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8341328: Refactor Assertion Predicate creation from scratch into sepa…
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…rate classes
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@chhagedorn
chhagedorn committed Oct 2, 2024
1 parent f309981 commit 1be0a73
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Showing 6 changed files with 410 additions and 228 deletions.
3 changes: 3 additions & 0 deletions src/hotspot/share/opto/ifnode.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1849,6 +1849,9 @@ void IfNode::dump_spec(outputStream* st) const {
case AssertionPredicateType::LastValue:
st->print("#Last Value Assertion Predicate ");
break;
case AssertionPredicateType::FinalIv:
st->print("#Final IV Assertion Predicate ");
break;
case AssertionPredicateType::None:
// No Assertion Predicate
break;
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81 changes: 22 additions & 59 deletions src/hotspot/share/opto/loopPredicate.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1153,7 +1153,8 @@ void PhaseIdealLoop::loop_predication_follow_branches(Node *n, IdealLoopTree *lo

bool PhaseIdealLoop::loop_predication_impl_helper(IdealLoopTree* loop, IfProjNode* if_success_proj,
ParsePredicateSuccessProj* parse_predicate_proj, CountedLoopNode* cl,
ConNode* zero, Invariance& invar, Deoptimization::DeoptReason reason) {
ConNode* zero, Invariance& invar,
Deoptimization::DeoptReason deopt_reason) {
// Following are changed to nonnull when a predicate can be hoisted
IfNode* iff = if_success_proj->in(0)->as_If();
Node* test = iff->in(1);
Expand All @@ -1165,7 +1166,7 @@ bool PhaseIdealLoop::loop_predication_impl_helper(IdealLoopTree* loop, IfProjNod
if (invar.is_invariant(bol)) {
C->print_method(PHASE_BEFORE_LOOP_PREDICATION_IC, 4, iff);
// Invariant test
IfProjNode* hoisted_check_predicate_proj = create_new_if_for_predicate(parse_predicate_proj, nullptr, reason,
IfProjNode* hoisted_check_predicate_proj = create_new_if_for_predicate(parse_predicate_proj, nullptr, deopt_reason,
iff->Opcode());
Node* ctrl = hoisted_check_predicate_proj->in(0)->as_If()->in(0);
BoolNode* hoisted_check_predicate_bool = invar.clone(bol, ctrl)->as_Bool();
Expand Down Expand Up @@ -1206,9 +1207,9 @@ bool PhaseIdealLoop::loop_predication_impl_helper(IdealLoopTree* loop, IfProjNod
const Node* cmp = bol->in(1)->as_Cmp();
Node* idx = cmp->in(1);
assert(!invar.is_invariant(idx), "index is variant");
Node* rng = cmp->in(2);
assert(rng->Opcode() == Op_LoadRange || iff->is_RangeCheck() || _igvn.type(rng)->is_int()->_lo >= 0, "must be");
assert(invar.is_invariant(rng), "range must be invariant");
Node* range = cmp->in(2);
assert(range->Opcode() == Op_LoadRange || iff->is_RangeCheck() || _igvn.type(range)->is_int()->_lo >= 0, "must be");
assert(invar.is_invariant(range), "range must be invariant");
int scale = 1;
Node* offset = zero;
bool ok = is_scaled_iv_plus_offset(idx, cl->phi(), &scale, &offset);
Expand Down Expand Up @@ -1237,18 +1238,18 @@ bool PhaseIdealLoop::loop_predication_impl_helper(IdealLoopTree* loop, IfProjNod
// late schedule will place invariant things in the loop.
ParsePredicateNode* parse_predicate = parse_predicate_proj->in(0)->as_ParsePredicate();
Node* ctrl = parse_predicate->in(0);
rng = invar.clone(rng, ctrl);
range = invar.clone(range, ctrl);
if (offset && offset != zero) {
assert(invar.is_invariant(offset), "offset must be loop invariant");
offset = invar.clone(offset, ctrl);
}
// If predicate expressions may overflow in the integer range, longs are used.
bool overflow = false;
// Test the lower bound
BoolNode* lower_bound_bol = rc_predicate(ctrl, scale, offset, init, limit, stride, rng, false, overflow);
BoolNode* lower_bound_bol = rc_predicate(ctrl, scale, offset, init, limit, stride, range, false, overflow);

const int if_opcode = iff->Opcode();
IfProjNode* lower_bound_proj = create_new_if_for_predicate(parse_predicate_proj, nullptr, reason, overflow ? Op_If : if_opcode);
IfProjNode* lower_bound_proj = create_new_if_for_predicate(parse_predicate_proj, nullptr, deopt_reason, overflow ? Op_If : if_opcode);
IfNode* lower_bound_iff = lower_bound_proj->in(0)->as_If();
_igvn.hash_delete(lower_bound_iff);
lower_bound_iff->set_req(1, lower_bound_bol);
Expand All @@ -1257,9 +1258,9 @@ bool PhaseIdealLoop::loop_predication_impl_helper(IdealLoopTree* loop, IfProjNod
}

// Test the upper bound
BoolNode* upper_bound_bol = rc_predicate(lower_bound_proj, scale, offset, init, limit, stride, rng, true, overflow);
BoolNode* upper_bound_bol = rc_predicate(lower_bound_proj, scale, offset, init, limit, stride, range, true, overflow);

IfProjNode* upper_bound_proj = create_new_if_for_predicate(parse_predicate_proj, nullptr, reason, overflow ? Op_If : if_opcode);
IfProjNode* upper_bound_proj = create_new_if_for_predicate(parse_predicate_proj, nullptr, deopt_reason, overflow ? Op_If : if_opcode);
assert(upper_bound_proj->in(0)->as_If()->in(0) == lower_bound_proj, "should dominate");
IfNode* upper_bound_iff = upper_bound_proj->in(0)->as_If();
_igvn.hash_delete(upper_bound_iff);
Expand All @@ -1272,8 +1273,8 @@ bool PhaseIdealLoop::loop_predication_impl_helper(IdealLoopTree* loop, IfProjNod
// upper bound test. We always need to create skeleton predicates in order to properly remove dead loops when later
// splitting the predicated loop into (unreachable) sub-loops (i.e. done by unrolling, peeling, pre/main/post etc.).
IfTrueNode* template_assertion_predicate_proj =
add_template_assertion_predicate(iff, loop, hoisted_check_proj, parse_predicate_proj, upper_bound_proj, scale,
offset, init, limit, stride, rng, overflow, reason);
create_template_assertion_predicate(if_opcode, cl, parse_predicate_proj, upper_bound_proj, scale, offset, range,
deopt_reason);

// Eliminate the old range check in the loop body.
// When a range check is eliminated, data dependent nodes (Load and range check CastII nodes) are now dependent on 2
Expand Down Expand Up @@ -1309,53 +1310,15 @@ void PhaseIdealLoop::eliminate_hoisted_range_check(IfTrueNode* hoisted_check_pro
// Each newly created Hoisted Check Predicate is accompanied by two Template Assertion Predicates. Later, we initialize
// them by making a copy of them when splitting a loop into sub loops. The Assertion Predicates ensure that dead sub
// loops are removed properly.
IfTrueNode* PhaseIdealLoop::add_template_assertion_predicate(IfNode* iff, IdealLoopTree* loop, IfProjNode* if_proj,
ParsePredicateSuccessProj* parse_predicate_proj,
IfProjNode* upper_bound_proj, const int scale, Node* offset,
Node* init, Node* limit, const jint stride,
Node* rng, bool& overflow, Deoptimization::DeoptReason reason) {
// First predicate for the initial value on first loop iteration
Node* opaque_init = new OpaqueLoopInitNode(C, init);
register_new_node(opaque_init, upper_bound_proj);
bool negate = (if_proj->_con != parse_predicate_proj->_con);
BoolNode* bol = rc_predicate(upper_bound_proj, scale, offset, opaque_init, limit, stride, rng,
(stride > 0) != (scale > 0), overflow);
Node* opaque_bol = new Opaque4Node(C, bol, _igvn.intcon(1)); // This will go away once loop opts are over
C->add_template_assertion_predicate_opaq(opaque_bol);
register_new_node(opaque_bol, upper_bound_proj);
IfTrueNode* new_proj = create_new_if_for_predicate(parse_predicate_proj, nullptr, reason, overflow ? Op_If : iff->Opcode(),
false NOT_PRODUCT(COMMA AssertionPredicateType::InitValue));
_igvn.replace_input_of(new_proj->in(0), 1, opaque_bol);
assert(opaque_init->outcnt() > 0, "should be used");

// Second predicate for init + (current stride - initial stride)
// This is identical to the previous predicate initially but as
// unrolling proceeds current stride is updated.
Node* init_stride = loop->_head->as_CountedLoop()->stride();
Node* opaque_stride = new OpaqueLoopStrideNode(C, init_stride);
register_new_node(opaque_stride, new_proj);
Node* max_value = new SubINode(opaque_stride, init_stride);
register_new_node(max_value, new_proj);
max_value = new AddINode(opaque_init, max_value);
register_new_node(max_value, new_proj);
// init + (current stride - initial stride) is within the loop so narrow its type by leveraging the type of the iv Phi
const Type* type_iv = loop->_head->as_CountedLoop()->phi()->bottom_type();
assert(!type_iv->is_int()->is_con(), "constant indicates one loop iteration for which we bailed out earlier");
max_value = new CastIINode(new_proj, max_value, type_iv);
register_new_node(max_value, new_proj);

bol = rc_predicate(new_proj, scale, offset, max_value, limit, stride, rng, (stride > 0) != (scale > 0),
overflow);
opaque_bol = new Opaque4Node(C, bol, _igvn.intcon(1));
C->add_template_assertion_predicate_opaq(opaque_bol);
register_new_node(opaque_bol, new_proj);
new_proj = create_new_if_for_predicate(parse_predicate_proj, nullptr, reason, overflow ? Op_If : iff->Opcode(),
false NOT_PRODUCT(COMMA AssertionPredicateType::LastValue));
_igvn.replace_input_of(new_proj->in(0), 1, opaque_bol);
assert(max_value->outcnt() > 0, "should be used");
assert(assertion_predicate_has_loop_opaque_node(new_proj->in(0)->as_If()), "unexpected");

return new_proj;
IfTrueNode* PhaseIdealLoop::create_template_assertion_predicate(const int if_opcode, CountedLoopNode* loop_head,
ParsePredicateSuccessProj* parse_predicate_proj,
IfProjNode* new_control, const int scale, Node* offset,
Node* range, Deoptimization::DeoptReason deopt_reason) {

TemplateAssertionPredicateCreator template_assertion_predicate_creator(loop_head, scale, offset, range, this);
return template_assertion_predicate_creator.create_with_uncommon_trap(new_control, parse_predicate_proj, deopt_reason,
if_opcode);

}

// Insert Hoisted Check Predicates for null checks and range checks and additional Template Assertion Predicates for
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