gcc.c (LINK_COMMAND_SPEC): Use libcilkrts.spec for -fcilkplus.

gcc/
2014-03-26  Tobias Burnus  <burnus@net-b.de>

        * gcc.c (LINK_COMMAND_SPEC): Use libcilkrts.spec for -fcilkplus.
        (CILK_SELF_SPECS): New define.
        (driver_self_specs): Use it.

libcilkrts/
2014-03-26  Tobias Burnus  <burnus@net-b.de>

        * libcilkrts.spec.in: New.
        * Makefile.am: Handle libcilkrts.spec.
        * configure.ac: Determine link options for libcilkrts.spec.
        * Makefile.in: Regenerate.
        * configure: Regenerate.
        * aclocal.m4: Regenerate.

From-SVN: r208847

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 53d58b38d70facde62c5fb3b31cc6fad02fb3faf..9b124fbe982d569e328f55f311e54dfd798364e0 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2014-03-26  Tobias Burnus  <burnus@net-b.de>
+
+       * gcc.c (LINK_COMMAND_SPEC): Use libcilkrts.spec for -fcilkplus.
+       (CILK_SELF_SPECS): New define.
+       (driver_self_specs): Use it.
+
 2014-03-26  Richard Biener  <rguenther@suse.de>
 
        * tree-pretty-print.c (percent_K_format): Implement special

diff --git a/gcc/gcc.c b/gcc/gcc.c
index 84ca317403cc907bc4ea753453a2568014468f1f..5cb485acbd3470c7161fc6a3393643bfd07053a8 100644 (file)
--- a/gcc/gcc.c
+++ b/gcc/gcc.c
@@ -766,6 +766,7 @@ proper position among the other output files.  */
     %{s} %{t} %{u*} %{z} %{Z} %{!nostdlib:%{!nostartfiles:%S}} " VTABLE_VERIFICATION_SPEC " \
     %{static:} %{L*} %(mfwrap) %(link_libgcc) " SANITIZER_EARLY_SPEC " %o\
     %{fopenmp|ftree-parallelize-loops=*:%:include(libgomp.spec)%(link_gomp)}\
+    %{fcilkplus:%:include(libcilkrts.spec)%(link_cilkrts)}\
     %{fgnu-tm:%:include(libitm.spec)%(link_itm)}\
     %(mflib) " STACK_SPLIT_SPEC "\
     %{fprofile-arcs|fprofile-generate*|coverage:-lgcov} " SANITIZER_SPEC " \
@@ -932,9 +933,15 @@ static const char *const multilib_defaults_raw[] = MULTILIB_DEFAULTS;
 #define GTM_SELF_SPECS "%{fgnu-tm: -pthread}"
 #endif
 
+/* Likewise for -fcilkplus.  */
+#ifndef CILK_SELF_SPECS
+#define CILK_SELF_SPECS "%{fcilkplus: -pthread}"
+#endif
+
 static const char *const driver_self_specs[] = {
   "%{fdump-final-insns:-fdump-final-insns=.} %<fdump-final-insns",
-  DRIVER_SELF_SPECS, CONFIGURE_SPECS, GOMP_SELF_SPECS, GTM_SELF_SPECS
+  DRIVER_SELF_SPECS, CONFIGURE_SPECS, GOMP_SELF_SPECS, GTM_SELF_SPECS,
+  CILK_SELF_SPECS
 };
 
 #ifndef OPTION_DEFAULT_SPECS

diff --git a/libcilkrts/ChangeLog b/libcilkrts/ChangeLog
index eb0d6ecea07882da12d2a1011a8c7cd86b7dd991..80b35c1405d37d153766495ee3ab8d4d9029f330 100644 (file)
--- a/libcilkrts/ChangeLog
+++ b/libcilkrts/ChangeLog
@@ -1,3 +1,12 @@
+2014-03-26  Tobias Burnus  <burnus@net-b.de>
+
+       * libcilkrts.spec.in: New.
+       * Makefile.am: Handle libcilkrts.spec.
+       * configure.ac: Determine link options for libcilkrts.spec.
+       * Makefile.in: Regenerate.
+       * configure: Regenerate.
+       * aclocal.m4: Regenerate.
+
 2014-03-20  Tobias Burnus  <burnus@net-b.de>
 
        PR other/60589

diff --git a/libcilkrts/Makefile.am b/libcilkrts/Makefile.am
index f2d13aabd88308796addd44d25ccdf3bd6cc02cf..84551c842274ec642c51e18b9d9b423e8eba5e46 100644 (file)
--- a/libcilkrts/Makefile.am
+++ b/libcilkrts/Makefile.am
@@ -51,6 +51,7 @@ AM_LDFLAGS = -lpthread
 gcc_version := $(shell cat $(top_srcdir)/../gcc/BASE-VER)
 
 # Target list.
+nodist_toolexeclib_HEADERS = libcilkrts.spec
 toolexeclib_LTLIBRARIES = libcilkrts.la
 
 libcilkrts_la_SOURCES =            \
@@ -110,7 +111,7 @@ libcilkrts_la_LDFLAGS += -no-undefined
 # C/C++ header files for Cilk.
 # cilkincludedir = $(includedir)/cilk
 cilkincludedir = $(libdir)/gcc/$(target_alias)/$(gcc_version)/include/cilk
-cilkinclude_HEADERS =              \
+nodist_cilkinclude_HEADERS =       \
   include/cilk/cilk_api.h          \
   include/cilk/cilk_api_linux.h    \
   include/cilk/cilk.h              \

diff --git a/libcilkrts/Makefile.in b/libcilkrts/Makefile.in
index 092e2f706ec413a836c6bdd9b2b38fd8e96107c3..1ee4d8270e52e931af657a3b2db97ac2d2b65251 100644 (file)
--- a/libcilkrts/Makefile.in
+++ b/libcilkrts/Makefile.in
@@ -112,8 +112,8 @@ target_triplet = @target@
 DIST_COMMON = $(srcdir)/include/internal/rev.mk README ChangeLog \
        $(srcdir)/Makefile.in $(srcdir)/Makefile.am \
        $(top_srcdir)/configure $(am__configure_deps) \
-       $(srcdir)/../mkinstalldirs $(srcdir)/../depcomp \
-       $(cilkinclude_HEADERS)
+       $(srcdir)/../mkinstalldirs $(srcdir)/libcilkrts.spec.in \
+       $(srcdir)/../depcomp
 
 # If we're building on Linux, use the Linux version script
 @LINUX_LINKER_SCRIPT_TRUE@am__append_1 = -Wl,--version-script,$(srcdir)/runtime/linux-symbols.ver
@@ -122,10 +122,8 @@ DIST_COMMON = $(srcdir)/include/internal/rev.mk README ChangeLog \
 @MAC_LINKER_SCRIPT_TRUE@am__append_2 = -Wl,-exported_symbols_list,$(srcdir)/runtime/mac-symbols.txt
 subdir = .
 ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
-am__aclocal_m4_deps = $(top_srcdir)/../config/acx.m4 \
-       $(top_srcdir)/../config/depstand.m4 \
+am__aclocal_m4_deps = $(top_srcdir)/../config/depstand.m4 \
        $(top_srcdir)/../config/lead-dot.m4 \
-       $(top_srcdir)/../config/libstdc++-raw-cxx.m4 \
        $(top_srcdir)/../config/multi.m4 \
        $(top_srcdir)/../config/override.m4 \
        $(top_srcdir)/../libtool.m4 $(top_srcdir)/../ltoptions.m4 \
@@ -136,7 +134,7 @@ am__configure_deps = $(am__aclocal_m4_deps) $(CONFIGURE_DEPENDENCIES) \
 am__CONFIG_DISTCLEAN_FILES = config.status config.cache config.log \
  configure.lineno config.status.lineno
 mkinstalldirs = $(SHELL) $(top_srcdir)/../mkinstalldirs
-CONFIG_CLEAN_FILES =
+CONFIG_CLEAN_FILES = libcilkrts.spec
 CONFIG_CLEAN_VPATH_FILES =
 am__vpath_adj_setup = srcdirstrip=`echo "$(srcdir)" | sed 's|.|.|g'`;
 am__vpath_adj = case $$p in \
@@ -160,7 +158,7 @@ am__base_list = \
   sed '$$!N;$$!N;$$!N;$$!N;$$!N;$$!N;$$!N;s/\n/ /g' | \
   sed '$$!N;$$!N;$$!N;$$!N;s/\n/ /g'
 am__installdirs = "$(DESTDIR)$(toolexeclibdir)" \
-       "$(DESTDIR)$(cilkincludedir)"
+       "$(DESTDIR)$(cilkincludedir)" "$(DESTDIR)$(toolexeclibdir)"
 LTLIBRARIES = $(toolexeclib_LTLIBRARIES)
 libcilkrts_la_LIBADD =
 am_libcilkrts_la_OBJECTS = cilk-abi-vla.lo os-unix-sysdep.lo bug.lo \
@@ -204,7 +202,7 @@ MULTIDIRS =
 MULTISUBDIR = 
 MULTIDO = true
 MULTICLEAN = true
-HEADERS = $(cilkinclude_HEADERS)
+HEADERS = $(nodist_cilkinclude_HEADERS) $(nodist_toolexeclib_HEADERS)
 ETAGS = etags
 CTAGS = ctags
 ACLOCAL = @ACLOCAL@
@@ -245,8 +243,6 @@ LD = @LD@
 LDFLAGS = @LDFLAGS@
 LIBOBJS = @LIBOBJS@
 LIBS = @LIBS@
-LIBSTDCXX_RAW_CXX_CXXFLAGS = @LIBSTDCXX_RAW_CXX_CXXFLAGS@
-LIBSTDCXX_RAW_CXX_LDFLAGS = @LIBSTDCXX_RAW_CXX_LDFLAGS@
 LIBTOOL = @LIBTOOL@
 LIPO = @LIPO@
 LN_S = @LN_S@
@@ -310,6 +306,7 @@ infodir = @infodir@
 install_sh = @install_sh@
 libdir = @libdir@
 libexecdir = @libexecdir@
+link_cilkrts = @link_cilkrts@
 localedir = @localedir@
 localstatedir = @localstatedir@
 lt_cv_dlopen_libs = @lt_cv_dlopen_libs@
@@ -328,7 +325,6 @@ sysconfdir = @sysconfdir@
 target = @target@
 target_alias = @target_alias@
 target_cpu = @target_cpu@
-target_noncanonical = @target_noncanonical@
 target_os = @target_os@
 target_vendor = @target_vendor@
 toolexecdir = @toolexecdir@
@@ -356,6 +352,7 @@ AM_LDFLAGS = -lpthread
 gcc_version := $(shell cat $(top_srcdir)/../gcc/BASE-VER)
 
 # Target list.
+nodist_toolexeclib_HEADERS = libcilkrts.spec
 toolexeclib_LTLIBRARIES = libcilkrts.la
 libcilkrts_la_SOURCES = \
   runtime/config/$(config_dir)/cilk-abi-vla.c           \
@@ -403,7 +400,7 @@ libcilkrts_la_LDFLAGS = -version-info 5:0:0 -lpthread \
 # C/C++ header files for Cilk.
 # cilkincludedir = $(includedir)/cilk
 cilkincludedir = $(libdir)/gcc/$(target_alias)/$(gcc_version)/include/cilk
-cilkinclude_HEADERS = \
+nodist_cilkinclude_HEADERS = \
   include/cilk/cilk_api.h          \
   include/cilk/cilk_api_linux.h    \
   include/cilk/cilk.h              \
@@ -505,6 +502,8 @@ $(top_srcdir)/configure: @MAINTAINER_MODE_TRUE@ $(am__configure_deps)
 $(ACLOCAL_M4): @MAINTAINER_MODE_TRUE@ $(am__aclocal_m4_deps)
        $(am__cd) $(srcdir) && $(ACLOCAL) $(ACLOCAL_AMFLAGS)
 $(am__aclocal_m4_deps):
+libcilkrts.spec: $(top_builddir)/config.status $(srcdir)/libcilkrts.spec.in
+       cd $(top_builddir) && $(SHELL) ./config.status $@
 install-toolexeclibLTLIBRARIES: $(toolexeclib_LTLIBRARIES)
        @$(NORMAL_INSTALL)
        test -z "$(toolexeclibdir)" || $(MKDIR_P) "$(DESTDIR)$(toolexeclibdir)"
@@ -853,10 +852,10 @@ distclean-multi:
        $(MULTICLEAN) $(AM_MAKEFLAGS) DO=distclean multi-clean # $(MAKE)
 maintainer-clean-multi:
        $(MULTICLEAN) $(AM_MAKEFLAGS) DO=maintainer-clean multi-clean # $(MAKE)
-install-cilkincludeHEADERS: $(cilkinclude_HEADERS)
+install-nodist_cilkincludeHEADERS: $(nodist_cilkinclude_HEADERS)
        @$(NORMAL_INSTALL)
        test -z "$(cilkincludedir)" || $(MKDIR_P) "$(DESTDIR)$(cilkincludedir)"
-       @list='$(cilkinclude_HEADERS)'; test -n "$(cilkincludedir)" || list=; \
+       @list='$(nodist_cilkinclude_HEADERS)'; test -n "$(cilkincludedir)" || list=; \
        for p in $$list; do \
          if test -f "$$p"; then d=; else d="$(srcdir)/"; fi; \
          echo "$$d$$p"; \
@@ -866,13 +865,33 @@ install-cilkincludeHEADERS: $(cilkinclude_HEADERS)
          $(INSTALL_HEADER) $$files "$(DESTDIR)$(cilkincludedir)" || exit $$?; \
        done
 
-uninstall-cilkincludeHEADERS:
+uninstall-nodist_cilkincludeHEADERS:
        @$(NORMAL_UNINSTALL)
-       @list='$(cilkinclude_HEADERS)'; test -n "$(cilkincludedir)" || list=; \
+       @list='$(nodist_cilkinclude_HEADERS)'; test -n "$(cilkincludedir)" || list=; \
        files=`for p in $$list; do echo $$p; done | sed -e 's|^.*/||'`; \
        test -n "$$files" || exit 0; \
        echo " ( cd '$(DESTDIR)$(cilkincludedir)' && rm -f" $$files ")"; \
        cd "$(DESTDIR)$(cilkincludedir)" && rm -f $$files
+install-nodist_toolexeclibHEADERS: $(nodist_toolexeclib_HEADERS)
+       @$(NORMAL_INSTALL)
+       test -z "$(toolexeclibdir)" || $(MKDIR_P) "$(DESTDIR)$(toolexeclibdir)"
+       @list='$(nodist_toolexeclib_HEADERS)'; test -n "$(toolexeclibdir)" || list=; \
+       for p in $$list; do \
+         if test -f "$$p"; then d=; else d="$(srcdir)/"; fi; \
+         echo "$$d$$p"; \
+       done | $(am__base_list) | \
+       while read files; do \
+         echo " $(INSTALL_HEADER) $$files '$(DESTDIR)$(toolexeclibdir)'"; \
+         $(INSTALL_HEADER) $$files "$(DESTDIR)$(toolexeclibdir)" || exit $$?; \
+       done
+
+uninstall-nodist_toolexeclibHEADERS:
+       @$(NORMAL_UNINSTALL)
+       @list='$(nodist_toolexeclib_HEADERS)'; test -n "$(toolexeclibdir)" || list=; \
+       files=`for p in $$list; do echo $$p; done | sed -e 's|^.*/||'`; \
+       test -n "$$files" || exit 0; \
+       echo " ( cd '$(DESTDIR)$(toolexeclibdir)' && rm -f" $$files ")"; \
+       cd "$(DESTDIR)$(toolexeclibdir)" && rm -f $$files
 
 ID: $(HEADERS) $(SOURCES) $(LISP) $(TAGS_FILES)
        list='$(SOURCES) $(HEADERS) $(LISP) $(TAGS_FILES)'; \
@@ -929,7 +948,7 @@ check-am: all-am
 check: check-am
 all-am: Makefile $(LTLIBRARIES) all-multi $(HEADERS)
 installdirs:
-       for dir in "$(DESTDIR)$(toolexeclibdir)" "$(DESTDIR)$(cilkincludedir)"; do \
+       for dir in "$(DESTDIR)$(toolexeclibdir)" "$(DESTDIR)$(cilkincludedir)" "$(DESTDIR)$(toolexeclibdir)"; do \
          test -z "$$dir" || $(MKDIR_P) "$$dir"; \
        done
 install: install-am
@@ -981,13 +1000,14 @@ info: info-am
 
 info-am:
 
-install-data-am: install-cilkincludeHEADERS
+install-data-am: install-nodist_cilkincludeHEADERS
 
 install-dvi: install-dvi-am
 
 install-dvi-am:
 
-install-exec-am: install-multi install-toolexeclibLTLIBRARIES
+install-exec-am: install-multi install-nodist_toolexeclibHEADERS \
+       install-toolexeclibLTLIBRARIES
 
 install-html: install-html-am
 
@@ -1029,7 +1049,8 @@ ps: ps-am
 
 ps-am:
 
-uninstall-am: uninstall-cilkincludeHEADERS \
+uninstall-am: uninstall-nodist_cilkincludeHEADERS \
+       uninstall-nodist_toolexeclibHEADERS \
        uninstall-toolexeclibLTLIBRARIES
 
 .MAKE: all-multi clean-multi distclean-multi install-am install-multi \
@@ -1040,17 +1061,20 @@ uninstall-am: uninstall-cilkincludeHEADERS \
        clean-toolexeclibLTLIBRARIES ctags distclean distclean-compile \
        distclean-generic distclean-libtool distclean-multi \
        distclean-tags dvi dvi-am html html-am info info-am install \
-       install-am install-cilkincludeHEADERS install-data \
-       install-data-am install-dvi install-dvi-am install-exec \
-       install-exec-am install-html install-html-am install-info \
-       install-info-am install-man install-multi install-pdf \
-       install-pdf-am install-ps install-ps-am install-strip \
+       install-am install-data install-data-am install-dvi \
+       install-dvi-am install-exec install-exec-am install-html \
+       install-html-am install-info install-info-am install-man \
+       install-multi install-nodist_cilkincludeHEADERS \
+       install-nodist_toolexeclibHEADERS install-pdf install-pdf-am \
+       install-ps install-ps-am install-strip \
        install-toolexeclibLTLIBRARIES installcheck installcheck-am \
        installdirs maintainer-clean maintainer-clean-generic \
        maintainer-clean-multi mostlyclean mostlyclean-compile \
        mostlyclean-generic mostlyclean-libtool mostlyclean-multi pdf \
        pdf-am ps ps-am tags uninstall uninstall-am \
-       uninstall-cilkincludeHEADERS uninstall-toolexeclibLTLIBRARIES
+       uninstall-nodist_cilkincludeHEADERS \
+       uninstall-nodist_toolexeclibHEADERS \
+       uninstall-toolexeclibLTLIBRARIES
 
 
 # Tell versions [3.59,3.63) of GNU make to not export all variables.

diff --git a/libcilkrts/aclocal.m4 b/libcilkrts/aclocal.m4
index c24d0b604153d9362d1f82bcb31f4438a849e17c..68107caffa075b0a8a198f60a0e1ee574eb6d58d 100644 (file)
--- a/libcilkrts/aclocal.m4
+++ b/libcilkrts/aclocal.m4
@@ -968,10 +968,8 @@ AC_SUBST([am__tar])
 AC_SUBST([am__untar])
 ]) # _AM_PROG_TAR
 
-m4_include([../config/acx.m4])
 m4_include([../config/depstand.m4])
 m4_include([../config/lead-dot.m4])
-m4_include([../config/libstdc++-raw-cxx.m4])
 m4_include([../config/multi.m4])
 m4_include([../config/override.m4])
 m4_include([../libtool.m4])

diff --git a/libcilkrts/configure b/libcilkrts/configure
index 63181d78ba588da6ae88b7605566f8a7b5316580..0dadbbda035885252acda1029d21ee4b9143ae44 100644 (file)
--- a/libcilkrts/configure
+++ b/libcilkrts/configure
@@ -604,6 +604,7 @@ ac_subst_vars='am__EXEEXT_FALSE
 am__EXEEXT_TRUE
 LTLIBOBJS
 LIBOBJS
+link_cilkrts
 lt_cv_dlopen_libs
 toolexeclibdir
 toolexecdir
@@ -4214,7 +4215,7 @@ fi
 
 # AC_PROG_LIBTOOL
 # AC_CONFIG_MACRO_DIR([..])
-ac_config_files="$ac_config_files Makefile"
+ac_config_files="$ac_config_files Makefile libcilkrts.spec"
 
 # Default to --enable-multilib
 # Check whether --enable-multilib was given.
@@ -11056,7 +11057,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11059 "configure"
+#line 11060 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -11162,7 +11163,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11165 "configure"
+#line 11166 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -14451,6 +14452,56 @@ fi
 rm -f core conftest.err conftest.$ac_objext \
     conftest$ac_exeext conftest.$ac_ext
 
+# Check to see if -pthread or -lpthread is needed.  Prefer the former.
+# Note that the CILK_SELF_SPEC in gcc.c may force -pthread.
+# In case the pthread.h system header is not found, this test will fail.
+CFLAGS="$CFLAGS -pthread"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <pthread.h>
+   void *g(void *d) { return NULL; }
+int
+main ()
+{
+pthread_t t; pthread_create(&t,NULL,g,NULL);
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+
+else
+  CFLAGS="$save_CFLAGS" LIBS="-lpthread $LIBS"
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <pthread.h>
+     void *g(void *d) { return NULL; }
+int
+main ()
+{
+pthread_t t; pthread_create(&t,NULL,g,NULL);
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+
+else
+  as_fn_error "Pthreads are required to build libcilkrts" "$LINENO" 5
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+
+if test $enable_shared = yes; then
+  link_cilkrts="-lcilkrts %{static: $LIBS}"
+else
+  link_cilkrts="-lcilkrts $LIBS"
+fi
+
+
 
 # Must be last
 cat >confcache <<\_ACEOF
@@ -15567,6 +15618,7 @@ do
   case $ac_config_target in
     "depfiles") CONFIG_COMMANDS="$CONFIG_COMMANDS depfiles" ;;
     "Makefile") CONFIG_FILES="$CONFIG_FILES Makefile" ;;
+    "libcilkrts.spec") CONFIG_FILES="$CONFIG_FILES libcilkrts.spec" ;;
     "default-1") CONFIG_COMMANDS="$CONFIG_COMMANDS default-1" ;;
     "libtool") CONFIG_COMMANDS="$CONFIG_COMMANDS libtool" ;;
 

diff --git a/libcilkrts/configure.ac b/libcilkrts/configure.ac
index 61b45b007230497ff1c6bc67387fb44d3b483aa9..fb215052dd63dd49d42aff36feebde93ea4ace60 100644 (file)
--- a/libcilkrts/configure.ac
+++ b/libcilkrts/configure.ac
@@ -49,7 +49,7 @@ AC_PROG_CC
 AC_PROG_CXX
 # AC_PROG_LIBTOOL
 # AC_CONFIG_MACRO_DIR([..])
-AC_CONFIG_FILES([Makefile])
+AC_CONFIG_FILES([Makefile libcilkrts.spec])
 AM_ENABLE_MULTILIB(, ..)
 AC_FUNC_ALLOCA
 
@@ -183,6 +183,32 @@ AC_LINK_IFELSE(
   AC_DEFINE(HAVE_PTHREAD_AFFINITY_NP, 1,
 [       Define if pthread_{,attr_}{g,s}etaffinity_np is supported.]))
 
+# Check to see if -pthread or -lpthread is needed.  Prefer the former.
+# Note that the CILK_SELF_SPEC in gcc.c may force -pthread.
+# In case the pthread.h system header is not found, this test will fail.
+CFLAGS="$CFLAGS -pthread"
+AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+  [#include <pthread.h>
+   void *g(void *d) { return NULL; }],
+  [pthread_t t; pthread_create(&t,NULL,g,NULL);])],
+ [],
+ [CFLAGS="$save_CFLAGS" LIBS="-lpthread $LIBS"
+  AC_LINK_IFELSE(
+   [AC_LANG_PROGRAM(
+    [#include <pthread.h>
+     void *g(void *d) { return NULL; }],
+    [pthread_t t; pthread_create(&t,NULL,g,NULL);])],
+   [],
+   [AC_MSG_ERROR([Pthreads are required to build libcilkrts])])])
+
+if test $enable_shared = yes; then
+  link_cilkrts="-lcilkrts %{static: $LIBS}"
+else
+  link_cilkrts="-lcilkrts $LIBS"
+fi
+AC_SUBST(link_cilkrts)
+
 
 # Must be last
 AC_OUTPUT