PowerPC: modf optimization

This patch implements modf/modff optimization for POWER by focus
on FP operations instead of relying in integer ones.
(backported from commit 3c0265394d9ffedff2b0de508602dc52e077ce5c)

This backport does not include the benchmark tests from the original
commit.

5 files changed, 118 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 8a23a3df00..3b1a5bc4a7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2013-04-23  Adhemerval Zanella  <azanella@linux.vnet.ibm.com>
+
+	* sysdeps/powerpc/power5/fpu/s_modf.c: New file: modf optimization for
+	POWER.
+	* sysdeps/powerpc/power5/fpu/s_modff.c: New file: modff optimization
+	for POWER.
+	* sysdeps/powerpc/powerpc64/power5/Implies: Add powerpc/power5 and
+	powerpc/power5/fpu folders.
+	* sysdeps/powerpc/powerpc32/power5/Implies: Likewise.
+
 2013-04-02  Adhemerval Zanella  <azanella@linux.vnet.ibm.com>
 
 	* sysdeps/powerpc/powerpc32/fpu/s_rint.S: Remove branch prediction
diff --git a/sysdeps/powerpc/power5/fpu/s_modf.c b/sysdeps/powerpc/power5/fpu/s_modf.c
new file mode 100644
index 0000000000..b45bf66169
--- /dev/null
+++ b/sysdeps/powerpc/power5/fpu/s_modf.c
@@ -0,0 +1,58 @@
+/* Copyright (C) 2013 Free Software Foundation, Inc.
+   This file is part of the GNU C Library
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <math.h>
+#include <math_private.h>
+#include <math_ldbl_opt.h>
+
+double
+__modf (double x, double *iptr)
+{
+  if (__builtin_isinf (x))
+    {
+      *iptr = x;
+      return __copysign (0.0, x);
+    }
+  else if (__builtin_isnan (x))
+    {
+      *iptr = NAN;
+      return NAN;
+    }
+
+  if (x >= 0.0)
+    {
+      *iptr = __floor (x);
+      return (x - *iptr);
+    }
+  else
+    {
+      *iptr = __ceil (x);
+      return (x - *iptr);
+    }
+}
+weak_alias (__modf, modf)
+#ifdef NO_LONG_DOUBLE
+strong_alias (__modf, __modfl)
+weak_alias (__modf, modfl)
+#endif
+#ifdef IS_IN_libm
+# if LONG_DOUBLE_COMPAT(libm, GLIBC_2_0)
+compat_symbol (libm, __modf, modfl, GLIBC_2_0);
+# endif
+#elif LONG_DOUBLE_COMPAT(libc, GLIBC_2_0)
+compat_symbol (libc, __modf, modfl, GLIBC_2_0);
+#endif
diff --git a/sysdeps/powerpc/power5/fpu/s_modff.c b/sysdeps/powerpc/power5/fpu/s_modff.c
new file mode 100644
index 0000000000..55759cde05
--- /dev/null
+++ b/sysdeps/powerpc/power5/fpu/s_modff.c
@@ -0,0 +1,46 @@
+/* Copyright (C) 2013 Free Software Foundation, Inc.
+   This file is part of the GNU C Library
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <math.h>
+#include <math_private.h>
+
+float
+__modff (float x, float *iptr)
+{
+  if (__builtin_isinff (x))
+    {
+      *iptr = x;
+      return __copysignf (0.0, x);
+    }
+  else if (__builtin_isnanf (x))
+    {
+      *iptr = NAN;
+      return NAN;
+    }
+
+  if (x >= 0.0)
+    {
+      *iptr = __floorf (x);
+      return (x - *iptr);
+    }
+  else
+    {
+      *iptr = __ceilf (x);
+      return (x - *iptr);
+    }
+}
+weak_alias (__modff, modff)
diff --git a/sysdeps/powerpc/powerpc32/power5/Implies b/sysdeps/powerpc/powerpc32/power5/Implies
index 17139bf21c..17949d41c5 100644
--- a/sysdeps/powerpc/powerpc32/power5/Implies
+++ b/sysdeps/powerpc/powerpc32/power5/Implies
@@ -1,2 +1,4 @@
+powerpc/power5/fpu
+powerpc/power5
 powerpc/powerpc32/power4/fpu
 powerpc/powerpc32/power4
diff --git a/sysdeps/powerpc/powerpc64/power5/Implies b/sysdeps/powerpc/powerpc64/power5/Implies
index bedb20b65c..b36831e287 100644
--- a/sysdeps/powerpc/powerpc64/power5/Implies
+++ b/sysdeps/powerpc/powerpc64/power5/Implies
@@ -1,2 +1,4 @@
+powerpc/power5/fpu
+powerpc/power5
 powerpc/powerpc64/power4/fpu
 powerpc/powerpc64/power4