diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 999ee028c6c73acd36d2b9c3564eafd01a2d0088..05337716498833c5dd5da4f5f9a68ac864359534 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2010-11-02  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
+
+	* configure.ac (*-*-irix6*): Disable set_have_as_tls.
+	(*-*-osf*): Likewise.
+	* configure: Regenerate.
+
 2010-11-02  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* config/i386/driver-i386.c (host_detect_local_cpu): Updated
diff --git a/gcc/configure b/gcc/configure
index da157e09f74606b28941dadffcc223805a224228..013ddec08ca20100ead5a86ea85b058fec5dd8cd 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -22443,6 +22443,16 @@ if test $gcc_cv_as_tls = yes; then
 fi
 fi
 case "$target" in
+  *-*-irix6*)
+    # IRIX 6.5 rld and libc.so lack TLS support, so even if gas and gld
+    # with TLS support are in use, native TLS cannot work.
+    set_have_as_tls=no
+    ;;
+  *-*-osf*)
+    # Tru64 UNIX loader and libc.so lack TLS support, so even if gas and
+    # gld with TLS support are in use, native TLS cannot work.
+    set_have_as_tls=no
+    ;;
   # TLS was introduced in the Solaris 9 FCS release and backported to
   # Solaris 8 patches.  Support for GNU-style TLS on x86 was only
   # introduced in Solaris 9 4/04, replacing the earlier Sun style that Sun
diff --git a/gcc/configure.ac b/gcc/configure.ac
index 966dbd38bc15c6fa0ed95fd7afb5043f94e3bd7c..9d0714bea2c2535c961c335be1a1e70d1658bc71 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -2982,6 +2982,16 @@ else
   [set_have_as_tls=yes])
 fi
 case "$target" in
+  *-*-irix6*)
+    # IRIX 6.5 rld and libc.so lack TLS support, so even if gas and gld
+    # with TLS support are in use, native TLS cannot work.
+    set_have_as_tls=no
+    ;;
+  *-*-osf*)
+    # Tru64 UNIX loader and libc.so lack TLS support, so even if gas and
+    # gld with TLS support are in use, native TLS cannot work.
+    set_have_as_tls=no
+    ;;
   # TLS was introduced in the Solaris 9 FCS release and backported to
   # Solaris 8 patches.  Support for GNU-style TLS on x86 was only
   # introduced in Solaris 9 4/04, replacing the earlier Sun style that Sun