From 1e7aaf682b19939cc85e863937c637f79ac61e0c Mon Sep 17 00:00:00 2001
From: Peter Osterlund <peterosterlund2@gmail.com>
Date: Sun, 20 Sep 2020 15:25:57 +0200
Subject: [PATCH] Don't use NEON instructions for non-NEON ARM CPUs

Since NDK r21b NEON instructions are used by default. Explicitly
disable them for non-NEON CPUs.
---
 DroidFishApp/src/main/cpp/gtb/Android.mk        | 4 ++++
 DroidFishApp/src/main/cpp/nativeutil/Android.mk | 9 +++++----
 DroidFishApp/src/main/cpp/rtb/Android.mk        | 5 ++++-
 DroidFishApp/src/main/cpp/stockfish/Android.mk  | 2 ++
 4 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/DroidFishApp/src/main/cpp/gtb/Android.mk b/DroidFishApp/src/main/cpp/gtb/Android.mk
index e6fcfa5..1cb0b46 100644
--- a/DroidFishApp/src/main/cpp/gtb/Android.mk
+++ b/DroidFishApp/src/main/cpp/gtb/Android.mk
@@ -14,6 +14,10 @@ LOCAL_SRC_FILES := \
 	compression/zlib/zutil.c compression/liblzf/lzf_c.c compression/liblzf/lzf_d.c \
 	GtbProbe.cpp
 
+ifeq ($(TARGET_ARCH_ABI),armeabi-v7a)
+  LOCAL_ARM_NEON := false
+endif
+
 LOCAL_CFLAGS    := \
 	-I $(LOCAL_PATH)/sysport/ -I $(LOCAL_PATH)/compression/ \
 	-I $(LOCAL_PATH)/compression/liblzf/ -I $(LOCAL_PATH)/compression/zlib/ \
diff --git a/DroidFishApp/src/main/cpp/nativeutil/Android.mk b/DroidFishApp/src/main/cpp/nativeutil/Android.mk
index f198f93..e96081d 100644
--- a/DroidFishApp/src/main/cpp/nativeutil/Android.mk
+++ b/DroidFishApp/src/main/cpp/nativeutil/Android.mk
@@ -12,16 +12,17 @@ CPU_FEATS_SRC_FILES += $(CPU_FEATS)/src/filesystem.c \
 			$(CPU_FEATS)/src/unix_features_aggregator.c
 
 ifeq ($(TARGET_ARCH_ABI),armeabi-v7a)
-    UTIL_SRC_FILES += $(CPU_FEATS_SRC_FILES) $(CPU_FEATS)/src/cpuinfo_arm.c
+  UTIL_SRC_FILES += $(CPU_FEATS_SRC_FILES) $(CPU_FEATS)/src/cpuinfo_arm.c
+  LOCAL_ARM_NEON := false
 endif
 #ifeq ($(TARGET_ARCH_ABI),arm64-v8a)
-#    UTIL_SRC_FILES += $(CPU_FEATS_SRC_FILES) $(CPU_FEATS)/src/cpuinfo_aarch64.c
+#  UTIL_SRC_FILES += $(CPU_FEATS_SRC_FILES) $(CPU_FEATS)/src/cpuinfo_aarch64.c
 #endif
 ifeq ($(TARGET_ARCH_ABI),x86)
-    UTIL_SRC_FILES += $(CPU_FEATS_SRC_FILES) $(CPU_FEATS)/src/cpuinfo_x86.c
+  UTIL_SRC_FILES += $(CPU_FEATS_SRC_FILES) $(CPU_FEATS)/src/cpuinfo_x86.c
 endif
 #ifeq ($(TARGET_ARCH_ABI),x86_64)
-#    UTIL_SRC_FILES += $(CPU_FEATS_SRC_FILES) $(CPU_FEATS)/src/cpuinfo_x86.c
+#  UTIL_SRC_FILES += $(CPU_FEATS_SRC_FILES) $(CPU_FEATS)/src/cpuinfo_x86.c
 #endif
 
 LOCAL_MODULE    := nativeutil
diff --git a/DroidFishApp/src/main/cpp/rtb/Android.mk b/DroidFishApp/src/main/cpp/rtb/Android.mk
index c19721b..8669af9 100644
--- a/DroidFishApp/src/main/cpp/rtb/Android.mk
+++ b/DroidFishApp/src/main/cpp/rtb/Android.mk
@@ -2,12 +2,15 @@ LOCAL_PATH := $(call my-dir)
 
 include $(CLEAR_VARS)
 
-
 LOCAL_MODULE    := rtb
 LOCAL_SRC_FILES := \
 	bitBoard.cpp material.cpp moveGen.cpp position.cpp rtb-probe.cpp tbprobe.cpp \
 	RtbProbe.cpp
 
+ifeq ($(TARGET_ARCH_ABI),armeabi-v7a)
+  LOCAL_ARM_NEON := false
+endif
+
 LOCAL_CFLAGS    := --std=c++11 \
 	-I $(LOCAL_PATH)/sysport/ -I -DNDEBUG -Wall
 
diff --git a/DroidFishApp/src/main/cpp/stockfish/Android.mk b/DroidFishApp/src/main/cpp/stockfish/Android.mk
index 72c7aff..a239b2e 100644
--- a/DroidFishApp/src/main/cpp/stockfish/Android.mk
+++ b/DroidFishApp/src/main/cpp/stockfish/Android.mk
@@ -10,6 +10,7 @@ SF_SRC_FILES := \
 MY_ARCH_DEF :=
 ifeq ($(TARGET_ARCH_ABI),armeabi-v7a)
   MY_ARCH_DEF += -DUSE_NEON -mthumb -march=armv7-a -mfloat-abi=softfp -mfpu=neon
+  LOCAL_ARM_NEON := true
 endif
 ifeq ($(TARGET_ARCH_ABI),arm64-v8a)
   MY_ARCH_DEF += -DIS_64BIT -DUSE_POPCNT -DUSE_NEON
@@ -28,6 +29,7 @@ include $(LOCAL_PATH)/build_sf.mk
 ifeq ($(TARGET_ARCH_ABI),armeabi-v7a)
   MY_ARCH_DEF := -mthumb -march=armv7-a -mfloat-abi=softfp
   include $(CLEAR_VARS)
+  LOCAL_ARM_NEON  := false
   LOCAL_MODULE    := stockfish_nosimd
   include $(LOCAL_PATH)/build_sf.mk
   stockfish : stockfish_nosimd