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7029152: Ideal nodes for String intrinsics miss memory edge optimization

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In Ideal() method of String intrinsics nodes look for TypeAryPtr::CHARS memory slice if memory is MergeMem. Do not unroll a loop with String intrinsics code.

Reviewed-by: never
This commit is contained in:
Vladimir Kozlov 2011-03-30 12:08:49 -07:00
parent fd8aac2f3c
commit 3ecb9f51df
4 changed files with 151 additions and 103 deletions
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79
hotspot/src/share/vm/opto/loopTransform.cpp
View file

@ -396,16 +396,16 @@ void PhaseIdealLoop::do_peeling( IdealLoopTree *loop, Node_List &old_new ) {
// Return exact loop trip count, or 0 if not maximally unrolling
bool IdealLoopTree::policy_maximally_unroll( PhaseIdealLoop *phase ) const {
CountedLoopNode *cl = _head->as_CountedLoop();
assert( cl->is_normal_loop(), "" );
assert(cl->is_normal_loop(), "");
Node *init_n = cl->init_trip();
Node *limit_n = cl->limit();
// Non-constant bounds
if( init_n == NULL || !init_n->is_Con() ||
if (init_n == NULL || !init_n->is_Con() ||
limit_n == NULL || !limit_n->is_Con() ||
// protect against stride not being a constant
!cl->stride_is_con() ) {
!cl->stride_is_con()) {
return false;
}
int init = init_n->get_int();
@ -428,7 +428,25 @@ bool IdealLoopTree::policy_maximally_unroll( PhaseIdealLoop *phase ) const {
uint unroll_limit = (uint)LoopUnrollLimit * 4;
assert( (intx)unroll_limit == LoopUnrollLimit * 4, "LoopUnrollLimit must fit in 32bits");
cl->set_trip_count(trip_count);
if( trip_count <= unroll_limit && body_size <= unroll_limit ) {
if (trip_count > unroll_limit || body_size > unroll_limit) {
return false;
}
// Do not unroll a loop with String intrinsics code.
// String intrinsics are large and have loops.
for (uint k = 0; k < _body.size(); k++) {
Node* n = _body.at(k);
switch (n->Opcode()) {
case Op_StrComp:
case Op_StrEquals:
case Op_StrIndexOf:
case Op_AryEq: {
return false;
}
} // switch
}
if (body_size <= unroll_limit) {
uint new_body_size = body_size * trip_count;
if (new_body_size <= unroll_limit &&
body_size == new_body_size / trip_count &&
@ -448,13 +466,13 @@ bool IdealLoopTree::policy_maximally_unroll( PhaseIdealLoop *phase ) const {
bool IdealLoopTree::policy_unroll( PhaseIdealLoop *phase ) const {
CountedLoopNode *cl = _head->as_CountedLoop();
assert( cl->is_normal_loop() || cl->is_main_loop(), "" );
assert(cl->is_normal_loop() || cl->is_main_loop(), "");
// protect against stride not being a constant
if( !cl->stride_is_con() ) return false;
if (!cl->stride_is_con()) return false;
// protect against over-unrolling
if( cl->trip_count() <= 1 ) return false;
if (cl->trip_count() <= 1) return false;
int future_unroll_ct = cl->unrolled_count() * 2;
@ -485,21 +503,21 @@ bool IdealLoopTree::policy_unroll( PhaseIdealLoop *phase ) const {
// Non-constant bounds.
// Protect against over-unrolling when init or/and limit are not constant
// (so that trip_count's init value is maxint) but iv range is known.
if( init_n == NULL || !init_n->is_Con() ||
limit_n == NULL || !limit_n->is_Con() ) {
if (init_n == NULL || !init_n->is_Con() ||
limit_n == NULL || !limit_n->is_Con()) {
Node* phi = cl->phi();
if( phi != NULL ) {
if (phi != NULL) {
assert(phi->is_Phi() && phi->in(0) == _head, "Counted loop should have iv phi.");
const TypeInt* iv_type = phase->_igvn.type(phi)->is_int();
int next_stride = cl->stride_con() * 2; // stride after this unroll
if( next_stride > 0 ) {
if( iv_type->_lo + next_stride <= iv_type->_lo || // overflow
iv_type->_lo + next_stride > iv_type->_hi ) {
if (next_stride > 0) {
if (iv_type->_lo + next_stride <= iv_type->_lo || // overflow
iv_type->_lo + next_stride > iv_type->_hi) {
return false; // over-unrolling
}
} else if( next_stride < 0 ) {
if( iv_type->_hi + next_stride >= iv_type->_hi || // overflow
iv_type->_hi + next_stride < iv_type->_lo ) {
} else if (next_stride < 0) {
if (iv_type->_hi + next_stride >= iv_type->_hi || // overflow
iv_type->_hi + next_stride < iv_type->_lo) {
return false; // over-unrolling
}
}
@ -511,24 +529,33 @@ bool IdealLoopTree::policy_unroll( PhaseIdealLoop *phase ) const {
// Key test to unroll CaffeineMark's Logic test
int xors_in_loop = 0;
// Also count ModL, DivL and MulL which expand mightly
for( uint k = 0; k < _body.size(); k++ ) {
switch( _body.at(k)->Opcode() ) {
case Op_XorI: xors_in_loop++; break; // CaffeineMark's Logic test
case Op_ModL: body_size += 30; break;
case Op_DivL: body_size += 30; break;
case Op_MulL: body_size += 10; break;
}
for (uint k = 0; k < _body.size(); k++) {
Node* n = _body.at(k);
switch (n->Opcode()) {
case Op_XorI: xors_in_loop++; break; // CaffeineMark's Logic test
case Op_ModL: body_size += 30; break;
case Op_DivL: body_size += 30; break;
case Op_MulL: body_size += 10; break;
case Op_StrComp:
case Op_StrEquals:
case Op_StrIndexOf:
case Op_AryEq: {
// Do not unroll a loop with String intrinsics code.
// String intrinsics are large and have loops.
return false;
}
} // switch
}
// Check for being too big
if( body_size > (uint)LoopUnrollLimit ) {
if( xors_in_loop >= 4 && body_size < (uint)LoopUnrollLimit*4) return true;
if (body_size > (uint)LoopUnrollLimit) {
if (xors_in_loop >= 4 && body_size < (uint)LoopUnrollLimit*4) return true;
// Normal case: loop too big
return false;
}
// Check for stride being a small enough constant
if( abs(cl->stride_con()) > (1<<3) ) return false;
if (abs(cl->stride_con()) > (1<<3)) return false;
// Unroll once! (Each trip will soon do double iterations)
return true;