truffle: src/share/vm/opto/node.cpp comparison

comparison src/share/vm/opto/node.cpp @ 85:f3b3fe64f59f

6692301: Side effect in NumberFormat tests with -server -Xcomp Summary: Optimization in CmpPNode::sub() removed the valid compare instruction because of false positive answer from detect_dominating_control(). Reviewed-by: jrose, sgoldman

author	kvn
date	Tue, 15 Apr 2008 10:49:32 -0700
parents	99269dbf4ba8
children	ec73d88d5b43

comparison

equal deleted inserted replaced

-:6e085831cad7
+:f3b3fe64f59f
 // Condition for subI(x,subI(y,z)) ==> subI(addI(x,z),y)
 return n->Opcode() == op && n->in(2) == this;
 }
 return false;
 };
+//--------------------------find_exact_control---------------------------------
+// Skip Proj and CatchProj nodes chains. Check for Null and Top.
+Node* Node::find_exact_control(Node* ctrl) {
+if (ctrl == NULL && this->is_Region())
+ctrl = this->as_Region()->is_copy();
+if (ctrl != NULL && ctrl->is_CatchProj()) {
+if (ctrl->as_CatchProj()->_con == CatchProjNode::fall_through_index)
+ctrl = ctrl->in(0);
+if (ctrl != NULL && !ctrl->is_top())
+ctrl = ctrl->in(0);
+}
+if (ctrl != NULL && ctrl->is_Proj())
+ctrl = ctrl->in(0);
+return ctrl;
+}
+//--------------------------dominates------------------------------------------
+// Helper function for MemNode::all_controls_dominate().
+// Check if 'this' control node dominates or equal to 'sub' control node.
+bool Node::dominates(Node* sub, Node_List &nlist) {
+assert(this->is_CFG(), "expecting control");
+assert(sub != NULL && sub->is_CFG(), "expecting control");
+Node* orig_sub = sub;
+nlist.clear();
+bool this_dominates = false;
+uint region_input = 0;
+while (sub != NULL) {        // walk 'sub' up the chain to 'this'
+if (sub == this) {
+if (nlist.size() == 0) {
+// No Region nodes except loops were visited before and the EntryControl
+// path was taken for loops: it did not walk in a cycle.
+return true;
+} else if (!this_dominates) {
+// Region nodes were visited. Continue walk up to Start or Root
+// to make sure that it did not walk in a cycle.
+this_dominates = true; // first time meet
+} else {
+return false;          // already met before: walk in a cycle
+}
+}
+if (sub->is_Start() || sub->is_Root())
+return this_dominates;
+Node* up = sub->find_exact_control(sub->in(0));
+if (up == NULL || up->is_top())
+return false; // Conservative answer for dead code
+if (sub == up && sub->is_Loop()) {
+up = sub->in(0); // in(LoopNode::EntryControl);
+} else if (sub == up && sub->is_Region()) {
+uint i = 1;
+if (nlist.size() == 0) {
+// No Region nodes (except Loops) were visited before.
+// Take first valid path on the way up to 'this'.
+} else if (nlist.at(nlist.size() - 1) == sub) {
+// This Region node was just visited. Take other path.
+i = region_input + 1;
+nlist.pop();
+} else {
+// Was this Region node visited before?
+uint size = nlist.size();
+for (uint j = 0; j < size; j++) {
+if (nlist.at(j) == sub) {
+return false; // The Region node was visited before. Give up.
+}
+}
+// The Region node was not visited before.
+// Take first valid path on the way up to 'this'.
+}
+for (; i < sub->req(); i++) {
+Node* in = sub->in(i);
+if (in != NULL && !in->is_top() && in != sub) {
+break;
+}
+}
+if (i < sub->req()) {
+nlist.push(sub);
+up = sub->in(i);
+region_input = i;
+}
+}
+if (sub == up)
+return false;    // some kind of tight cycle
+if (orig_sub == up)
+return false;    // walk in a cycle
+sub = up;
+}
+return false;
+}
 //------------------------------remove_dead_region-----------------------------
 // This control node is dead.  Follow the subgraph below it making everything
 // using it dead as well.  This will happen normally via the usual IterGVN
 // worklist but this call is more efficient.  Do not update use-def info

Mercurial > hg > truffle

comparison src/share/vm/opto/node.cpp @ 85:f3b3fe64f59f