From b58032ae6a34afc1887d9a6f3d05891d0d4fdbab Mon Sep 17 00:00:00 2001
From: Natanael Copa <natanael.copa@gmail.com>
Date: Sun, 28 Nov 2010 12:43:33 +0000
Subject: [PATCH] libm/x86_64: implement fesetround

from glibc
---
 libm/x86_64/Makefile.arch |   24 +++++++++++++++++++++++
 libm/x86_64/fesetround.c  |   46 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 70 insertions(+), 0 deletions(-)
 create mode 100644 libm/x86_64/Makefile.arch
 create mode 100644 libm/x86_64/fesetround.c

diff --git a/libm/x86_64/Makefile.arch b/libm/x86_64/Makefile.arch
new file mode 100644
index 0000000..e1be961
--- /dev/null
+++ b/libm/x86_64/Makefile.arch
@@ -0,0 +1,24 @@
+# Makefile for uClibc
+#
+# Copyright (C) 2000-2008 Erik Andersen <andersen@uclibc.org>
+#
+# Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+#
+# The routines included in this math library are derived from
+# glibc's libm.
+#
+
+ifeq ($(UCLIBC_HAS_FENV),y)
+libm_ARCH_SRC:=$(wildcard $(libm_ARCH_DIR)/*.c)
+libm_ARCH_OBJ:=$(patsubst $(libm_ARCH_DIR)/%.c,$(libm_ARCH_OUT)/%.o,$(libm_ARCH_SRC))
+endif
+
+libm_ARCH_OBJS:=$(libm_ARCH_OBJ)
+
+ifeq ($(DOPIC),y)
+libm-a-y+=$(libm_ARCH_OBJS:.o=.os)
+else
+libm-a-y+=$(libm_ARCH_OBJS)
+endif
+libm-so-y+=$(libm_ARCH_OBJS:.o=.os)
+
diff --git a/libm/x86_64/fesetround.c b/libm/x86_64/fesetround.c
new file mode 100644
index 0000000..3d2ef4c
--- /dev/null
+++ b/libm/x86_64/fesetround.c
@@ -0,0 +1,46 @@
+/* Set current rounding direction.
+   Copyright (C) 2001, 2005 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 Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <fenv.h>
+
+int
+fesetround (int round)
+{
+  unsigned short int cw;
+  int mxcsr;
+
+  if ((round & ~0xc00) != 0)
+    /* ROUND is no valid rounding mode.  */
+    return 1;
+
+  /* First set the x87 FPU.  */
+  __asm__ ("fnstcw %0" : "=m" (*&cw));
+  cw &= ~0xc00;
+  cw |= round;
+  __asm__ ("fldcw %0" : : "m" (*&cw));
+
+  /* And now the MSCSR register for SSE, the precision is at different bit
+     positions in the different units, we need to shift it 3 bits.  */
+  __asm__ ("stmxcsr %0" : "=m" (*&mxcsr));
+  mxcsr &= ~ 0x6000;
+  mxcsr |= round << 3;
+  __asm__ ("ldmxcsr %0" : : "m" (*&mxcsr));
+
+  return 0;
+}
-- 
1.7.3.2