x86: Extend assembler to generate GNU property notes

Add -mx86-used-note=[yes|no] option to generate (or not) GNU property
notes with GNU_PROPERTY_X86_FEATURE_2_USED and GNU_PROPERTY_X86_ISA_1_USED
properties.  If the assembly input contains no instructions, set the
GNU_PROPERTY_X86_UINT32_VALID bit in GNU_PROPERTY_X86_FEATURE_2_USED
property.  Add a --enable-x86-used-note configure time option to set the
default behavior.  Set the default if the configure option is not used
to "no".

	* NEWS: Mention -mx86-used-note=[no|yes].
	* configure.ac: Add --enable-x86-used-note.  Define
	DEFAULT_X86_USED_NOTE.
	* config.in: Regenerated.
	* configure: Likewise.
	* config/tc-i386.c (x86_isa_1_used): New.
	(x86_feature_2_used): Likewise.
	(x86_used_note): Likewise.
	(_i386_insn): Add has_regmmx, has_regxmm, has_regymm and
	has_regzmm.
	(build_modrm_byte): Set i.has_regmmx, i.has_regzmm.
	i.has_regymm and i.has_regxmm.
	(x86_cleanup): New function.
	(output_insn): Update x86_isa_1_used and x86_feature_2_used.
	(OPTION_X86_USED_NOTE): New.
	(md_longopts): Add -mx86-used-note=.
	(md_parse_option): Handle OPTION_X86_USED_NOTE.
	(md_show_usage): Display -mx86-used-note=.
	* config/tc-i386.h (x86_cleanup): New prototype.
	(md_cleanup): New.
	* doc/c-i386.texi: Document -mx86-used-note=.

1 files changed, 26 insertions, 2 deletions

diff --git a/gas/configure b/gas/configure
index 7dc72c0..35effb4 100755
--- a/gas/configure
+++ b/gas/configure
@@ -808,6 +808,7 @@ enable_compressed_debug_sections
 enable_x86_relax_relocations
 enable_elf_stt_common
 enable_generate_build_notes
+enable_x86_used_note
 enable_werror
 enable_build_warnings
 with_cpu
@@ -1469,6 +1470,7 @@ Optional Features:
   --enable-generate-build-notes
                           generate GNU Build notes if none are provided by the
                           input
+  --enable-x86-used-note  generate GNU x86 used ISA and feature properties
   --enable-werror         treat compile warnings as errors
   --enable-build-warnings enable build-time compiler warnings
   --disable-nls           do not use Native Language Support
@@ -11335,7 +11337,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11338 "configure"
+#line 11340 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -11441,7 +11443,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11444 "configure"
+#line 11446 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -12111,6 +12113,19 @@ esac
 fi
 
 
+# Decide if the x86 ELF assembler should default to generating GNU x86
+# used ISA and feature properties.
+ac_default_generate_x86_used_note=unset
+# Provide a configuration option to override the default.
+# Check whether --enable-x86-used-note was given.
+if test "${enable_x86_used_note+set}" = set; then :
+  enableval=$enable_x86_used_note; case "${enableval}" in
+  yes)  ac_default_generate_x86_used_note=1 ;;
+  no)   ac_default_generate_x86_used_note=0 ;;
+esac
+fi
+
+
 using_cgen=no
 
 
@@ -13039,6 +13054,15 @@ cat >>confdefs.h <<_ACEOF
 _ACEOF
 
 
+if test ${ac_default_generate_x86_used_note} = unset; then
+  ac_default_generate_x86_used_note=0
+fi
+
+cat >>confdefs.h <<_ACEOF
+#define DEFAULT_X86_USED_NOTE $ac_default_generate_x86_used_note
+_ACEOF
+
+
 if test x$ac_default_compressed_debug_sections = xyes ; then
 
 $as_echo "#define DEFAULT_FLAG_COMPRESS_DEBUG 1" >>confdefs.h