Fix lrint, llrint, lround, llround missing exceptions for MIPS (bug 16399).

For 32-bit MIPS and some other systems, various of the lrint, llrint,
lround, llround functions can be missing exceptions on overflow
because casts do not (in current GCC) result in the proper
exceptions.  In the MIPS case there are two problems here: MIPS I code
generation uses an assembler macro that doesn't raise exceptions,
while the libgcc conversions of floating-point values to long long
also do not raise "invalid" on all overflow cases (and can raise
spurious "inexact").

This patch adds support in the generic code (only the functions for
which this problem has actually been seen) for forcing the "invalid"
exception in the problem cases, and enables that support for the
affected MIPS cases.

Tested for MIPS; also tested for x86_64 and x86 that installed
stripped shared libraries are unchanged by this patch.

	[BZ #16399]
	* sysdeps/generic/fix-fp-int-convert-overflow.h: New file.
	* sysdeps/ieee754/dbl-64/s_llrint.c: Include <fenv.h>, <limits.h>
	and <fix-fp-int-convert-overflow.h>.
	(__llrint) [FE_INVALID]: Force FE_INVALID exception as needed if
	FIX_DBL_LLONG_CONVERT_OVERFLOW.
	* sysdeps/ieee754/dbl-64/s_llround.c: Include <fenv.h>, <limits.h>
	and <fix-fp-int-convert-overflow.h>.
	(__llround) [FE_INVALID]: Force FE_INVALID exception as needed if
	FIX_DBL_LLONG_CONVERT_OVERFLOW.
	* sysdeps/ieee754/dbl-64/s_lrint.c: Include
	<fix-fp-int-convert-overflow.h>.
	(__lrint) [FE_INVALID]: Force FE_INVALID exception as needed if
	FIX_DBL_LLONG_CONVERT_OVERFLOW.
	* sysdeps/ieee754/dbl-64/s_lround.c: Include
	<fix-fp-int-convert-overflow.h>.
	(__lround) [FE_INVALID]: Force FE_INVALID exception as needed if
	FIX_DBL_LLONG_CONVERT_OVERFLOW.
	* sysdeps/ieee754/flt-32/s_llrintf.c: Include <fenv.h>, <limits.h>
	and <fix-fp-int-convert-overflow.h>.
	(__llrintf) [FE_INVALID]: Force FE_INVALID exception as needed if
	FIX_DBL_LLONG_CONVERT_OVERFLOW.
	* sysdeps/ieee754/flt-32/s_llroundf.c: Include <fenv.h>,
	<limits.h> and <fix-fp-int-convert-overflow.h>.
	(__llroundf) [FE_INVALID]: Force FE_INVALID exception as needed if
	FIX_DBL_LLONG_CONVERT_OVERFLOW.
	* sysdeps/ieee754/flt-32/s_lrintf.c: Include <fenv.h>, <limits.h>
	and <fix-fp-int-convert-overflow.h>.
	(__lrintf) [FE_INVALID]: Force FE_INVALID exception as needed if
	FIX_DBL_LLONG_CONVERT_OVERFLOW.
	* sysdeps/ieee754/flt-32/s_lroundf.c: Include <fenv.h>, <limits.h>
	and <fix-fp-int-convert-overflow.h>.
	(__lroundf) [FE_INVALID]: Force FE_INVALID exception as needed if
	FIX_DBL_LLONG_CONVERT_OVERFLOW.
	* sysdeps/mips/mips32/fpu/fix-fp-int-convert-overflow.h: New file.

1 files changed, 13 insertions, 2 deletions

diff --git a/sysdeps/ieee754/flt-32/s_lroundf.c b/sysdeps/ieee754/flt-32/s_lroundf.c
index f20352a..da3551c 100644
--- a/sysdeps/ieee754/flt-32/s_lroundf.c
+++ b/sysdeps/ieee754/flt-32/s_lroundf.c
@@ -17,9 +17,12 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
+#include <fenv.h>
+#include <limits.h>
 #include <math.h>
 
 #include <math_private.h>
+#include <fix-fp-int-convert-overflow.h>
 
 
 long int
@@ -51,8 +54,16 @@ __lroundf (float x)
     }
   else
     {
-      /* The number is too large.  It is left implementation defined
-	 what happens.  */
+#ifdef FE_INVALID
+      /* The number is too large.  Unless it rounds to LONG_MIN,
+	 FE_INVALID must be raised and the return value is
+	 unspecified.  */
+      if (FIX_FLT_LONG_CONVERT_OVERFLOW && x != (float) LONG_MIN)
+	{
+	  feraiseexcept (FE_INVALID);
+	  return sign == 1 ? LONG_MAX : LONG_MIN;
+	}
+#endif
       return (long int) x;
     }