dsp.h: enable NEON w/VS2019+ ARM64 targets
Visual Studio added ARM64 support, but requires arm64_neon.h to be
included rather than arm_neon.h. Visual Studio 2019 addressed this so
we'll start with that version and leave a local adapter include for a
follow up.
@@ -119,7 +119,12 @@ extern "C" {
#define WEBP_USE_NEON
#endif
-#if defined(_MSC_VER) && _MSC_VER >= 1700 && defined(_M_ARM)
+// Note: ARM64 is supported in Visual Studio 2017, but requires the direct
+// inclusion of arm64_neon.h; Visual Studio 2019 includes this file in
+// arm_neon.h.
+#if defined(_MSC_VER) && \
+ ((_MSC_VER >= 1700 && defined(_M_ARM)) || \
+ (_MSC_VER >= 1920 && defined(_M_ARM64)))
#define WEBP_USE_NEON
#define WEBP_USE_INTRINSICS
#endif
