Fix ldbl-96 hypotl of subnormals (bug 15529).

diff --git a/ChangeLog b/ChangeLog
index bddd4d5..6c5111c 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2013-05-24  Joseph Myers  <joseph@codesourcery.com>
 
+       [BZ #15529]
+       * sysdeps/ieee754/ldbl-96/e_hypotl.c (__ieee754_hypotl): Set high
+       bit of mantissa of 2^16382.
+       * math/libm-test.inc (hypot_test_data): Add more tests.
+
        * math/libm-test.inc: Add drem and pow10 to list of tested
        functions.
        (pow10_test): New function.

diff --git a/NEWS b/NEWS
index a9377eb..c25b62e 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -18,7 +18,8 @@ Version 2.18
   15287, 15304, 15305, 15307, 15309, 15327, 15330, 15335, 15336, 15337,
   15339, 15342, 15346, 15359, 15361, 15366, 15380, 15381, 15394, 15395,
   15405, 15406, 15409, 15416, 15418, 15419, 15423, 15424, 15426, 15429,
-  15441, 15442, 15448, 15480, 15485, 15488, 15490, 15493, 15497, 15506.
+  15441, 15442, 15448, 15480, 15485, 15488, 15490, 15493, 15497, 15506,
+  15529.
 
 * CVE-2013-0242 Buffer overrun in regexp matcher has been fixed (Bugzilla
   #15078).

diff --git a/math/libm-test.inc b/math/libm-test.inc
index 91af668..7a6bf09 100644 (file)
--- a/math/libm-test.inc
+++ b/math/libm-test.inc
@@ -9387,6 +9387,19 @@ static const struct test_ff_f_data hypot_test_data[] =
 #if defined TEST_LDOUBLE && LDBL_MAX_EXP >= 16384 && !defined TEST_INLINE
     TEST_ff_f (hypot, 0x3p16381L, 0x4p16381L, 0x5p16381L),
 #endif
+
+    TEST_ff_f (hypot, 0x1p-149L, 0x1p-149L, 1.9817352931807469938024533350782879785095e-45L, UNDERFLOW_EXCEPTION_FLOAT),
+
+#ifndef TEST_FLOAT
+    TEST_ff_f (hypot, 0x1p-1074L, 0x1p-1074L, 6.9871433705131320800651344656990806305791e-324L, UNDERFLOW_EXCEPTION_DOUBLE),
+#endif
+
+#if defined TEST_LDOUBLE && LDBL_MIN_EXP <= -16381 && !defined TEST_INLINE
+    TEST_ff_f (hypot, 0x1p-16445L, 0x1p-16445L, 5.1550906155442528702558159159596215039925e-4951L, UNDERFLOW_EXCEPTION),
+# if LDBL_MANT_DIG >= 113
+    TEST_ff_f (hypot, 0x1p-16494L, 0x1p-16494L, 9.1572804726500807075521065242888978445857e-4966L, UNDERFLOW_EXCEPTION),
+# endif
+#endif
   };
 
 static void

diff --git a/sysdeps/ieee754/ldbl-96/e_hypotl.c b/sysdeps/ieee754/ldbl-96/e_hypotl.c
index 306f929..7895488 100644 (file)
--- a/sysdeps/ieee754/ldbl-96/e_hypotl.c
+++ b/sysdeps/ieee754/ldbl-96/e_hypotl.c
@@ -85,7 +85,7 @@ long double __ieee754_hypotl(long double x, long double y)
                u_int32_t high,low;
                GET_LDOUBLE_WORDS(exp,high,low,b);
                if((high|low)==0) return a;
-               SET_LDOUBLE_WORDS(t1, 0x7ffd, 0, 0);    /* t1=2^16382 */
+               SET_LDOUBLE_WORDS(t1, 0x7ffd, 0x80000000, 0); /* t1=2^16382 */
                b *= t1;
                a *= t1;
                k -= 16382;