[AARCH64] Document .arch and .arch_extension directive

2015-02-03  Renlin Li  <renlin.li@arm.com>

  gas/
    * doc/c-aarch64.texi (.arch): Document the directive.
    (.arch_extension): Likewise.

Change-Id: I8ec6bf2a389dd1c39fa0a65648a816c61764962c

diff --git a/gas/ChangeLog b/gas/ChangeLog
index bb2d5b5a387dad92edddb8ca10a7bd6b166e5a79..74a5f7e3acdfdbfcda8229959299418fe12c6546 100644 (file)
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,8 @@
+2015-02-03  Renlin Li  <renlin.li@arm.com>
+
+       * doc/c-aarch64.texi (.arch): Document the directive.
+       (.arch_extension): Likewise.
+
 2014-11-18  Jan Beulich  <jbeulich@suse.com>
 
        * config/tc-aarch64.c (s_aarch64_arch_extension): New.

diff --git a/gas/doc/c-aarch64.texi b/gas/doc/c-aarch64.texi
index 8fbae0615303bec93a70e2ef57724a19766601c4..bc8e4569c31e4335f4552385d798ecd80ae73071 100644 (file)
--- a/gas/doc/c-aarch64.texi
+++ b/gas/doc/c-aarch64.texi
@@ -231,6 +231,24 @@ The AArch64 architecture uses @sc{ieee} floating-point numbers.
 @table @code
 
 @c AAAAAAAAAAAAAAAAAAAAAAAAA
+
+@cindex @code{.arch} directive, AArch64
+@item .arch @var{name}
+Select the target architecture.  Valid values for @var{name} are the same as
+for the @option{-march} commandline option.
+
+Specifying @code{.arch} clears any previously selected architecture
+extensions.
+
+@cindex @code{.arch_extension} directive, AArch64
+@item .arch_extension @var{name}
+Add or remove an architecture extension to the target architecture.  Valid
+values for @var{name} are the same as those accepted as architectural
+extensions by the @option{-mcpu} commandline option.
+
+@code{.arch_extension} may be used multiple times to add or remove extensions
+incrementally to the architecture being compiled for.
+
 @c BBBBBBBBBBBBBBBBBBBBBBBBBB
 
 @cindex @code{.bss} directive, AArch64