arm64: add ".arch armv8-a+crc" to allow use of crc instructions

With Clang 5.0 the .arch directive is required, otherwise Clang complains "error: instruction requires: crc". This was reported in D10499 but not added initially, because clang 3.8 available on a ref machine reported unknown directive. Clang 4.0 allows but does not require the directive. Submitted by: andrew MFC after: 1 week Sponsored by: The FreeBSD Foundation
2017-06-08 20:06:09 +00:00 · 2017-06-08 20:06:09 +00:00 · c2aa86d19c
commit c2aa86d19c
parent 45c2cf11d2
1 changed files with 1 additions and 0 deletions
--- a/sys/libkern/arm64/crc32c_armv8.S
+++ b/sys/libkern/arm64/crc32c_armv8.S
@ -27,6 +27,7 @@

 #include <machine/asm.h>
 __FBSDID("$FreeBSD$");
+.arch armv8-a+crc

 /*
 * uint32_t