packet y_signmask = pand(y, kSignMask);
+  const Packet x_signmask = pand(x, kSignMask);
+  const Packet result_signmask = pxor(y_signmask, x_signmask);
   const Packet shift = por(pand(x_has_signbit, kPi), y_signmask);
 
-  const Packet xor_xy = pxor(x, y);
-  // if x and y have the same absolute value, then xor(x,y) is zero
-  // make sure that neither x nor y is nan
-  // furthermore, xor(x,y) has the sign of the result
-  const Packet x_and_y_are_same = pand(pcmp_eq(xor_xy, kZero), pcmp_eq(x, x));
-  // more strictly, if x and y are both zero, then or(x,y) is zero
-  // this implicitly checks for nan
-  // the sign of or(x,y) is not meaningful
+  const Packet x_and_y_are_same = pcmp_eq(pabs(x), pabs(y));
   const Packet x_and_y_are_zero = pcmp_eq(por(x, y), kZero);
 
   Packet arg = pdiv(y, x);
-  arg = pselect(x_and_y_are_same, por(kOne, xor_xy), arg);
-  arg = pselect(x_and_y_are_zero, xor_xy, arg);
+  arg = pselect(x_and_y_are_same, por(kOne, result_signmask), arg);
+  arg = pselect(x_and_y_are_zero, result_signmask, arg);
 
   Packet result = patan(arg);
   result = padd(result, shift);