3 files changed, 89 insertions, 1 deletions

diff --git a/sysdeps/powerpc/fpu/round_to_integer.h b/sysdeps/powerpc/fpu/round_to_integer.h
index ff77dde394..b318e37190 100644
--- a/sysdeps/powerpc/fpu/round_to_integer.h
+++ b/sysdeps/powerpc/fpu/round_to_integer.h
@@ -24,7 +24,8 @@
 enum round_mode
 {
   CEIL,
-  FLOOR
+  FLOOR,
+  ROUND
 };
 
 static inline void
@@ -35,6 +36,7 @@ set_fenv_mode (enum round_mode mode)
   {
   case CEIL:  rmode = FE_UPWARD; break;
   case FLOOR: rmode = FE_DOWNWARD; break;
+  case ROUND: rmode = FE_TOWARDZERO; break;
   default:    rmode = FE_TONEAREST; break;
   }
   __fesetround_inline_nocheck (rmode);
@@ -57,12 +59,24 @@ round_to_integer_float (enum round_mode mode, float x)
   set_fenv_mode (mode);
   if (x > 0.0)
     {
+      /* IEEE 1003.1 round function.  IEEE specifies "round to the nearest
+	 integer value, rounding halfway cases away from zero, regardless of
+	 the current rounding mode."  However PowerPC Architecture defines
+	 "Round to Nearest" as "Choose the best approximation. In case of a
+	 tie, choose the one that is even (least significant bit o).".
+	 So we can't use the PowerPC "Round to Nearest" mode. Instead we set
+	 "Round toward Zero" mode and round by adding +-0.5 before rounding
+	 to the integer value.  */
+      if (mode == ROUND)
+	r += 0.5f;
       r += 0x1p+23;
       r -= 0x1p+23;
       r = fabs (r);
     }
   else if (x < 0.0)
     {
+      if (mode == ROUND)
+	r -= 0.5f;
       r -= 0x1p+23;
       r += 0x1p+23;
       r = -fabs (r);
@@ -89,12 +103,16 @@ round_to_integer_double (enum round_mode mode, double x)
   set_fenv_mode (mode);
   if (x > 0.0)
     {
+      if (mode == ROUND)
+	r += 0.5;
       r += 0x1p+52;
       r -= 0x1p+52;
       r = fabs (r);
     }
   else if (x < 0.0)
     {
+      if (mode == ROUND)
+	r -= 0.5;
       r -= 0x1p+52;
       r += 0x1p+52;
       r = -fabs (r);
diff --git a/sysdeps/powerpc/fpu/s_round.c b/sysdeps/powerpc/fpu/s_round.c
new file mode 100644
index 0000000000..cd105567ef
--- /dev/null
+++ b/sysdeps/powerpc/fpu/s_round.c
@@ -0,0 +1,35 @@
+/* Largest integral value not greater than argument.  PowerPC version.
+   Copyright (C) 2019 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/>.  */
+
+#define NO_MATH_REDIRECT
+#include <math.h>
+#include <libm-alias-double.h>
+#include <round_to_integer.h>
+
+double
+__round (double x)
+{
+#ifdef _ARCH_PWR5X
+  return __builtin_round (x);
+#else
+  return round_to_integer_double (ROUND, x);
+#endif
+}
+#ifndef __round
+libm_alias_double (__round, round)
+#endif
diff --git a/sysdeps/powerpc/fpu/s_roundf.c b/sysdeps/powerpc/fpu/s_roundf.c
new file mode 100644
index 0000000000..418062adba
--- /dev/null
+++ b/sysdeps/powerpc/fpu/s_roundf.c
@@ -0,0 +1,35 @@
+/* Smallest integral value not less than argument.  PowerPC version.
+   Copyright (C) 2019 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/>.  */
+
+#define NO_MATH_REDIRECT
+#include <math.h>
+#include <libm-alias-float.h>
+#include <round_to_integer.h>
+
+float
+__roundf (float x)
+{
+#ifdef _ARCH_PWR5X
+  return __builtin_roundf (x);
+#else
+  return round_to_integer_float (ROUND, x);
+#endif
+}
+#ifndef __roundf
+libm_alias_float (__round, round)
+#endif