From fd23962fc4fc03206ecadea12b214d0231f18637 Mon Sep 17 00:00:00 2001
From: Peter Osterlund <peterosterlund2@gmail.com>
Date: Sun, 25 Feb 2024 20:41:45 +0100
Subject: [PATCH] Use NEON dotprod instructions in Stockfish if supported by
 CPU

---
 DroidFishApp/src/main/cpp/nativeutil/Android.mk     |  6 +++---
 DroidFishApp/src/main/cpp/nativeutil/nativeutil.cpp |  8 +++++++-
 DroidFishApp/src/main/cpp/stockfish/Android.mk      | 11 ++++++++++-
 3 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/DroidFishApp/src/main/cpp/nativeutil/Android.mk b/DroidFishApp/src/main/cpp/nativeutil/Android.mk
index e96081d..d07cfce 100644
--- a/DroidFishApp/src/main/cpp/nativeutil/Android.mk
+++ b/DroidFishApp/src/main/cpp/nativeutil/Android.mk
@@ -15,9 +15,9 @@ ifeq ($(TARGET_ARCH_ABI),armeabi-v7a)
   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) $(CPU_FEATS)/src/cpuinfo_aarch64.c
-#endif
+ifeq ($(TARGET_ARCH_ABI),arm64-v8a)
+  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
 endif
diff --git a/DroidFishApp/src/main/cpp/nativeutil/nativeutil.cpp b/DroidFishApp/src/main/cpp/nativeutil/nativeutil.cpp
index 09c327c..e3cbd47 100644
--- a/DroidFishApp/src/main/cpp/nativeutil/nativeutil.cpp
+++ b/DroidFishApp/src/main/cpp/nativeutil/nativeutil.cpp
@@ -25,6 +25,8 @@
 
 #if defined(__arm__)
   #include "cpuinfo_arm.h"
+#elif defined(__aarch64__)
+  #include "cpuinfo_aarch64.h"
 #elif defined(__i386__)
   #include "cpuinfo_x86.h"
 #endif
@@ -65,10 +67,14 @@ extern "C" JNIEXPORT jboolean JNICALL Java_org_petero_droidfish_engine_EngineUti
     using namespace cpu_features;
     ArmFeatures features = GetArmInfo().features;
     return features.neon ? JNI_TRUE : JNI_FALSE;
+#elif defined(__aarch64__)
+    using namespace cpu_features;
+    Aarch64Features features = GetAarch64Info().features;
+    return features.asimddp ? JNI_TRUE : JNI_FALSE;
 #elif defined(__i386__)
     using namespace cpu_features;
     X86Features features = GetX86Info().features;
     return features.sse4_1 ? JNI_TRUE : JNI_FALSE;
 #endif
-    return true;
+    return JNI_TRUE;
 }
diff --git a/DroidFishApp/src/main/cpp/stockfish/Android.mk b/DroidFishApp/src/main/cpp/stockfish/Android.mk
index 3e8a9f2..5645487 100644
--- a/DroidFishApp/src/main/cpp/stockfish/Android.mk
+++ b/DroidFishApp/src/main/cpp/stockfish/Android.mk
@@ -12,7 +12,7 @@ ifeq ($(TARGET_ARCH_ABI),armeabi-v7a)
   LOCAL_ARM_NEON := true
 endif
 ifeq ($(TARGET_ARCH_ABI),arm64-v8a)
-  MY_ARCH_DEF += -DIS_64BIT -DUSE_POPCNT -DUSE_NEON
+  MY_ARCH_DEF += -DIS_64BIT -DUSE_POPCNT -DUSE_NEON -march=armv8.2-a+dotprod -DUSE_NEON_DOTPROD
 endif
 ifeq ($(TARGET_ARCH_ABI),x86_64)
   MY_ARCH_DEF += -DIS_64BIT -DUSE_SSE41 -msse4.1
@@ -25,6 +25,15 @@ include $(CLEAR_VARS)
 LOCAL_MODULE    := stockfish
 include $(LOCAL_PATH)/build_sf.mk
 
+ifeq ($(TARGET_ARCH_ABI),arm64-v8a)
+  MY_ARCH_DEF := -DIS_64BIT -DUSE_POPCNT -DUSE_NEON
+  include $(CLEAR_VARS)
+  LOCAL_ARM_NEON := true
+  LOCAL_MODULE    := stockfish_nosimd
+  include $(LOCAL_PATH)/build_sf.mk
+  stockfish : stockfish_nosimd
+endif
+
 ifeq ($(TARGET_ARCH_ABI),armeabi-v7a)
   MY_ARCH_DEF := -mthumb -march=armv7-a -mfloat-abi=softfp
   include $(CLEAR_VARS)