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6709093: Compressed Oops: reduce size of compiled methods

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Exclude UEP size from nmethod code size and use narrow klass oop to load prototype header.

Reviewed-by: jrose, never
This commit is contained in:
Vladimir Kozlov 2008-06-05 13:02:51 -07:00
parent 54eeffff83
commit dbdeade3b7
6 changed files with 64 additions and 13 deletions
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40
hotspot/src/share/vm/opto/compile.cpp
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@ -1992,11 +1992,49 @@ static void final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &fpu ) {
}
case Op_AddP: { // Assert sane base pointers
const Node *addp = n->in(AddPNode::Address);
Node *addp = n->in(AddPNode::Address);
assert( !addp->is_AddP() ||
addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
addp->in(AddPNode::Base) == n->in(AddPNode::Base),
"Base pointers must match" );
#ifdef _LP64
if (UseCompressedOops &&
addp->Opcode() == Op_ConP &&
addp == n->in(AddPNode::Base) &&
n->in(AddPNode::Offset)->is_Con()) {
// Use addressing with narrow klass to load with offset on x86.
// On sparc loading 32-bits constant and decoding it have less
// instructions (4) then load 64-bits constant (7).
// Do this transformation here since IGVN will convert ConN back to ConP.
const Type* t = addp->bottom_type();
if (t->isa_oopptr()) {
Node* nn = NULL;
// Look for existing ConN node of the same exact type.
Compile* C = Compile::current();
Node* r = C->root();
uint cnt = r->outcnt();
for (uint i = 0; i < cnt; i++) {
Node* m = r->raw_out(i);
if (m!= NULL && m->Opcode() == Op_ConN &&
m->bottom_type()->is_narrowoop()->make_oopptr() == t) {
nn = m;
break;
}
}
if (nn != NULL) {
// Decode a narrow oop to match address
// [R12 + narrow_oop_reg<<3 + offset]
nn = new (C, 2) DecodeNNode(nn, t);
n->set_req(AddPNode::Base, nn);
n->set_req(AddPNode::Address, nn);
if (addp->outcnt() == 0) {
addp->disconnect_inputs(NULL);
}
}
}
}
#endif
break;
}