Improve performance on non-GCC hosts with __aligned__.

3 files changed, 16 insertions, 3 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index f91ec458464..6e950569fbc 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,11 @@
+2011-01-18  Paul Eggert  <eggert@cs.ucla.edu>
+
+        * lisp.h (DECL_ALIGN): Define if HAVE_ATTRIBUTE_ALIGNED, not if
+        defined __GNUC__.  ../configure now checks for this GCC feature,
+        which is now also supported by IBM and Oracle compilers.
+        (USE_LSB_TAG) [defined DECL_ALIGN]: Also define if defined __sun,
+        since Solaris malloc returns mult-of-8.
+
 2011-01-18  Stefan Monnier  <monnier@iro.umontreal.ca>
 
         * image.c (syms_of_image): Don't access XSYMBOL's internals directly.
diff --git a/src/config.in b/src/config.in
index d8a9722d316..62e83eea334 100644
--- a/src/config.in
+++ b/src/config.in
@@ -115,6 +115,9 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 /* Define to 1 if ALSA is available. */
 #undef HAVE_ALSA
 
+/* Define to 1 if GCC-style __attribute__ ((__aligned__ (expr))) works. */
+#undef HAVE_ATTRIBUTE_ALIGNED
+
 /* Define to 1 if strtold conforms to C99. */
 #undef HAVE_C99_STRTOLD
 
diff --git a/src/lisp.h b/src/lisp.h
index d00dbdc5def..5424bf7b83d 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -122,16 +122,18 @@ extern void die (const char *, const char *, int) NO_RETURN;
    TYPEBITS-aligned. */
 #ifndef NO_DECL_ALIGN
 # ifndef DECL_ALIGN
-/* What compiler directive should we use for non-gcc compilers?  -stef  */
-#  if defined (__GNUC__)
+#  if HAVE_ATTRIBUTE_ALIGNED
 #   define DECL_ALIGN(type, var) \
      type __attribute__ ((__aligned__ (1 << GCTYPEBITS))) var
+#  else
+     /* What directives do other compilers use?  */
 #  endif
 # endif
 #endif
 
 /* Let's USE_LSB_TAG on systems where we know malloc returns mult-of-8.  */
-#if defined GNU_MALLOC || defined DOUG_LEA_MALLOC || defined __GLIBC__ || defined DARWIN_OS
+#if (defined GNU_MALLOC || defined DOUG_LEA_MALLOC || defined __GLIBC__ \
+     || defined DARWIN_OS || defined __sun)
 /* We also need to be able to specify mult-of-8 alignment on static vars.  */
 # if defined DECL_ALIGN
 #  define USE_LSB_TAG