[PATCH] Fix fnsplit ICE (PR tree-optimization/69209)

[Jakub Jelinek]

Hi!

This fixes an ICE, where the split part doesn't return a value
of a is_gimple_reg_type retval, only compares its address (therefore it is
addressable), and the main part only uses the var in return_bb.
In that case, retval is not gimple val, but needs to be returned
as gimple val.  So we need to load it into a SSA_NAME.
I've tried to construct testcases for other cases where we might need
something similar, but have not succeeded, so maybe it is the only spot
that needs such handling.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2016-02-08  Jakub Jelinek  <ja...@redhat.com>

        PR tree-optimization/69209
        * ipa-split.c (split_function): If split part is not
        returning retval, retval has gimple type but is not
        gimple value, force it into a SSA_NAME first.

        * gcc.c-torture/compile/pr69209.c: New test.

--- gcc/ipa-split.c.jj  2016-02-03 23:36:29.000000000 +0100
+++ gcc/ipa-split.c     2016-02-08 15:56:41.701994621 +0100
@@ -1628,8 +1628,22 @@ split_function (basic_block return_bb, s
                gimple_call_set_lhs (call, build_simple_mem_ref (retval));
              else
                gimple_call_set_lhs (call, retval);
+             gsi_insert_after (&gsi, call, GSI_NEW_STMT);
+           }
+         else
+           {
+             gsi_insert_after (&gsi, call, GSI_NEW_STMT);
+             if (retval
+                 && is_gimple_reg_type (TREE_TYPE (retval))
+                 && !is_gimple_val (retval))
+               {
+                 gassign *g
+                   = gimple_build_assign (make_ssa_name (TREE_TYPE (retval)),
+                                          retval);
+                 retval = gimple_assign_lhs (g);
+                 gsi_insert_after (&gsi, g, GSI_NEW_STMT);
+               }
            }
-          gsi_insert_after (&gsi, call, GSI_NEW_STMT);
          /* Build bndret call to obtain returned bounds.  */
          if (retbnd)
            chkp_insert_retbnd_call (retbnd, retval, &gsi);
--- gcc/testsuite/gcc.c-torture/compile/pr69209.c.jj    2016-02-08 
16:13:32.527138280 +0100
+++ gcc/testsuite/gcc.c-torture/compile/pr69209.c       2016-02-08 
16:13:19.000000000 +0100
@@ -0,0 +1,28 @@
+/* PR tree-optimization/69209 */
+
+int a, c, *d, e;
+
+void foo (void) __attribute__ ((__noreturn__));
+
+int
+bar (void)
+{
+  int f;
+  if (a)
+    {
+      if (e)
+       foo ();
+      foo ();
+    }
+  if (d != &f)
+    foo ();
+  if (!c)
+    foo ();
+  return f;
+}
+
+void
+baz ()
+{
+  bar ();
+}

        Jakub