Fix lround() loses precision

diff --git a/ChangeLog b/ChangeLog
index 6b12f3b..34e9e37 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2011-08-18  Paul Pluzhnikov  <ppluzhnikov@google.com>
+           Ian Lance Taylor  <iant@google.com>
+
+       * math/libm-test.inc (lround_test): New testcase.
+       * sysdeps/ieee754/dbl-64/s_lround.c (__lround): Don't lose precision.
+
 2011-09-08  Ulrich Drepper  <drepper@gmail.com>
 
        * Makefile: Remove support for automatic cvs check-ins.

diff --git a/math/libm-test.inc b/math/libm-test.inc
index c6ed7a3..301d4a8 100644 (file)
--- a/math/libm-test.inc
+++ b/math/libm-test.inc
@@ -4386,6 +4386,7 @@ lround_test (void)
   TEST_f_l (lround, 1073741824.01, 1073741824);
 # if LONG_MAX > 281474976710656
   TEST_f_l (lround, 281474976710656.025, 281474976710656);
+  TEST_f_l (llround, -3.65309740835E17, -365309740835000000);
 # endif
   TEST_f_l (lround, 2097152.5, 2097153);
   TEST_f_l (lround, -2097152.5, -2097153);

diff --git a/sysdeps/ieee754/dbl-64/s_lround.c b/sysdeps/ieee754/dbl-64/s_lround.c
index 4e1302a..a849997 100644 (file)
--- a/sysdeps/ieee754/dbl-64/s_lround.c
+++ b/sysdeps/ieee754/dbl-64/s_lround.c
@@ -51,7 +51,7 @@ __lround (double x)
   else if (j0 < (int32_t) (8 * sizeof (long int)) - 1)
     {
       if (j0 >= 52)
-       result = ((long int) i0 << (j0 - 20)) | (i1 << (j0 - 52));
+       result = ((long int) i0 << (j0 - 20)) | ((long int) i1 << (j0 - 52));
       else
        {
          u_int32_t j = i1 + (0x80000000 >> (j0 - 20));