[PATCH] Support official CLooG.org versions.

[Andreas SimbÃrger <simbuerg at googlemail dot com>]

--------------------------
Changes to previous patch:
  * Moved AC_SUBST's inside CLOOG_INIT_FLAGS
  * Separated in-tree opts from CLOOG_INIT_FLAGS

As discussed with Paolo, I will prepare a separate patch to implement
his proposal of moving the version checking inside the gcc/configure.ac
script.

Sorry for the delay, after a small break after my exams I got pulled off
by some other work and completely forgot about sending in this patch :-(.
--------------------------

Add support for official CLooG releases.
CLooG's configuration gets detected within 2 stages:

Stage 1: Detect the installed CLooG version.
  This is done by linking test programs against the various
  CLooG libraries. As CLooG's library sonames depend on the
  used backend, this is sufficient to detect the used backend.

  We only detect this backends, in order:
    1) CLooG-PPL (Legacy): The "old" CLooG.
    2) CLooG-ISL: The "new" CLooG.
    3) CLooG-Parma: An alternative backend, to compare it with
    CLooG-ISL.

  CLooG-Poly is not detected, as the PolyLib may conflict
  with GCC's license.

Stage 2: Version checks.
  After detecting the right configuration, we finally check
  if the installed version is usable. There are 2 different
  checks: One for CLooG-PPL (Legacy) and one for CLooG-ISL.

  * CLooG-ISL:
    As the "new" CLooG provides methods to check for its version at
    both compile and run time, we use the compile time check.
    We check for the constants to verify the header's compatibility.

  * CLooG-PPL (Legacy):
    This version check provides the same semantics as before.
    As CLooG-PPL (Legacy) provides the same constants as the
    official CLooG, we can use the same test program for the
    compile time check.

Tested with CLooG-ISL and CLooG-PPL (Legacy).
As for now, CLooG-Parma fails to build.

2010-08-11  Andreas Simbuerger  <simbuerg@fim.uni-passau.de>

	* configure.ac: Support official CLooG.org versions.
	* configure: Regenerate.
	* config/cloog.m4: New.
---
 ChangeLog.graphite |    6 +
 config/cloog.m4    |  252 +++++++++++++++++++++++++++++++++++++++++++
 configure          |  304 ++++++++++++++++++++++++++++++++++++++++++----------
 configure.ac       |   83 +++++----------
 4 files changed, 533 insertions(+), 112 deletions(-)
 create mode 100644 config/cloog.m4

diff --git a/ChangeLog.graphite b/ChangeLog.graphite
index 46f1290..d067200 100644
--- a/ChangeLog.graphite
+++ b/ChangeLog.graphite
@@ -1,3 +1,9 @@
+2010-08-11  Andreas Simbuerger  <simbuerg@fim.uni-passau.de>
+
+	* configure.ac: Support official CLooG.org versions.
+	* configure: Regenerate.
+	* config/cloog.m4: New.
+
 2010-10-20  Sebastian Pop  <sebastian.pop@amd.com>
 
 	* Merge from mainline (164578:165734).
diff --git a/config/cloog.m4 b/config/cloog.m4
new file mode 100644
index 0000000..9ddea98
--- /dev/null
+++ b/config/cloog.m4
@@ -0,0 +1,252 @@
+# This file is part of GCC.
+#
+# GCC is free software; you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free
+# Software Foundation; either version 3, or (at your option) any later
+# version.
+#
+# GCC is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+# for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3.  If not see
+# <http://www.gnu.org/licenses/>.
+#
+# Contributed by Andreas Simbuerger <simbuerg@fim.uni-passau.de>
+
+# CLOOG_INIT_FLAGS ()
+# -------------------------
+# Provide configure switches for CLooG support.
+# Initialize clooglibs/clooginc according to the user input.
+AC_DEFUN([CLOOG_INIT_FLAGS],
+[
+  AC_ARG_WITH(cloog,
+    [AS_HELP_STRING(
+      [--with-cloog=PATH],
+      [Specify prefix directory for the installed CLooG-PPL package.
+       Equivalent to --with-cloog-include=PATH/include
+       plus --with-cloog-lib=PATH/lib])])
+  AC_ARG_WITH(cloog_include,
+    [AS_HELP_STRING(
+      [--with-cloog-include=PATH],
+      [Specify directory for installed CLooG include files])])
+  AC_ARG_WITH(cloog_lib,
+    [AS_HELP_STRING(
+      [--with-cloog-lib=PATH],
+      [Specify the directory for the installed CLooG library])])
+  
+  AC_ARG_ENABLE(cloog-version-check,
+    [AS_HELP_STRING(
+      [--disable-cloog-version-check],
+      [disable check for CLooG version])],
+    ENABLE_CLOOG_CHECK=$enableval,
+    ENABLE_CLOOG_CHECK=yes)
+  
+  # Initialize clooglibs and clooginc.
+  case $with_cloog in
+    no)
+      clooglibs=
+      clooginc=
+      ;;
+    "" | yes)
+      ;;
+    *)
+      clooglibs="-L$with_cloog/lib"
+      clooginc="-I$with_cloog/include"
+      ;;
+  esac
+  if test "x${with_cloog_include}" != x ; then
+    clooginc="-I$with_cloog_include"
+  fi
+  if test "x${with_cloog_lib}" != x; then
+    clooglibs="-L$with_cloog_lib"
+  fi
+
+  dnl Flags needed for CLOOG
+  AC_SUBST(clooglibs)
+  AC_SUBST(clooginc)
+]
+)
+
+# CLOOG_REQUESTED (ACTION-IF-REQUESTED, ACTION-IF-NOT)
+# ----------------------------------------------------
+# Provide actions for failed CLooG detection.
+AC_DEFUN([CLOOG_REQUESTED],
+[
+  AC_REQUIRE([CLOOG_INIT_FLAGS])
+
+  if test "x${with_cloog}" != x \
+    || test "x${with_cloog_include}" != x \
+    || test "x${with_cloog_lib}" != x ; then
+    $1
+  else
+    $2
+  fi
+]
+)
+
+# _CLOOG_ORG_PROG ()
+# ------------------
+# Helper for detecting CLooG.org's backend.
+m4_define([_CLOOG_ORG_PROG],[AC_LANG_PROGRAM(
+  [#include <cloog/cloog.h>],
+  [cloog_version ()])])
+
+# _CLOOG_PPL_LEGACY_PROG ()
+# -------------------------
+# Helper for detecting CLooG-Legacy (CLooG-PPL).
+m4_define([_CLOOG_PPL_LEGACY_PROG], [AC_LANG_PROGRAM(
+  [#include <cloog/cloog.h>],
+  [ppl_version_major ()])])
+
+# CLOOG_FIND_FLAGS ()
+# ------------------
+# Detect the used CLooG-backend and set clooginc/clooglibs/cloog_org.
+# Preference: CLooG-PPL (Legacy) > CLooG-ISL > CLooG-PPL
+AC_DEFUN([CLOOG_FIND_FLAGS],
+[
+  AC_REQUIRE([CLOOG_INIT_FLAGS])
+
+  _cloog_saved_CFLAGS=$CFLAGS
+  _cloog_saved_CPPFLAGS=$CPPFLAGS
+  _cloog_saved_LDFLAGS=$LDFLAGS
+  _cloog_saved_LIBS=$LIBS
+
+  _clooglegacyinc="-DCLOOG_PPL_BACKEND"
+  _cloogorginc="-DCLOOG_INT_GMP -DCLOOG_ORG"
+ 
+  dnl clooglibs & clooginc may have been initialized by CLOOG_INIT_FLAGS.
+  CFLAGS="${CFLAGS} ${clooginc} ${pplinc} ${gmpinc}"
+  CPPFLAGS="${CPPFLAGS} ${_clooglegacyinc} ${_cloogorginc}"
+  LDFLAGS="${LDFLAGS} ${clooglibs}"
+
+  AC_CACHE_CHECK([for installed CLooG],
+                 [gcc_cv_cloog_type],
+    [LIBS="-lcloog ${_cloog_saved_LIBS}"
+     AC_LINK_IFELSE([_CLOOG_PPL_LEGACY_PROG],
+      [gcc_cv_cloog_type="PPL Legacy"],
+      [LIBS="-lcloog-isl -lisl ${_cloog_saved_LIBS}"
+       AC_LINK_IFELSE([_CLOOG_ORG_PROG],
+        [gcc_cv_cloog_type=ISL],
+        [LIBS="-lcloog-ppl ${_cloog_saved_LIBS}"
+         AC_LINK_IFELSE([_CLOOG_ORG_PROG],
+          [gcc_cv_cloog_type=PPL],
+          [gcc_cv_cloog_type=no])])])])
+
+  case $gcc_cv_cloog_type in
+    "PPL Legacy")
+      clooginc="${clooginc} ${_clooglegacyinc}"
+      clooglibs="${clooglibs} -lcloog"
+      cloog_org=no
+      ;;
+    "ISL")
+      clooginc="${clooginc} ${_cloogorginc}"
+      clooglibs="${clooglibs} -lcloog-isl"
+      cloog_org=yes
+      ;;
+    "PPL")
+      clooginc="${clooginc} ${_cloogorginc}"
+      clooglibs="${clooglibs} -lcloog-ppl"
+      cloog_org=yes
+      ;;
+    *)
+      clooglibs=
+      clooginc=
+      cloog_org=
+      ;;
+  esac
+
+  LIBS=$_cloog_saved_LIBS
+  CFLAGS=$_cloog_saved_CFLAGS
+  CPPFLAGS=$_cloog_saved_CPPFLAGS
+  LDFLAGS=$_cloog_saved_LDFLAGS
+]
+)
+
+# _CLOOG_CHECK_CT_PROG(MAJOR, MINOR, REVISION)
+# --------------------------------------------
+# Helper for verifying CLooG's compile time version.
+m4_define([_CLOOG_CHECK_CT_PROG],[AC_LANG_PROGRAM(
+  [#include "cloog/cloog.h"],
+  [#if CLOOG_VERSION_MAJOR != $1 \
+    || CLOOG_VERSION_MINOR != $2 \
+    || CLOOG_VERSION_REVISION < $3
+    choke me
+   #endif])])
+
+# _CLOOG_CHECK_RT_PROG ()
+# -----------------------
+# Helper for verifying that CLooG's compile time version
+# matches the run time version.
+m4_define([_CLOOG_CHECK_RT_PROG],[AC_LANG_PROGRAM(
+  [#include "cloog/cloog.h"],
+  [if ((cloog_version_major () != CLOOG_VERSION_MAJOR)
+    && (cloog_version_minor () != CLOOG_VERSION_MINOR)
+    && (cloog_version_revision () != CLOOG_VERSION_REVISION))
+    {
+      return 1;
+    }])])
+
+# CLOOG_CHECK_VERSION CLOOG_CHECK_VERSION (MAJOR, MINOR, REVISION)
+# ----------------------------------------------------------------
+# Test the found CLooG to be exact of version MAJOR.MINOR and at least
+# REVISION.
+# If we're using the old CLooG-PPL (Legacy), the old version check will
+# be executed (Ignores the provided version information).
+AC_DEFUN([CLOOG_CHECK_VERSION],
+[
+  AC_REQUIRE([CLOOG_FIND_FLAGS])
+
+  if test "${ENABLE_CLOOG_CHECK}" = yes ; then
+    _cloog_saved_CFLAGS=$CFLAGS
+    _cloog_saved_LDFLAGS=$LDFLAGS
+
+    CFLAGS="${_cloog_saved_CFLAGS} ${clooginc} ${pplinc} ${gmpinc}"
+    LDFLAGS="${_cloog_saved_LDFLAGS} ${clooglibs}"
+
+    if test "${cloog_org}" = yes ; then
+      AC_CACHE_CHECK([for verison $1.$2.$3 of CLooG],
+        [gcc_cv_cloog_ct_0_14_0],
+        [AC_COMPILE_IFELSE([_CLOOG_CHECK_CT_PROG($1,$2,$3)],
+          [gcc_cv_cloog_ct_0_14_0=yes],
+          [gcc_cv_cloog_ct_0_14_0=no])])
+    elif test "${cloog_org}" = no ; then
+      AC_CACHE_CHECK([for version 0.15.5 (or later revision) of CLooG],
+        [gcc_cv_cloog_ct_0_15_5],
+        [AC_COMPILE_IFELSE([_CLOOG_CHECK_CT_PROG(0,15,5)],
+          [AC_COMPILE_IFELSE([_CLOOG_CHECK_CT_PROG(0,15,9)],
+           [gcc_cv_cloog_ct_0_15_5=yes],
+            [gcc_cv_cloog_ct_0_15_5="buggy but acceptable"])],
+          [gcc_cv_cloog_ct_0_15_5=no])])
+    fi
+
+    CFLAGS=$_cloog_saved_CFLAGS
+    LDFLAGS=$_cloog_saved_LDFLAGS
+  fi
+]
+)
+
+# CLOOG_IF_FAILED (ACTION-IF-FAILED)
+# ----------------------------------
+# Executes ACTION-IF-FAILED, if GRAPHITE was requested and
+# the checks failed.
+AC_DEFUN([CLOOG_IF_FAILED],
+[
+  CLOOG_REQUESTED([graphite_requested=yes], [graphite_requested=no])
+  
+  if test "${gcc_cv_cloog_ct_0_14_0}" = no \
+    || test "${gcc_cv_cloog_rt_0_14_0}" = no \
+    || test "${gcc_cv_cloog_ct_0_15_5}" = no; then
+    clooglibs=
+    clooginc=
+  fi
+
+  if test "${graphite_requested}" = yes \
+    && test "x${clooglibs}" = x \
+    && test "x${clooginc}" = x ; then
+    $1
+  fi
+]
+)
diff --git a/configure b/configure
index b1fbfaa..372459c 100755
--- a/configure
+++ b/configure
@@ -833,6 +833,9 @@ LIBS
 CPPFLAGS
 CXX
 CXXFLAGS
+LDFLAGS
+LIBS
+CPPFLAGS
 CCC
 CPP
 build_configargs
@@ -1491,7 +1494,8 @@ Optional Features:
   --enable-libssp         build libssp directory
   --enable-build-with-cxx build with C++ compiler instead of C compiler
   --disable-ppl-version-check    disable check for PPL version
-  --disable-cloog-version-check  disable check for CLooG version
+  --disable-cloog-version-check
+                          disable check for CLooG version
   --enable-lto            enable link time optimization support
   --enable-stage1-languages[=all]   choose additional languages to build during
                           stage1.  Mostly useful for compiler development.
@@ -1542,11 +1546,14 @@ Optional Packages:
                           plus --with-ppl-lib=PATH/lib
   --with-ppl-include=PATH Specify directory for installed PPL include files
   --with-ppl-lib=PATH     Specify the directory for the installed PPL library
-  --with-cloog=PATH       Specify prefix directory for the installed CLooG-PPL package
-                          Equivalent to --with-cloog-include=PATH/include
-                          plus --with-cloog-lib=PATH/lib
-  --with-cloog-include=PATH Specify directory for installed CLooG include files
-  --with-cloog-lib=PATH   Specify the directory for the installed CLooG library
+  --with-cloog=PATH       Specify prefix directory for the installed CLooG-PPL
+                          package. Equivalent to
+                          --with-cloog-include=PATH/include plus
+                          --with-cloog-lib=PATH/lib
+  --with-cloog-include=PATH
+                          Specify directory for installed CLooG include files
+  --with-cloog-lib=PATH   Specify the directory for the installed CLooG
+                          library
   --with-libelf=PATH       Specify prefix directory for the installed libelf package
                           Equivalent to --with-libelf-include=PATH/include
                           plus --with-libelf-lib=PATH/lib
@@ -5894,8 +5901,7 @@ fi
 
 
 # Check for CLOOG
-clooglibs=" -lcloog "
-clooginc=" -DCLOOG_PPL_BACKEND "
+
 
 
 # Check whether --with-cloog was given.
@@ -5916,58 +5922,212 @@ if test "${with_cloog_lib+set}" = set; then :
 fi
 
 
+  # Check whether --enable-cloog-version-check was given.
+if test "${enable_cloog_version_check+set}" = set; then :
+  enableval=$enable_cloog_version_check; ENABLE_CLOOG_CHECK=$enableval
+else
+  ENABLE_CLOOG_CHECK=yes
+fi
+
+
+  # Initialize clooglibs and clooginc.
+  case $with_cloog in
+    no)
+      clooglibs=
+      clooginc=
+      ;;
+    "" | yes)
+      ;;
+    *)
+      clooglibs="-L$with_cloog/lib"
+      clooginc="-I$with_cloog/include"
+      ;;
+  esac
+  if test "x${with_cloog_include}" != x ; then
+    clooginc="-I$with_cloog_include"
+  fi
+  if test "x${with_cloog_lib}" != x; then
+    clooglibs="-L$with_cloog_lib"
+  fi
+
+
+
+
+
 if test "x$with_ppl" = "xno"; then
   with_cloog=no
 fi
+if test "x${with_cloog}" = x && test "x${with_cloog_include}" = x \
+  && test "x${with_cloog_lib}" = x && test -d ${srcdir}/cloog; then
+  clooglibs='-L$$r/$(HOST_SUBDIR)/cloog/'"$lt_cv_objdir"' '
+  clooginc='-I$$r/$(HOST_SUBDIR)/cloog/include -I$$s/cloog/include '
+fi
+if test "x$with_cloog" != "xno"; then
 
-case $with_cloog in
-  no)
-    clooglibs=
-    clooginc=
-    ;;
-  "" | yes)
-    ;;
-  *)
-    clooglibs="-L$with_cloog/lib -lcloog"
-    clooginc="-I$with_cloog/include -DCLOOG_PPL_BACKEND "
-    ;;
-esac
-if test "x$with_cloog_include" != x; then
-  clooginc="-I$with_cloog_include -DCLOOG_PPL_BACKEND "
+
+
+  _cloog_saved_CFLAGS=$CFLAGS
+  _cloog_saved_CPPFLAGS=$CPPFLAGS
+  _cloog_saved_LDFLAGS=$LDFLAGS
+  _cloog_saved_LIBS=$LIBS
+
+  _clooglegacyinc="-DCLOOG_PPL_BACKEND"
+  _cloogorginc="-DCLOOG_INT_GMP -DCLOOG_ORG"
+
+    CFLAGS="${CFLAGS} ${clooginc} ${pplinc} ${gmpinc}"
+  CPPFLAGS="${CPPFLAGS} ${_clooglegacyinc} ${_cloogorginc}"
+  LDFLAGS="${LDFLAGS} ${clooglibs}"
+
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for installed CLooG" >&5
+$as_echo_n "checking for installed CLooG... " >&6; }
+if test "${gcc_cv_cloog_type+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+  LIBS="-lcloog ${_cloog_saved_LIBS}"
+     cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <cloog/cloog.h>
+int
+main ()
+{
+ppl_version_major ()
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  gcc_cv_cloog_type="PPL Legacy"
+else
+  LIBS="-lcloog-isl -lisl ${_cloog_saved_LIBS}"
+       cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <cloog/cloog.h>
+int
+main ()
+{
+cloog_version ()
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  gcc_cv_cloog_type=ISL
+else
+  LIBS="-lcloog-ppl ${_cloog_saved_LIBS}"
+         cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <cloog/cloog.h>
+int
+main ()
+{
+cloog_version ()
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  gcc_cv_cloog_type=PPL
+else
+  gcc_cv_cloog_type=no
 fi
-if test "x$with_cloog_lib" != x; then
-  clooglibs="-L$with_cloog_lib -lcloog"
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
 fi
-if test "x$with_cloog$with_cloog_include$with_cloog_lib" = x && test -d ${srcdir}/cloog; then
-  clooglibs='-L$$r/$(HOST_SUBDIR)/cloog/'"$lt_cv_objdir"' -lcloog '
-  clooginc='-I$$r/$(HOST_SUBDIR)/cloog/include -I$$s/cloog/include -DCLOOG_PPL_BACKEND '
-  enable_cloog_version_check=no
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
 fi
-
-# Check whether --enable-cloog-version-check was given.
-if test "${enable_cloog_version_check+set}" = set; then :
-  enableval=$enable_cloog_version_check; ENABLE_CLOOG_CHECK=$enableval
-else
-  ENABLE_CLOOG_CHECK=yes
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
 fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_cloog_type" >&5
+$as_echo "$gcc_cv_cloog_type" >&6; }
 
+  case $gcc_cv_cloog_type in
+    "PPL Legacy")
+      clooginc="${clooginc} ${_clooglegacyinc}"
+      clooglibs="${clooglibs} -lcloog"
+      cloog_org=no
+      ;;
+    "ISL")
+      clooginc="${clooginc} ${_cloogorginc}"
+      clooglibs="${clooglibs} -lcloog-isl"
+      cloog_org=yes
+      ;;
+    "PPL")
+      clooginc="${clooginc} ${_cloogorginc}"
+      clooglibs="${clooglibs} -lcloog-ppl"
+      cloog_org=yes
+      ;;
+    *)
+      clooglibs=
+      clooginc=
+      cloog_org=
+      ;;
+  esac
 
-if test "x$with_cloog" != "xno" -a "${ENABLE_CLOOG_CHECK}" = "yes"; then
-  saved_CFLAGS="$CFLAGS"
-  CFLAGS="$CFLAGS $clooginc $gmpinc $pplinc"
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for version 0.15.5 (or later revision) of CLooG" >&5
+  LIBS=$_cloog_saved_LIBS
+  CFLAGS=$_cloog_saved_CFLAGS
+  CPPFLAGS=$_cloog_saved_CPPFLAGS
+  LDFLAGS=$_cloog_saved_LDFLAGS
+
+
+
+
+
+  if test "${ENABLE_CLOOG_CHECK}" = yes ; then
+    _cloog_saved_CFLAGS=$CFLAGS
+    _cloog_saved_LDFLAGS=$LDFLAGS
+
+    CFLAGS="${_cloog_saved_CFLAGS} ${clooginc} ${pplinc} ${gmpinc}"
+    LDFLAGS="${_cloog_saved_LDFLAGS} ${clooglibs}"
+
+    if test "${cloog_org}" = yes ; then
+      { $as_echo "$as_me:${as_lineno-$LINENO}: checking for verison 0.14.0 of CLooG" >&5
+$as_echo_n "checking for verison 0.14.0 of CLooG... " >&6; }
+if test "${gcc_cv_cloog_ct_0_14_0+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include "cloog/cloog.h"
+int
+main ()
+{
+#if CLOOG_VERSION_MAJOR != 0 \
+    || CLOOG_VERSION_MINOR != 14 \
+    || CLOOG_VERSION_REVISION < 0
+    choke me
+   #endif
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  gcc_cv_cloog_ct_0_14_0=yes
+else
+  gcc_cv_cloog_ct_0_14_0=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_cloog_ct_0_14_0" >&5
+$as_echo "$gcc_cv_cloog_ct_0_14_0" >&6; }
+    elif test "${cloog_org}" = no ; then
+      { $as_echo "$as_me:${as_lineno-$LINENO}: checking for version 0.15.5 (or later revision) of CLooG" >&5
 $as_echo_n "checking for version 0.15.5 (or later revision) of CLooG... " >&6; }
+if test "${gcc_cv_cloog_ct_0_15_5+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 #include "cloog/cloog.h"
 int
 main ()
 {
-
-  #if CLOOG_VERSION_MAJOR != 0 || CLOOG_VERSION_MINOR != 15 || CLOOG_VERSION_REVISION < 5
-  choke me
-  #endif
-
+#if CLOOG_VERSION_MAJOR != 0 \
+    || CLOOG_VERSION_MINOR != 15 \
+    || CLOOG_VERSION_REVISION < 5
+    choke me
+   #endif
   ;
   return 0;
 }
@@ -5979,34 +6139,66 @@ if ac_fn_c_try_compile "$LINENO"; then :
 int
 main ()
 {
-
-  #if CLOOG_VERSION_MAJOR != 0 || CLOOG_VERSION_MINOR != 15 || CLOOG_VERSION_REVISION < 9
-  choke me
-  #endif
-
+#if CLOOG_VERSION_MAJOR != 0 \
+    || CLOOG_VERSION_MINOR != 15 \
+    || CLOOG_VERSION_REVISION < 9
+    choke me
+   #endif
   ;
   return 0;
 }
 _ACEOF
 if ac_fn_c_try_compile "$LINENO"; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
+  gcc_cv_cloog_ct_0_15_5=yes
 else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: buggy but acceptable" >&5
-$as_echo "buggy but acceptable" >&6; }
+  gcc_cv_cloog_ct_0_15_5="buggy but acceptable"
 fi
 rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
 else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }; clooglibs= ; clooginc=
+  gcc_cv_cloog_ct_0_15_5=no
 fi
 rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-  CFLAGS="$saved_CFLAGS"
 fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_cloog_ct_0_15_5" >&5
+$as_echo "$gcc_cv_cloog_ct_0_15_5" >&6; }
+    fi
+
+    CFLAGS=$_cloog_saved_CFLAGS
+    LDFLAGS=$_cloog_saved_LDFLAGS
+  fi
+
+
+
+
+
+
+
+  if test "x${with_cloog}" != x \
+    || test "x${with_cloog_include}" != x \
+    || test "x${with_cloog_lib}" != x ; then
+    graphite_requested=yes
+  else
+    graphite_requested=no
+  fi
 
-# Flags needed for CLOOG
 
 
+  if test "${gcc_cv_cloog_ct_0_14_0}" = no \
+    || test "${gcc_cv_cloog_rt_0_14_0}" = no \
+    || test "${gcc_cv_cloog_ct_0_15_5}" = no; then
+    clooglibs=
+    clooginc=
+  fi
+
+  if test "${graphite_requested}" = yes \
+    && test "x${clooglibs}" = x \
+    && test "x${clooginc}" = x ; then
+
+    as_fn_error "Unable to find a usable CLooG. See config.log for details." "$LINENO" 5
+  fi
+
+
+fi
 
 # Check for LTO support.
 # Check whether --enable-lto was given.
diff --git a/configure.ac b/configure.ac
index bf5fe3a..1b8260c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -28,6 +28,7 @@ m4_include([ltoptions.m4])
 m4_include([ltsugar.m4])
 m4_include([ltversion.m4])
 m4_include([lt~obsolete.m4])
+m4_include([config/cloog.m4])
 
 AC_INIT(move-if-change)
 AC_PREREQ(2.64)
@@ -1580,68 +1581,38 @@ AC_SUBST(pplinc)
 
 
 # Check for CLOOG
-clooglibs=" -lcloog "
-clooginc=" -DCLOOG_PPL_BACKEND "
-
-AC_ARG_WITH(cloog, [  --with-cloog=PATH       Specify prefix directory for the installed CLooG-PPL package
-                          Equivalent to --with-cloog-include=PATH/include
-                          plus --with-cloog-lib=PATH/lib])
-AC_ARG_WITH(cloog_include, [  --with-cloog-include=PATH Specify directory for installed CLooG include files])
-AC_ARG_WITH(cloog_lib, [  --with-cloog-lib=PATH   Specify the directory for the installed CLooG library])
 
+dnl Provide configure switches and initialize clooginc & clooglibs
+dnl with user input.
+CLOOG_INIT_FLAGS
 if test "x$with_ppl" = "xno"; then
   with_cloog=no
 fi
-
-case $with_cloog in 
-  no)
-    clooglibs=
-    clooginc=
-    ;;
-  "" | yes)
-    ;;
-  *)
-    clooglibs="-L$with_cloog/lib -lcloog"
-    clooginc="-I$with_cloog/include -DCLOOG_PPL_BACKEND "
-    ;;
-esac
-if test "x$with_cloog_include" != x; then
-  clooginc="-I$with_cloog_include -DCLOOG_PPL_BACKEND "
+if test "x${with_cloog}" = x && test "x${with_cloog_include}" = x \
+  && test "x${with_cloog_lib}" = x && test -d ${srcdir}/cloog; then
+  clooglibs='-L$$r/$(HOST_SUBDIR)/cloog/'"$lt_cv_objdir"' '
+  clooginc='-I$$r/$(HOST_SUBDIR)/cloog/include -I$$s/cloog/include '
 fi
-if test "x$with_cloog_lib" != x; then
-  clooglibs="-L$with_cloog_lib -lcloog"
+if test "x$with_cloog" != "xno"; then
+  dnl Version check for CLooG-Org
+  dnl As long as there is no new release of CLooG,
+  dnl we will check for 0.14.0.
+  dnl
+  dnl The first git revision that will work with
+  dnl GCC is: bd91b845a65805c290d43fc1bef8139864a163fb
+  dnl This is enforced implictly, as this is the commit that
+  dnl introduced the versioning information used within our
+  dnl checks.
+  dnl
+  dnl If we're using CLooG-Legacy, the provided version information
+  dnl will be ignored.
+  CLOOG_CHECK_VERSION(0,14,0)
+
+  dnl Only execute fail-action, if CLooG has been
+  dnl requested.
+  CLOOG_IF_FAILED([
+    AC_MSG_ERROR([Unable to find a usable CLooG. See config.log for details.])])
 fi
-if test "x$with_cloog$with_cloog_include$with_cloog_lib" = x && test -d ${srcdir}/cloog; then
-  clooglibs='-L$$r/$(HOST_SUBDIR)/cloog/'"$lt_cv_objdir"' -lcloog '
-  clooginc='-I$$r/$(HOST_SUBDIR)/cloog/include -I$$s/cloog/include -DCLOOG_PPL_BACKEND '
-  enable_cloog_version_check=no
-fi
-
-AC_ARG_ENABLE(cloog-version-check,
-[  --disable-cloog-version-check  disable check for CLooG version],
-ENABLE_CLOOG_CHECK=$enableval,
-ENABLE_CLOOG_CHECK=yes)
-
-if test "x$with_cloog" != "xno" -a "${ENABLE_CLOOG_CHECK}" = "yes"; then
-  saved_CFLAGS="$CFLAGS"
-  CFLAGS="$CFLAGS $clooginc $gmpinc $pplinc"
-  AC_MSG_CHECKING([for version 0.15.5 (or later revision) of CLooG])
-  AC_TRY_COMPILE([#include "cloog/cloog.h"],[
-  #if CLOOG_VERSION_MAJOR != 0 || CLOOG_VERSION_MINOR != 15 || CLOOG_VERSION_REVISION < 5
-  choke me
-  #endif
-  ], [AC_TRY_COMPILE([#include "cloog/cloog.h"],[
-  #if CLOOG_VERSION_MAJOR != 0 || CLOOG_VERSION_MINOR != 15 || CLOOG_VERSION_REVISION < 9
-  choke me
-  #endif
-  ], [AC_MSG_RESULT([yes])], [AC_MSG_RESULT([buggy but acceptable])])],
-  [AC_MSG_RESULT([no]); clooglibs= ; clooginc= ])
-  CFLAGS="$saved_CFLAGS"
-fi
-
-# Flags needed for CLOOG
-AC_SUBST(clooglibs)
-AC_SUBST(clooginc)
 
 # Check for LTO support.
 AC_ARG_ENABLE(lto,
-- 
1.7.3.2