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comparison src/share/vm/opto/compile.cpp @ 13045:94a83e0f9ce1

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8017065: C2 allows safepoint checks to leak into G1 pre-barriers Summary: Make all raw loads strictly respect control dependencies, make sure RCE doesn't move raw loads, add verification of G1 pre-barriers. Reviewed-by: kvn, roland
author iveresov
date Tue, 05 Nov 2013 01:57:18 -0800
parents b2ee5dc63353
children 613e6a6fc328
comparison
equal deleted inserted replaced
13044:a905d33ce13a 13045:94a83e0f9ce1
846 xtty->tail("ideal"); 846 xtty->tail("ideal");
847 } 847 }
848 } 848 }
849 #endif 849 #endif
850 850
851 NOT_PRODUCT( verify_barriers(); )
851 // Now that we know the size of all the monitors we can add a fixed slot 852 // Now that we know the size of all the monitors we can add a fixed slot
852 // for the original deopt pc. 853 // for the original deopt pc.
853 854
854 _orig_pc_slot = fixed_slots(); 855 _orig_pc_slot = fixed_slots();
855 int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size); 856 int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
3366 } 3367 }
3367 assert(dead_nodes == 0, "using nodes must be reachable from root"); 3368 assert(dead_nodes == 0, "using nodes must be reachable from root");
3368 } 3369 }
3369 } 3370 }
3370 } 3371 }
3372
3373 // Verify GC barriers consistency
3374 // Currently supported:
3375 // - G1 pre-barriers (see GraphKit::g1_write_barrier_pre())
3376 void Compile::verify_barriers() {
3377 if (UseG1GC) {
3378 // Verify G1 pre-barriers
3379 const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + PtrQueue::byte_offset_of_active());
3380
3381 ResourceArea *area = Thread::current()->resource_area();
3382 Unique_Node_List visited(area);
3383 Node_List worklist(area);
3384 // We're going to walk control flow backwards starting from the Root
3385 worklist.push(_root);
3386 while (worklist.size() > 0) {
3387 Node* x = worklist.pop();
3388 if (x == NULL || x == top()) continue;
3389 if (visited.member(x)) {
3390 continue;
3391 } else {
3392 visited.push(x);
3393 }
3394
3395 if (x->is_Region()) {
3396 for (uint i = 1; i < x->req(); i++) {
3397 worklist.push(x->in(i));
3398 }
3399 } else {
3400 worklist.push(x->in(0));
3401 // We are looking for the pattern:
3402 // /->ThreadLocal
3403 // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset)
3404 // \->ConI(0)
3405 // We want to verify that the If and the LoadB have the same control
3406 // See GraphKit::g1_write_barrier_pre()
3407 if (x->is_If()) {
3408 IfNode *iff = x->as_If();
3409 if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) {
3410 CmpNode *cmp = iff->in(1)->in(1)->as_Cmp();
3411 if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0
3412 && cmp->in(1)->is_Load()) {
3413 LoadNode* load = cmp->in(1)->as_Load();
3414 if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal
3415 && load->in(2)->in(3)->is_Con()
3416 && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) {
3417
3418 Node* if_ctrl = iff->in(0);
3419 Node* load_ctrl = load->in(0);
3420
3421 if (if_ctrl != load_ctrl) {
3422 // Skip possible CProj->NeverBranch in infinite loops
3423 if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
3424 && (if_ctrl->in(0)->is_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) {
3425 if_ctrl = if_ctrl->in(0)->in(0);
3426 }
3427 }
3428 assert(load_ctrl != NULL && if_ctrl == load_ctrl, "controls must match");
3429 }
3430 }
3431 }
3432 }
3433 }
3434 }
3435 }
3436 }
3437
3371 #endif 3438 #endif
3372 3439
3373 // The Compile object keeps track of failure reasons separately from the ciEnv. 3440 // The Compile object keeps track of failure reasons separately from the ciEnv.
3374 // This is required because there is not quite a 1-1 relation between the 3441 // This is required because there is not quite a 1-1 relation between the
3375 // ciEnv and its compilation task and the Compile object. Note that one 3442 // ciEnv and its compilation task and the Compile object. Note that one