re PR middle-end/81030 (ICE on valid code at -O1 (only) on x86_64-linux-gnu:…

re PR middle-end/81030 (ICE on valid code at -O1 (only) on x86_64-linux-gnu: verify_flow_info failed)


	PR middle-end/81030
	* cfgbuild.c (find_many_sub_basic_blocks): Update REG_BR_PROB note
	when gimple level profile disagrees with what RTL expander did.
	* gcc.dg/pr81030.c: New test.

From-SVN: r250383

gcc/ChangeLog

+2017-07-18  Jan Hubicka  <hubicka@ucw.cz>
+	    Tom de Vries  <tom@codesourcery.com>
+
+	PR middle-end/81030
+	* cfgbuild.c (find_many_sub_basic_blocks): Update REG_BR_PROB note
+	when gimple level profile disagrees with what RTL expander did.
+
 2017-07-20  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/61171

gcc/cfgbuild.c

@@ -673,10 +673,18 @@ find_many_sub_basic_blocks (sbitmap blocks)
 		     && profile_status_for_fn (cfun) != PROFILE_READ))
 	      bb->count = profile_count::uninitialized ();
 	  }
-	else
-	  /* If nothing changed, there is no need to create new BBs.  */
-	  if (EDGE_COUNT (bb->succs) == n_succs[bb->index])
+ 	/* If nothing changed, there is no need to create new BBs.  */
+	else if (EDGE_COUNT (bb->succs) == n_succs[bb->index])
+	  {
+	    /* In rare occassions RTL expansion might have mistakely assigned
+	       a probabilities different from what is in CFG.  This happens
+	       when we try to split branch to two but optimize out the
+	       second branch during the way. See PR81030.  */
+	    if (JUMP_P (BB_END (bb)) && any_condjump_p (BB_END (bb))
+		&& EDGE_COUNT (bb->succs) >= 2)
+	      update_br_prob_note (bb);
 	    continue;
+	  }
 
 	compute_outgoing_frequencies (bb);
       }

gcc/testsuite/ChangeLog

+2017-07-17  Tom de Vries  <tom@codesourcery.com>
+
+	PR middle-end/81030
+	* gcc.dg/pr81030.c: New test.
+
 2017-07-20  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/61171

gcc/testsuite/gcc.dg/pr81030.c

+/* { dg-do compile } */
+/* { dg-options "-O1" } */
+
+void __assert_fail (const char *, const char *, unsigned int, const char *);
+
+int a, b, c, d, e, f, h;
+unsigned char g;
+
+int main ()
+{
+  int i, *j = &b;
+  if (a)
+    {
+      if (h)
+	{
+	  int **k = &j;
+	  d = 0;
+	  *k = &e;
+	}
+      else
+	for (b = 0; b > -28; b = g)
+	  ;
+      c || !j ? : __assert_fail ("c || !j", "small.c", 20, "main");
+      if (f)
+	for (i = 0; i < 1; i++)
+	  ;
+    }
+  return 0;
+}