From patchwork Mon Feb 21 22:41:51 2011
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Subject: [trans-mem] PR47746: handle OBJ_TYPE_REF correctly
Date: Mon, 21 Feb 2011 12:41:51 -0000
From: Aldy Hernandez <aldyh@redhat.com>
X-Patchwork-Id: 83884
Message-Id: <4D62EA2F.7090306@redhat.com>
To: Richard Henderson <rth@redhat.com>, gcc-patches <gcc-patches@gcc.gnu.org>, 
 Patrick MARLIER <patrick.marlier@unine.ch>

While building the call to TM_GETTMCLONE, we discard OBJ_TYPE_REF's if 
we can't fold them:

   /* Discard OBJ_TYPE_REF, since we weren't able to fold it.  */
   if (TREE_CODE (old_fn) == OBJ_TYPE_REF)
     old_fn = OBJ_TYPE_REF_EXPR (old_fn);

However, this discard can get rid of an implicit conversion.  In the 
attached testcase, the inner type of the OBJ_TYPE_REF_EXPR is signed, 
but the type of the OBJ_TYPE_REF_EXPR is unsigned.  This causes an ICE 
while verifying the gimple call.

I have fixed this by adding an appropriate conversion after the 
GETTMCLONE call.

I can make sure the conversion only happens for the OBJ_TYPE_REF, but I 
was lazy.  I don't think it'll hurt.

OK for branch?
PR 47746
	* trans-mem.c (ipa_tm_insert_gettmclone_call): Verify type
	compatibility in call.


Index: testsuite/g++.dg/tm/pr47746.C
===================================================================
--- testsuite/g++.dg/tm/pr47746.C	(revision 0)
+++ testsuite/g++.dg/tm/pr47746.C	(revision 0)
@@ -0,0 +1,27 @@
+// { dg-do compile }
+// { dg-options "-fgnu-tm" }
+
+class InputStream
+{
+        public:
+        virtual unsigned int readUint32 () = 0;
+};
+
+class Building
+{
+        public:
+        __attribute__((transaction_safe)) Building (InputStream *stream);
+        __attribute__((transaction_safe)) void freeGradients ();
+        void load (InputStream *stream);
+};
+
+Building::Building (InputStream *stream)
+{
+        load(stream);
+}
+
+void Building::load (InputStream *stream)
+{
+        int j = (int)stream->readUint32 ();
+        freeGradients ();
+}
Index: trans-mem.c
===================================================================
--- trans-mem.c	(revision 170360)
+++ trans-mem.c	(working copy)
@@ -4274,6 +4274,27 @@ ipa_tm_insert_gettmclone_call (struct cg
   gimple_call_set_noinline_p (stmt);
 
   gimple_call_set_fn (stmt, callfn);
+
+  /* Discard OBJ_TYPE_REF above, may produce incompatible LHS and RHS
+     for a call statement.  Fix it.  */
+  {
+    tree lhs = gimple_call_lhs (stmt);
+    tree rettype =  TREE_TYPE (TREE_TYPE (TREE_TYPE (callfn)));
+    if (lhs
+	&& !useless_type_conversion_p (TREE_TYPE (lhs), rettype))
+    {
+      tree temp;
+
+      temp = make_rename_temp (rettype, 0);
+      gimple_call_set_lhs (stmt, temp);
+
+      g2 = gimple_build_assign (lhs,
+				fold_build1 (VIEW_CONVERT_EXPR,
+					     TREE_TYPE (lhs), temp));
+      gsi_insert_after (gsi, g2, GSI_SAME_STMT);
+    }
+  }
+
   update_stmt (stmt);
 
   return true;