Imported gcc-4.4.3

[msp430-gcc.git] / gcc / config / i386 / crtprec.c

diff --git a/gcc/config/i386/crtprec.c b/gcc/config/i386/crtprec.c
new file mode 100644 (file)
index 0000000..4f42a8f
--- /dev/null
+++ b/gcc/config/i386/crtprec.c
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2007, 2009 Free Software Foundation, Inc.
+ *
+ * This file 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, or (at your option) any
+ * later version.
+ * 
+ * This file 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/>.
+ */
+
+#if __PREC == 32
+ #define X87CW         (0 << 8)        /* Single precision (24 bits) */
+#elif __PREC == 64
+ #define X87CW         (2 << 8)        /* Double precision (53 bits) */
+#elif __PREC == 80
+ #define X87CW         (3 << 8)        /* Extended precision (64 bits) */
+#else
+ #error "Wrong precision requested."
+#endif
+
+#define X87CW_PCMASK   (3 << 8)
+
+static void __attribute__((constructor))
+set_precision (void)
+{
+  unsigned short int cwd;
+
+  asm volatile ("fstcw\t%0" : "=m" (cwd));
+
+  cwd &= ~X87CW_PCMASK;
+  cwd |= X87CW;
+
+  asm volatile ("fldcw\t%0" : : "m" (cwd));
+}