configure.ac: Enable C extension for decimal float if invoked with --enable-decimal-float.

	* configure.ac: Enable C extension for decimal float if invoked
	with --enable-decimal-float.
	* doc/install.texi (Configuration): Document it.
	* configure, config.in: Regenerate.

From-SVN: r108887

gcc/ChangeLog

+2005-12-21  Janis Johnson  <janis187@us.ibm.com>
+	    Ben Elliston  <bje@au.ibm.com>
+
+	* configure.ac: Enable C extension for decimal float if invoked
+	with --enable-decimal-float.
+	* doc/install.texi (Configuration): Document it.
+	* configure, config.in: Regenerate.
+
 2005-12-20  Mike Stump  <mrs@apple.com>
 
 	* config/darwin.h (TARGET_OPTION_TRANSLATE_TABLE): Handle the
@@ -192,10 +200,10 @@
 2005-12-18  Richard Guenther  <rguenther@suse.de>
 
 	PR tree-optimization/25481
-	* tree-ssa-structalias.c (handle_ptr_arith): Handle
-	accesses we don't have a varinfo for.
+	* tree-ssa-structalias.c (handle_ptr_arith): Handle accesses we
+	don't have a varinfo for.
 
-2005-12-17  Jon Grimm  <jgrimm2@us.ibm.com>
+2005-12-18  Jon Grimm  <jgrimm2@us.ibm.com>
 	    Janis Johnson  <janis187@us.ibm.com>
 	    Ben Elliston  <bje@au.ibm.com>
 

gcc/config.in

@@ -46,6 +46,12 @@
 #endif
 
 
+/* Define to 1 to enable decimal float extension to C. */
+#ifndef USED_FOR_TARGET
+#undef ENABLE_DECIMAL_FLOAT
+#endif
+
+
 /* Define if you want fold checked that it never destructs its argument. This
    is quite expensive. */
 #ifndef USED_FOR_TARGET

gcc/configure.ac

@@ -639,6 +639,38 @@ AC_ARG_ENABLE(__cxa_atexit,
 [  --enable-__cxa_atexit   enable __cxa_atexit for C++],
 [], [])
 
+# Enable C extension for decimal float if target supports it.
+AC_ARG_ENABLE(decimal-float,
+[  --enable-decimal-float  enable decimal float extension to C],
+[
+  if test x$enablevar = xyes ; then
+    case $target in
+    powerpc*-*-linux* | i?86*-*-linux*)
+      ;;
+    *)
+      AC_MSG_WARN(decimal float is not supported for this target, ignored)
+      enable_decimal_float=no
+      ;;
+    esac
+  fi
+],
+[
+  case $target in
+  powerpc*-*-linux*)
+    enable_decimal_float=yes
+    ;;
+  *)
+    enable_decimal_float=no
+    ;;
+  esac
+])
+
+AC_SUBST(enable_decimal_float)
+
+dfp=`if test $enable_decimal_float = yes; then echo 1; else echo 0; fi`
+AC_DEFINE_UNQUOTED(ENABLE_DECIMAL_FLOAT, $dfp,
+[Define to 1 to enable decimal float extension to C.])
+
 # Enable threads
 # Pass with no value to take the default
 # Pass with a value to specify a thread package

gcc/doc/install.texi

@@ -1212,6 +1212,14 @@ error message.
 All support for systems which have been obsoleted in one release of GCC
 is removed entirely in the next major release, unless someone steps
 forward to maintain the port.
+
+@item --enable-decimal-float
+@itemx --disable-decimal-float
+Enable (or disable) support for the C decimal floating point
+extension.  This is enabled by default only on PowerPC GNU/Linux
+systems.  Other systems may also support it, but require the user to
+specifically enable it.
+
 @end table
 
 @subheading Cross-Compiler-Specific Options