[Bug tree-optimization/15555] New: compute_may_alias failes when scheduled again

["dorit at il dot ibm dot com" <gcc-bugzilla at gcc dot gnu dot org>]

Applying this patch to gcc mainline:

*** tree-optimize.c     13 May 2004 06:39:48 -0000      2.15
--- tree-optimize.c     19 May 2004 13:57:41 -0000
*************** init_tree_optimization_passes (void)
*** 307,312 ****
--- 307,317 ----
    NEXT_PASS (pass_fold_builtins);
    NEXT_PASS (pass_split_crit_edges);
    NEXT_PASS (pass_pre);
+ #if 1 
+   NEXT_PASS (DUP_PASS (pass_build_pta));
+   NEXT_PASS (DUP_PASS (pass_may_alias));
+   NEXT_PASS (DUP_PASS (pass_del_pta));
+ #endif
    NEXT_PASS (DUP_PASS (pass_dominator));
    NEXT_PASS (DUP_PASS (pass_redundant_phi));
    NEXT_PASS (pass_cd_dce);

Is causing a compilation error at verify_ssa right after the new invocation of 
compute_may_aliases, on the testcase below: 

float *gl_copy_map_points1f( int uorder,
              const float *points, unsigned int size)
{
   float *buffer, *p;
   unsigned int i;
   buffer = (float *) malloc(uorder * size * sizeof(float));
   if (buffer)
     for (i=0, p=buffer; i<uorder; i++)
       *p++ = points[i];
   return buffer;
}

with the following error:

aaa.c: In function `gl_copy_map_points1f':
aaa.c:4: error: Missing definition
for SSA_NAME: TMT.9<D1145>_25

in statement:
TMT.9<D1145>_27 = PHI <TMT.9<D1145>_25(2), TMT.9<D1145>_23(1)>;

PHI argument
TMT.9<D1145>_25

PHI argument
TMT.9<D1145>_23

for PHI node
TMT.9<D1145>_27 = PHI <TMT.9<D1145>_25(2), TMT.9<D1145>_23(1)>;

aaa.c:4: internal compiler error: verify_ssa failed.

more details here: http://gcc.gnu.org/ml/gcc/2004-05/msg01034.html

-- 
           Summary: compute_may_alias failes when scheduled again
           Product: gcc
           Version: 3.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: tree-optimization
        AssignedTo: dnovillo at gcc dot gnu dot org
        ReportedBy: dorit at il dot ibm dot com
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15555