re PR rtl-optimization/33737 (verify_flow_info failed: Wrong probability of edge 94->1 -6651)

	PR rtl-optimization/33737
	* cfgcleanup.c (try_crossjump_to_edge): Add count and frequency of
	target block after computing the probabilities of outgoing edges.
	Cap the frequency to BB_FREQ_MAX.
	* tree-ssa-threadupdate.c (redirect_edges): Also adjust count and
	frequency of the basic block if it has been reused.

From-SVN: r129973

gcc/ChangeLog

 2007-11-07  Eric Botcazou  <ebotcazou@libertysurf.fr>
 
+	PR rtl-optimization/33737
+	* cfgcleanup.c (try_crossjump_to_edge): Add count and frequency of
+	target block after computing the probabilities of outgoing edges.
+	Cap the frequency to BB_FREQ_MAX.
+	* tree-ssa-threadupdate.c (redirect_edges): Also adjust count and
+	frequency of the basic block if it has been reused.
+
+2007-11-07  Eric Botcazou  <ebotcazou@libertysurf.fr>
+
 	PR rtl-optimization/33822
 	* rtl.h (REG_OFFSET): Fix comment.
 	* var-tracking.c (INT_MEM_OFFSET): New macro.

gcc/cfgcleanup.c

@@ -1699,8 +1699,6 @@ try_crossjump_to_edge (int mode, edge e1, edge e2)
 	     "Cross jumping from bb %i to bb %i; %i common insns\n",
 	     src1->index, src2->index, nmatch);
 
-  redirect_to->count += src1->count;
-  redirect_to->frequency += src1->frequency;
   /* We may have some registers visible through the block.  */
   df_set_bb_dirty (redirect_to);
 
@@ -1757,6 +1755,14 @@ try_crossjump_to_edge (int mode, edge e1, edge e2)
 	     / (redirect_to->frequency + src1->frequency));
     }
 
+  /* Adjust count and frequency for the block.  An earlier jump
+     threading pass may have left the profile in an inconsistent
+     state (see update_bb_profile_for_threading) so we must be
+     prepared for overflows.  */
+  redirect_to->count += src1->count;
+  redirect_to->frequency += src1->frequency;
+  if (redirect_to->frequency > BB_FREQ_MAX)
+    redirect_to->frequency = BB_FREQ_MAX;
   update_br_prob_note (redirect_to);
 
   /* Edit SRC1 to go to REDIRECT_TO at NEWPOS1.  */

gcc/testsuite/ChangeLog

 2007-11-07  Eric Botcazou  <ebotcazou@libertysurf.fr>
 
+	* gcc.c-torture/compile/20071107-1.c: New test.
+
+2007-11-07  Eric Botcazou  <ebotcazou@libertysurf.fr>
+
 	* gcc.dg/out-of-bounds-1.c: New test.
 
 2007-11-07  Jakub Jelinek  <jakub@redhat.com>

gcc/tree-ssa-threadupdate.c

@@ -442,10 +442,14 @@ redirect_edges (void **slot, void *data)
 	  remove_ctrl_stmt_and_useless_edges (local_info->bb,
 					      rd->outgoing_edge->dest);
 
-	  /* And fixup the flags on the single remaining edge.  */
+	  /* Fixup the flags on the single remaining edge.  */
 	  single_succ_edge (local_info->bb)->flags
 	    &= ~(EDGE_TRUE_VALUE | EDGE_FALSE_VALUE | EDGE_ABNORMAL);
 	  single_succ_edge (local_info->bb)->flags |= EDGE_FALLTHRU;
+
+	  /* And adjust count and frequency on BB.  */
+	  local_info->bb->count = e->count;
+	  local_info->bb->frequency = EDGE_FREQUENCY (e);
 	}
     }