Fix profile updating bug in tree-ssa-threadupdate

ssa_fix_duplicate_block_edges later calls update_profile to correct profile after threading.
In the testcase this does not work since we lose track of the duplicated edge.  This
happens because redirect_edge_and_branch returns NULL if the edge already has correct
destination which is the case.

gcc/ChangeLog:

	* tree-ssa-threadupdate.cc (ssa_fix_duplicate_block_edges): Fix profile update.

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/phi_on_compare-1.c: Check profile consistency.

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/phi_on_compare-1.c b/gcc/testsuite/gcc.dg/tree-ssa/phi_on_compare-1.c
index be504ddb11ae880bdb87f29856b7b13df750a75e..923497f789682e3ab5189f502b4196d49079b374 100644 (file)
--- a/gcc/testsuite/gcc.dg/tree-ssa/phi_on_compare-1.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/phi_on_compare-1.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-Ofast -fdump-tree-dom2" } */
+/* { dg-options "-Ofast -fdump-tree-dom2 -fdump-tree-optimized-details-blocks" } */
 
 void g (int);
 void g1 (int);
@@ -33,3 +33,4 @@ f (long a, long b, long c, long d, long x)
    optimization in the backward threader before killing the forward
    threader.  Similarly for the other phi_on_compare-*.c tests.  */
 /* { dg-final { scan-tree-dump-times "Removing basic block" 1 "dom2" } } */
+/* { dg-final { scan-tree-dump-not "Invalid sum" "optimized" } } */

diff --git a/gcc/tree-ssa-threadupdate.cc b/gcc/tree-ssa-threadupdate.cc
index d5416b21a78387c2b9f27c95cb170c6b22efbde6..a5b9a002a8ab6cf2d1657f1359ede6980acbce42 100644 (file)
--- a/gcc/tree-ssa-threadupdate.cc
+++ b/gcc/tree-ssa-threadupdate.cc
@@ -1059,14 +1059,19 @@ ssa_fix_duplicate_block_edges (struct redirection_data *rd,
             threading path.  */
          if (!any_remaining_duplicated_blocks (path, i))
            {
-             e2 = redirect_edge_and_branch (victim, elast->dest);
-             /* If we redirected the edge, then we need to copy PHI arguments
-                at the target.  If the edge already existed (e2 != victim
-                case), then the PHIs in the target already have the correct
-                arguments.  */
-             if (e2 == victim)
-               copy_phi_args (e2->dest, elast, e2,
-                              path, multi_incomings ? 0 : i);
+             if (victim->dest != elast->dest)
+               {
+                 e2 = redirect_edge_and_branch (victim, elast->dest);
+                 /* If we redirected the edge, then we need to copy PHI arguments
+                    at the target.  If the edge already existed (e2 != victim
+                    case), then the PHIs in the target already have the correct
+                    arguments.  */
+                 if (e2 == victim)
+                   copy_phi_args (e2->dest, elast, e2,
+                                  path, multi_incomings ? 0 : i);
+               }
+             else
+               e2 = victim;
            }
          else
            {