From: Richard Biener <rguenther@suse.de>
Date: Fri, 7 Oct 2016 07:47:38 +0000 (+0000)
Subject: gimple-low.c (lower_gimple_bind): Clear DECL_CHAIN of vars in gimple_bind_vars but... 
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=014b59e68837b998593b03b5eab3f7ff707d5d69;p=gcc.git

gimple-low.c (lower_gimple_bind): Clear DECL_CHAIN of vars in gimple_bind_vars but not in BLOCK_VARS.

2016-10-07  Richard Biener  <rguenther@suse.de>

	* gimple-low.c (lower_gimple_bind): Clear DECL_CHAIN of
	vars in gimple_bind_vars but not in BLOCK_VARS.

From-SVN: r240855
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 9125650a545..e1eb08d28bc 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2016-10-07  Richard Biener  <rguenther@suse.de>
+
+	* gimple-low.c (lower_gimple_bind): Clear DECL_CHAIN of
+	vars in gimple_bind_vars but not in BLOCK_VARS.
+
 2016-10-07  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/77879
diff --git a/gcc/gimple-low.c b/gcc/gimple-low.c
index 5f3361acba8..1bccf44e5d7 100644
--- a/gcc/gimple-low.c
+++ b/gcc/gimple-low.c
@@ -416,6 +416,23 @@ lower_gimple_bind (gimple_stmt_iterator *gsi, struct lower_data *data)
     }
 
   record_vars (gimple_bind_vars (stmt));
+
+  /* Scrap DECL_CHAIN up to BLOCK_VARS to ease GC after we no longer
+     need gimple_bind_vars.  */
+  tree next;
+  tree end = NULL_TREE;
+  if (gimple_bind_block (stmt))
+    end = BLOCK_VARS (gimple_bind_block (stmt));
+  for (tree var = gimple_bind_vars (stmt); var != end; var = next)
+    {
+      /* Ugh, something is violating the constraint that BLOCK_VARS
+         is a sub-chain of gimple_bind_vars.  */
+      if (! var)
+	break;
+      next = DECL_CHAIN (var);
+      DECL_CHAIN (var) = NULL_TREE;
+    }
+
   lower_sequence (gimple_bind_body_ptr (stmt), data);
 
   if (new_block)