re PR ipa/88788 (Infinite loop in malloc_candidate_p_1 since r264838)

2019-01-15  Richard Biener  <rguenther@suse.de>
	    Prathamesh Kulkarni  <prathamesh.kulkarni@linaro.org>

	PR ipa/88788
	* ipa-pure-const.c (malloc_candidate_p_1): Add parameter visited and
	return true if SSA_NAME is already marked in visited bitmap.
	(malloc_candidate_p): Pass visited to malloc_candidate_p_1.

Co-Authored-By: Prathamesh Kulkarni <prathamesh.kulkarni@linaro.org>
From-SVN: r267933

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c350d1c..576541e 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2019-01-15  Richard Biener  <rguenther@suse.de>
+           Prathamesh Kulkarni  <prathamesh.kulkarni@linaro.org>
+
+       PR ipa/88788
+       * ipa-pure-const.c (malloc_candidate_p_1): Add parameter visited and
+       return true if SSA_NAME is already marked in visited bitmap.
+       (malloc_candidate_p): Pass visited to malloc_candidate_p_1.
+
 2019-01-15  Jakub Jelinek  <jakub@redhat.com>
 
        PR tree-optimization/88775

diff --git a/gcc/ipa-pure-const.c b/gcc/ipa-pure-const.c
index 37b5885..8227eed 100644 (file)
--- a/gcc/ipa-pure-const.c
+++ b/gcc/ipa-pure-const.c
@@ -878,9 +878,12 @@ 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,
+                     bitmap visited)
 {
   cgraph_node *node = cgraph_node::get_create (fun->decl);
+  if (!bitmap_set_bit (visited, SSA_NAME_VERSION (retval)))
+    return true;
 
   if (!check_retval_uses (retval, ret_stmt))
     DUMP_AND_RETURN("Return value has uses outside return stmt"
@@ -925,7 +928,7 @@ 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, visited))
                    DUMP_AND_RETURN ("nested phi fail")
                continue;
              }
@@ -971,6 +974,7 @@ malloc_candidate_p (function *fun, bool ipa)
       || !flag_delete_null_pointer_checks)
     return false;
 
+  auto_bitmap visited;
   FOR_EACH_EDGE (e, ei, exit_block->preds)
     {
       gimple_stmt_iterator gsi = gsi_last_bb (e->src);
@@ -987,7 +991,7 @@ 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, visited))
        return false;
     }