6809798: SafePointScalarObject node placed into incorrect block during GCM
Summary: Replace the control edge of a pinned node before scheduling.
Reviewed-by: never
--- a/hotspot/src/share/vm/opto/block.cpp Wed Feb 25 14:36:27 2009 -0800
+++ b/hotspot/src/share/vm/opto/block.cpp Thu Feb 26 14:26:02 2009 -0800
@@ -909,6 +909,10 @@
!(n->jvms() != NULL && n->jvms()->is_monitor_use(k)) ) {
assert( b->find_node(def) < j, "uses must follow definitions" );
}
+ if( def->is_SafePointScalarObject() ) {
+ assert(_bbs[def->_idx] == b, "SafePointScalarObject Node should be at the same block as its SafePoint node");
+ assert(_bbs[def->_idx] == _bbs[def->in(0)->_idx], "SafePointScalarObject Node should be at the same block as its control edge");
+ }
}
}
}
--- a/hotspot/src/share/vm/opto/block.hpp Wed Feb 25 14:36:27 2009 -0800
+++ b/hotspot/src/share/vm/opto/block.hpp Thu Feb 26 14:26:02 2009 -0800
@@ -347,6 +347,8 @@
// Helper function to insert a node into a block
void schedule_node_into_block( Node *n, Block *b );
+ void PhaseCFG::replace_block_proj_ctrl( Node *n );
+
// Set the basic block for pinned Nodes
void schedule_pinned_nodes( VectorSet &visited );
--- a/hotspot/src/share/vm/opto/callnode.cpp Wed Feb 25 14:36:27 2009 -0800
+++ b/hotspot/src/share/vm/opto/callnode.cpp Thu Feb 26 14:26:02 2009 -0800
@@ -975,6 +975,7 @@
}
bool SafePointScalarObjectNode::pinned() const { return true; }
+bool SafePointScalarObjectNode::depends_only_on_test() const { return false; }
uint SafePointScalarObjectNode::ideal_reg() const {
return 0; // No matching to machine instruction
--- a/hotspot/src/share/vm/opto/callnode.hpp Wed Feb 25 14:36:27 2009 -0800
+++ b/hotspot/src/share/vm/opto/callnode.hpp Thu Feb 26 14:26:02 2009 -0800
@@ -437,6 +437,10 @@
// of the SafePoint node for which it was generated.
virtual bool pinned() const; // { return true; }
+ // SafePointScalarObject depends on the SafePoint node
+ // for which it was generated.
+ virtual bool depends_only_on_test() const; // { return false; }
+
virtual uint size_of() const { return sizeof(*this); }
// Assumes that "this" is an argument to a safepoint node "s", and that
--- a/hotspot/src/share/vm/opto/gcm.cpp Wed Feb 25 14:36:27 2009 -0800
+++ b/hotspot/src/share/vm/opto/gcm.cpp Thu Feb 26 14:26:02 2009 -0800
@@ -57,6 +57,37 @@
}
}
+//----------------------------replace_block_proj_ctrl-------------------------
+// Nodes that have is_block_proj() nodes as their control need to use
+// the appropriate Region for their actual block as their control since
+// the projection will be in a predecessor block.
+void PhaseCFG::replace_block_proj_ctrl( Node *n ) {
+ const Node *in0 = n->in(0);
+ assert(in0 != NULL, "Only control-dependent");
+ const Node *p = in0->is_block_proj();
+ if (p != NULL && p != n) { // Control from a block projection?
+ assert(!n->pinned() || n->is_SafePointScalarObject(), "only SafePointScalarObject pinned node is expected here");
+ // Find trailing Region
+ Block *pb = _bbs[in0->_idx]; // Block-projection already has basic block
+ uint j = 0;
+ if (pb->_num_succs != 1) { // More then 1 successor?
+ // Search for successor
+ uint max = pb->_nodes.size();
+ assert( max > 1, "" );
+ uint start = max - pb->_num_succs;
+ // Find which output path belongs to projection
+ for (j = start; j < max; j++) {
+ if( pb->_nodes[j] == in0 )
+ break;
+ }
+ assert( j < max, "must find" );
+ // Change control to match head of successor basic block
+ j -= start;
+ }
+ n->set_req(0, pb->_succs[j]->head());
+ }
+}
+
//------------------------------schedule_pinned_nodes--------------------------
// Set the basic block for Nodes pinned into blocks
@@ -68,8 +99,10 @@
Node *n = spstack.pop();
if( !visited.test_set(n->_idx) ) { // Test node and flag it as visited
if( n->pinned() && !_bbs.lookup(n->_idx) ) { // Pinned? Nail it down!
+ assert( n->in(0), "pinned Node must have Control" );
+ // Before setting block replace block_proj control edge
+ replace_block_proj_ctrl(n);
Node *input = n->in(0);
- assert( input, "pinned Node must have Control" );
while( !input->is_block_start() )
input = input->in(0);
Block *b = _bbs[input->_idx]; // Basic block of controlling input
@@ -158,34 +191,12 @@
uint i = nstack_top_i;
if (i == 0) {
- // Special control input processing.
- // While I am here, go ahead and look for Nodes which are taking control
- // from a is_block_proj Node. After I inserted RegionNodes to make proper
- // blocks, the control at a is_block_proj more properly comes from the
- // Region being controlled by the block_proj Node.
+ // Fixup some control. Constants without control get attached
+ // to root and nodes that use is_block_proj() nodes should be attached
+ // to the region that starts their block.
const Node *in0 = n->in(0);
if (in0 != NULL) { // Control-dependent?
- const Node *p = in0->is_block_proj();
- if (p != NULL && p != n) { // Control from a block projection?
- // Find trailing Region
- Block *pb = _bbs[in0->_idx]; // Block-projection already has basic block
- uint j = 0;
- if (pb->_num_succs != 1) { // More then 1 successor?
- // Search for successor
- uint max = pb->_nodes.size();
- assert( max > 1, "" );
- uint start = max - pb->_num_succs;
- // Find which output path belongs to projection
- for (j = start; j < max; j++) {
- if( pb->_nodes[j] == in0 )
- break;
- }
- assert( j < max, "must find" );
- // Change control to match head of successor basic block
- j -= start;
- }
- n->set_req(0, pb->_succs[j]->head());
- }
+ replace_block_proj_ctrl(n);
} else { // n->in(0) == NULL
if (n->req() == 1) { // This guy is a constant with NO inputs?
n->set_req(0, _root);
@@ -226,6 +237,8 @@
if (!n->pinned()) {
// Set earliest legal block.
_bbs.map(n->_idx, find_deepest_input(n, _bbs));
+ } else {
+ assert(_bbs[n->_idx] == _bbs[n->in(0)->_idx], "Pinned Node should be at the same block as its control edge");
}
if (nstack.is_empty()) {
--- a/hotspot/src/share/vm/opto/macro.cpp Wed Feb 25 14:36:27 2009 -0800
+++ b/hotspot/src/share/vm/opto/macro.cpp Thu Feb 26 14:26:02 2009 -0800
@@ -64,6 +64,7 @@
uint old_unique = C->unique();
Node* new_in = old_sosn->clone(jvms_adj, sosn_map);
if (old_unique != C->unique()) {
+ new_in->set_req(0, newcall->in(0)); // reset control edge
new_in = transform_later(new_in); // Register new node.
}
old_in = new_in;