Make strtod respect the rounding mode (bug 14518).

1 files changed, 124 insertions, 0 deletions

diff --git a/sysdeps/generic/get-rounding-mode.h b/sysdeps/generic/get-rounding-mode.h
new file mode 100644
index 0000000000..0ecaddd7bf
--- /dev/null
+++ b/sysdeps/generic/get-rounding-mode.h
@@ -0,0 +1,124 @@
+/* Determine floating-point rounding mode within libc.  Generic version.
+   Copyright (C) 2012 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, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _GET_ROUNDING_MODE_H
+#define _GET_ROUNDING_MODE_H	1
+
+#include <fpu_control.h>
+
+/* Define values for FE_* modes not defined for this architecture.  */
+#ifdef FE_DOWNWARD
+# define ORIG_FE_DOWNWARD FE_DOWNWARD
+#else
+# define ORIG_FE_DOWNWARD 0
+#endif
+#ifdef FE_TONEAREST
+# define ORIG_FE_TONEAREST FE_TONEAREST
+#else
+# define ORIG_FE_TONEAREST 0
+#endif
+#ifdef FE_TOWARDZERO
+# define ORIG_FE_TOWARDZERO FE_TOWARDZERO
+#else
+# define ORIG_FE_TOWARDZERO 0
+#endif
+#ifdef FE_UPWARD
+# define ORIG_FE_UPWARD FE_UPWARD
+#else
+# define ORIG_FE_UPWARD 0
+#endif
+#define FE_CONSTRUCT_DISTINCT_VALUE(X, Y, Z) \
+  ((((X) & 1) | ((Y) & 2) | ((Z) & 4)) ^ 7)
+#ifndef FE_DOWNWARD
+# define FE_DOWNWARD FE_CONSTRUCT_DISTINCT_VALUE (ORIG_FE_TONEAREST,	\
+						  ORIG_FE_TOWARDZERO,	\
+						  ORIG_FE_UPWARD)
+#endif
+#ifndef FE_TONEAREST
+# define FE_TONEAREST FE_CONSTRUCT_DISTINCT_VALUE (FE_DOWNWARD,		\
+						   ORIG_FE_TOWARDZERO,	\
+						   ORIG_FE_UPWARD)
+#endif
+#ifndef FE_TOWARDZERO
+# define FE_TOWARDZERO FE_CONSTRUCT_DISTINCT_VALUE (FE_DOWNWARD,	\
+						    FE_TONEAREST,	\
+						    ORIG_FE_UPWARD)
+#endif
+#ifndef FE_UPWARD
+# define FE_UPWARD FE_CONSTRUCT_DISTINCT_VALUE (FE_DOWNWARD,	\
+						FE_TONEAREST,	\
+						FE_TOWARDZERO)
+#endif
+
+/* Return the floating-point rounding mode.  */
+
+static inline int
+get_rounding_mode (void)
+{
+#if (defined _FPU_RC_DOWN			\
+     || defined _FPU_RC_NEAREST			\
+     || defined _FPU_RC_ZERO			\
+     || defined _FPU_RC_UP)
+  fpu_control_t fc;
+  const fpu_control_t mask = (0
+# ifdef _FPU_RC_DOWN
+			      | _FPU_RC_DOWN
+# endif
+# ifdef _FPU_RC_NEAREST
+			      | _FPU_RC_NEAREST
+# endif
+# ifdef _FPU_RC_ZERO
+			      | _FPU_RC_ZERO
+# endif
+# ifdef _FPU_RC_UP
+			      | _FPU_RC_UP
+# endif
+			      );
+
+  _FPU_GETCW (fc);
+  switch (fc & mask)
+    {
+# ifdef _FPU_RC_DOWN
+    case _FPU_RC_DOWN:
+      return FE_DOWNWARD;
+# endif
+
+# ifdef _FPU_RC_NEAREST
+    case _FPU_RC_NEAREST:
+      return FE_TONEAREST;
+# endif
+
+# ifdef _FPU_RC_ZERO
+    case _FPU_RC_ZERO:
+      return FE_TOWARDZERO;
+# endif
+
+# ifdef _FPU_RC_UP
+    case _FPU_RC_UP:
+      return FE_UPWARD;
+# endif
+
+    default:
+      abort ();
+    }
+#else
+  return FE_TONEAREST;
+#endif
+}
+
+#endif /* get-rounding-mode.h */