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-rw-r--r--libgcc/config/i386/crtprec.c47
1 files changed, 47 insertions, 0 deletions
diff --git a/libgcc/config/i386/crtprec.c b/libgcc/config/i386/crtprec.c
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index 00000000000..4f42a8fa1c1
--- /dev/null
+++ b/libgcc/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));
+}