Fix strtod rounding of half the least subnormal (bug 16151).

diff --git a/ChangeLog b/ChangeLog
index f1e09b1..c05a9c6 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2013-11-13  Joseph Myers  <joseph@codesourcery.com>
+
+       [BZ #16151]
+       * stdlib/strtod_l.c (round_and_return): Do not consider
+       retval[RETURN_LIBM_SIZE - 1] when determining more_bits for an
+       exponent one less than half the least subnormal exponent.
+       * stdlib/test-strtod-round-data: Add more tests.
+       * stdlib/tst-strtod-round.c (tests): Regenerated.
+
 2013-11-13  Adhemerval Zanella  <azanella@linux.vnet.ibm.com>
 
        [BZ #14143]

diff --git a/NEWS b/NEWS
index 3b44124..c6ec272 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -17,7 +17,8 @@ Version 2.19
   15825, 15844, 15847, 15849, 15855, 15856, 15857, 15859, 15867, 15886,
   15887, 15890, 15892, 15893, 15895, 15897, 15905, 15909, 15917, 15919,
   15921, 15923, 15939, 15948, 15963, 15966, 15985, 15988, 16032, 16034,
-  16036, 16037, 16041, 16071, 16072, 16074, 16078, 16112, 16150, 16153.
+  16036, 16037, 16041, 16071, 16072, 16074, 16078, 16112, 16150, 16151,
+  16153.
 
 * CVE-2012-4412 The strcoll implementation caches indices and rules for
   large collation sequences to optimize multiple passes.  This cache

diff --git a/stdlib/strtod_l.c b/stdlib/strtod_l.c
index 90541cd..c1c5c0d 100644 (file)
--- a/stdlib/strtod_l.c
+++ b/stdlib/strtod_l.c
@@ -228,7 +228,7 @@ round_and_return (mp_limb_t *retval, intmax_t exponent, int negative,
 
          round_limb = retval[RETURN_LIMB_SIZE - 1];
          round_bit = (MANT_DIG - 1) % BITS_PER_MP_LIMB;
-         for (i = 0; i < RETURN_LIMB_SIZE; ++i)
+         for (i = 0; i < RETURN_LIMB_SIZE - 1; ++i)
            more_bits |= retval[i] != 0;
          MPN_ZERO (retval, RETURN_LIMB_SIZE);
        }

diff --git a/stdlib/tst-strtod-round-data b/stdlib/tst-strtod-round-data
index 86d460e..a6c3767 100644 (file)
--- a/stdlib/tst-strtod-round-data
+++ b/stdlib/tst-strtod-round-data
@@ -109,3 +109,11 @@
 -0x0.7p-1074
 -0x0.7p-16445
 -0x0.7p-16494
+0x1p-150
+0x1p-1075
+0x1p-16446
+0x1p-16495
+-0x1p-150
+-0x1p-1075
+-0x1p-16446
+-0x1p-16495

diff --git a/stdlib/tst-strtod-round.c b/stdlib/tst-strtod-round.c
index 9a44026..e7aaed1 100644 (file)
--- a/stdlib/tst-strtod-round.c
+++ b/stdlib/tst-strtod-round.c
@@ -7535,6 +7535,294 @@ static const struct test tests[] = {
        -0x0p+0L,
        -0x0p+0L,
        -0x0p+0L),
+  TEST ("0x1p-150",
+       false,
+       0x0p+0f,
+       0x0p+0f,
+       0x0p+0f,
+       0x8p-152f,
+       true,
+       0x4p-152,
+       0x4p-152,
+       0x4p-152,
+       0x4p-152,
+       true,
+       0x4p-152L,
+       0x4p-152L,
+       0x4p-152L,
+       0x4p-152L,
+       true,
+       0x4p-152L,
+       0x4p-152L,
+       0x4p-152L,
+       0x4p-152L,
+       true,
+       0x4p-152L,
+       0x4p-152L,
+       0x4p-152L,
+       0x4p-152L,
+       true,
+       0x4p-152L,
+       0x4p-152L,
+       0x4p-152L,
+       0x4p-152L,
+       true,
+       0x4p-152L,
+       0x4p-152L,
+       0x4p-152L,
+       0x4p-152L),
+  TEST ("0x1p-1075",
+       false,
+       0x0p+0f,
+       0x0p+0f,
+       0x0p+0f,
+       0x8p-152f,
+       false,
+       0x0p+0,
+       0x0p+0,
+       0x0p+0,
+       0x4p-1076,
+       false,
+       0x0p+0L,
+       0x0p+0L,
+       0x0p+0L,
+       0x4p-1076L,
+       true,
+       0x2p-1076L,
+       0x2p-1076L,
+       0x2p-1076L,
+       0x2p-1076L,
+       true,
+       0x2p-1076L,
+       0x2p-1076L,
+       0x2p-1076L,
+       0x2p-1076L,
+       false,
+       0x0p+0L,
+       0x0p+0L,
+       0x0p+0L,
+       0x4p-1076L,
+       true,
+       0x2p-1076L,
+       0x2p-1076L,
+       0x2p-1076L,
+       0x2p-1076L),
+  TEST ("0x1p-16446",
+       false,
+       0x0p+0f,
+       0x0p+0f,
+       0x0p+0f,
+       0x8p-152f,
+       false,
+       0x0p+0,
+       0x0p+0,
+       0x0p+0,
+       0x4p-1076,
+       false,
+       0x0p+0L,
+       0x0p+0L,
+       0x0p+0L,
+       0x4p-1076L,
+       false,
+       0x0p+0L,
+       0x0p+0L,
+       0x0p+0L,
+       0x8p-16448L,
+       true,
+       0x4p-16448L,
+       0x4p-16448L,
+       0x4p-16448L,
+       0x4p-16448L,
+       false,
+       0x0p+0L,
+       0x0p+0L,
+       0x0p+0L,
+       0x4p-1076L,
+       true,
+       0x4p-16448L,
+       0x4p-16448L,
+       0x4p-16448L,
+       0x4p-16448L),
+  TEST ("0x1p-16495",
+       false,
+       0x0p+0f,
+       0x0p+0f,
+       0x0p+0f,
+       0x8p-152f,
+       false,
+       0x0p+0,
+       0x0p+0,
+       0x0p+0,
+       0x4p-1076,
+       false,
+       0x0p+0L,
+       0x0p+0L,
+       0x0p+0L,
+       0x4p-1076L,
+       false,
+       0x0p+0L,
+       0x0p+0L,
+       0x0p+0L,
+       0x8p-16448L,
+       false,
+       0x0p+0L,
+       0x0p+0L,
+       0x0p+0L,
+       0x4p-16448L,
+       false,
+       0x0p+0L,
+       0x0p+0L,
+       0x0p+0L,
+       0x4p-1076L,
+       false,
+       0x0p+0L,
+       0x0p+0L,
+       0x0p+0L,
+       0x4p-16496L),
+  TEST ("-0x1p-150",
+       false,
+       -0x8p-152f,
+       -0x0p+0f,
+       -0x0p+0f,
+       -0x0p+0f,
+       true,
+       -0x4p-152,
+       -0x4p-152,
+       -0x4p-152,
+       -0x4p-152,
+       true,
+       -0x4p-152L,
+       -0x4p-152L,
+       -0x4p-152L,
+       -0x4p-152L,
+       true,
+       -0x4p-152L,
+       -0x4p-152L,
+       -0x4p-152L,
+       -0x4p-152L,
+       true,
+       -0x4p-152L,
+       -0x4p-152L,
+       -0x4p-152L,
+       -0x4p-152L,
+       true,
+       -0x4p-152L,
+       -0x4p-152L,
+       -0x4p-152L,
+       -0x4p-152L,
+       true,
+       -0x4p-152L,
+       -0x4p-152L,
+       -0x4p-152L,
+       -0x4p-152L),
+  TEST ("-0x1p-1075",
+       false,
+       -0x8p-152f,
+       -0x0p+0f,
+       -0x0p+0f,
+       -0x0p+0f,
+       false,
+       -0x4p-1076,
+       -0x0p+0,
+       -0x0p+0,
+       -0x0p+0,
+       false,
+       -0x4p-1076L,
+       -0x0p+0L,
+       -0x0p+0L,
+       -0x0p+0L,
+       true,
+       -0x2p-1076L,
+       -0x2p-1076L,
+       -0x2p-1076L,
+       -0x2p-1076L,
+       true,
+       -0x2p-1076L,
+       -0x2p-1076L,
+       -0x2p-1076L,
+       -0x2p-1076L,
+       false,
+       -0x4p-1076L,
+       -0x0p+0L,
+       -0x0p+0L,
+       -0x0p+0L,
+       true,
+       -0x2p-1076L,
+       -0x2p-1076L,
+       -0x2p-1076L,
+       -0x2p-1076L),
+  TEST ("-0x1p-16446",
+       false,
+       -0x8p-152f,
+       -0x0p+0f,
+       -0x0p+0f,
+       -0x0p+0f,
+       false,
+       -0x4p-1076,
+       -0x0p+0,
+       -0x0p+0,
+       -0x0p+0,
+       false,
+       -0x4p-1076L,
+       -0x0p+0L,
+       -0x0p+0L,
+       -0x0p+0L,
+       false,
+       -0x8p-16448L,
+       -0x0p+0L,
+       -0x0p+0L,
+       -0x0p+0L,
+       true,
+       -0x4p-16448L,
+       -0x4p-16448L,
+       -0x4p-16448L,
+       -0x4p-16448L,
+       false,
+       -0x4p-1076L,
+       -0x0p+0L,
+       -0x0p+0L,
+       -0x0p+0L,
+       true,
+       -0x4p-16448L,
+       -0x4p-16448L,
+       -0x4p-16448L,
+       -0x4p-16448L),
+  TEST ("-0x1p-16495",
+       false,
+       -0x8p-152f,
+       -0x0p+0f,
+       -0x0p+0f,
+       -0x0p+0f,
+       false,
+       -0x4p-1076,
+       -0x0p+0,
+       -0x0p+0,
+       -0x0p+0,
+       false,
+       -0x4p-1076L,
+       -0x0p+0L,
+       -0x0p+0L,
+       -0x0p+0L,
+       false,
+       -0x8p-16448L,
+       -0x0p+0L,
+       -0x0p+0L,
+       -0x0p+0L,
+       false,
+       -0x4p-16448L,
+       -0x0p+0L,
+       -0x0p+0L,
+       -0x0p+0L,
+       false,
+       -0x4p-1076L,
+       -0x0p+0L,
+       -0x0p+0L,
+       -0x0p+0L,
+       false,
+       -0x4p-16496L,
+       -0x0p+0L,
+       -0x0p+0L,
+       -0x0p+0L),
 };
 
 static int