Added fegetround() and fesetround(), disabled special SSE support for the latter, though.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@16835 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/system/libroot/posix/glibc/arch/x86/Jamfile

@@ -94,6 +94,8 @@ local genericSources =
 MergeObject posix_gnu_arch_$(TARGET_ARCH)_other.o :
 	add_n.S
 	addmul_1.S
+	fegetround.c
+	fesetround.c
 	fraiseexcpt.c
 	ldbl2mpn.c
 	mpa.c mpatan.c mpatan2.c mptan.c

src/system/libroot/posix/glibc/arch/x86/fegetround.c

@@ -0,0 +1,31 @@
+/* Return current rounding direction.
+   Copyright (C) 1997 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <[email protected]>, 1997.
+
+   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
+fegetround (void)
+{
+  int cw;
+
+  __asm__ ("fnstcw %0" : "=m" (*&cw));
+
+  return cw & 0xc00;
+}

src/system/libroot/posix/glibc/arch/x86/fesetround.c

@@ -0,0 +1,54 @@
+/* Set current rounding direction.
+   Copyright (C) 1997, 2003, 2004, 2005 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <[email protected]>, 1997.
+
+   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>
+#include <unistd.h>
+
+int
+fesetround (int round)
+{
+  unsigned short int cw;
+
+  if ((round & ~0xc00) != 0)
+    /* ROUND is no valid rounding mode.  */
+    return 1;
+
+  __asm__ ("fnstcw %0" : "=m" (*&cw));
+  cw &= ~0xc00;
+  cw |= round;
+  __asm__ ("fldcw %0" : : "m" (*&cw));
+
+// TODO: temporarily disabled
+#if 0
+  /* If the CPU supports SSE we set the MXCSR as well.  */
+  if ((GLRO(dl_hwcap) & HWCAP_I386_XMM) != 0)
+    {
+      unsigned int xcw;
+
+      __asm__ ("stmxcsr %0" : "=m" (*&xcw));
+      xcw &= ~0x6000;
+      xcw |= round << 3;
+      __asm__ ("ldmxcsr %0" : : "m" (*&xcw));
+    }
+#endif
+
+  return 0;
+}
+libm_hidden_def (fesetround)