PR target/21623:

[pf3gnuchains/gcc-fork.git] / gcc / real.c

diff --git a/gcc/real.c b/gcc/real.c
index 5d1a79f..9b165ec 100644 (file)
--- a/gcc/real.c
+++ b/gcc/real.c
@@ -18,8 +18,8 @@
 
    You should have received a copy of the GNU General Public License
    along with GCC; see the file COPYING.  If not, write to the Free
-   Software Foundation, 59 Temple Place - Suite 330, Boston, MA
-   02111-1307, USA.  */
+   Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
+   02110-1301, USA.  */
 
 #include "config.h"
 #include "system.h"
@@ -1789,6 +1789,10 @@ real_from_string (REAL_VALUE_TYPE *r, const char *str)
                |= (unsigned long) d << (pos % HOST_BITS_PER_LONG);
              pos -= 4;
            }
+         else if (d)
+           /* Ensure correct rounding by setting last bit if there is
+              a subsequent nonzero digit.  */
+           r->sig[0] |= 1;
          exp += 4;
          str++;
        }
@@ -1811,6 +1815,10 @@ real_from_string (REAL_VALUE_TYPE *r, const char *str)
                    |= (unsigned long) d << (pos % HOST_BITS_PER_LONG);
                  pos -= 4;
                }
+             else if (d)
+               /* Ensure correct rounding by setting last bit if there is
+                  a subsequent nonzero digit.  */
+               r->sig[0] |= 1;
              str++;
            }
        }
@@ -2391,7 +2399,19 @@ real_value_truncate (enum machine_mode mode, REAL_VALUE_TYPE a)
 bool
 exact_real_truncate (enum machine_mode mode, const REAL_VALUE_TYPE *a)
 {
+  const struct real_format *fmt;
   REAL_VALUE_TYPE t;
+  int emin2m1;
+
+  fmt = REAL_MODE_FORMAT (mode);
+  gcc_assert (fmt);
+
+  /* Don't allow conversion to denormals.  */
+  emin2m1 = (fmt->emin - 1) * fmt->log2_b;
+  if (REAL_EXP (a) <= emin2m1)
+    return false;
+
+  /* After conversion to the new mode, the value must be identical.  */
   real_convert (&t, mode, a);
   return real_identical (&t, a);
 }
@@ -2651,6 +2671,7 @@ const struct real_format ieee_single_format =
     -125,
     128,
     31,
+    31,
     true,
     true,
     true,
@@ -2669,6 +2690,7 @@ const struct real_format mips_single_format =
     -125,
     128,
     31,
+    31,
     true,
     true,
     true,
@@ -2874,6 +2896,7 @@ const struct real_format ieee_double_format =
     -1021,
     1024,
     63,
+    63,
     true,
     true,
     true,
@@ -2892,6 +2915,7 @@ const struct real_format mips_double_format =
     -1021,
     1024,
     63,
+    63,
     true,
     true,
     true,
@@ -3221,6 +3245,7 @@ const struct real_format ieee_extended_motorola_format =
     -16382,
     16384,
     95,
+    95,
     true,
     true,
     true,
@@ -3239,6 +3264,7 @@ const struct real_format ieee_extended_intel_96_format =
     -16381,
     16384,
     79,
+    79,
     true,
     true,
     true,
@@ -3257,6 +3283,7 @@ const struct real_format ieee_extended_intel_128_format =
     -16381,
     16384,
     79,
+    79,
     true,
     true,
     true,
@@ -3277,6 +3304,7 @@ const struct real_format ieee_extended_intel_96_round_53_format =
     -16381,
     16384,
     79,
+    79,
     true,
     true,
     true,
@@ -3361,6 +3389,7 @@ const struct real_format ibm_extended_format =
     53,
     -1021 + 53,
     1024,
+    127,
     -1,
     true,
     true,
@@ -3379,6 +3408,7 @@ const struct real_format mips_extended_format =
     53,
     -1021 + 53,
     1024,
+    127,
     -1,
     true,
     true,
@@ -3646,6 +3676,7 @@ const struct real_format ieee_quad_format =
     -16381,
     16384,
     127,
+    127,
     true,
     true,
     true,
@@ -3664,6 +3695,7 @@ const struct real_format mips_quad_format =
     -16381,
     16384,
     127,
+    127,
     true,
     true,
     true,
@@ -3961,6 +3993,7 @@ const struct real_format vax_f_format =
     -127,
     127,
     15,
+    15,
     false,
     false,
     false,
@@ -3979,6 +4012,7 @@ const struct real_format vax_d_format =
     -127,
     127,
     15,
+    15,
     false,
     false,
     false,
@@ -3997,6 +4031,7 @@ const struct real_format vax_g_format =
     -1023,
     1023,
     15,
+    15,
     false,
     false,
     false,
@@ -4172,6 +4207,7 @@ const struct real_format i370_single_format =
     -64,
     63,
     31,
+    31,
     false,
     false,
     false, /* ??? The encoding does allow for "unnormals".  */
@@ -4190,6 +4226,7 @@ const struct real_format i370_double_format =
     -64,
     63,
     63,
+    63,
     false,
     false,
     false, /* ??? The encoding does allow for "unnormals".  */
@@ -4397,6 +4434,7 @@ const struct real_format c4x_single_format =
     24,
     -126,
     128,
+    23,
     -1,
     false,
     false,
@@ -4415,6 +4453,7 @@ const struct real_format c4x_extended_format =
     32,
     -126,
     128,
+    31,
     -1,
     false,
     false,
@@ -4459,6 +4498,7 @@ const struct real_format real_internal_format =
     -MAX_EXP,
     MAX_EXP,
     -1,
+    -1,
     true,
     true,
     false,