fenv.c: New file.

	* config/x86/fenv.c: New file.

From-SVN: r204634

libatomic/ChangeLog

+2013-11-10  Uros Bizjak  <ubizjak@gmail.com>
+
+	* config/x86/fenv.c: New file.
+
 2013-11-07  Joseph Myers  <joseph@codesourcery.com>
 
 	* fenv.c: New file.

libatomic/config/x86/fenv.c

+/* Copyright (C) 2013 Free Software Foundation, Inc.
+
+   This file is part of the GNU Atomic Library (libatomic).
+
+   Libatomic is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   Libatomic 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 General Public License for
+   more details.
+
+   Under Section 7 of GPL version 3, you are granted additional
+   permissions described in the GCC Runtime Library Exception, version
+   3.1, as published by the Free Software Foundation.
+
+   You should have received a copy of the GNU General Public License and
+   a copy of the GCC Runtime Library Exception along with this program;
+   see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include "libatomic_i.h"
+
+#define FE_INVALID	0x01
+#define FE_DENORM	0x02
+#define FE_DIVBYZERO	0x04
+#define FE_OVERFLOW	0x08
+#define FE_UNDERFLOW	0x10
+#define FE_INEXACT	0x20
+
+struct fenv
+{
+  unsigned short int __control_word;
+  unsigned short int __unused1;
+  unsigned short int __status_word;
+  unsigned short int __unused2;
+  unsigned short int __tags;
+  unsigned short int __unused3;
+  unsigned int __eip;
+  unsigned short int __cs_selector;
+  unsigned int __opcode:11;
+  unsigned int __unused4:5;
+  unsigned int __data_offset;
+  unsigned short int __data_selector;
+  unsigned short int __unused5;
+};
+
+/* Raise the supported floating-point exceptions from EXCEPTS.  Other
+   bits in EXCEPTS are ignored.  */
+
+void
+__atomic_feraiseexcept (int excepts)
+{
+  if (excepts & FE_INVALID)
+    {
+      float f = 0.0f;
+#ifdef __x86_64__
+      volatile float r __attribute__ ((unused));
+      asm volatile ("%vdivss\t{%0, %d0|%d0, %0}" : "+x" (f));
+      r = f; /* Needed to trigger exception.   */
+#else
+      asm volatile ("fdiv\t{%y0, %0|%0, %y0}" : "+t" (f));
+      /* No need for fwait, exception is triggered by emitted fstp.  */
+#endif
+    }
+  if (excepts & FE_DENORM)
+    {
+      struct fenv temp;
+      asm volatile ("fnstenv\t%0" : "=m" (temp));
+      temp.__status_word |= FE_DENORM;
+      asm volatile ("fldenv\t%0" : : "m" (temp));
+      asm volatile ("fwait");
+    }
+  if (excepts & FE_DIVBYZERO)
+    {
+      float f = 1.0f, g = 0.0f;
+#ifdef __x86_64__
+      volatile float r __attribute__ ((unused));
+      asm volatile ("%vdivss\t{%1, %d0|%d0, %1}" : "+x" (f) : "xm" (g));
+      r = f; /* Needed to trigger exception.   */
+#else
+      asm volatile ("fdivs\t%1" : "+t" (f) : "m" (g));
+      /* No need for fwait, exception is triggered by emitted fstp.  */
+#endif
+    }
+  if (excepts & FE_OVERFLOW)
+    {
+      struct fenv temp;
+      asm volatile ("fnstenv\t%0" : "=m" (temp));
+      temp.__status_word |= FE_OVERFLOW;
+      asm volatile ("fldenv\t%0" : : "m" (temp));
+      asm volatile ("fwait");
+    }
+  if (excepts & FE_UNDERFLOW)
+    {
+      struct fenv temp;
+      asm volatile ("fnstenv\t%0" : "=m" (temp));
+      temp.__status_word |= FE_UNDERFLOW;
+      asm volatile ("fldenv\t%0" : : "m" (temp));
+      asm volatile ("fwait");
+    }
+  if (excepts & FE_INEXACT)
+    {
+      float f = 1.0f, g = 3.0f;
+#ifdef __x86_64__
+      volatile float r __attribute__ ((unused));
+      asm volatile ("%vdivss\t{%1, %d0|%d0, %1}" : "+x" (f) : "xm" (g));
+      r = f; /* Needed to trigger exception.   */
+#else
+      asm volatile ("fdivs\t%1" : "+t" (f) : "m" (g));
+      /* No need for fwait, exception is triggered by emitted fstp.  */
+#endif
+    }
+}