Optimize powerpc*-*-linux* 32-bit classic hard/soft float 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 32-bit
classic hard-float and soft-float cases.  (e500 will be dealt with in
a separate patch which will need to add new features to t-hardfp and
t-softfp; this patch keeps the status quo for e500.)

For hard-float, while the functions in question are part of the libgcc
ABI there is no need for them to contain software floating point code:
no newly built code should use them, and if anything does use them
it's most efficient (space and speed) for them to pass straight
through to floating-point hardware instructions; this case is made to
use t-hardfp to achieve that.  For soft-float, direct use of soft-fp
functions for operations involving DImode or unsigned integers is more
efficient than using the libgcc2.c versions of those operations to
convert to operations on other types (which then end up calling
soft-fp functions for those other types, possibly more than once);
this case is thus stopped from using t-softfp-excl.  (A future patch
will stop the e500 cases from using t-softfp-excl as well.)

Tested with no regressions for crosses to powerpc-linux-gnu (soft
float and classic hard float); also checked that the same set of
symbols and versions is exported from shared libgcc before and after
the patch.

	* configure.ac (ppc_fp_type): Set variable on powerpc*-*-linux*.
	* configure: Regenerate.
	* config.host (powerpc*-*-linux*): Use $ppc_fp_type to determine
	additions to tmake_file.  Use t-hardfp-sfdf and t-hardfp instead
	of soft-fp for 32-bit classic hard float.  Do not use
	t-softfp-excl for soft float.

From-SVN: r216687

diff --git a/libgcc/ChangeLog b/libgcc/ChangeLog
index 14b0e364b3145f5116035f216a326e45c148cfd6..d1a3b7394da8b28b58ed81b6108f3c5914be925d 100644 (file)
--- a/libgcc/ChangeLog
+++ b/libgcc/ChangeLog
@@ -1,3 +1,12 @@
+2014-10-25  Joseph Myers  <joseph@codesourcery.com>
+
+       * configure.ac (ppc_fp_type): Set variable on powerpc*-*-linux*.
+       * configure: Regenerate.
+       * config.host (powerpc*-*-linux*): Use $ppc_fp_type to determine
+       additions to tmake_file.  Use t-hardfp-sfdf and t-hardfp instead
+       of soft-fp for 32-bit classic hard float.  Do not use
+       t-softfp-excl for soft float.
+
 2014-10-22  Joseph Myers  <joseph@codesourcery.com>
 
        * config.host (powerpc*-*-linux*): Only use soft-fp for 32-bit

diff --git a/libgcc/config.host b/libgcc/config.host
index 10c25f5384f4aa39ffeb65952fa5fe25c808d52a..d6c7df73bbfb50b72cacda81f4c9e60938405f1f 100644 (file)
--- a/libgcc/config.host
+++ b/libgcc/config.host
@@ -991,9 +991,23 @@ powerpc-*-rtems*)
        ;;
 powerpc*-*-linux*)
        tmake_file="${tmake_file} rs6000/t-ppccomm rs6000/t-savresfgpr rs6000/t-crtstuff rs6000/t-linux t-dfprules rs6000/t-ppc64-fp t-slibgcc-libgcc"
-       if test "${host_address}" = 32; then
+       case $ppc_fp_type in
+       64)
+               ;;
+       hard)
+               tmake_file="${tmake_file} t-hardfp-sfdf t-hardfp"
+               ;;
+       soft)
+               tmake_file="${tmake_file} t-softfp-sfdf t-softfp"
+               ;;
+       e500v1|e500v2)
                tmake_file="${tmake_file} t-softfp-sfdf t-softfp-excl t-softfp"
-       fi
+               ;;
+       *)
+               echo "Unknown ppc_fp_type $ppc_fp_type" 1>&2
+               exit 1
+               ;;
+       esac
        extra_parts="$extra_parts ecrti.o ecrtn.o ncrti.o ncrtn.o"
        md_unwind_header=rs6000/linux-unwind.h
        ;;

diff --git a/libgcc/configure b/libgcc/configure
index 19c4ed69b19603bb7c826f65d6c82c28c5ba313d..7a154db9de9bc59f7966b4e7ffad16973df2ade6 100644 (file)
--- a/libgcc/configure
+++ b/libgcc/configure
@@ -4376,6 +4376,29 @@ fi
 $as_echo "$libgcc_cv_mips_hard_float" >&6; }
 esac
 
+# Determine floating-point type for powerpc*-*-linux*.
+# Single-precision-only FPRs are not a supported configuration for
+# this target, so are not allowed for in this test.
+case ${host} in
+powerpc*-*-linux*)
+  cat > conftest.c <<EOF
+#ifdef __powerpc64__
+ppc_fp_type=64
+#elif defined _SOFT_FLOAT
+ppc_fp_type=soft
+#elif defined _SOFT_DOUBLE
+ppc_fp_type=e500v1
+#elif defined __NO_FPRS__
+ppc_fp_type=e500v2
+#else
+ppc_fp_type=hard
+#endif
+EOF
+eval `${CC-cc} -E conftest.c | grep ppc_fp_type=`
+rm -f conftest.c
+;;
+esac
+
 # Collect host-machine-specific information.
 . ${srcdir}/config.host
 

diff --git a/libgcc/configure.ac b/libgcc/configure.ac
index 72a21a97e797f88503c4f4bb1d6d5655764c5021..710f15a827967528c4910d9dfa5a1f8e1faa2fc8 100644 (file)
--- a/libgcc/configure.ac
+++ b/libgcc/configure.ac
@@ -320,6 +320,29 @@ mips*-*-*)
     [libgcc_cv_mips_hard_float=no])])
 esac
 
+# Determine floating-point type for powerpc*-*-linux*.
+# Single-precision-only FPRs are not a supported configuration for
+# this target, so are not allowed for in this test.
+case ${host} in
+powerpc*-*-linux*)
+  cat > conftest.c <<EOF
+#ifdef __powerpc64__
+ppc_fp_type=64
+#elif defined _SOFT_FLOAT
+ppc_fp_type=soft
+#elif defined _SOFT_DOUBLE
+ppc_fp_type=e500v1
+#elif defined __NO_FPRS__
+ppc_fp_type=e500v2
+#else
+ppc_fp_type=hard
+#endif
+EOF
+eval `${CC-cc} -E conftest.c | grep ppc_fp_type=`
+rm -f conftest.c
+;;
+esac
+
 # Collect host-machine-specific information.
 . ${srcdir}/config.host