[Bug middle-end/30704] [4.2/4.3 Regression] Incorrect constant generation for long long

["pinskia at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #9 from pinskia at gcc dot gnu dot org  2007-03-12 23:18 -------
Here is my new patch:
Index: ../../gcc/fold-const.c
===================================================================
--- ../../gcc/fold-const.c      (revision 122864)
+++ ../../gcc/fold-const.c      (working copy)
@@ -7357,6 +7357,7 @@ native_interpret_real (tree type, unsign
      up to 192 bits.  */
   REAL_VALUE_TYPE r;
   long tmp[6];
+  long tmp1[6];

   total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
   if (total_bytes > len || total_bytes > 24)
@@ -7367,6 +7368,7 @@ native_interpret_real (tree type, unsign
   for (byte = 0; byte < total_bytes; byte++)
     {
       int bitpos = byte * BITS_PER_UNIT;
+      int bytepos;
       if (total_bytes > UNITS_PER_WORD)
        {
          word = byte / UNITS_PER_WORD;
@@ -7381,11 +7383,18 @@ native_interpret_real (tree type, unsign
       else
        offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
       value = ptr[offset];
+      bytepos = FLOAT_WORDS_BIG_ENDIAN ? total_bytes / 4 - bitpos / 32 - 1 :
bitpos / 32;

-      tmp[bitpos / 32] |= (unsigned long)value << (bitpos & 31);
+      tmp[bytepos] |= (unsigned long)value << (bitpos & 31);
+      printf("%ld %ld [%d,%d]\n", tmp[0], tmp[1], bytepos, bitpos);
     }

   real_from_target (&r, tmp, mode);
+  real_to_target (tmp1, &r, mode);
+  /* If the encoded real is going to decode differently, then reject the
constant
+     conversion. */
+  if (memcmp (tmp, tmp1, total_bytes) != 0)
+    return NULL;
   return build_real (type, r);
 }



I am not 100 % sure this is correct but we get the correct constant now for
this one.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30704