Add SSE2NEON for ARM (Nvidia Tegra, PI, etc) support

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "thirdparty/sse2neon"]
+	path = thirdparty/sse2neon
+	url = https://github.com/jratcliff63367/sse2neon.git

CMakeLists.txt

@@ -22,8 +22,6 @@ find_package(LibZip QUIET)
 find_package(Pangolin 0.2 QUIET)
 find_package(OpenCV QUIET)
 
-
-
 # flags
 add_definitions("-DENABLE_SSE")
 set(CMAKE_CXX_FLAGS
@@ -62,6 +60,7 @@ set(dso_SOURCE_FILES
 include_directories(
   ${PROJECT_SOURCE_DIR}/src
   ${PROJECT_SOURCE_DIR}/thirdparty/Sophus
+  ${PROJECT_SOURCE_DIR}/thirdparty/sse2neon
   ${EIGEN3_INCLUDE_DIR}
 ) 
 

README.md

@@ -61,6 +61,9 @@ to unzip the dataset image archives before loading them).
 	sudo make install
 	sudo cp lib/zipconf.h /usr/local/include/zipconf.h   # (no idea why that is needed).
 
+##### sse2neon (required for ARM builds).
+After cloning, just run `git submodule update --init` to include this.  It translates Intel-native SSE functions to ARM-native NEON functions during the compilation process.
+
 #### 2.3 Build
 
 		cd dso

src/FullSystem/CoarseInitializer.cpp

@@ -37,6 +37,9 @@
 #include "FullSystem/PixelSelector2.h"
 #include "util/nanoflann.h"
 
+#ifndef __SSE3__
+#include "SSE2NEON.h"
+#endif
 
 namespace dso
 {

src/FullSystem/CoarseTracker.cpp

@@ -37,6 +37,10 @@
 #include "IOWrapper/ImageRW.h"
 #include <algorithm>
 
+#ifndef __SSE3__
+#include "SSE2NEON.h"
+#endif
+
 namespace dso
 {
 

src/OptimizationBackend/AccumulatedTopHessian.cpp

@@ -27,6 +27,10 @@
 #include "OptimizationBackend/EnergyFunctionalStructs.h"
 #include <iostream>
 
+#ifndef __SSE3__
+#include "SSE2NEON.h"
+#endif
+
 namespace dso
 {
 

src/OptimizationBackend/EnergyFunctional.cpp

@@ -30,7 +30,9 @@
 #include "OptimizationBackend/AccumulatedSCHessian.h"
 #include "OptimizationBackend/AccumulatedTopHessian.h"
 
-
+#ifndef __SSE3__
+#include "SSE2NEON.h"
+#endif
 
 namespace dso
 {

src/OptimizationBackend/EnergyFunctionalStructs.cpp

@@ -28,7 +28,9 @@
 #include "FullSystem/HessianBlocks.h"
 #include "FullSystem/Residuals.h"
 
-
+#ifndef __SSE3__
+#include "SSE2NEON.h"
+#endif
 
 namespace dso
 {

src/OptimizationBackend/MatrixAccumulators.h

@@ -25,6 +25,9 @@
 #pragma once
 #include "util/NumType.h"
 
+#ifndef __SSE3__
+#include "SSE2NEON.h"
+#endif
 
 namespace dso
 {