glibc: add buildroot patches

9 files changed, 651 insertions, 437 deletions

diff --git a/toolchain/glibc/patches/2.25/glibc-cross.patch b/toolchain/glibc/patches/2.25/glibc-cross.patch
deleted file mode 100644
index c38ea8a3c..000000000
--- a/toolchain/glibc/patches/2.25/glibc-cross.patch
+++ /dev/null
@@ -1,41 +0,0 @@
-diff -Nur glibc-2.22.orig/sunrpc/rpc_main.c glibc-2.22/sunrpc/rpc_main.c
---- glibc-2.22.orig/sunrpc/rpc_main.c	2015-08-05 08:42:21.000000000 +0200
-+++ glibc-2.22/sunrpc/rpc_main.c	2015-12-08 06:21:38.000000000 +0100
-@@ -38,7 +38,11 @@
- #include <stdio.h>
- #include <string.h>
- #include <unistd.h>
-+#if defined(__APPLE__) || defined(__CYGWIN__)
-+#define gettext(X) (X)
-+#else
- #include <libintl.h>
-+#endif
- #include <locale.h>
- #include <ctype.h>
- #include <sys/types.h>
-@@ -51,6 +55,10 @@
- #include "rpc_scan.h"
- #include "proto.h"
- 
-+#ifdef __CYGWIN__
-+#define stat64 stat
-+#endif
-+
- #include "../version.h"
- #define PACKAGE _libc_intl_domainname
- 
-diff -Nur glibc-2.22.orig/sunrpc/rpc_scan.c glibc-2.22/sunrpc/rpc_scan.c
---- glibc-2.22.orig/sunrpc/rpc_scan.c	2015-08-05 08:42:21.000000000 +0200
-+++ glibc-2.22/sunrpc/rpc_scan.c	2015-12-08 06:22:36.000000000 +0100
-@@ -37,7 +37,11 @@
- #include <stdio.h>
- #include <ctype.h>
- #include <string.h>
-+#if defined(__APPLE__) || defined(__CYGWIN__)
-+#define gettext(X) (X)
-+#else
- #include <libintl.h>
-+#endif
- #include "rpc_scan.h"
- #include "rpc_parse.h"
- #include "rpc_util.h"
diff --git a/toolchain/glibc/patches/2.25/sh.patch b/toolchain/glibc/patches/2.25/sh.patch
deleted file mode 100644
index fa43bddc8..000000000
--- a/toolchain/glibc/patches/2.25/sh.patch
+++ /dev/null
@@ -1,56 +0,0 @@
-From 3840d4c2add1dd282f5f01fa51720b2d5b8fd8d2 Mon Sep 17 00:00:00 2001
-From: Alexey Neyman <stilor@att.net>
-Date: Wed, 8 Feb 2017 16:00:57 -0200
-Subject: [PATCH] sh: Fix building with gcc5/6
-
-Build glibc for sh4-unknown-linux-gnu currently fails if one's
-using GCC5/6: in dl-conflict.c, the elf_machine_rela() function
-is called with NULL as its 3rd argument, sym. The implementation
-of that function in sysdeps/sh/dl-machine.h dereferences that pointer:
-
-const Elf32_Sym *const refsym = sym;
-...
-if (map == &GL(dl_rtld_map))
-  value -= map->l_addr + refsym->st_value + reloc->r_addend;
-
-GCC discovers a null pointer dereference, and in accordance with
--fdelete-null-pointer-checks (which is enabled in -O2) replaces this
-code with a trap - which, as SH does not implement a trap pattern in
-GCC, evaluates to an abort() call. This abort() call pulls many more
-objects from libc_nonshared.a, eventually resulting in link failure
-due to multiple definitions for a number of symbols.
-
-As far as I see, the conditional before this code is always false in
-rtld: _dl_resolve_conflicts() is called with main_map as the first
-argument, not GL(_dl_rtld_map), but since that call is in yet another
-compilation unit, GCC does not know about it. Patch that wraps this
-conditional into !defined RESOLVE_CONFLICT_FIND_MAP attached.
-
-	* sysdeps/sh/dl-machine.h (elf_machine_rela): The condition
-	in R_SH_DIR32 case is always false when inlined from
-	dl-conflict.c. Ifdef out to prevent GCC from insertin an
-	abort() call.
-
-[Waldemar: backport of
-https://sourceware.org/git/?p=glibc.git;a=commit;h=d40dbe722f004f999b589de776f7e57e564dda01.]
-Signed-off-by: Waldemar Brodkorb <wbx@openadk.org>
----
- sysdeps/sh/dl-machine.h | 2 +-
- 1 file changed, 1 insertion(+), 1 deletion(-)
-
-diff --git a/sysdeps/sh/dl-machine.h b/sysdeps/sh/dl-machine.h
-index 449deea..2b468af 100644
---- a/sysdeps/sh/dl-machine.h
-+++ b/sysdeps/sh/dl-machine.h
-@@ -389,7 +389,7 @@ elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
- 	  break;
- 	case R_SH_DIR32:
- 	  {
--#ifndef RTLD_BOOTSTRAP
-+#if !defined RTLD_BOOTSTRAP && !defined RESOLVE_CONFLICT_FIND_MAP
- 	   /* This is defined in rtld.c, but nowhere in the static
- 	      libc.a; make the reference weak so static programs can
- 	      still link.  This declaration cannot be done when
--- 
-2.7.4
-
diff --git a/toolchain/glibc/patches/2.25/sh4-trap.patch b/toolchain/glibc/patches/2.25/sh4-trap.patch
deleted file mode 100644
index 99fad46cc..000000000
--- a/toolchain/glibc/patches/2.25/sh4-trap.patch
+++ /dev/null
@@ -1,340 +0,0 @@
-commit db3d848e154b00071f4a5e729d5884efad410109
-Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
-Date:   Wed Mar 15 15:44:59 2017 -0300
-
-    Build divdi3 only for architecture that required it
-    
-    As noted in [1], divdi3 object is only exported in a handful ABIs
-    (i386, m68k, powerpc32, s390-32, and ia64), however it is built
-    for all current architectures regardless.
-    
-    This patch refact the make rules for this object to so only the
-    aforementioned architectures that actually require it builds it.
-    
-    Also, to avoid internal PLT calls to the exported symbol from the
-    module, glibc uses an internal header (symbol-hacks.h) which is
-    unrequired (and in fact breaks the build for architectures that
-    intend to get symbol definitions from libgcc.a).  The patch also
-    changes it to create its own header (divdi3-symbol-hacks.h) and
-    adjust the architectures that require it accordingly.
-    
-    I checked the build/check (with run-built-tests=no) on the
-    following architectures (which I think must cover all supported
-    ABI/builds) using GCC 6.3:
-    
-    aarch64-linux-gnu
-    alpha-linux-gnu
-    arm-linux-gnueabihf
-    hppa-linux-gnu
-    ia64-linux-gnu
-    m68k-linux-gnu
-    microblaze-linux-gnu
-    mips64-n32-linux-gnu
-    mips-linux-gnu
-    mips64-linux-gnu
-    nios2-linux-gnu
-    powerpc-linux-gnu
-    powerpc-linux-gnu-power4
-    powerpc64-linux-gnu
-    powerpc64le-linux-gnu
-    s390x-linux-gnu
-    s390-linux-gnu
-    sh4-linux-gnu
-    sh4-linux-gnu-soft
-    sparc64-linux-gnu
-    sparcv9-linux-gnu
-    tilegx-linux-gnu
-    tilegx-linux-gnu-32
-    tilepro-linux-gnu
-    x86_64-linux-gnu
-    x86_64-linux-gnu-x32
-    i686-linux-gnu
-    
-    I only saw one regression on sparcv9-linux-gnu (extra PLT call to
-    .udiv) which I address in next patch in the set.  It also correctly
-    build SH with GCC 7.0.1 (without any regression from c89721e25d).
-    
-    [1] https://sourceware.org/ml/libc-alpha/2017-03/msg00243.html
-    
-            * sysdeps/i386/symbol-hacks.h: New file.
-            * sysdeps/m68k/symbol-hacks.h: New file.
-            * sysdeps/powerpc/powerpc32/symbol-hacks.h: New file.
-            * sysdeps/s390/s390-32/symbol-hacks.h: New file.
-            * sysdeps/unix/sysv/linux/i386/Makefile
-            [$(subdir) = csu] (sysdep_routines): New rule: divdi3 object.
-            [$(subdir) = csu] (sysdep-only-routines): Likewise.
-            [$(subdir) = csu] (CFLAGS-divdi3.c): Likewise.
-            * sysdeps/unix/sysv/linux/m68k/Makefile
-            [$(subdir) = csu] (sysdep_routines): Likewise.
-            [$(subdir) = csu] (sysdep-only-routines): Likewise.
-            [$(subdir) = csu] (CFLAGS-divdi3.c): Likewise.
-            * sysdeps/unix/sysv/linux/powerpc/powerpc32/Makefile
-            [$(subdir) = csu] (sysdep_routines): Likewise.
-            [$(subdir) = csu] (sysdep-only-routines): Likewise.
-            [$(subdir) = csu] (CFLAGS-divdi3.c): Likewise.
-            * sysdeps/unix/sysv/linux/s390/s390-32/Makefile
-            [$(subdir) = csu] (sysdep_routines): Likewise.
-            [$(subdir) = csu] (sysdep-only-routines): Likewise.
-            [$(subdir) = csu] (CFLAGS-divdi3.c): Likewise.
-            * sysdeps/wordsize-32/Makefile: Remove file.
-            * sysdeps/wordsize-32/symbol-hacks.h: Definitions move to ...
-            * sysdeps/wordsize-32/divdi3-symbol-hacks.h: ... here.
-
-diff --git a/sysdeps/i386/symbol-hacks.h b/sysdeps/i386/symbol-hacks.h
-new file mode 100644
-index 0000000000..36a13c83f7
---- /dev/null
-+++ b/sysdeps/i386/symbol-hacks.h
-@@ -0,0 +1,21 @@
-+/* Hacks needed for symbol manipulation.  i386 version.
-+   Copyright (C) 2017 Free Software Foundation, Inc.
-+   This file is part of the GNU C Library.
-+
-+   The GNU C Library is free software; you can redistribute it and/or
-+   modify it under the terms of the GNU Lesser General Public
-+   License as published by the Free Software Foundation; either
-+   version 2.1 of the License, or (at your option) any later version.
-+
-+   The GNU C Library 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
-+   Lesser General Public License for more details.
-+
-+   You should have received a copy of the GNU Lesser General Public
-+   License along with the GNU C Library; if not, see
-+   <http://www.gnu.org/licenses/>.  */
-+
-+#include <sysdeps/wordsize-32/divdi3-symbol-hacks.h>
-+
-+#include_next "symbol-hacks.h"
-diff --git a/sysdeps/m68k/symbol-hacks.h b/sysdeps/m68k/symbol-hacks.h
-new file mode 100644
-index 0000000000..e449d29810
---- /dev/null
-+++ b/sysdeps/m68k/symbol-hacks.h
-@@ -0,0 +1,21 @@
-+/* Hacks needed for symbol manipulation.  m68k version.
-+   Copyright (C) 2017 Free Software Foundation, Inc.
-+   This file is part of the GNU C Library.
-+
-+   The GNU C Library is free software; you can redistribute it and/or
-+   modify it under the terms of the GNU Lesser General Public
-+   License as published by the Free Software Foundation; either
-+   version 2.1 of the License, or (at your option) any later version.
-+
-+   The GNU C Library 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
-+   Lesser General Public License for more details.
-+
-+   You should have received a copy of the GNU Lesser General Public
-+   License along with the GNU C Library; if not, see
-+   <http://www.gnu.org/licenses/>.  */
-+
-+#include <sysdeps/wordsize-32/divdi3-symbol-hacks.h>
-+
-+#include_next "symbol-hacks.h"
-diff --git a/sysdeps/powerpc/powerpc32/symbol-hacks.h b/sysdeps/powerpc/powerpc32/symbol-hacks.h
-new file mode 100644
-index 0000000000..dbb3141621
---- /dev/null
-+++ b/sysdeps/powerpc/powerpc32/symbol-hacks.h
-@@ -0,0 +1,21 @@
-+/* Hacks needed for symbol manipulation.  powerpc version.
-+   Copyright (C) 2017 Free Software Foundation, Inc.
-+   This file is part of the GNU C Library.
-+
-+   The GNU C Library is free software; you can redistribute it and/or
-+   modify it under the terms of the GNU Lesser General Public
-+   License as published by the Free Software Foundation; either
-+   version 2.1 of the License, or (at your option) any later version.
-+
-+   The GNU C Library 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
-+   Lesser General Public License for more details.
-+
-+   You should have received a copy of the GNU Lesser General Public
-+   License along with the GNU C Library; if not, see
-+   <http://www.gnu.org/licenses/>.  */
-+
-+#include <sysdeps/wordsize-32/divdi3-symbol-hacks.h>
-+
-+#include_next "symbol-hacks.h"
-diff --git a/sysdeps/s390/s390-32/symbol-hacks.h b/sysdeps/s390/s390-32/symbol-hacks.h
-new file mode 100644
-index 0000000000..585c42365a
---- /dev/null
-+++ b/sysdeps/s390/s390-32/symbol-hacks.h
-@@ -0,0 +1,21 @@
-+/* Hacks needed for symbol manipulation.  s390 version.
-+   Copyright (C) 2017 Free Software Foundation, Inc.
-+   This file is part of the GNU C Library.
-+
-+   The GNU C Library is free software; you can redistribute it and/or
-+   modify it under the terms of the GNU Lesser General Public
-+   License as published by the Free Software Foundation; either
-+   version 2.1 of the License, or (at your option) any later version.
-+
-+   The GNU C Library 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
-+   Lesser General Public License for more details.
-+
-+   You should have received a copy of the GNU Lesser General Public
-+   License along with the GNU C Library; if not, see
-+   <http://www.gnu.org/licenses/>.  */
-+
-+#include <sysdeps/wordsize-32/divdi3-symbol-hacks.h>
-+
-+#include_next "symbol-hacks.h"
-diff --git a/sysdeps/unix/sysv/linux/i386/Makefile b/sysdeps/unix/sysv/linux/i386/Makefile
-index 6aac0dfe15..4080b8c966 100644
---- a/sysdeps/unix/sysv/linux/i386/Makefile
-+++ b/sysdeps/unix/sysv/linux/i386/Makefile
-@@ -26,6 +26,11 @@ endif
- 
- ifeq ($(subdir),csu)
- sysdep-dl-routines += sysdep
-+ifeq (yes,$(build-shared))
-+sysdep_routines += divdi3
-+shared-only-routines += divdi3
-+CPPFLAGS-divdi3.c = -Din_divdi3_c
-+endif
- endif
- 
- ifeq ($(subdir),nptl)
-diff --git a/sysdeps/unix/sysv/linux/m68k/Makefile b/sysdeps/unix/sysv/linux/m68k/Makefile
-index 5c50ce6927..ce1f696a6f 100644
---- a/sysdeps/unix/sysv/linux/m68k/Makefile
-+++ b/sysdeps/unix/sysv/linux/m68k/Makefile
-@@ -4,6 +4,11 @@ m68k-syntax-flag = -DMOTOROLA_SYNTAX
- 
- ifeq ($(subdir),csu)
- sysdep_routines += m68k-helpers
-+ifeq (yes,$(build-shared))
-+sysdep_routines += divdi3
-+shared-only-routines += divdi3
-+CPPFLAGS-divdi3.c = -Din_divdi3_c
-+endif
- endif
- 
- ifeq ($(subdir),misc)
-diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/Makefile b/sysdeps/unix/sysv/linux/powerpc/powerpc32/Makefile
-index 3d6c150582..1f45659ed1 100644
---- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/Makefile
-+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/Makefile
-@@ -1,2 +1,10 @@
- # See Makeconfig regarding the use of default-abi.
- default-abi := 32
-+
-+ifeq ($(subdir),csu)
-+ifeq (yes,$(build-shared))
-+sysdep_routines += divdi3
-+shared-only-routines += divdi3
-+CPPFLAGS-divdi3.c = -Din_divdi3_c
-+endif
-+endif
-diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/Makefile b/sysdeps/unix/sysv/linux/s390/s390-32/Makefile
-index da3b3c76b4..fd8cf92633 100644
---- a/sysdeps/unix/sysv/linux/s390/s390-32/Makefile
-+++ b/sysdeps/unix/sysv/linux/s390/s390-32/Makefile
-@@ -21,3 +21,11 @@ endif
- ifeq ($(subdir),stdlib)
- sysdep_routines += __makecontext_ret
- endif
-+
-+ifeq ($(subdir),csu)
-+ifeq (yes,$(build-shared))
-+sysdep_routines += divdi3
-+shared-only-routines += divdi3
-+CPPFLAGS-divdi3.c = -Din_divdi3_c
-+endif
-+endif
-diff --git a/sysdeps/wordsize-32/Makefile b/sysdeps/wordsize-32/Makefile
-deleted file mode 100644
-index 82beac44ed..0000000000
---- a/sysdeps/wordsize-32/Makefile
-+++ /dev/null
-@@ -1,7 +0,0 @@
--ifeq ($(subdir),csu)
--ifeq (yes,$(build-shared))
--sysdep_routines += divdi3
--shared-only-routines += divdi3
--CPPFLAGS-divdi3.c = -Din_divdi3_c
--endif
--endif
-diff --git a/sysdeps/wordsize-32/divdi3-symbol-hacks.h b/sysdeps/wordsize-32/divdi3-symbol-hacks.h
-new file mode 100644
-index 0000000000..6c90cb796d
---- /dev/null
-+++ b/sysdeps/wordsize-32/divdi3-symbol-hacks.h
-@@ -0,0 +1,31 @@
-+/* Hacks needed for divdi3 symbol manipulation.
-+   Copyright (C) 2004-2017 Free Software Foundation, Inc.
-+   This file is part of the GNU C Library.
-+
-+   The GNU C Library is free software; you can redistribute it and/or
-+   modify it under the terms of the GNU Lesser General Public
-+   License as published by the Free Software Foundation; either
-+   version 2.1 of the License, or (at your option) any later version.
-+
-+   The GNU C Library 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
-+   Lesser General Public License for more details.
-+
-+   You should have received a copy of the GNU Lesser General Public
-+   License along with the GNU C Library; if not, see
-+   <http://www.gnu.org/licenses/>.  */
-+
-+/* A very dirty trick: gcc emits references to __divdi3, __udivdi3,
-+   __moddi3, and __umoddi3.  These functions are exported and
-+   therefore we get PLTs.  Unnecessarily so.  Changing gcc is a big
-+   task which might not be worth it so we play tricks with the
-+   assembler.
-+   Note: in_divdi3_c is only used to avoid symbol alias on divdi3
-+   build itself.  */
-+#if !defined __ASSEMBLER__ && !defined in_divdi3_c && IS_IN (libc) && defined SHARED
-+asm ("__divdi3 = __divdi3_internal");
-+asm ("__udivdi3 = __udivdi3_internal");
-+asm ("__moddi3 = __moddi3_internal");
-+asm ("__umoddi3 = __umoddi3_internal");
-+#endif
-diff --git a/sysdeps/wordsize-32/symbol-hacks.h b/sysdeps/wordsize-32/symbol-hacks.h
-deleted file mode 100644
-index 0aec1e0b97..0000000000
---- a/sysdeps/wordsize-32/symbol-hacks.h
-+++ /dev/null
-@@ -1,31 +0,0 @@
--/* Hacks needed for symbol manipulation.
--   Copyright (C) 2004-2017 Free Software Foundation, Inc.
--   This file is part of the GNU C Library.
--
--   The GNU C Library is free software; you can redistribute it and/or
--   modify it under the terms of the GNU Lesser General Public
--   License as published by the Free Software Foundation; either
--   version 2.1 of the License, or (at your option) any later version.
--
--   The GNU C Library 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
--   Lesser General Public License for more details.
--
--   You should have received a copy of the GNU Lesser General Public
--   License along with the GNU C Library; if not, see
--   <http://www.gnu.org/licenses/>.  */
--
--#include_next "symbol-hacks.h"
--
--/* A very dirty trick: gcc emits references to __divdi3, __udivdi3,
--   __moddi3, and __umoddi3.  These functions are exported and
--   therefore we get PLTs.  Unnecessarily so.  Changing gcc is a big
--   task which might not be worth it so we play tricks with the
--   assembler.  */
--#if !defined __ASSEMBLER__ && !defined in_divdi3_c && IS_IN (libc) && defined SHARED
--asm ("__divdi3 = __divdi3_internal");
--asm ("__udivdi3 = __udivdi3_internal");
--asm ("__moddi3 = __moddi3_internal");
--asm ("__umoddi3 = __umoddi3_internal");
--#endif
diff --git a/toolchain/glibc/patches/2.26/0001-Do-not-use-__builtin_types_compatible_p-in-C-mode-bu.patch b/toolchain/glibc/patches/2.26/0001-Do-not-use-__builtin_types_compatible_p-in-C-mode-bu.patch
new file mode 100644
index 000000000..27a785e31
--- /dev/null
+++ b/toolchain/glibc/patches/2.26/0001-Do-not-use-__builtin_types_compatible_p-in-C-mode-bu.patch
@@ -0,0 +1,50 @@
+From f7439f9b1089e17b6721f28e228682831a2f0135 Mon Sep 17 00:00:00 2001
+From: "Gabriel F. T. Gomes" <gftg@linux.vnet.ibm.com>
+Date: Mon, 21 Aug 2017 14:23:27 +0200
+Subject: [PATCH] Do not use __builtin_types_compatible_p in C++ mode (bug
+ 21930)
+
+The logic to define isinf for float128 depends on the availability of
+__builtin_types_compatible_p, which is only available in C mode,
+however, the conditionals do not check for C or C++ mode.  This lead to
+an error in libstdc++ configure, as reported by bug 21930.
+
+This patch adds a conditional for C mode in the definition of isinf for
+float128.  No definition is provided in C++ mode, since libstdc++
+headers undefine isinf.
+
+Tested for powerpc64le (glibc test suite and libstdc++-v3 configure).
+
+	[BZ #21930]
+	* math/math.h (isinf): Check if in C or C++ mode before using
+	__builtin_types_compatible_p, since this is a C mode feature.
+
+(cherry picked from commit 47a67213a9f51c5f8816d240500b10db605d8b77)
+[Romain rebase on glibc 2.26]
+Signed-off-by: Romain Naour <romain.naour@gmail.com>
+---
+ math/math.h | 8 ++++++--
+ 1 file changed, 6 insertions(+), 2 deletions(-)
+
+diff --git a/math/math.h b/math/math.h
+index e217080..dea8dbe 100644
+--- a/math/math.h
++++ b/math/math.h
+@@ -442,8 +442,12 @@ enum
+ 
+ /* Return nonzero value if X is positive or negative infinity.  */
+ # if __HAVE_DISTINCT_FLOAT128 && !__GNUC_PREREQ (7,0) \
+-     && !defined __SUPPORT_SNAN__
+-   /* __builtin_isinf_sign is broken for float128 only before GCC 7.0.  */
++     && !defined __SUPPORT_SNAN__ && !defined __cplusplus
++   /* Since __builtin_isinf_sign is broken for float128 before GCC 7.0,
++      use the helper function, __isinff128, with older compilers.  This is
++      only provided for C mode, because in C++ mode, GCC has no support
++      for __builtin_types_compatible_p (and when in C++ mode, this macro is
++      not used anyway, because libstdc++ headers undefine it).  */
+ #  define isinf(x) \
+     (__builtin_types_compatible_p (__typeof (x), _Float128) \
+      ? __isinff128 (x) : __builtin_isinf_sign (x))
+-- 
+2.9.5
+
diff --git a/toolchain/glibc/patches/2.26/0002-Do-not-use-generic-selection-in-C-mode.patch b/toolchain/glibc/patches/2.26/0002-Do-not-use-generic-selection-in-C-mode.patch
new file mode 100644
index 000000000..7321eebd6
--- /dev/null
+++ b/toolchain/glibc/patches/2.26/0002-Do-not-use-generic-selection-in-C-mode.patch
@@ -0,0 +1,56 @@
+From bb21afc362a3ecba07ab386a0bc4385e75fbd4b5 Mon Sep 17 00:00:00 2001
+From: "Gabriel F. T. Gomes" <gftg@linux.vnet.ibm.com>
+Date: Mon, 14 Aug 2017 17:51:51 -0300
+Subject: [PATCH] Do not use generic selection in C++ mode
+
+The logic to protect the use of generic selection (_Generic) does not
+check for C or C++ mode, however, generic selection is a C-only
+feature.
+
+Tested for powerpc64le.
+
+	* misc/sys/cdefs.h (__HAVE_GENERIC_SELECTION): Define to 0, if
+	in C++ mode.
+
+(cherry picked from commit 6913ad65e00bb32417ad39c41d292b976171e27e)
+[Romain rebase on glibc 2.26]
+Signed-off-by: Romain Naour <romain.naour@gmail.com>
+---
+ misc/sys/cdefs.h | 19 ++++++++++---------
+ 1 file changed, 10 insertions(+), 9 deletions(-)
+
+diff --git a/misc/sys/cdefs.h b/misc/sys/cdefs.h
+index 06523bf..0c80821 100644
+--- a/misc/sys/cdefs.h
++++ b/misc/sys/cdefs.h
+@@ -464,17 +464,18 @@
+ # define __glibc_macro_warning(msg)
+ #endif
+ 
+-/* Support for generic selection (ISO C11) is available in GCC since
+-   version 4.9.  Previous versions do not provide generic selection,
+-   even though they might set __STDC_VERSION__ to 201112L, when in
+-   -std=c11 mode.  Thus, we must check for !defined __GNUC__ when
+-   testing __STDC_VERSION__ for generic selection support.
++/* Generic selection (ISO C11) is a C-only feature, available in GCC
++   since version 4.9.  Previous versions do not provide generic
++   selection, even though they might set __STDC_VERSION__ to 201112L,
++   when in -std=c11 mode.  Thus, we must check for !defined __GNUC__
++   when testing __STDC_VERSION__ for generic selection support.
+    On the other hand, Clang also defines __GNUC__, so a clang-specific
+    check is required to enable the use of generic selection.  */
+-#if __GNUC_PREREQ (4, 9) \
+-    || __glibc_clang_has_extension (c_generic_selections) \
+-    || (!defined __GNUC__ && defined __STDC_VERSION__ \
+-	&& __STDC_VERSION__ >= 201112L)
++#if !defined __cplusplus \
++    && (__GNUC_PREREQ (4, 9) \
++	|| __glibc_clang_has_extension (c_generic_selections) \
++	|| (!defined __GNUC__ && defined __STDC_VERSION__ \
++	    && __STDC_VERSION__ >= 201112L))
+ # define __HAVE_GENERIC_SELECTION 1
+ #else
+ # define __HAVE_GENERIC_SELECTION 0
+-- 
+2.9.5
+
diff --git a/toolchain/glibc/patches/2.26/0003-Provide-a-C-version-of-issignaling-that-does-not-use.patch b/toolchain/glibc/patches/2.26/0003-Provide-a-C-version-of-issignaling-that-does-not-use.patch
new file mode 100644
index 000000000..b9cd3df39
--- /dev/null
+++ b/toolchain/glibc/patches/2.26/0003-Provide-a-C-version-of-issignaling-that-does-not-use.patch
@@ -0,0 +1,225 @@
+From 9bcf391a21677c6d5fa1c2be71554ec181e24f39 Mon Sep 17 00:00:00 2001
+From: "Gabriel F. T. Gomes" <gftg@linux.vnet.ibm.com>
+Date: Mon, 14 Aug 2017 13:46:15 -0300
+Subject: [PATCH] Provide a C++ version of issignaling that does not use
+ __MATH_TG
+
+The macro __MATH_TG contains the logic to select between long double and
+_Float128, when these types are ABI-distinct.  This logic relies on
+__builtin_types_compatible_p, which is not available in C++ mode.
+
+On the other hand, C++ function overloading provides the means to
+distinguish between the floating-point types.  The overloading
+resolution will match the correct parameter regardless of type
+qualifiers, i.e.: const and volatile.
+
+Tested for powerpc64le, s390x, and x86_64.
+
+	* math/math.h [defined __cplusplus] (issignaling): Provide a C++
+	definition for issignaling that does not rely on __MATH_TG,
+	since __MATH_TG uses __builtin_types_compatible_p, which is only
+	available in C mode.
+	(CFLAGS-test-math-issignaling.cc): New variable.
+	* math/Makefile [CXX] (tests): Add test-math-issignaling.
+	* math/test-math-issignaling.cc: New test for C++ implementation
+	of type-generic issignaling.
+	* sysdeps/powerpc/powerpc64le/Makefile [subdir == math]
+	(CXXFLAGS-test-math-issignaling.cc): Add -mfloat128 to the build
+	options of test-math-issignaling on powerpc64le.
+
+(cherry picked from commit a16e8bc08edca84d507715c66d6cddbbc7ed3b62)
+[Romain rebase on glibc 2.26]
+Signed-off-by: Romain Naour <romain.naour@gmail.com>
+---
+ math/Makefile                        |   3 +-
+ math/math.h                          |  19 +++++-
+ math/test-math-issignaling.cc        | 113 +++++++++++++++++++++++++++++++++++
+ sysdeps/powerpc/powerpc64le/Makefile |   1 +
+ 4 files changed, 134 insertions(+), 2 deletions(-)
+ create mode 100644 math/test-math-issignaling.cc
+
+diff --git a/math/Makefile b/math/Makefile
+index e09b0c0..0130fcf 100644
+--- a/math/Makefile
++++ b/math/Makefile
+@@ -203,7 +203,7 @@ tests-static = test-fpucw-static test-fpucw-ieee-static \
+ 	       test-signgam-ullong-static test-signgam-ullong-init-static
+ 
+ ifneq (,$(CXX))
+-tests += test-math-isinff test-math-iszero
++tests += test-math-isinff test-math-iszero test-math-issignaling
+ endif
+ 
+ ifneq (no,$(PERL))
+@@ -350,6 +350,7 @@ CFLAGS-test-signgam-ullong-init-static.c = -std=c99
+ 
+ CFLAGS-test-math-isinff.cc = -std=gnu++11
+ CFLAGS-test-math-iszero.cc = -std=gnu++11
++CFLAGS-test-math-issignaling.cc = -std=gnu++11
+ 
+ CFLAGS-test-iszero-excess-precision.c = -fexcess-precision=standard
+ CFLAGS-test-iseqsig-excess-precision.c = -fexcess-precision=standard
+diff --git a/math/math.h b/math/math.h
+index dea8dbe..add86af 100644
+--- a/math/math.h
++++ b/math/math.h
+@@ -474,7 +474,24 @@ enum
+ # include <bits/iscanonical.h>
+ 
+ /* Return nonzero value if X is a signaling NaN.  */
+-# define issignaling(x) __MATH_TG ((x), __issignaling, (x))
++# ifndef __cplusplus
++#  define issignaling(x) __MATH_TG ((x), __issignaling, (x))
++# else
++   /* In C++ mode, __MATH_TG cannot be used, because it relies on
++      __builtin_types_compatible_p, which is a C-only builtin.  On the
++      other hand, overloading provides the means to distinguish between
++      the floating-point types.  The overloading resolution will match
++      the correct parameter (regardless of type qualifiers (i.e.: const
++      and volatile).  */
++extern "C++" {
++inline int issignaling (float __val) { return __issignalingf (__val); }
++inline int issignaling (double __val) { return __issignaling (__val); }
++inline int issignaling (long double __val) { return __issignalingl (__val); }
++#  if __HAVE_DISTINCT_FLOAT128
++inline int issignaling (_Float128 __val) { return __issignalingf128 (__val); }
++#  endif
++} /* extern C++ */
++# endif
+ 
+ /* Return nonzero value if X is subnormal.  */
+ # define issubnormal(x) (fpclassify (x) == FP_SUBNORMAL)
+diff --git a/math/test-math-issignaling.cc b/math/test-math-issignaling.cc
+new file mode 100644
+index 0000000..22ae9e1
+--- /dev/null
++++ b/math/test-math-issignaling.cc
+@@ -0,0 +1,113 @@
++/* Test for the C++ implementation of issignaling.
++   Copyright (C) 2017 Free Software Foundation, Inc.
++   This file is part of the GNU C Library.
++
++   The GNU C Library is free software; you can redistribute it and/or
++   modify it under the terms of the GNU Lesser General Public
++   License as published by the Free Software Foundation; either
++   version 2.1 of the License, or (at your option) any later version.
++
++   The GNU C Library 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
++   Lesser General Public License for more details.
++
++   You should have received a copy of the GNU Lesser General Public
++   License along with the GNU C Library; if not, see
++   <http://www.gnu.org/licenses/>.  */
++
++#define _GNU_SOURCE 1
++#include <math.h>
++#include <stdio.h>
++
++#include <limits>
++
++/* There is no signaling_NaN for _Float128 in std::numeric_limits.
++   Include ieee754_float128.h and use the bitfields in the union
++   ieee854_float128.ieee_nan to build a signaling NaN.  */
++#if __HAVE_DISTINCT_FLOAT128
++# include <ieee754_float128.h>
++#endif
++
++static bool errors;
++
++static void
++check (int actual, int expected, const char *actual_expr, int line)
++{
++  if (actual != expected)
++    {
++      errors = true;
++      printf ("%s:%d: error: %s\n", __FILE__, line, actual_expr);
++      printf ("%s:%d:   expected: %d\n", __FILE__, line, expected);
++      printf ("%s:%d:   actual: %d\n", __FILE__, line, actual);
++    }
++}
++
++#define CHECK(actual, expected) \
++  check ((actual), (expected), #actual, __LINE__)
++
++template <class T>
++static void
++check_type ()
++{
++  typedef std::numeric_limits<T> limits;
++  CHECK (issignaling (T{0}), 0);
++  if (limits::has_infinity)
++    {
++      CHECK (issignaling (limits::infinity ()), 0);
++      CHECK (issignaling (-limits::infinity ()), 0);
++    }
++  if (limits::has_quiet_NaN)
++    CHECK (issignaling (limits::quiet_NaN ()), 0);
++  if (limits::has_signaling_NaN)
++    CHECK (issignaling (limits::signaling_NaN ()), 1);
++}
++
++#if __HAVE_DISTINCT_FLOAT128
++static void
++check_float128 ()
++{
++  ieee854_float128 q;
++
++  q.d = 0;
++  CHECK (issignaling (q.d), 0);
++
++  /* Infinity.  */
++  q.ieee.negative = 0;
++  q.ieee.exponent = 0x7FFF;
++  q.ieee.mantissa0 = 0x0000;
++  q.ieee.mantissa1 = 0x00000000;
++  q.ieee.mantissa2 = 0x00000000;
++  q.ieee.mantissa3 = 0x00000000;
++  CHECK (issignaling (q.d), 0);
++
++  /* Quiet NaN.  */
++  q.ieee_nan.quiet_nan = 1;
++  q.ieee_nan.mantissa0 = 0x0000;
++  CHECK (issignaling (q.d), 0);
++
++  /* Still a quiet NaN.  */
++  q.ieee_nan.quiet_nan = 1;
++  q.ieee_nan.mantissa0 = 0x4000;
++  CHECK (issignaling (q.d), 0);
++
++  /* Signaling NaN.  */
++  q.ieee_nan.quiet_nan = 0;
++  q.ieee_nan.mantissa0 = 0x4000;
++  CHECK (issignaling (q.d), 1);
++}
++#endif
++
++static int
++do_test (void)
++{
++  check_type<float> ();
++  check_type<double> ();
++  check_type<long double> ();
++#if __HAVE_DISTINCT_FLOAT128
++  check_float128 ();
++#endif
++  return errors;
++}
++
++#include <support/test-driver.c>
+diff --git a/sysdeps/powerpc/powerpc64le/Makefile b/sysdeps/powerpc/powerpc64le/Makefile
+index 77617b6..19adbfa 100644
+--- a/sysdeps/powerpc/powerpc64le/Makefile
++++ b/sysdeps/powerpc/powerpc64le/Makefile
+@@ -16,6 +16,7 @@ $(foreach suf,$(all-object-suffixes),%f128_r$(suf)): CFLAGS += -mfloat128
+ $(foreach suf,$(all-object-suffixes),$(objpfx)test-float128%$(suf)): CFLAGS += -mfloat128
+ $(foreach suf,$(all-object-suffixes),$(objpfx)test-ifloat128%$(suf)): CFLAGS += -mfloat128
+ CFLAGS-libm-test-support-float128.c += -mfloat128
++CFLAGS-test-math-issignaling.cc += -mfloat128
+ $(objpfx)test-float128% $(objpfx)test-ifloat128%: \
+   gnulib-tests += $(f128-loader-link)
+ endif
+-- 
+2.9.5
+
diff --git a/toolchain/glibc/patches/2.26/0004-Fix-the-C-version-of-issignaling-when-__NO_LONG_DOUB.patch b/toolchain/glibc/patches/2.26/0004-Fix-the-C-version-of-issignaling-when-__NO_LONG_DOUB.patch
new file mode 100644
index 000000000..5e32f754d
--- /dev/null
+++ b/toolchain/glibc/patches/2.26/0004-Fix-the-C-version-of-issignaling-when-__NO_LONG_DOUB.patch
@@ -0,0 +1,47 @@
+From 9dbd8386a1b706beb30291a7e76bbfe69c2620cf Mon Sep 17 00:00:00 2001
+From: "Gabriel F. T. Gomes" <gftg@linux.vnet.ibm.com>
+Date: Wed, 23 Aug 2017 10:16:54 -0300
+Subject: [PATCH] Fix the C++ version of issignaling when __NO_LONG_DOUBLE_MATH
+ is defined
+
+When __NO_LONG_DOUBLE_MATH is defined, __issignalingl is not available,
+thus issignaling with long double argument should call __issignaling,
+instead.
+
+Tested for powerpc64le.
+
+	* math/math.h [defined __cplusplus] (issignaling): In the long
+	double case, call __issignalingl only if __NO_LONG_DOUBLE_MATH
+	is not defined.  Call __issignaling, otherwise.
+
+(cherry picked from commit 3d7b66f66cb223e899a7ebc0f4c20f13e711c9e0)
+[Romain rebase on glibc 2.26]
+Signed-off-by: Romain Naour <romain.naour@gmail.com>
+---
+ math/math.h | 10 +++++++++-
+ 1 file changed, 9 insertions(+), 1 deletion(-)
+
+diff --git a/math/math.h b/math/math.h
+index add86af..60dfa31 100644
+--- a/math/math.h
++++ b/math/math.h
+@@ -486,7 +486,15 @@ enum
+ extern "C++" {
+ inline int issignaling (float __val) { return __issignalingf (__val); }
+ inline int issignaling (double __val) { return __issignaling (__val); }
+-inline int issignaling (long double __val) { return __issignalingl (__val); }
++inline int
++issignaling (long double __val)
++{
++#  ifdef __NO_LONG_DOUBLE_MATH
++  return __issignaling (__val);
++#  else
++  return __issignalingl (__val);
++#  endif
++}
+ #  if __HAVE_DISTINCT_FLOAT128
+ inline int issignaling (_Float128 __val) { return __issignalingf128 (__val); }
+ #  endif
+-- 
+2.9.5
+
diff --git a/toolchain/glibc/patches/2.26/0005-Provide-a-C-version-of-iszero-that-does-not-use-__MA.patch b/toolchain/glibc/patches/2.26/0005-Provide-a-C-version-of-iszero-that-does-not-use-__MA.patch
new file mode 100644
index 000000000..e12c8438f
--- /dev/null
+++ b/toolchain/glibc/patches/2.26/0005-Provide-a-C-version-of-iszero-that-does-not-use-__MA.patch
@@ -0,0 +1,210 @@
+From 45970aa26d1af87b016ef95b4b35c566aeb6e841 Mon Sep 17 00:00:00 2001
+From: "Gabriel F. T. Gomes" <gftg@linux.vnet.ibm.com>
+Date: Tue, 22 Aug 2017 16:34:42 -0300
+Subject: [PATCH] Provide a C++ version of iszero that does not use __MATH_TG
+ (bug 21930)
+
+When signaling nans are enabled (with -fsignaling-nans), the C++ version
+of iszero uses the fpclassify macro, which is defined with __MATH_TG.
+However, when support for float128 is available, __MATH_TG uses the
+builtin __builtin_types_compatible_p, which is only available in C mode.
+
+This patch refactors the C++ version of iszero so that it uses function
+overloading to select between the floating-point types, instead of
+relying on fpclassify and __MATH_TG.
+
+Tested for powerpc64le, s390x, x86_64, and with build-many-glibcs.py.
+
+	[BZ #21930]
+	* math/math.h [defined __cplusplus && defined __SUPPORT_SNAN__]
+	(iszero): New C++ implementation that does not use
+	fpclassify/__MATH_TG/__builtin_types_compatible_p, when
+	signaling nans are enabled, since __builtin_types_compatible_p
+	is a C-only feature.
+	* math/test-math-iszero.cc: When __HAVE_DISTINCT_FLOAT128 is
+	defined, include ieee754_float128.h for access to the union and
+	member ieee854_float128.ieee.
+	[__HAVE_DISTINCT_FLOAT128] (do_test): Call check_float128.
+	[__HAVE_DISTINCT_FLOAT128] (check_float128): New function.
+	* sysdeps/powerpc/powerpc64le/Makefile [subdir == math]
+	(CXXFLAGS-test-math-iszero.cc): Add -mfloat128 to the build
+	options of test-math-zero on powerpc64le.
+
+(cherry picked from commit 42496114ec0eb7d6d039d05d4262e109951c600c)
+[Romain rebase on glibc 2.26]
+Signed-off-by: Romain Naour <romain.naour@gmail.com>
+---
+ math/math.h                          | 33 +++++++++++++--
+ math/test-math-iszero.cc             | 79 ++++++++++++++++++++++++++++++++++++
+ sysdeps/powerpc/powerpc64le/Makefile |  3 +-
+ 3 files changed, 110 insertions(+), 5 deletions(-)
+
+diff --git a/math/math.h b/math/math.h
+index 60dfa31..7c0fc6d 100644
+--- a/math/math.h
++++ b/math/math.h
+@@ -513,15 +513,40 @@ inline int issignaling (_Float128 __val) { return __issignalingf128 (__val); }
+ #  endif
+ # else	/* __cplusplus */
+ extern "C++" {
++#  ifdef __SUPPORT_SNAN__
++inline int
++iszero (float __val)
++{
++  return __fpclassifyf (__val) == FP_ZERO;
++}
++inline int
++iszero (double __val)
++{
++  return __fpclassify (__val) == FP_ZERO;
++}
++inline int
++iszero (long double __val)
++{
++#   ifdef __NO_LONG_DOUBLE_MATH
++  return __fpclassify (__val) == FP_ZERO;
++#   else
++  return __fpclassifyl (__val) == FP_ZERO;
++#   endif
++}
++#   if __HAVE_DISTINCT_FLOAT128
++inline int
++iszero (_Float128 __val)
++{
++  return __fpclassifyf128 (__val) == FP_ZERO;
++}
++#   endif
++#  else
+ template <class __T> inline bool
+ iszero (__T __val)
+ {
+-#  ifdef __SUPPORT_SNAN__
+-  return fpclassify (__val) == FP_ZERO;
+-#  else
+   return __val == 0;
+-#  endif
+ }
++#  endif
+ } /* extern C++ */
+ # endif	/* __cplusplus */
+ #endif /* Use IEC_60559_BFP_EXT.  */
+diff --git a/math/test-math-iszero.cc b/math/test-math-iszero.cc
+index 027e972..5c07261 100644
+--- a/math/test-math-iszero.cc
++++ b/math/test-math-iszero.cc
+@@ -22,6 +22,13 @@
+ 
+ #include <limits>
+ 
++/* Support for _Float128 in std::numeric_limits is limited.
++   Include ieee754_float128.h and use the bitfields in the union
++   ieee854_float128.ieee_nan to build corner-case inputs.  */
++#if __HAVE_DISTINCT_FLOAT128
++# include <ieee754_float128.h>
++#endif
++
+ static bool errors;
+ 
+ static void
+@@ -72,12 +79,84 @@ check_type ()
+          std::numeric_limits<T>::has_denorm == std::denorm_absent);
+ }
+ 
++#if __HAVE_DISTINCT_FLOAT128
++static void
++check_float128 ()
++{
++  ieee854_float128 q;
++
++  q.d = 0.0Q;
++  CHECK (iszero (q.d), 1);
++  q.d = -0.0Q;
++  CHECK (iszero (q.d), 1);
++  q.d = 1.0Q;
++  CHECK (iszero (q.d), 0);
++  q.d = -1.0Q;
++  CHECK (iszero (q.d), 0);
++
++  /* Normal min.  */
++  q.ieee.negative = 0;
++  q.ieee.exponent = 0x0001;
++  q.ieee.mantissa0 = 0x0000;
++  q.ieee.mantissa1 = 0x00000000;
++  q.ieee.mantissa2 = 0x00000000;
++  q.ieee.mantissa3 = 0x00000000;
++  CHECK (iszero (q.d), 0);
++  q.ieee.negative = 1;
++  CHECK (iszero (q.d), 0);
++
++  /* Normal max.  */
++  q.ieee.negative = 0;
++  q.ieee.exponent = 0x7FFE;
++  q.ieee.mantissa0 = 0xFFFF;
++  q.ieee.mantissa1 = 0xFFFFFFFF;
++  q.ieee.mantissa2 = 0xFFFFFFFF;
++  q.ieee.mantissa3 = 0xFFFFFFFF;
++  CHECK (iszero (q.d), 0);
++  q.ieee.negative = 1;
++  CHECK (iszero (q.d), 0);
++
++  /* Infinity.  */
++  q.ieee.negative = 0;
++  q.ieee.exponent = 0x7FFF;
++  q.ieee.mantissa0 = 0x0000;
++  q.ieee.mantissa1 = 0x00000000;
++  q.ieee.mantissa2 = 0x00000000;
++  q.ieee.mantissa3 = 0x00000000;
++  CHECK (iszero (q.d), 0);
++
++  /* Quiet NaN.  */
++  q.ieee_nan.quiet_nan = 1;
++  q.ieee_nan.mantissa0 = 0x0000;
++  CHECK (iszero (q.d), 0);
++
++  /* Signaling NaN.  */
++  q.ieee_nan.quiet_nan = 0;
++  q.ieee_nan.mantissa0 = 0x4000;
++  CHECK (iszero (q.d), 0);
++
++  /* Denormal min.  */
++  q.ieee.negative = 0;
++  q.ieee.exponent = 0x0000;
++  q.ieee.mantissa0 = 0x0000;
++  q.ieee.mantissa1 = 0x00000000;
++  q.ieee.mantissa2 = 0x00000000;
++  q.ieee.mantissa3 = 0x00000001;
++  CHECK (iszero (q.d), 0);
++  q.ieee.negative = 1;
++  CHECK (iszero (q.d), 0);
++}
++#endif
++
+ static int
+ do_test (void)
+ {
+   check_type<float> ();
+   check_type<double> ();
+   check_type<long double> ();
++#if __HAVE_DISTINCT_FLOAT128
++  check_float128 ();
++#endif
+   return errors;
+ }
+ 
+diff --git a/sysdeps/powerpc/powerpc64le/Makefile b/sysdeps/powerpc/powerpc64le/Makefile
+index 19adbfa..dea2290 100644
+--- a/sysdeps/powerpc/powerpc64le/Makefile
++++ b/sysdeps/powerpc/powerpc64le/Makefile
+@@ -17,7 +17,8 @@ $(foreach suf,$(all-object-suffixes),$(objpfx)test-float128%$(suf)): CFLAGS += -
+ $(foreach suf,$(all-object-suffixes),$(objpfx)test-ifloat128%$(suf)): CFLAGS += -mfloat128
+ CFLAGS-libm-test-support-float128.c += -mfloat128
+ CFLAGS-test-math-issignaling.cc += -mfloat128
+-$(objpfx)test-float128% $(objpfx)test-ifloat128%: \
++CFLAGS-test-math-iszero.cc += -mfloat128
++$(objpfx)test-float128% $(objpfx)test-ifloat128% $(objpfx)test-math-iszero: \
+   gnulib-tests += $(f128-loader-link)
+ endif
+ 
+-- 
+2.9.5
+
diff --git a/toolchain/glibc/patches/2.26/0006-Let-fpclassify-use-the-builtin-when-optimizing-for-s.patch b/toolchain/glibc/patches/2.26/0006-Let-fpclassify-use-the-builtin-when-optimizing-for-s.patch
new file mode 100644
index 000000000..37807c459
--- /dev/null
+++ b/toolchain/glibc/patches/2.26/0006-Let-fpclassify-use-the-builtin-when-optimizing-for-s.patch
@@ -0,0 +1,63 @@
+From 33f54cf4f81a51e5c8cbfb2408edd439bdee9435 Mon Sep 17 00:00:00 2001
+From: "Gabriel F. T. Gomes" <gabriel@inconstante.eti.br>
+Date: Wed, 20 Sep 2017 15:10:26 -0300
+Subject: [PATCH] Let fpclassify use the builtin when optimizing for size in
+ C++ mode (bug 22146)
+
+When optimization for size is on (-Os), fpclassify does not use the
+type-generic __builtin_fpclassify builtin, instead it uses __MATH_TG.
+However, when library support for float128 is available, __MATH_TG uses
+__builtin_types_compatible_p, which is not available in C++ mode.
+
+On the other hand, libstdc++ undefines (in cmath) many macros from
+math.h, including fpclassify, so that it can provide its own functions.
+However, during its configure tests, libstdc++ just tests for the
+availability of the macros (it does not undefine them, nor does it
+provide its own functions).
+
+Finally, when libstdc++ is configured with optimization for size
+enabled, its configure tests include math.h and get the definition of
+fpclassify that uses __MATH_TG (and __builtin_types_compatible_p).
+Since libstdc++ does not undefine the macros during its configure tests,
+they fail.
+
+This patch lets fpclassify use the builtin in C++ mode, even when
+optimization for size is on.  This allows the configure test in
+libstdc++ to work.
+
+Tested for powerpc64le and x86_64.
+
+	[BZ #22146]
+	math/math.h: Let fpclassify use the builtin in C++ mode, even
+	when optimazing for size.
+
+(cherry picked from commit c5c4a626098ec884b8527356abdf2a4bb7b6bf27)
+
+[Romain rebase on glibc 2.26)
+Signed-off-by: Romain Naour <romain.naour@gmail.com>
+---
+ math/math.h | 8 +++++++-
+ 1 file changed, 7 insertions(+), 1 deletion(-)
+
+diff --git a/math/math.h b/math/math.h
+index 7c0fc6d..f9348ec 100644
+--- a/math/math.h
++++ b/math/math.h
+@@ -402,7 +402,13 @@ enum
+ 
+ /* Return number of classification appropriate for X.  */
+ # if __GNUC_PREREQ (4,4) && !defined __SUPPORT_SNAN__			      \
+-     && !defined __OPTIMIZE_SIZE__
++     && (!defined __OPTIMIZE_SIZE__ || defined __cplusplus)
++     /* The check for __cplusplus allows the use of the builtin, even
++	when optimization for size is on.  This is provided for
++	libstdc++, only to let its configure test work when it is built
++	with -Os.  No further use of this definition of fpclassify is
++	expected in C++ mode, since libstdc++ provides its own version
++	of fpclassify in cmath (which undefines fpclassify).  */
+ #  define fpclassify(x) __builtin_fpclassify (FP_NAN, FP_INFINITE,	      \
+      FP_NORMAL, FP_SUBNORMAL, FP_ZERO, x)
+ # else
+-- 
+2.9.5
+