[Bug ipa/88788] [9 Regression] Infinite loop in malloc_candidate_p_1 since r264838

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88788

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P1
             Status|UNCONFIRMED                 |NEW
      Known to work|                            |8.2.0
           Keywords|                            |needs-reduction
   Last reconfirmed|                            |2019-01-10
     Ever confirmed|0                           |1
   Target Milestone|---                         |9.0
      Known to fail|                            |9.0

--- Comment #1 from Martin Liška <marxin at gcc dot gnu.org> ---
Patch that can trigger ICE:

diff --git a/gcc/ipa-pure-const.c b/gcc/ipa-pure-const.c
index ba0c7c2d83e..3481719aa9d 100644
--- a/gcc/ipa-pure-const.c
+++ b/gcc/ipa-pure-const.c
@@ -878,8 +878,10 @@ check_retval_uses (tree retval, gimple *stmt)
 }

 static bool
-malloc_candidate_p_1 (function *fun, tree retval, gimple *ret_stmt, bool ipa)
+malloc_candidate_p_1 (function *fun, tree retval, gimple *ret_stmt, bool ipa,
+                     int depth)
 {
+  gcc_assert (depth < 40);
   cgraph_node *node = cgraph_node::get_create (fun->decl);

   if (!check_retval_uses (retval, ret_stmt))
@@ -925,7 +927,7 @@ malloc_candidate_p_1 (function *fun, tree retval, gimple
*ret_stmt, bool ipa)
            gimple *arg_def = SSA_NAME_DEF_STMT (arg);
            if (is_a<gphi *> (arg_def))
              {
-               if (!malloc_candidate_p_1 (fun, arg, phi, ipa))
+               if (!malloc_candidate_p_1 (fun, arg, phi, ipa, depth + 1))
                    DUMP_AND_RETURN ("nested phi fail")
                continue;
              }
@@ -987,7 +989,7 @@ malloc_candidate_p (function *fun, bool ipa)
          || TREE_CODE (TREE_TYPE (retval)) != POINTER_TYPE)
        DUMP_AND_RETURN("Return value is not SSA_NAME or not a pointer type.")

-      if (!malloc_candidate_p_1 (fun, retval, ret_stmt, ipa))
+      if (!malloc_candidate_p_1 (fun, retval, ret_stmt, ipa, 0))
        return false;
     }

I'll try to reduce that.