[PATCH] Fix PR91162

[Richard Biener]

Bootstrapped / tested on x86_64-unknown-linux-gnu, applied.

Richard.

2019-07-15  Richard Biener  <rguent...@suse.de>

        PR middle-end/91162
        * tree-cfg.c (move_block_to_fn): When releasing a virtual PHI
        node make sure to replace all uses with something valid.

        * gcc.dg/autopar/pr91162.c: New testcase.

Index: gcc/tree-cfg.c
===================================================================
--- gcc/tree-cfg.c      (revision 273490)
+++ gcc/tree-cfg.c      (working copy)
@@ -7088,7 +7088,14 @@ move_block_to_fn (struct function *dest_
       if (virtual_operand_p (op))
        {
          /* Remove the phi nodes for virtual operands (alias analysis will be
-            run for the new function, anyway).  */
+            run for the new function, anyway).  But replace all uses that
+            might be outside of the region we move.  */
+         use_operand_p use_p;
+         imm_use_iterator iter;
+         gimple *use_stmt;
+         FOR_EACH_IMM_USE_STMT (use_stmt, iter, op)
+           FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
+             SET_USE (use_p, SSA_NAME_VAR (op));
           remove_phi_node (&psi, true);
          continue;
        }
Index: gcc/testsuite/gcc.dg/autopar/pr91162.c
===================================================================
--- gcc/testsuite/gcc.dg/autopar/pr91162.c      (nonexistent)
+++ gcc/testsuite/gcc.dg/autopar/pr91162.c      (working copy)
@@ -0,0 +1,25 @@
+/* { dg-do compile } */
+/* { dg-options "-O -ftree-parallelize-loops=2 -fno-tree-dominator-opts 
--param parloops-min-per-thread=30" } */
+
+void
+zf (__int128 ct)
+{
+  __int128 *rk = &ct;
+
+  if (0)
+    {
+      int jj;
+
+t9:
+      for (jj = 0; jj < 60; ++jj)
+       {
+       }
+
+      __builtin_unreachable ();
+    }
+
+  while (*rk < 1)
+    ++*rk;
+
+  goto t9;
+}