Optimize powerpc*-*-linux* e500 hardfp/soft-fp use.

Continuing the cleanups of libgcc soft-fp configuration for
powerpc*-*-linux* in preparation for implementing
TARGET_ATOMIC_ASSIGN_EXPAND_FENV for soft-float and e500, this patch
optimizes the choice of which functions to build for the e500 cases.

For e500v2, use of hardfp is generally right, except that calls to
__unordsf2 and __unorddf2 are actually generated by GCC from
__builtin_isunordered and so they need to be implemented with soft-fp
to avoid recursively calling themselves.  For e500v1, hardfp is right
for SFmode (except for __unordsf2) but soft-fp for DFmode (and when
using soft-fp, as usual it's best for the conversions between DFmode
and integers all to come directly from soft-fp rather than some coming
from libgcc2.c).  Thus, new variables hardfp_exclusions and
softfp_extras are added that configurations using t-hardfp and
t-softfp can use to achieve the desired effect of selectively mixing
the two sources of functions.

Tested with no regressions for crosses to powerpc-linux-gnuspe (both
e500v1 and e500v2); also checked that the same set of symbols and
versions is exported from shared libgcc before and after the patch.

	* config/t-hardfp (hardfp_exclusions): Document new variable for
	user to define.
	(hardfp_func_list): Exclude functions from $(hardfp_exclusions).
	* config/t-softfp (softfp_extras): Document new variable for user
	to define.
	(softfp_func_list): Add functions from $(softfp_extras).
	* config/rs6000/t-e500v1-fp, config/rs6000/t-e500v2-fp: New files.
	* config.host (powerpc*-*-linux*): For e500v1, use
	rs6000/t-e500v1-fp and t-hardfp; do not use t-softfp-sfdf and
	t-softfp-excl.  For e500v2, use t-hardfp-sfdf, rs6000/t-e500v2-fp
	and t-hardfp; do not use t-softfp-sfdf and t-softfp-excl.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@216835 138bc75d-0d04-0410-961f-82ee72b054a4

2 files changed, 58 insertions, 0 deletions

diff --git a/libgcc/config/rs6000/t-e500v1-fp b/libgcc/config/rs6000/t-e500v1-fp
new file mode 100644
index 00000000000..c1f7a0c47bd
--- /dev/null
+++ b/libgcc/config/rs6000/t-e500v1-fp
@@ -0,0 +1,32 @@
+# Copyright (C) 2014 Free Software Foundation, Inc.
+
+# This file is part of GCC.
+
+# GCC is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+
+# GCC 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 General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3.  If not see
+# <http://www.gnu.org/licenses/>.
+
+# Use hardfp.c for SFmode (except __unordsf2), soft-fp for DFmode.
+# For SFmode, libgcc2.c functions are used where applicable; for
+# DFmode, they are excluded.
+hardfp_float_modes := sf
+hardfp_int_modes := si
+hardfp_extensions :=
+hardfp_truncations :=
+hardfp_exclusions := unordsf2
+softfp_float_modes := df
+softfp_int_modes := si di
+softfp_extensions := sfdf
+softfp_truncations := dfsf
+softfp_exclude_libgcc2 := n
+softfp_extras := unordsf2
diff --git a/libgcc/config/rs6000/t-e500v2-fp b/libgcc/config/rs6000/t-e500v2-fp
new file mode 100644
index 00000000000..636b28f0cc8
--- /dev/null
+++ b/libgcc/config/rs6000/t-e500v2-fp
@@ -0,0 +1,26 @@
+# Copyright (C) 2014 Free Software Foundation, Inc.
+
+# This file is part of GCC.
+
+# GCC is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+
+# GCC 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 General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3.  If not see
+# <http://www.gnu.org/licenses/>.
+
+# All operations except __unordsf2 and __unorddf2 can come from hardfp.c.
+hardfp_exclusions := unordsf2 unorddf2
+softfp_float_modes :=
+softfp_int_modes :=
+softfp_extensions :=
+softfp_truncations :=
+softfp_exclude_libgcc2 := n
+softfp_extras := unordsf2 unorddf2