This patch renames the configure switches to be explicit that they are for the
PowerPC, and that they are temporary. I would hope by the time GCC 7 exits
stage1 that these switches will be removed, but having them now will allow us
to move to LRA and __float128 in an orderly fashion.
I built a bootstrap compiler using the --enable-powerpc-lra option, and it ran
fine. There were two additional tests that generate different code with -mlra
and now fail. These will be fixed in later patches.
I also built a C only compiler using the --enable-powerpc-float128 option
(disabling libquadmath and bootstrap), and the C tests looked fine.
Can I install these patches in the trunk?
2016-07-20 Michael Meissner <meiss...@linux.vnet.ibm.com>
* doc/install.texi (Configuration): Document PowerPC specific
configuration options --enable-powerpc-lra and
--enable-powerpc-float128.
* configure.ac: Add support for the configuration option
--enable-powerpc-lra to enable the use of the LRA register
allocator by default. Add support for the configuration option
--enable-powerpc-float128 to enable the use of the __float128 type
in PowerPC Linux systems.
* configure: Regenerate.
* config.gcc (powerpc*-*-linux*): Add --enable-powerpc-lra and
--enable-powerpc-float128 support.
* config/rs6000/rs6000.c (rs6000_option_override_internal): Add
support for --enable-powerpc-lra and --enable-powerpc-float128.
--
Michael Meissner, IBM
IBM, M/S 2506R, 550 King Street, Littleton, MA 01460-6245, USA
email: meiss...@linux.vnet.ibm.com, phone: +1 (978) 899-4797
Index: gcc/config/rs6000/rs6000.c
===================================================================
--- gcc/config/rs6000/rs6000.c
(.../svn+ssh://meiss...@gcc.gnu.org/svn/gcc/trunk/gcc/config/rs6000)
(revision 238445)
+++ gcc/config/rs6000/rs6000.c (.../gcc/config/rs6000) (working copy)
@@ -4306,6 +4306,17 @@ rs6000_option_override_internal (bool gl
rs6000_isa_flags &= ~OPTION_MASK_P9_DFORM_SCALAR;
}
+ /* Enable LRA if the compiler was configured with --enable-lra. */
+#ifdef ENABLE_LRA
+ if ((rs6000_isa_flags_explicit & OPTION_MASK_LRA) == 0)
+ {
+ if (ENABLE_LRA)
+ rs6000_isa_flags |= OPTION_MASK_LRA;
+ else
+ rs6000_isa_flags &= ~OPTION_MASK_LRA;
+ }
+#endif
+
/* There have been bugs with -mvsx-timode that don't show up with -mlra,
but do show up with -mno-lra. Given -mlra will become the default once
PR 69847 is fixed, turn off the options with problems by default if
@@ -4372,6 +4383,17 @@ rs6000_option_override_internal (bool gl
}
}
+ /* Enable FLOAT128 if the compiler was configured with --enable-float128. */
+#ifdef ENABLE_FLOAT128
+ if (TARGET_VSX && (rs6000_isa_flags_explicit & OPTION_MASK_FLOAT128) == 0)
+ {
+ if (ENABLE_FLOAT128)
+ rs6000_isa_flags |= OPTION_MASK_FLOAT128;
+ else
+ rs6000_isa_flags &= ~(OPTION_MASK_FLOAT128 | OPTION_MASK_FLOAT128_HW);
+ }
+#endif
+
/* __float128 requires VSX support. */
if (TARGET_FLOAT128 && !TARGET_VSX)
{
Index: gcc/doc/install.texi
===================================================================
--- gcc/doc/install.texi
(.../svn+ssh://meiss...@gcc.gnu.org/svn/gcc/trunk/gcc/doc) (revision
238445)
+++ gcc/doc/install.texi (.../gcc/doc) (working copy)
@@ -1661,6 +1661,35 @@ Using the GNU Compiler Collection (GCC)}
See ``RS/6000 and PowerPC Options'' in the main manual
@end ifhtml
+@item --enable-powerpc-lra
+This option enables @option{-mlra} by default for powerpc-linux. This
+switch is a temporary configuration switch that is intended to allow
+for the transition from the reload register allocator to the newer lra
+register allocator. When the transition is complete, this switch
+may be deleted.
+@ifnothtml
+@xref{RS/6000 and PowerPC Options,, RS/6000 and PowerPC Options, gcc,
+Using the GNU Compiler Collection (GCC)},
+@end ifnothtml
+@ifhtml
+See ``RS/6000 and PowerPC Options'' in the main manual
+@end ifhtml
+
+@item --enable-powerpc-float128
+This option enables @option{-mfloat128} by default for powerpc-linux.
+This switch is a temporary configuation switch that is intended to
+allow the PowerPC GCC developers to work on implementing library
+support for PowerPC IEEE 128-bit floating point functions. When the
+standard GCC libraries are enhanced to support @code{__float128} by
+default, this switch may be deleted.
+@ifnothtml
+@xref{RS/6000 and PowerPC Options,, RS/6000 and PowerPC Options, gcc,
+Using the GNU Compiler Collection (GCC)},
+@end ifnothtml
+@ifhtml
+See ``RS/6000 and PowerPC Options'' in the main manual
+@end ifhtml
+
@item --enable-default-ssp
Turn on @option{-fstack-protector-strong} by default.
