[llvm-commits] [dragonegg] r155113 - /dragonegg/trunk/src/Convert.cpp

[Duncan Sands]

Author: baldrick
Date: Thu Apr 19 05:03:56 2012
New Revision: 155113

URL: http://llvm.org/viewvc/llvm-project?rev=155113&view=rev
Log:
In gcc-4.7, to indicate that a variable is dead from that point on, a
constructor with TREE_CLOBBER_P is written to it.  Turn this into a
no-op (another possibility is to output an llvm.lifetime.end intrinsic).

Modified:
    dragonegg/trunk/src/Convert.cpp

Modified: dragonegg/trunk/src/Convert.cpp
URL: http://llvm.org/viewvc/llvm-project/dragonegg/trunk/src/Convert.cpp?rev=155113&r1=155112&r2=155113&view=diff
==============================================================================
--- dragonegg/trunk/src/Convert.cpp (original)
+++ dragonegg/trunk/src/Convert.cpp Thu Apr 19 05:03:56 2012
@@ -8145,6 +8145,16 @@
 
 void TreeToLLVM::RenderGIMPLE_ASSIGN(gimple stmt) {
   tree lhs = gimple_assign_lhs(stmt);
+
+#if (GCC_MINOR > 6)
+  // Assigning a right-hand side with TREE_CLOBBER_P says that the left-hand
+  // side is dead from this point on.
+  // TODO: Consider outputting an llvm.lifetime.end intrinsic to indicate this.
+  if (get_gimple_rhs_class(gimple_expr_code(stmt)) == GIMPLE_SINGLE_RHS &&
+      TREE_CLOBBER_P(gimple_assign_rhs1(stmt)))
+    return;
+#endif
+
   if (isa<AGGREGATE_TYPE>(TREE_TYPE(lhs))) {
     assert(get_gimple_rhs_class(gimple_expr_code(stmt)) == GIMPLE_SINGLE_RHS &&
            "Aggregate type but rhs not simple!");