configure.ac (--with-long-double-format): Add support for the configuration…

configure.ac (--with-long-double-format): Add support for the configuration option to change the default long double...

2018-01-11  Michael Meissner  <meissner@linux.vnet.ibm.com>

	* configure.ac (--with-long-double-format): Add support for the
	configuration option to change the default long double format on
	PowerPC systems.
	* config.gcc (powerpc*-linux*-*): Likewise.
	* configure: Regenerate.
	* config/rs6000/rs6000-c.c (rs6000_cpu_cpp_builtins): If long
	double is IEEE, define __KC__ and __KF__ to allow floatn.h to be
	used without modification.

From-SVN: r256558

gcc/ChangeLog

+2018-01-11  Michael Meissner  <meissner@linux.vnet.ibm.com>
+
+	* configure.ac (--with-long-double-format): Add support for the
+	configuration option to change the default long double format on
+	PowerPC systems.
+	* config.gcc (powerpc*-linux*-*): Likewise.
+	* configure: Regenerate.
+	* config/rs6000/rs6000-c.c (rs6000_cpu_cpp_builtins): If long
+	double is IEEE, define __KC__ and __KF__ to allow floatn.h to be
+	used without modification.
+
 2018-01-11  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>
 
 	* config/rs6000/rs6000-builtin.def (BU_P7_MISC_X): New #define.

gcc/config.gcc

@@ -4400,6 +4400,14 @@ case "${target}" in
 			exit 1
 		    fi
 		fi
+
+		# Set up the default long double format if the user changed it.
+		if test x$with_long_double_format = xieee; then
+		    tm_defines="${tm_defines} TARGET_IEEEQUAD_DEFAULT=1"
+
+		elif test x$with_long_double_format = xibm; then
+		    tm_defines="${tm_defines} TARGET_IEEEQUAD_DEFAULT=0"
+		fi
 		;;
 
 	s390*-*-*)

gcc/config/rs6000/rs6000-c.c

@@ -708,7 +708,18 @@ rs6000_cpu_cpp_builtins (cpp_reader *pfile)
       builtin_define ("__LONGDOUBLE128");
 
       if (TARGET_IEEEQUAD)
-	builtin_define ("__LONG_DOUBLE_IEEE128__");
+	{
+	  /* Older versions of GLIBC used __attribute__((__KC__)) to create the
+	     IEEE 128-bit floating point complex type for C++ (which does not
+	     support _Float128 _Complex).  If the default for long double is
+	     IEEE 128-bit mode, the library would need to use
+	     __attribute__((__TC__)) instead.  Defining __KF__ and __KC__
+	     is a stop-gap to build with the older libraries, until we
+	     get an updated library.  */
+	  builtin_define ("__LONG_DOUBLE_IEEE128__");
+	  builtin_define ("__KF__=__TF__");
+	  builtin_define ("__KC__=__TC__");
+	}
       else
 	builtin_define ("__LONG_DOUBLE_IBM128__");
     }

gcc/configure

@@ -945,6 +945,7 @@ enable_linker_build_id
 enable_libssp
 enable_default_ssp
 with_long_double_128
+with_long_double_format
 with_gc
 with_system_zlib
 enable_maintainer_mode
@@ -1738,6 +1739,9 @@ Optional Packages:
   --with-glibc-version=M.N
                           assume GCC used with glibc version M.N or later
   --with-long-double-128  use 128-bit long double by default
+  --with-long-double-format={ieee,ibm}
+		  Specify whether PowerPC long double uses IEEE or IBM format
+
   --with-gc={page,zone}   this option is not supported anymore. It used to
                           choose the garbage collection mechanism to use with
                           the compiler
@@ -18442,7 +18446,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 18445 "configure"
+#line 18449 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -18548,7 +18552,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 18551 "configure"
+#line 18555 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -29185,6 +29189,45 @@ $as_echo "#define TARGET_DEFAULT_LONG_DOUBLE_128 1" >>confdefs.h
 
 fi
 
+# Check if TFmode long double target should use the IBM extended double or IEEE
+# 128-bit floating point formats if long doubles are 128-bits long.  The long
+# double type can only be switched on powerpc64 bit Linux systems where VSX is
+# supported.  Other PowerPC systems do not build the IEEE 128-bit emulator in
+# libgcc.
+
+# Check whether --with-long-double-format was given.
+if test "${with_long_double_format+set}" = set; then :
+  withval=$with_long_double_format;
+case "$target:$with_long_double_format" in
+  powerpc64le-*-linux*:ieee | powerpc64le-*-linux*:ibm)
+    :
+    ;;
+  powerpc64-*-linux*:ieee | powerpc64-*-linux*:ibm)
+    # IEEE 128-bit emulation is only built on 64-bit VSX Linux systems
+    case "$with_cpu" in
+      power7 | power8 | power9 | power1*)
+	:
+	;;
+      *)
+	as_fn_error "Configuration option --with-long-double-format is only \
+supported if the default cpu is power7 or newer" "$LINENO" 5
+	with_long_double_format=""
+	;;
+      esac
+      ;;
+  xpowerpc64*-*-linux*:*)
+    as_fn_error "--with-long-double-format argument should be ibm or ieee" "$LINENO" 5
+    with_long_double_format=""
+    ;;
+  *)
+    as_fn_error "Configure option --with-long-double-format is only supported \
+on 64-bit PowerPC VSX Linux systems" "$LINENO" 5
+    with_long_double_format=""
+    ;;
+esac
+fi
+
+
 # Check if the target LIBC supports exporting the AT_PLATFORM and AT_HWCAP
 # values in the TCB.  Currently, only GLIBC 2.23 and later support this.
 gcc_cv_libc_provides_hwcap_in_tcb=no

gcc/configure.ac

@@ -5885,6 +5885,43 @@ if test x$gcc_cv_target_ldbl128 = xyes; then
 	    [Define if TFmode long double should be the default])
 fi
 
+# Check if TFmode long double target should use the IBM extended double or IEEE
+# 128-bit floating point formats if long doubles are 128-bits long.  The long
+# double type can only be switched on powerpc64 bit Linux systems where VSX is
+# supported.  Other PowerPC systems do not build the IEEE 128-bit emulator in
+# libgcc.
+AC_ARG_WITH([long-double-format],
+  [AS_HELP_STRING([--with-long-double-format={ieee,ibm}]
+		  [Specify whether PowerPC long double uses IEEE or IBM format])],[
+case "$target:$with_long_double_format" in
+  powerpc64le-*-linux*:ieee | powerpc64le-*-linux*:ibm)
+    :
+    ;;
+  powerpc64-*-linux*:ieee | powerpc64-*-linux*:ibm)
+    # IEEE 128-bit emulation is only built on 64-bit VSX Linux systems
+    case "$with_cpu" in
+      power7 | power8 | power9 | power1*)
+	:
+	;;
+      *)
+	AC_MSG_ERROR([Configuration option --with-long-double-format is only \
+supported if the default cpu is power7 or newer])
+	with_long_double_format=""
+	;;
+      esac
+      ;;
+  xpowerpc64*-*-linux*:*)
+    AC_MSG_ERROR([--with-long-double-format argument should be ibm or ieee])
+    with_long_double_format=""
+    ;;
+  *)
+    AC_MSG_ERROR([Configure option --with-long-double-format is only supported \
+on 64-bit PowerPC VSX Linux systems])
+    with_long_double_format=""
+    ;;
+esac],
+  [])
+
 # Check if the target LIBC supports exporting the AT_PLATFORM and AT_HWCAP
 # values in the TCB.  Currently, only GLIBC 2.23 and later support this.
 gcc_cv_libc_provides_hwcap_in_tcb=no