re PR tree-optimization/87263 (ICE on valid code at -O1: verify_ssa failed)

2018-09-13  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/87263
	* tree-ssa-sccvn.c (visit_phi): Revert some earlier changes.
	(struct unwind_state): Add max_rpo field.
	(do_rpo_vn): Allow up-to-date loop state to be used when not iterating.
	Compute max_rpo, the max RPO number a block can be backwards reached
	from.  Re-write non-iterating mode to a RPO ordered worklist approach,
	separating it from the iterating mode.

	* gcc.dg/torture/pr87263.c: New testcase.
	* gcc.dg/torture/ssa-fre-2.c: Likewise.
	* gcc.dg/torture/ssa-fre-3.c: Likewise.
	* gcc.dg/torture/ssa-fre-4.c: Likewise.

From-SVN: r264273

gcc/ChangeLog

+2018-09-13  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/87263
+	* tree-ssa-sccvn.c (visit_phi): Revert some earlier changes.
+	(struct unwind_state): Add max_rpo field.
+	(do_rpo_vn): Allow up-to-date loop state to be used when not iterating.
+	Compute max_rpo, the max RPO number a block can be backwards reached
+	from.  Re-write non-iterating mode to a RPO ordered worklist approach,
+	separating it from the iterating mode.
+
 2018-09-13  Vlad Lazar  <vlad.lazar@arm.com>
 
 	* haifa-sched.c (rank_for_schedule): Schedule by INSN_COST.

gcc/testsuite/ChangeLog

+2018-09-13  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/87263
+	* gcc.dg/torture/pr87263.c: New testcase.
+	* gcc.dg/torture/ssa-fre-2.c: Likewise.
+	* gcc.dg/torture/ssa-fre-3.c: Likewise.
+	* gcc.dg/torture/ssa-fre-4.c: Likewise.
+
 2018-09-13  Omar Sandoval  <osandov@osandov.com>
 	    Tom de Vries  <tdevries@suse.de>
 

gcc/testsuite/gcc.dg/torture/pr87263.c

+/* { dg-do compile } */
+
+int a, b, c;
+
+int main ()
+{ 
+  int g, *h[3] = {&g, &g, &g};
+  if (h[2] == 0)
+    ;
+  else
+    { 
+      int i[1];
+      if (a)
+	while (a)
+	  L:;
+      else
+	{
+	  int k = b;
+	}
+    }
+  if ((b < c) > b)
+    goto L;
+  return 0;
+}

gcc/testsuite/gcc.dg/torture/ssa-fre-2.c

+/* { dg-do run } */
+
+int x;
+int main()
+{
+  int i = 0;
+  x = 0;
+  if (x)
+    {
+      for (; i < 10; ++i)
+	{
+doit:
+	  x = i;
+	}
+    }
+  if (!x)
+    goto doit;
+  if (x != 9)
+    __builtin_abort ();
+  return 0;
+}

gcc/testsuite/gcc.dg/torture/ssa-fre-3.c

+/* { dg-do compile } */
+/* { dg-skip-if "" { *-*-* } { "-O0" } { "" } } */
+/* { dg-additional-options "-fdump-tree-fre1" } */
+
+int x;
+int main()
+{
+  x = 0;
+  int z = x;
+  int w = 1;
+  for (int i = 0; i < 32; ++i)
+    {
+      if (z)
+	w = 2;
+      else
+	w = 1;
+      if (w == 2)
+	__builtin_abort ();
+    }
+  return w;
+}
+
+/* { dg-final { scan-tree-dump-not "abort" "fre1" } } */

gcc/testsuite/gcc.dg/torture/ssa-fre-4.c

+/* { dg-do compile } */
+/* { dg-skip-if "" { *-*-* } { "-O0" } { "" } } */
+/* { dg-additional-options "-fdump-tree-fre1" } */
+
+int x;
+int main()
+{
+  x = 0;
+  if (x)
+    {
+      for (int i = 0; i < 10; ++i)
+	x = i;
+    }
+  return x;
+}
+
+/* { dg-final { scan-tree-dump "return 0;" "fre1" } } */