https://bugs.gentoo.org/926891
https://bugs.gentoo.org/924757
https://src.fedoraproject.org/rpms/tesseract/raw/rawhide/f/tesseract_neon.patch
(See https://github.com/tesseract-ocr/tesseract/pull/4154 too)
--- a/tesseract/CMakeLists.txt
+++ b/tesseract/CMakeLists.txt
@@ -249,7 +249,7 @@ elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "arm64|aarch64.*|AARCH64.*")
   set(HAVE_AVX512F FALSE)
   set(HAVE_FMA FALSE)
   set(HAVE_SSE4_1 FALSE)
-  set(HAVE_NEON TRUE)
+  check_cxx_compiler_flag("-mfpu=neon" HAVE_NEON)
 
 elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "arm.*")
 
--- a/tesseract/src/arch/simddetect.cpp
+++ b/tesseract/src/arch/simddetect.cpp
@@ -254,7 +254,7 @@ SIMDDetect::SIMDDetect() {
     // SSE detected.
     SetDotProduct(DotProductSSE, &IntSimdMatrix::intSimdMatrixSSE);
 #endif
-#if defined(HAVE_NEON) || defined(__aarch64__)
+#if defined(HAVE_NEON)
   } else if (neon_available_) {
     // NEON detected.
     SetDotProduct(DotProductNEON, &IntSimdMatrix::intSimdMatrixNEON);
@@ -311,7 +311,7 @@ void SIMDDetect::Update() {
   } else if (dotproduct == "accelerate") {
     SetDotProduct(DotProductAccelerate, IntSimdMatrix::intSimdMatrix);
 #endif
-#if defined(HAVE_NEON) || defined(__aarch64__)
+#if defined(HAVE_NEON)
   } else if (dotproduct == "neon" && neon_available_) {
     // NEON selected by config variable.
     SetDotProduct(DotProductNEON, &IntSimdMatrix::intSimdMatrixNEON);