Made rintf() actually work. It was completely broken (when s_rint.c

was compiled with -O) by the precision bug in the i386 version of
gcc (assignments and casts don't clip the precision).  E.g.,
rintf(12.3456789) was 12.125.

Avoid the same bug in rint().  It was only broken for the unusual
case when the i387 precision is 64 bits.  FreeBSD defaults to 53
bit precision to avoid problems like this, but the standard math
emulator always uses 64 bit precision.

2 files changed, 19 insertions, 6 deletions

diff --git a/lib/msun/src/s_rint.c b/lib/msun/src/s_rint.c
index 3476eeff4cad..81a13965bc28 100644
--- a/lib/msun/src/s_rint.c
+++ b/lib/msun/src/s_rint.c
@@ -11,7 +11,7 @@
  */
 
 #ifndef lint
-static char rcsid[] = "$Id: s_rint.c,v 1.1.1.1 1994/08/19 09:39:52 jkh Exp $";
+static char rcsid[] = "$Id: s_rint.c,v 1.2 1995/05/30 05:50:18 rgrimes Exp $";
 #endif
 
 /*
@@ -27,10 +27,17 @@ static char rcsid[] = "$Id: s_rint.c,v 1.1.1.1 1994/08/19 09:39:52 jkh Exp $";
 #include "math.h"
 #include "math_private.h"
 
+/*
+ * TWO23 is long double instead of double to avoid a bug in gcc.  Without
+ * this, gcc thinks that TWO23[sx]+x and w-TWO23[sx] already have double
+ * precision and doesn't clip them to double precision when they are
+ * assigned and returned.  Use long double even in the !__STDC__ case in
+ * case this is compiled with gcc -traditional.
+ */
 #ifdef __STDC__
-static const double
+static const long double
 #else
-static double
+static long double
 #endif
 TWO52[2]={
   4.50359962737049600000e+15, /* 0x43300000, 0x00000000 */
diff --git a/lib/msun/src/s_rintf.c b/lib/msun/src/s_rintf.c
index 4e77aab2391d..90a85a310b48 100644
--- a/lib/msun/src/s_rintf.c
+++ b/lib/msun/src/s_rintf.c
@@ -14,16 +14,22 @@
  */
 
 #ifndef lint
-static char rcsid[] = "$Id: s_rintf.c,v 1.1.1.1 1994/08/19 09:39:58 jkh Exp $";
+static char rcsid[] = "$Id: s_rintf.c,v 1.2 1995/05/30 05:50:21 rgrimes Exp $";
 #endif
 
 #include "math.h"
 #include "math_private.h"
 
+/*
+ * TWO23 is double instead of float to avoid a bug in gcc.  Without
+ * this, gcc thinks that TWO23[sx]+x and w-TWO23[sx] already have float
+ * precision and doesn't clip them to float precision when they are
+ * assigned and returned.
+ */
 #ifdef __STDC__
-static const float
+static const double
 #else
-static float
+static double
 #endif
 TWO23[2]={
   8.3886080000e+06, /* 0x4b000000 */