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6706829: Compressed Oops: add debug info for narrow oops

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Add support for narrow oops in debug info to avoid decoding.

Reviewed-by: rasbold, never
This commit is contained in:
Vladimir Kozlov 2008-09-10 18:23:32 -07:00
parent 63c98ed888
commit 659ca734bb
11 changed files with 169 additions and 48 deletions
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78
hotspot/src/share/vm/opto/compile.cpp
View file

@ -1967,6 +1967,7 @@ static void final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &fpu ) {
!n->is_Proj() &&
nop != Op_CreateEx &&
nop != Op_CheckCastPP &&
nop != Op_DecodeN &&
!n->is_Mem() ) {
Node *x = n->clone();
call->set_req( TypeFunc::Parms, x );
@ -2075,20 +2076,27 @@ static void final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &fpu ) {
case Op_CmpP:
// Do this transformation here to preserve CmpPNode::sub() and
// other TypePtr related Ideal optimizations (for example, ptr nullness).
if( n->in(1)->is_DecodeN() ) {
if (n->in(1)->is_DecodeN() || n->in(2)->is_DecodeN()) {
Node* in1 = n->in(1);
Node* in2 = n->in(2);
if (!in1->is_DecodeN()) {
in2 = in1;
in1 = n->in(2);
}
assert(in1->is_DecodeN(), "sanity");
Compile* C = Compile::current();
Node* in2 = NULL;
if( n->in(2)->is_DecodeN() ) {
in2 = n->in(2)->in(1);
} else if ( n->in(2)->Opcode() == Op_ConP ) {
const Type* t = n->in(2)->bottom_type();
Node* new_in2 = NULL;
if (in2->is_DecodeN()) {
new_in2 = in2->in(1);
} else if (in2->Opcode() == Op_ConP) {
const Type* t = in2->bottom_type();
if (t == TypePtr::NULL_PTR) {
Node *in1 = n->in(1);
if (Matcher::clone_shift_expressions) {
// x86, ARM and friends can handle 2 adds in addressing mode.
// Decode a narrow oop and do implicit NULL check in address
// [R12 + narrow_oop_reg<<3 + offset]
in2 = ConNode::make(C, TypeNarrowOop::NULL_PTR);
new_in2 = ConNode::make(C, TypeNarrowOop::NULL_PTR);
} else {
// Don't replace CmpP(o ,null) if 'o' is used in AddP
// to generate implicit NULL check on Sparc where
@ -2099,16 +2107,22 @@ static void final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &fpu ) {
break;
}
if (i >= in1->outcnt()) {
in2 = ConNode::make(C, TypeNarrowOop::NULL_PTR);
new_in2 = ConNode::make(C, TypeNarrowOop::NULL_PTR);
}
}
} else if (t->isa_oopptr()) {
in2 = ConNode::make(C, t->make_narrowoop());
new_in2 = ConNode::make(C, t->make_narrowoop());
}
}
if( in2 != NULL ) {
Node* cmpN = new (C, 3) CmpNNode(n->in(1)->in(1), in2);
if (new_in2 != NULL) {
Node* cmpN = new (C, 3) CmpNNode(in1->in(1), new_in2);
n->subsume_by( cmpN );
if (in1->outcnt() == 0) {
in1->disconnect_inputs(NULL);
}
if (in2->outcnt() == 0) {
in2->disconnect_inputs(NULL);
}
}
}
break;
@ -2214,6 +2228,9 @@ static void final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &fpu ) {
// Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
// requires that the walk visits a node's inputs before visiting the node.
static void final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &fpu ) {
ResourceArea *area = Thread::current()->resource_area();
Unique_Node_List sfpt(area);
fpu._visited.set(root->_idx); // first, mark node as visited
uint cnt = root->req();
Node *n = root;
@ -2224,6 +2241,8 @@ static void final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Re
Node* m = n->in(i);
++i;
if (m != NULL && !fpu._visited.test_set(m->_idx)) {
if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL)
sfpt.push(m);
cnt = m->req();
nstack.push(n, i); // put on stack parent and next input's index
n = m;
@ -2240,6 +2259,41 @@ static void final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Re
nstack.pop(); // Shift to the next node on stack
}
}
// Go over safepoints nodes to skip DecodeN nodes for debug edges.
// It could be done for an uncommon traps or any safepoints/calls
// if the DecodeN node is referenced only in a debug info.
while (sfpt.size() > 0) {
n = sfpt.pop();
JVMState *jvms = n->as_SafePoint()->jvms();
assert(jvms != NULL, "sanity");
int start = jvms->debug_start();
int end = n->req();
bool is_uncommon = (n->is_CallStaticJava() &&
n->as_CallStaticJava()->uncommon_trap_request() != 0);
for (int j = start; j < end; j++) {
Node* in = n->in(j);
if (in->is_DecodeN()) {
bool safe_to_skip = true;
if (!is_uncommon ) {
// Is it safe to skip?
for (uint i = 0; i < in->outcnt(); i++) {
Node* u = in->raw_out(i);
if (!u->is_SafePoint() ||
u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
safe_to_skip = false;
}
}
}
if (safe_to_skip) {
n->set_req(j, in->in(1));
}
if (in->outcnt() == 0) {
in->disconnect_inputs(NULL);
}
}
}
}
}
//------------------------------final_graph_reshaping--------------------------