diff --git a/pkgs/development/compilers/gcc/common/platform-flags.nix b/pkgs/development/compilers/gcc/common/platform-flags.nix
index bd5a72f9603..c0593cd781e 100644
--- a/pkgs/development/compilers/gcc/common/platform-flags.nix
+++ b/pkgs/development/compilers/gcc/common/platform-flags.nix
@@ -1,7 +1,8 @@
 { lib, targetPlatform }:
 
 let
-  p =  targetPlatform.gcc or {}
+  gcc = targetPlatform.gcc or {};
+  p =  gcc
     // targetPlatform.parsed.abi;
 in lib.concatLists [
   (lib.optional (!targetPlatform.isx86_64 && p ? arch) "--with-arch=${p.arch}") # --with-arch= is unknown flag on x86_64
@@ -10,7 +11,18 @@ in lib.concatLists [
   (lib.optional (p ? fpu) "--with-fpu=${p.fpu}")
   (lib.optional (p ? float) "--with-float=${p.float}")
   (lib.optional (p ? mode) "--with-mode=${p.mode}")
-  (lib.optional
-    (let tp = targetPlatform; in tp.isPower && tp.libc == "glibc" && tp.is64bit)
-    "--with-long-double-128")
+  (lib.optionals targetPlatform.isPower64
+    # musl explicitly rejects 128-bit long double on
+    # powerpc64; see musl/arch/powerpc64/bits/float.h
+    (lib.optionals
+      (!targetPlatform.isMusl
+       && (targetPlatform.isLittleEndian ||
+           # "... --with-long-double-format is only supported if the default cpu is power7 or newer"
+           #  https://github.com/NixOS/nixpkgs/pull/170215#issuecomment-1202164709
+           (lib.lists.elem
+             (lib.strings.substring 0 6 (p.cpu or ""))
+             [ "power7" "power8" "power9" "power1"/*0, 11, etc*/ ]))) [
+      "--with-long-double-128"
+      "--with-long-double-format=${gcc.long-double-format or "ieee"}"
+    ]))
 ]
diff --git a/pkgs/development/libraries/gettext/default.nix b/pkgs/development/libraries/gettext/default.nix
index 81f7abc90a3..5443f1eeac0 100644
--- a/pkgs/development/libraries/gettext/default.nix
+++ b/pkgs/development/libraries/gettext/default.nix
@@ -1,4 +1,6 @@
-{ stdenv, lib, fetchurl, fetchpatch, libiconv, xz, bash }:
+{ stdenv, lib, fetchurl, fetchpatch, libiconv, xz, bash
+, gnulib
+}:
 
 # Note: this package is used for bootstrapping fetchurl, and thus
 # cannot use fetchpatch! All mutable patches (generated by GitHub or
@@ -45,6 +47,14 @@ stdenv.mkDerivation rec {
   '' + lib.optionalString stdenv.hostPlatform.isCygwin ''
     sed -i -e "s/\(cldr_plurals_LDADD = \)/\\1..\/gnulib-lib\/libxml_rpl.la /" gettext-tools/src/Makefile.in
     sed -i -e "s/\(libgettextsrc_la_LDFLAGS = \)/\\1..\/gnulib-lib\/libxml_rpl.la /" gettext-tools/src/Makefile.in
+  '' +
+  # This change to gettext's vendored copy of gnulib is already
+  # merged upstream; we can drop this patch on the next version
+  # bump.  It must be applied twice because gettext vendors gnulib
+  # not once, but twice!
+  ''
+    patch -p2 -d gettext-tools/gnulib-lib/ < ${gnulib.passthru.longdouble-redirect-patch}
+    patch -p2 -d gettext-tools/libgrep/    < ${gnulib.passthru.longdouble-redirect-patch}
   '';
 
   strictDeps = true;
diff --git a/pkgs/development/libraries/glibc/default.nix b/pkgs/development/libraries/glibc/default.nix
index 8ad9c90ff7a..1c0c1b09e15 100644
--- a/pkgs/development/libraries/glibc/default.nix
+++ b/pkgs/development/libraries/glibc/default.nix
@@ -63,6 +63,13 @@ in
             # Same for musl: https://github.com/NixOS/nixpkgs/issues/78805
             "-Wno-error=missing-attributes"
           ])
+          (lib.optionals (stdenv.hostPlatform.isPower64) [
+            # Do not complain about the Processor Specific ABI (i.e. the
+            # choice to use IEEE-standard `long double`).  We pass this
+            # flag in order to mute a `-Werror=psabi` passed by glibc;
+            # hopefully future glibc releases will not pass that flag.
+            "-Wno-error=psabi"
+          ])
         ]);
     };
 
diff --git a/pkgs/development/libraries/goffice/default.nix b/pkgs/development/libraries/goffice/default.nix
index 36a9c79ea68..ece0f168ec5 100644
--- a/pkgs/development/libraries/goffice/default.nix
+++ b/pkgs/development/libraries/goffice/default.nix
@@ -27,7 +27,6 @@ stdenv.mkDerivation rec {
   buildInputs = [ libxslt librsvg ];
 
   enableParallelBuilding = true;
-  doCheck = !stdenv.hostPlatform.isPower64;
 
   passthru = {
     updateScript = gnome.updateScript {
diff --git a/pkgs/development/libraries/mpfr/default.nix b/pkgs/development/libraries/mpfr/default.nix
index e0a33e27c12..aba3a413a66 100644
--- a/pkgs/development/libraries/mpfr/default.nix
+++ b/pkgs/development/libraries/mpfr/default.nix
@@ -28,9 +28,13 @@ stdenv.mkDerivation rec {
   # mpfr.h requires gmp.h
   propagatedBuildInputs = [ gmp ];
 
-  configureFlags =
-    lib.optional stdenv.hostPlatform.isSunOS "--disable-thread-safe" ++
-    lib.optional stdenv.hostPlatform.is64bit "--with-pic";
+  configureFlags = lib.optional stdenv.hostPlatform.isSunOS "--disable-thread-safe"
+    ++ lib.optional stdenv.hostPlatform.is64bit "--with-pic"
+    ++ lib.optional stdenv.hostPlatform.isPower64 [
+      # Without this, the `tget_set_d128` test experiences a link
+      # error due to missing `__dpd_trunctdkf`.
+      "--disable-decimal-float"
+    ];
 
   doCheck = true; # not cross;
 
diff --git a/pkgs/development/tools/gnulib/default.nix b/pkgs/development/tools/gnulib/default.nix
index afc91cb6030..a55589c5a63 100644
--- a/pkgs/development/tools/gnulib/default.nix
+++ b/pkgs/development/tools/gnulib/default.nix
@@ -26,6 +26,17 @@ stdenv.mkDerivation {
   # do not change headers to not update all vendored build files
   dontFixup = true;
 
+  passthru = {
+    # This patch is used by multiple other packages (currently:
+    # gnused, gettext) which contain vendored copies of gnulib.
+    # Without it, compilation will fail with error messages about
+    # "__LDBL_REDIR1_DECL" or similar on platforms with longdouble
+    # redirects (currently powerpc64).  Once all of those other
+    # packages make a release with a newer gnulib we can drop this
+    # patch.
+    longdouble-redirect-patch = ./gnulib-longdouble-redirect.patch;
+  };
+
   meta = with lib; {
     description = "Central location for code to be shared among GNU packages";
     homepage = "https://www.gnu.org/software/gnulib/";
diff --git a/pkgs/development/tools/gnulib/gnulib-longdouble-redirect.patch b/pkgs/development/tools/gnulib/gnulib-longdouble-redirect.patch
new file mode 100644
index 00000000000..f684292dc8b
--- /dev/null
+++ b/pkgs/development/tools/gnulib/gnulib-longdouble-redirect.patch
@@ -0,0 +1,72 @@
+
+Below is the subset of gnulib commit
+776af40e09b476a41073131a90022572f448c189 which deals with long double
+redirects.  The rest of that commit has been removed.
+
+diff --git a/lib/cdefs.h b/lib/cdefs.h
+index fd72b7b..4383e70 100644
+--- a/lib/cdefs.h
++++ b/lib/cdefs.h
+@@ -483,7 +493,37 @@
+ # include <bits/long-double.h>
+ #endif
+ 
+-#if defined __LONG_DOUBLE_MATH_OPTIONAL && defined __NO_LONG_DOUBLE_MATH
++#if __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 1
++# ifdef __REDIRECT
++
++/* Alias name defined automatically.  */
++#  define __LDBL_REDIR(name, proto) ... unused__ldbl_redir
++#  define __LDBL_REDIR_DECL(name) \
++  extern __typeof (name) name __asm (__ASMNAME ("__" #name "ieee128"));
++
++/* Alias name defined automatically, with leading underscores.  */
++#  define __LDBL_REDIR2_DECL(name) \
++  extern __typeof (__##name) __##name \
++    __asm (__ASMNAME ("__" #name "ieee128"));
++
++/* Alias name defined manually.  */
++#  define __LDBL_REDIR1(name, proto, alias) ... unused__ldbl_redir1
++#  define __LDBL_REDIR1_DECL(name, alias) \
++  extern __typeof (name) name __asm (__ASMNAME (#alias));
++
++#  define __LDBL_REDIR1_NTH(name, proto, alias) \
++  __REDIRECT_NTH (name, proto, alias)
++#  define __REDIRECT_NTH_LDBL(name, proto, alias) \
++  __LDBL_REDIR1_NTH (name, proto, __##alias##ieee128)
++
++/* Unused.  */
++#  define __REDIRECT_LDBL(name, proto, alias) ... unused__redirect_ldbl
++#  define __LDBL_REDIR_NTH(name, proto) ... unused__ldbl_redir_nth
++
++# else
++_Static_assert (0, "IEEE 128-bits long double requires redirection on this platform");
++# endif
++#elif defined __LONG_DOUBLE_MATH_OPTIONAL && defined __NO_LONG_DOUBLE_MATH
+ # define __LDBL_COMPAT 1
+ # ifdef __REDIRECT
+ #  define __LDBL_REDIR1(name, proto, alias) __REDIRECT (name, proto, alias)
+@@ -492,6 +532,8 @@
+ #  define __LDBL_REDIR1_NTH(name, proto, alias) __REDIRECT_NTH (name, proto, alias)
+ #  define __LDBL_REDIR_NTH(name, proto) \
+   __LDBL_REDIR1_NTH (name, proto, __nldbl_##name)
++#  define __LDBL_REDIR2_DECL(name) \
++  extern __typeof (__##name) __##name __asm (__ASMNAME ("__nldbl___" #name));
+ #  define __LDBL_REDIR1_DECL(name, alias) \
+   extern __typeof (name) name __asm (__ASMNAME (#alias));
+ #  define __LDBL_REDIR_DECL(name) \
+@@ -502,11 +544,13 @@
+   __LDBL_REDIR1_NTH (name, proto, __nldbl_##alias)
+ # endif
+ #endif
+-#if !defined __LDBL_COMPAT || !defined __REDIRECT
++#if (!defined __LDBL_COMPAT && __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 0) \
++    || !defined __REDIRECT
+ # define __LDBL_REDIR1(name, proto, alias) name proto
+ # define __LDBL_REDIR(name, proto) name proto
+ # define __LDBL_REDIR1_NTH(name, proto, alias) name proto __THROW
+ # define __LDBL_REDIR_NTH(name, proto) name proto __THROW
++# define __LDBL_REDIR2_DECL(name)
+ # define __LDBL_REDIR_DECL(name)
+ # ifdef __REDIRECT
+ #  define __REDIRECT_LDBL(name, proto, alias) __REDIRECT (name, proto, alias)
diff --git a/pkgs/development/tools/misc/texinfo/common.nix b/pkgs/development/tools/misc/texinfo/common.nix
index af0d26fe1f3..51df8c555e6 100644
--- a/pkgs/development/tools/misc/texinfo/common.nix
+++ b/pkgs/development/tools/misc/texinfo/common.nix
@@ -1,6 +1,7 @@
 { version, sha256, patches ? [] }:
 
 { lib, stdenv, buildPackages, fetchurl, perl, xz, libintl, bash
+, gnulib
 
 # we are a dependency of gcc, this simplifies bootstraping
 , interactive ? false, ncurses, procps
@@ -30,6 +31,12 @@ stdenv.mkDerivation {
 
   postPatch = ''
     patchShebangs tp/maintain
+  ''
+  # This patch is needed for IEEE-standard long doubles on
+  # powerpc64; it does not apply cleanly to texinfo 5.x or
+  # earlier.  It is merged upstream in texinfo 6.8.
+  + lib.optionalString (with lib.strings; versionAtLeast version "6.0" && versionOlder version "6.8") ''
+    patch -p1 -d gnulib < ${gnulib.passthru.longdouble-redirect-patch}
   '';
 
   # ncurses is required to build `makedoc'
@@ -82,6 +89,8 @@ stdenv.mkDerivation {
     license = licenses.gpl3Plus;
     platforms = platforms.all;
     maintainers = with maintainers; [ vrthra oxij ];
+    # see comment above in patches section
+    broken = stdenv.hostPlatform.isPower64 && lib.strings.versionOlder version "6.0";
 
     longDescription = ''
       Texinfo is the official documentation format of the GNU project.