Fix sin, sincos missing underflows (bug 16526, bug 16538).

[thirdparty/glibc.git] / sysdeps / ieee754 / ldbl-128ibm / k_sincosl.c

diff --git a/sysdeps/ieee754/ldbl-128ibm/k_sincosl.c b/sysdeps/ieee754/ldbl-128ibm/k_sincosl.c
index f831e3f1f380abc21eb5b5f3284e549e4cf1d966..0a76e1c7e79614285f5950c2efd2d5296f315f2e 100644 (file)
--- a/sysdeps/ieee754/ldbl-128ibm/k_sincosl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/k_sincosl.c
@@ -17,6 +17,7 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
+#include <float.h>
 #include <math.h>
 #include <math_private.h>
 
@@ -112,12 +113,19 @@ __kernel_sincosl(long double x, long double y, long double *sinx, long double *c
       /* Argument is small enough to approximate it by a Chebyshev
         polynomial of degree 16(17).  */
       if (tix < 0x3c600000)            /* |x| < 2^-57 */
-       if (!((int)x))                  /* generate inexact */
-         {
-           *sinx = x;
-           *cosx = ONE;
-           return;
-         }
+       {
+         if (fabsl (x) < LDBL_MIN)
+           {
+             long double force_underflow = x * x;
+             math_force_eval (force_underflow);
+           }
+         if (!((int)x))                        /* generate inexact */
+           {
+             *sinx = x;
+             *cosx = ONE;
+             return;
+           }
+       }
       z = x * x;
       *sinx = x + (x * (z*(SIN1+z*(SIN2+z*(SIN3+z*(SIN4+
                        z*(SIN5+z*(SIN6+z*(SIN7+z*SIN8)))))))));