changeset 3492:ed21db7b3fda

7123926: Some CTW test crash: !_control.contains(ctrl) Summary: Don't eliminate Integer::toString() call node during String concatenation optimization if it has several uses. Reviewed-by: twisti
author kvn
date Fri, 13 Jul 2012 17:48:26 -0700
parents 6d8f36bcef55
children 56c4f88474b3
files src/share/vm/opto/stringopts.cpp
diffstat 1 files changed, 11 insertions(+), 1 deletions(-) [+]
line wrap: on
line diff
--- a/src/share/vm/opto/stringopts.cpp	Thu Jul 12 00:39:53 2012 -0700
+++ b/src/share/vm/opto/stringopts.cpp	Fri Jul 13 17:48:26 2012 -0700
@@ -533,7 +533,17 @@
         if (arg->is_Proj() && arg->in(0)->is_CallStaticJava()) {
           CallStaticJavaNode* csj = arg->in(0)->as_CallStaticJava();
           if (csj->method() != NULL &&
-              csj->method()->intrinsic_id() == vmIntrinsics::_Integer_toString) {
+              csj->method()->intrinsic_id() == vmIntrinsics::_Integer_toString &&
+              arg->outcnt() == 1) {
+            // _control is the list of StringBuilder calls nodes which
+            // will be replaced by new String code after this optimization.
+            // Integer::toString() call is not part of StringBuilder calls
+            // chain. It could be eliminated only if its result is used
+            // only by this SB calls chain.
+            // Another limitation: it should be used only once because
+            // it is unknown that it is used only by this SB calls chain
+            // until all related SB calls nodes are collected.
+            assert(arg->unique_out() == cnode, "sanity");
             sc->add_control(csj);
             sc->push_int(csj->in(TypeFunc::Parms));
             continue;