1.1 --- a/src/share/vm/opto/macro.cpp Wed Jul 15 13:37:35 2009 -0700
1.2 +++ b/src/share/vm/opto/macro.cpp Thu Jul 16 14:10:42 2009 -0700
1.3 @@ -198,14 +198,79 @@
1.4 }
1.5
1.6 // Eliminate a card mark sequence. p2x is a ConvP2XNode
1.7 -void PhaseMacroExpand::eliminate_card_mark(Node *p2x) {
1.8 +void PhaseMacroExpand::eliminate_card_mark(Node* p2x) {
1.9 assert(p2x->Opcode() == Op_CastP2X, "ConvP2XNode required");
1.10 - Node *shift = p2x->unique_out();
1.11 - Node *addp = shift->unique_out();
1.12 - for (DUIterator_Last jmin, j = addp->last_outs(jmin); j >= jmin; --j) {
1.13 - Node *st = addp->last_out(j);
1.14 - assert(st->is_Store(), "store required");
1.15 - _igvn.replace_node(st, st->in(MemNode::Memory));
1.16 + if (!UseG1GC) {
1.17 + // vanilla/CMS post barrier
1.18 + Node *shift = p2x->unique_out();
1.19 + Node *addp = shift->unique_out();
1.20 + for (DUIterator_Last jmin, j = addp->last_outs(jmin); j >= jmin; --j) {
1.21 + Node *st = addp->last_out(j);
1.22 + assert(st->is_Store(), "store required");
1.23 + _igvn.replace_node(st, st->in(MemNode::Memory));
1.24 + }
1.25 + } else {
1.26 + // G1 pre/post barriers
1.27 + assert(p2x->outcnt() == 2, "expects 2 users: Xor and URShift nodes");
1.28 + // It could be only one user, URShift node, in Object.clone() instrinsic
1.29 + // but the new allocation is passed to arraycopy stub and it could not
1.30 + // be scalar replaced. So we don't check the case.
1.31 +
1.32 + // Remove G1 post barrier.
1.33 +
1.34 + // Search for CastP2X->Xor->URShift->Cmp path which
1.35 + // checks if the store done to a different from the value's region.
1.36 + // And replace Cmp with #0 (false) to collapse G1 post barrier.
1.37 + Node* xorx = NULL;
1.38 + for (DUIterator_Fast imax, i = p2x->fast_outs(imax); i < imax; i++) {
1.39 + Node* u = p2x->fast_out(i);
1.40 + if (u->Opcode() == Op_XorX) {
1.41 + xorx = u;
1.42 + break;
1.43 + }
1.44 + }
1.45 + assert(xorx != NULL, "missing G1 post barrier");
1.46 + Node* shift = xorx->unique_out();
1.47 + Node* cmpx = shift->unique_out();
1.48 + assert(cmpx->is_Cmp() && cmpx->unique_out()->is_Bool() &&
1.49 + cmpx->unique_out()->as_Bool()->_test._test == BoolTest::ne,
1.50 + "missing region check in G1 post barrier");
1.51 + _igvn.replace_node(cmpx, makecon(TypeInt::CC_EQ));
1.52 +
1.53 + // Remove G1 pre barrier.
1.54 +
1.55 + // Search "if (marking != 0)" check and set it to "false".
1.56 + Node* this_region = p2x->in(0);
1.57 + assert(this_region != NULL, "");
1.58 + // There is no G1 pre barrier if previous stored value is NULL
1.59 + // (for example, after initialization).
1.60 + if (this_region->is_Region() && this_region->req() == 3) {
1.61 + int ind = 1;
1.62 + if (!this_region->in(ind)->is_IfFalse()) {
1.63 + ind = 2;
1.64 + }
1.65 + if (this_region->in(ind)->is_IfFalse()) {
1.66 + Node* bol = this_region->in(ind)->in(0)->in(1);
1.67 + assert(bol->is_Bool(), "");
1.68 + cmpx = bol->in(1);
1.69 + if (bol->as_Bool()->_test._test == BoolTest::ne &&
1.70 + cmpx->is_Cmp() && cmpx->in(2) == intcon(0) &&
1.71 + cmpx->in(1)->is_Load()) {
1.72 + Node* adr = cmpx->in(1)->as_Load()->in(MemNode::Address);
1.73 + const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() +
1.74 + PtrQueue::byte_offset_of_active());
1.75 + if (adr->is_AddP() && adr->in(AddPNode::Base) == top() &&
1.76 + adr->in(AddPNode::Address)->Opcode() == Op_ThreadLocal &&
1.77 + adr->in(AddPNode::Offset) == MakeConX(marking_offset)) {
1.78 + _igvn.replace_node(cmpx, makecon(TypeInt::CC_EQ));
1.79 + }
1.80 + }
1.81 + }
1.82 + }
1.83 + // Now CastP2X can be removed since it is used only on dead path
1.84 + // which currently still alive until igvn optimize it.
1.85 + assert(p2x->unique_out()->Opcode() == Op_URShiftX, "");
1.86 + _igvn.replace_node(p2x, top());
1.87 }
1.88 }
1.89
1.90 @@ -760,14 +825,11 @@
1.91 if (n->is_Store()) {
1.92 _igvn.replace_node(n, n->in(MemNode::Memory));
1.93 } else {
1.94 - assert( n->Opcode() == Op_CastP2X, "CastP2X required");
1.95 eliminate_card_mark(n);
1.96 }
1.97 k -= (oc2 - use->outcnt());
1.98 }
1.99 } else {
1.100 - assert( !use->is_SafePoint(), "safepoint uses must have been already elimiated");
1.101 - assert( use->Opcode() == Op_CastP2X, "CastP2X required");
1.102 eliminate_card_mark(use);
1.103 }
1.104 j -= (oc1 - res->outcnt());
