Author: emaste
Date: Thu Aug 15 14:54:18 2019
New Revision: 351073

  stand: remove CLANG_NO_IAS from boot2
  Many components under stand/ had CLANG_NO_IAS added when Clang's
  Integrated Assembler (IAS) did not handle .codeNN directives.  Clang
  gained support quite some time ago, and we can now build stand/ with
  IAS.  In most cases IAS- and GNU as-assembled boot components were
  identical, and CLANG_NO_IAS was already removed from other components.
  Clang IAS produces different output for some components, including
  boot2, so CLANG_NO_IAS was not previously removed for those.
  In the case of boot2 the difference is that IAS produces a larger
  encoding for one instruction (the testb at the beginning of read).
  GNU as produces:
      2e    f6 06 b0 08       80
  while IAS includes an address size override prefix (67) and produces:
      2e 67 f6 05 b3 08 00 00 80
  This results in three fewer NOPs elsewhere in boot2 but no functional
  change, so switch to IAS for boot2.
  (We can separately pursue improved 16-bit IAS support with the LLVM
  Sponsored by: The FreeBSD Foundation


Modified: head/stand/i386/boot2/Makefile
--- head/stand/i386/boot2/Makefile      Thu Aug 15 14:11:11 2019        
+++ head/stand/i386/boot2/Makefile      Thu Aug 15 14:54:18 2019        
@@ -91,6 +91,3 @@ boot2.h: boot1.out
            REL1=`printf "%d" ${REL1}` > ${.TARGET}
 .include <>
-# XXX: clang integrated-as doesn't grok .codeNN directives yet
-CFLAGS.boot1.S=                ${CLANG_NO_IAS}
_______________________________________________ mailing list
To unsubscribe, send any mail to ""

Reply via email to