From a1a81cc2acfd4f06c04197518c0195e3bdc7f5b2 Mon Sep 17 00:00:00 2001
From: Gabor Kertesz <gabor.kertesz@linaro.org>
Date: Mon, 25 Oct 2021 12:03:42 +0200
Subject: [PATCH] Fix arm neon config for win-arm64 with MSVC

Fixes #398
It adds win-arm64 as an arm64 platform, by using a define which
is set to 1 for compilations that target 64-bit ARM processors,
otherwise undefined.
---
 pngpriv.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pngpriv.h b/pngpriv.h
index 583c26f9b..1edea74cb 100644
--- a/pngpriv.h
+++ b/pngpriv.h
@@ -174,7 +174,7 @@
 #     else /* !defined __ARM_NEON__ */
          /* The 'intrinsics' code simply won't compile without this -mfpu=neon:
           */
-#        if !defined(__aarch64__)
+#        if !defined(__aarch64__) && !defined(_M_ARM64)
             /* The assembler code currently does not work on ARM64 */
 #          define PNG_ARM_NEON_IMPLEMENTATION 2
 #        endif /* __aarch64__ */