1.1 --- a/src/share/vm/opto/compile.cpp Tue Nov 05 00:59:30 2013 -0800
1.2 +++ b/src/share/vm/opto/compile.cpp Tue Nov 05 01:57:18 2013 -0800
1.3 @@ -848,6 +848,7 @@
1.4 }
1.5 #endif
1.6
1.7 + NOT_PRODUCT( verify_barriers(); )
1.8 // Now that we know the size of all the monitors we can add a fixed slot
1.9 // for the original deopt pc.
1.10
1.11 @@ -3368,6 +3369,72 @@
1.12 }
1.13 }
1.14 }
1.15 +
1.16 +// Verify GC barriers consistency
1.17 +// Currently supported:
1.18 +// - G1 pre-barriers (see GraphKit::g1_write_barrier_pre())
1.19 +void Compile::verify_barriers() {
1.20 + if (UseG1GC) {
1.21 + // Verify G1 pre-barriers
1.22 + const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + PtrQueue::byte_offset_of_active());
1.23 +
1.24 + ResourceArea *area = Thread::current()->resource_area();
1.25 + Unique_Node_List visited(area);
1.26 + Node_List worklist(area);
1.27 + // We're going to walk control flow backwards starting from the Root
1.28 + worklist.push(_root);
1.29 + while (worklist.size() > 0) {
1.30 + Node* x = worklist.pop();
1.31 + if (x == NULL || x == top()) continue;
1.32 + if (visited.member(x)) {
1.33 + continue;
1.34 + } else {
1.35 + visited.push(x);
1.36 + }
1.37 +
1.38 + if (x->is_Region()) {
1.39 + for (uint i = 1; i < x->req(); i++) {
1.40 + worklist.push(x->in(i));
1.41 + }
1.42 + } else {
1.43 + worklist.push(x->in(0));
1.44 + // We are looking for the pattern:
1.45 + // /->ThreadLocal
1.46 + // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset)
1.47 + // \->ConI(0)
1.48 + // We want to verify that the If and the LoadB have the same control
1.49 + // See GraphKit::g1_write_barrier_pre()
1.50 + if (x->is_If()) {
1.51 + IfNode *iff = x->as_If();
1.52 + if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) {
1.53 + CmpNode *cmp = iff->in(1)->in(1)->as_Cmp();
1.54 + if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0
1.55 + && cmp->in(1)->is_Load()) {
1.56 + LoadNode* load = cmp->in(1)->as_Load();
1.57 + if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal
1.58 + && load->in(2)->in(3)->is_Con()
1.59 + && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) {
1.60 +
1.61 + Node* if_ctrl = iff->in(0);
1.62 + Node* load_ctrl = load->in(0);
1.63 +
1.64 + if (if_ctrl != load_ctrl) {
1.65 + // Skip possible CProj->NeverBranch in infinite loops
1.66 + if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
1.67 + && (if_ctrl->in(0)->is_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) {
1.68 + if_ctrl = if_ctrl->in(0)->in(0);
1.69 + }
1.70 + }
1.71 + assert(load_ctrl != NULL && if_ctrl == load_ctrl, "controls must match");
1.72 + }
1.73 + }
1.74 + }
1.75 + }
1.76 + }
1.77 + }
1.78 + }
1.79 +}
1.80 +
1.81 #endif
1.82
1.83 // The Compile object keeps track of failure reasons separately from the ciEnv.
