https://sources.debian.org/src/x265/2.9-3/debian/patches/0001-Fix-arm-flags.patch/

From: Sebastian Ramacher <sramacher@debian.org>
Date: Wed, 26 Apr 2017 22:05:06 +0200
Subject: Fix arm* flags

---
 source/CMakeLists.txt | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/source/CMakeLists.txt b/source/CMakeLists.txt
index 33b6523..25aecbb 100644
--- a/source/CMakeLists.txt
+++ b/source/CMakeLists.txt
@@ -72,7 +72,7 @@ elseif(ARMMATCH GREATER "-1")
     endif()
     message(STATUS "Detected ARM target processor")
     set(ARM 1)
-    add_definitions(-DX265_ARCH_ARM=1 -DHAVE_ARMV6=1)
+    # add_definitions(-DX265_ARCH_ARM=1 -DHAVE_ARMV6=1)
 else()
     message(STATUS "CMAKE_SYSTEM_PROCESSOR value `${CMAKE_SYSTEM_PROCESSOR}` is unknown")
     message(STATUS "Please add this value near ${CMAKE_CURRENT_LIST_FILE}:${CMAKE_CURRENT_LIST_LINE}")
@@ -230,12 +230,8 @@ if(GCC)
     if(ARM AND CROSS_COMPILE_ARM)
         set(ARM_ARGS -march=armv6 -mfloat-abi=soft -mfpu=vfp -marm -fPIC)
     elseif(ARM)
-        find_package(Neon)
         if(CPU_HAS_NEON)
-            set(ARM_ARGS -mcpu=native -mfloat-abi=hard -mfpu=neon -marm -fPIC)
             add_definitions(-DHAVE_NEON)
-        else()
-            set(ARM_ARGS -mcpu=native -mfloat-abi=hard -mfpu=vfp -marm)
         endif()
     endif()
     add_definitions(${ARM_ARGS})
