From 751e097c57e84d368d782c4a18b960ed2350c2f0 Mon Sep 17 00:00:00 2001
From: Benoit Jacob <benoitjacob@google.com>
Date: Mon, 19 Dec 2016 13:44:46 -0500
Subject: [PATCH] Use 32 registers on ARM64

---
 Eigen/src/Core/arch/NEON/PacketMath.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/Eigen/src/Core/arch/NEON/PacketMath.h b/Eigen/src/Core/arch/NEON/PacketMath.h
index 2a8f58d74..d392bf3ff 100644
--- a/Eigen/src/Core/arch/NEON/PacketMath.h
+++ b/Eigen/src/Core/arch/NEON/PacketMath.h
@@ -28,11 +28,13 @@ namespace internal {
 #define EIGEN_HAS_SINGLE_INSTRUCTION_CJMADD
 #endif
 
-// FIXME NEON has 16 quad registers, but since the current register allocator
-// is so bad, it is much better to reduce it to 8
 #ifndef EIGEN_ARCH_DEFAULT_NUMBER_OF_REGISTERS
+#if EIGEN_ARCH_ARM64
+#define EIGEN_ARCH_DEFAULT_NUMBER_OF_REGISTERS 32
+#else
 #define EIGEN_ARCH_DEFAULT_NUMBER_OF_REGISTERS 16 
 #endif
+#endif
 
 typedef float32x2_t Packet2f;
 typedef float32x4_t Packet4f;