gnu: Simplify the use of --with-long-double-128.

Fixes <https://bugs.gnu.org/48825>.

In short, this change adds the hard-coded "--with-long-double-128" configure
option in one place and removes it from two other places.  This changes and
simplifies the use of this option for various architectures that start with
the string "powerpc".

* gnu/packages/gcc.scm (gcc-configure-flags-for-triplet): Add a clause for
targets starting with "powerpc64le-" or "powerpc-" which adds the
"--with-long-double-128" option.  This causes any package using this procedure
to be built using this new option on these architectures.  In particular, this
affects the gcc package and the gcc-final package, in addition to all the
other versions of GCC defined in (gnu packages gcc).
* gnu/packages/commencement.scm (gcc-boot0)[#:configure-flags]: Remove the
code that adds the "--with-long-double-128" configure option for all
architectures starting with "powerpc", since it is now redundant on the
architectures where it is needed. The gcc-boot0 package uses (and adds to) the
gcc package's configure options. This means that the above change in gcc.scm
is sufficient to ensure that the gcc-boot0 package's configure options will
include "--with-long-double-128" on powerpc64le and powerpc architectures.
Additionally, since the option is apparently not required on the big-endian
powerpc64 architecture, this change also has the nice effect of omitting the
option in that case.
* gnu/packages/cross-base.scm (cross-gcc-arguments)[#:configure-flags]: Remove
the code that adds the "--with-long-double-128" configure option for
powerpc64le, since it is now redundant. The cross-gcc-arguments procedure uses
(and adds to) the configure options of its xgcc argument (a package).  This
means that regardless of which gcc from gcc.scm is used as the xgcc, the above
change in gcc.scm is sufficient to ensure that the cross-gcc-arguments
procedure's configure options will include "--with-long-double-128" on the
powerpc64le and powerpc architectures.

3 files changed, 5 insertions, 13 deletions

diff --git a/gnu/packages/commencement.scm b/gnu/packages/commencement.scm
index d44d1dd3ca..af61512129 100644
--- a/gnu/packages/commencement.scm
+++ b/gnu/packages/commencement.scm
@@ -2733,13 +2733,6 @@ exec " gcc "/bin/" program
                            "--disable-shared"
                            "--enable-languages=c,c++"
 
-                           ;; On POWER9 (little endian) glibc needs the 128-bit
-                           ;; long double type.  32-bit PPC is affected by the
-                           ;; changes applied for powerpc64le.
-                           ,@(if (string-prefix? "powerpc" (boot-triplet))
-                               '("--with-long-double-128")
-                               '())
-
                            ;; libstdc++ cannot be built at this stage
                            ;; ("Link tests are not allowed after
                            ;; GCC_NO_EXECUTABLES.").
diff --git a/gnu/packages/cross-base.scm b/gnu/packages/cross-base.scm
index 926b00ccdf..ced226ef34 100644
--- a/gnu/packages/cross-base.scm
+++ b/gnu/packages/cross-base.scm
@@ -153,12 +153,6 @@ base compiler and using LIBC (which may be either a libc package or #f.)"
                                "--disable-decimal-float" ;would need libc
                                "--disable-libcilkrts"
 
-                              ,@(if (string-prefix? "powerpc64le-" target)
-                                   ;; On POWER9 (little endian) glibc needs
-                                   ;; the 128-bit long double type.
-                                   '("--with-long-double-128")
-                                   '())
-
                                ;; When target is any OS other than 'none' these
                                ;; libraries will fail if there is no libc
                                ;; present. See
diff --git a/gnu/packages/gcc.scm b/gnu/packages/gcc.scm
index 24a4b42000..c7fcb22693 100644
--- a/gnu/packages/gcc.scm
+++ b/gnu/packages/gcc.scm
@@ -79,6 +79,11 @@ where the OS part is overloaded to denote a specific ABI---into GCC
          ;; Cilk has been removed from GCC 8 anyway.
          '("--disable-libcilkrts"))
 
+        ;; glibc needs the 128-bit long double type on these architectures.
+        ((or (string-prefix? "powerpc64le-" target)
+             (string-prefix? "powerpc-" target))
+         '("--with-long-double-128"))
+
         (else
          ;; TODO: Add `arm.*-gnueabi', etc.
          '())))