[Bug rtl-optimization/33669] [4.3 Regression] Revision 128957 miscompiles 481.wrf

["zadeck at naturalbridge dot com" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #15 from zadeck at naturalbridge dot com  2007-10-09 15:41 -------
Subject: Re:  [4.3 Regression]  Revision 128957
 miscompiles 481.wrf

This patch fixes the problem in a slightly different way.  The other
patch was too conservative in that it ended up setting the added flag
too often what has some downstream quality issues.

I just finished testing this on x86-64, x86-32, ppc-32 and ia-64

kenny


2007-10-07  Kenneth Zadeck <zadeck@naturalbridge.com>

    PR middle-end/33669
    * ra-conflict.c (record_one_conflict_between_regnos,
    set_conflicts_for_earlyclobber, global_conflicts): Improved logging.
    (global_conflicts): Removed incorrect check.

2007-10-07  Kenneth Zadeck <zadeck@naturalbridge.com>

    PR middle-end/33669
    * gcc.c-torture/execute/pr33669.c: New.


Index: ra-conflict.c
===================================================================
--- ra-conflict.c       (revision 129053)
+++ ra-conflict.c       (working copy)
@@ -196,7 +196,7 @@ record_one_conflict_between_regnos (enum
   int allocno2 = reg_allocno[r2];

   if (dump_file)
-    fprintf (dump_file, "  rocbr adding %d<=>%d\n", r1, r2);
+    fprintf (dump_file, "    rocbr adding %d<=>%d\n", r1, r2);

   if (allocno1 >= 0 && allocno2 >= 0)
     set_conflict (allocno1, allocno2);
@@ -401,9 +401,6 @@ set_conflicts_for_earlyclobber (rtx insn
                                                    recog_data.operand[use +
1]);
                }
        }
-
-  if (dump_file) 
-    fprintf (dump_file, "  finished early clobber conflicts.\n");
 }


@@ -983,12 +980,12 @@ global_conflicts (void)
                        set_renumbers_live (&renumbers_live, live_subregs,
live_subregs_used, 
                                            allocnum, renumber);
                    }
-                 
-                 else if (!sparseset_bit_p (allocnos_live, allocnum))
+                 else if (live_subregs_used[allocnum] > 0
+                          || !sparseset_bit_p (allocnos_live, allocnum))
                    {
                      if (dump_file)
-                       fprintf (dump_file, "    dying pseudo\n");
-                     
+                       fprintf (dump_file, "    %sdying pseudo\n", 
+                                (live_subregs_used[allocnum] > 0) ? "partially
": "");
                      /* Resetting the live_subregs_used is
                         effectively saying do not use the subregs
                         because we are reading the whole pseudo.  */
@@ -1071,6 +1068,8 @@ global_conflicts (void)
                 FIXME: We should consider either adding a new kind of
                 clobber, or adding a flag to the clobber distinguish
                 these two cases.  */
+             if (dump_file && VEC_length (df_ref_t, clobbers))
+               fprintf (dump_file, "  clobber conflicts\n");
              for (k = VEC_length (df_ref_t, clobbers) - 1; k >= 0; k--)
                {
                  struct df_ref *def = VEC_index (df_ref_t, clobbers, k);
@@ -1132,6 +1131,8 @@ global_conflicts (void)
              if (GET_CODE (PATTERN (insn)) == PARALLEL && multiple_sets
(insn))
                { 
                  int j;
+                 if (dump_file)
+                   fprintf (dump_file, "  multiple sets\n");
                  for (j = VEC_length (df_ref_t, dying_regs) - 1; j >= 0; j--)
                    {
                      int used_in_output = 0;
@@ -1166,7 +1167,7 @@ global_conflicts (void)
            }
        }

-           /* Add the renumbers live to the hard_regs_live for the next few
+      /* Add the renumbers live to the hard_regs_live for the next few
         calls.  All of this gets recomputed at the top of the loop so
         there is no harm.  */
       IOR_HARD_REG_SET (hard_regs_live, renumbers_live);
Index: testsuite/gcc.c-torture/execute/pr33669.c
===================================================================
--- testsuite/gcc.c-torture/execute/pr33669.c   (revision 0)
+++ testsuite/gcc.c-torture/execute/pr33669.c   (revision 0)
@@ -0,0 +1,40 @@
+extern void abort (void);
+
+typedef struct foo_t
+{ 
+  unsigned int blksz;
+  unsigned int bf_cnt; 
+} foo_t;
+
+#define _RNDUP(x, unit)  ((((x) + (unit) - 1) / (unit)) * (unit))
+#define _RNDDOWN(x, unit)  ((x) - ((x)%(unit)))
+
+long long
+foo (foo_t *const pxp,  long long offset, unsigned int extent)
+{
+  long long blkoffset = _RNDDOWN(offset, (long long )pxp->blksz);
+  unsigned int diff = (unsigned int)(offset - blkoffset);
+  unsigned int blkextent = _RNDUP(diff + extent, pxp->blksz);
+
+  if (pxp->blksz < blkextent)
+    return -1LL;
+
+  if (pxp->bf_cnt > pxp->blksz)
+    pxp->bf_cnt = pxp->blksz;
+
+  return blkoffset;
+}
+
+int
+main ()
+{
+  foo_t x;
+  long long xx;
+
+  x.blksz = 8192;
+  x.bf_cnt = 0;
+  xx = foo (&x, 0, 4096);
+  if (xx != 0LL)
+    abort ();
+  return 0;
+}


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33669