From b6ec9b9d8c6b1a03e8fbed494951b2625740e92f Mon Sep 17 00:00:00 2001
From: Tomoaki Teshima <tomoaki.teshima@gmail.com>
Date: Tue, 19 Dec 2023 09:40:35 +0900
Subject: [PATCH] prepare to build for ARM64 on Windows with Visual Studio

---
 cmake/OpenCVCompilerOptimizations.cmake | 28 ++++++++++++++++---------
 cmake/checks/cpu_fp16.cpp               |  2 +-
 cmake/checks/cpu_neon_bf16.cpp          |  2 +-
 cmake/checks/cpu_neon_dotprod.cpp       |  2 +-
 cmake/checks/cpu_neon_fp16.cpp          |  2 +-
 5 files changed, 22 insertions(+), 14 deletions(-)

diff --git a/cmake/OpenCVCompilerOptimizations.cmake b/cmake/OpenCVCompilerOptimizations.cmake
index 8a46a97ae0..ea577e4a1c 100644
--- a/cmake/OpenCVCompilerOptimizations.cmake
+++ b/cmake/OpenCVCompilerOptimizations.cmake
@@ -349,12 +349,18 @@ elseif(ARM OR AARCH64)
     ocv_update(CPU_KNOWN_OPTIMIZATIONS "NEON;FP16;NEON_DOTPROD;NEON_FP16;NEON_BF16")
     ocv_update(CPU_NEON_FLAGS_ON "")
     ocv_update(CPU_FP16_IMPLIES "NEON")
-    ocv_update(CPU_NEON_DOTPROD_FLAGS_ON "-march=armv8.2-a+dotprod")
     ocv_update(CPU_NEON_DOTPROD_IMPLIES "NEON")
-    ocv_update(CPU_NEON_FP16_FLAGS_ON "-march=armv8.2-a+fp16")
     ocv_update(CPU_NEON_FP16_IMPLIES "NEON")
-    ocv_update(CPU_NEON_BF16_FLAGS_ON "-march=armv8.2-a+bf16")
     ocv_update(CPU_NEON_BF16_IMPLIES "NEON")
+    if(MSVC)
+      ocv_update(CPU_NEON_DOTPROD_FLAGS_ON "")
+      ocv_update(CPU_NEON_FP16_FLAGS_ON "")
+      ocv_update(CPU_NEON_BF16_FLAGS_ON "")
+    else()
+      ocv_update(CPU_NEON_DOTPROD_FLAGS_ON "-march=armv8.2-a+dotprod")
+      ocv_update(CPU_NEON_FP16_FLAGS_ON "-march=armv8.2-a+fp16")
+      ocv_update(CPU_NEON_BF16_FLAGS_ON "-march=armv8.2-a+bf16")
+    endif()
     set(CPU_BASELINE "NEON;FP16" CACHE STRING "${HELP_CPU_BASELINE}")
     set(CPU_DISPATCH "NEON_FP16;NEON_BF16;NEON_DOTPROD" CACHE STRING "${HELP_CPU_DISPATCH}")
   endif()
@@ -478,20 +484,22 @@ macro(ocv_check_compiler_optimization OPT)
 endmacro()
 
 macro(ocv_cpu_aarch64_baseline_merge_feature_options FEATURE_NAME_LIST FLAG_STRING COMMON_OPTION)
+  if(NOT MSVC)
     unset(_POSTFIX)
     # Check each feature option
     foreach(OPT IN LISTS ${FEATURE_NAME_LIST})
-        string(FIND "${${FLAG_STRING}}" "${CPU_${OPT}_FLAGS_ON}" OPT_FOUND)
-        if(NOT ${OPT_FOUND} EQUAL -1)
-            string(REPLACE "${COMMON_OPTION}" "" TRAILING_PART "${CPU_${OPT}_FLAGS_ON}")
-            string(APPEND _POSTFIX "${TRAILING_PART}")
-            string(REPLACE " ${CPU_${OPT}_FLAGS_ON}" "" ${FLAG_STRING} ${${FLAG_STRING}})
-        endif()
+      string(FIND "${${FLAG_STRING}}" "${CPU_${OPT}_FLAGS_ON}" OPT_FOUND)
+      if(NOT ${OPT_FOUND} EQUAL -1)
+        string(REPLACE "${COMMON_OPTION}" "" TRAILING_PART "${CPU_${OPT}_FLAGS_ON}")
+        string(APPEND _POSTFIX "${TRAILING_PART}")
+        string(REPLACE " ${CPU_${OPT}_FLAGS_ON}" "" ${FLAG_STRING} ${${FLAG_STRING}})
+      endif()
     endforeach()
     # If more than one option found, merge them
     if(NOT "x${_POSTFIX}" STREQUAL "x")
-        set(${FLAG_STRING} "${${FLAG_STRING}} ${COMMON_OPTION}${_POSTFIX}")
+      set(${FLAG_STRING} "${${FLAG_STRING}} ${COMMON_OPTION}${_POSTFIX}")
     endif()
+  endif()
 endmacro()
 
 foreach(OPT ${CPU_KNOWN_OPTIMIZATIONS})
diff --git a/cmake/checks/cpu_fp16.cpp b/cmake/checks/cpu_fp16.cpp
index f12cb10f4d..6bffc4792a 100644
--- a/cmake/checks/cpu_fp16.cpp
+++ b/cmake/checks/cpu_fp16.cpp
@@ -11,7 +11,7 @@ int test()
     _mm_storel_epi64((__m128i*)dst, v_dst);
     return (int)dst[0];
 }
-#elif defined __GNUC__ && (defined __arm__ || defined __aarch64__)
+#elif (defined __GNUC__ && (defined __arm__ || defined __aarch64__)) || (defined _MSC_VER && defined _M_ARM64)
 #include "arm_neon.h"
 int test()
 {
diff --git a/cmake/checks/cpu_neon_bf16.cpp b/cmake/checks/cpu_neon_bf16.cpp
index c18d63c579..a9045d7117 100644
--- a/cmake/checks/cpu_neon_bf16.cpp
+++ b/cmake/checks/cpu_neon_bf16.cpp
@@ -1,4 +1,4 @@
-#if defined __GNUC__ && (defined __arm__ || defined __aarch64__)
+#if (defined __GNUC__ && (defined __arm__ || defined __aarch64__)) || (defined _MSC_VER && defined _M_ARM64)
 #include <stdio.h>
 #include "arm_neon.h"
 
diff --git a/cmake/checks/cpu_neon_dotprod.cpp b/cmake/checks/cpu_neon_dotprod.cpp
index 4f39c50659..74f44a1832 100644
--- a/cmake/checks/cpu_neon_dotprod.cpp
+++ b/cmake/checks/cpu_neon_dotprod.cpp
@@ -1,6 +1,6 @@
 #include <stdio.h>
 
-#if defined __GNUC__ && (defined __arm__ || defined __aarch64__)
+#if (defined __GNUC__ && (defined __arm__ || defined __aarch64__)) || (defined _MSC_VER && defined _M_ARM64)
 #include "arm_neon.h"
 int test()
 {
diff --git a/cmake/checks/cpu_neon_fp16.cpp b/cmake/checks/cpu_neon_fp16.cpp
index 20fbab25d5..bba5b97026 100644
--- a/cmake/checks/cpu_neon_fp16.cpp
+++ b/cmake/checks/cpu_neon_fp16.cpp
@@ -1,6 +1,6 @@
 #include <stdio.h>
 
-#if defined __GNUC__ && (defined __arm__ || defined __aarch64__)
+#if (defined __GNUC__ && (defined __arm__ || defined __aarch64__)) || (defined _MSC_VER && defined _M_ARM64)
 #include "arm_neon.h"
 
 float16x8_t vld1q_as_f16(const float* src)