8042786: Proper fix for 8032566
Summary: Check for overflow cases in range checks and collapse it if we can.
Reviewed-by: jrose, iveresov
--- a/hotspot/src/share/vm/opto/c2_globals.hpp Mon Jan 27 10:20:51 2014 -0800
+++ b/hotspot/src/share/vm/opto/c2_globals.hpp Fri May 16 12:05:14 2014 -0700
@@ -452,7 +452,7 @@
notproduct(bool, PrintEliminateLocks, false, \
"Print out when locks are eliminated") \
\
- product(bool, EliminateAutoBox, false, \
+ product(bool, EliminateAutoBox, true, \
"Control optimizations for autobox elimination") \
\
diagnostic(bool, UseImplicitStableValues, true, \
--- a/hotspot/src/share/vm/opto/callGenerator.cpp Mon Jan 27 10:20:51 2014 -0800
+++ b/hotspot/src/share/vm/opto/callGenerator.cpp Fri May 16 12:05:14 2014 -0700
@@ -391,7 +391,7 @@
}
// Setup default node notes to be picked up by the inlining
- Node_Notes* old_nn = C->default_node_notes();
+ Node_Notes* old_nn = C->node_notes_at(call->_idx);
if (old_nn != NULL) {
Node_Notes* entry_nn = old_nn->clone(C);
entry_nn->set_jvms(jvms);
--- a/hotspot/src/share/vm/opto/doCall.cpp Mon Jan 27 10:20:51 2014 -0800
+++ b/hotspot/src/share/vm/opto/doCall.cpp Fri May 16 12:05:14 2014 -0700
@@ -364,7 +364,7 @@
bool Compile::should_delay_boxing_inlining(ciMethod* call_method, JVMState* jvms) {
if (eliminate_boxing() && call_method->is_boxing_method()) {
set_has_boxed_value(true);
- return true;
+ return aggressive_unboxing();
}
return false;
}
--- a/hotspot/src/share/vm/opto/ifnode.cpp Mon Jan 27 10:20:51 2014 -0800
+++ b/hotspot/src/share/vm/opto/ifnode.cpp Fri May 16 12:05:14 2014 -0700
@@ -673,7 +673,7 @@
// / Region
//
Node* IfNode::fold_compares(PhaseGVN* phase) {
- if (!phase->C->eliminate_boxing() || Opcode() != Op_If) return NULL;
+ if (Opcode() != Op_If) return NULL;
Node* this_cmp = in(1)->in(1);
if (this_cmp != NULL && this_cmp->Opcode() == Op_CmpI &&
--- a/hotspot/src/share/vm/opto/phaseX.cpp Mon Jan 27 10:20:51 2014 -0800
+++ b/hotspot/src/share/vm/opto/phaseX.cpp Fri May 16 12:05:14 2014 -0700
@@ -1393,6 +1393,15 @@
_worklist.push(u);
}
}
+ // If changed AddI/SubI inputs, check CmpU for range check optimization.
+ if (use_op == Op_AddI || use_op == Op_SubI) {
+ for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) {
+ Node* u = use->fast_out(i2);
+ if (u->is_Cmp() && (u->Opcode() == Op_CmpU)) {
+ _worklist.push(u);
+ }
+ }
+ }
// If changed AddP inputs, check Stores for loop invariant
if( use_op == Op_AddP ) {
for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) {
--- a/hotspot/src/share/vm/opto/subnode.cpp Mon Jan 27 10:20:51 2014 -0800
+++ b/hotspot/src/share/vm/opto/subnode.cpp Fri May 16 12:05:14 2014 -0700
@@ -80,7 +80,7 @@
//------------------------------Value------------------------------------------
// A subtract node differences it's two inputs.
-const Type *SubNode::Value( PhaseTransform *phase ) const {
+const Type* SubNode::Value_common(PhaseTransform *phase) const {
const Node* in1 = in(1);
const Node* in2 = in(2);
// Either input is TOP ==> the result is TOP
@@ -97,6 +97,16 @@
if( t1 == Type::BOTTOM || t2 == Type::BOTTOM )
return bottom_type();
+ return NULL;
+}
+
+const Type* SubNode::Value(PhaseTransform *phase) const {
+ const Type* t = Value_common(phase);
+ if (t != NULL) {
+ return t;
+ }
+ const Type* t1 = phase->type(in(1));
+ const Type* t2 = phase->type(in(2));
return sub(t1,t2); // Local flavor of type subtraction
}
@@ -570,6 +580,81 @@
return TypeInt::CC; // else use worst case results
}
+const Type* CmpUNode::Value(PhaseTransform *phase) const {
+ const Type* t = SubNode::Value_common(phase);
+ if (t != NULL) {
+ return t;
+ }
+ const Node* in1 = in(1);
+ const Node* in2 = in(2);
+ const Type* t1 = phase->type(in1);
+ const Type* t2 = phase->type(in2);
+ assert(t1->isa_int(), "CmpU has only Int type inputs");
+ if (t2 == TypeInt::INT) { // Compare to bottom?
+ return bottom_type();
+ }
+ uint in1_op = in1->Opcode();
+ if (in1_op == Op_AddI || in1_op == Op_SubI) {
+ // The problem rise when result of AddI(SubI) may overflow
+ // signed integer value. Let say the input type is
+ // [256, maxint] then +128 will create 2 ranges due to
+ // overflow: [minint, minint+127] and [384, maxint].
+ // But C2 type system keep only 1 type range and as result
+ // it use general [minint, maxint] for this case which we
+ // can't optimize.
+ //
+ // Make 2 separate type ranges based on types of AddI(SubI) inputs
+ // and compare results of their compare. If results are the same
+ // CmpU node can be optimized.
+ const Node* in11 = in1->in(1);
+ const Node* in12 = in1->in(2);
+ const Type* t11 = (in11 == in1) ? Type::TOP : phase->type(in11);
+ const Type* t12 = (in12 == in1) ? Type::TOP : phase->type(in12);
+ // Skip cases when input types are top or bottom.
+ if ((t11 != Type::TOP) && (t11 != TypeInt::INT) &&
+ (t12 != Type::TOP) && (t12 != TypeInt::INT)) {
+ const TypeInt *r0 = t11->is_int();
+ const TypeInt *r1 = t12->is_int();
+ jlong lo_r0 = r0->_lo;
+ jlong hi_r0 = r0->_hi;
+ jlong lo_r1 = r1->_lo;
+ jlong hi_r1 = r1->_hi;
+ if (in1_op == Op_SubI) {
+ jlong tmp = hi_r1;
+ hi_r1 = -lo_r1;
+ lo_r1 = -tmp;
+ // Note, for substructing [minint,x] type range
+ // long arithmetic provides correct overflow answer.
+ // The confusion come from the fact that in 32-bit
+ // -minint == minint but in 64-bit -minint == maxint+1.
+ }
+ jlong lo_long = lo_r0 + lo_r1;
+ jlong hi_long = hi_r0 + hi_r1;
+ int lo_tr1 = min_jint;
+ int hi_tr1 = (int)hi_long;
+ int lo_tr2 = (int)lo_long;
+ int hi_tr2 = max_jint;
+ bool underflow = lo_long != (jlong)lo_tr2;
+ bool overflow = hi_long != (jlong)hi_tr1;
+ // Use sub(t1, t2) when there is no overflow (one type range)
+ // or when both overflow and underflow (too complex).
+ if ((underflow != overflow) && (hi_tr1 < lo_tr2)) {
+ // Overflow only on one boundary, compare 2 separate type ranges.
+ int w = MAX2(r0->_widen, r1->_widen); // _widen does not matter here
+ const TypeInt* tr1 = TypeInt::make(lo_tr1, hi_tr1, w);
+ const TypeInt* tr2 = TypeInt::make(lo_tr2, hi_tr2, w);
+ const Type* cmp1 = sub(tr1, t2);
+ const Type* cmp2 = sub(tr2, t2);
+ if (cmp1 == cmp2) {
+ return cmp1; // Hit!
+ }
+ }
+ }
+ }
+
+ return sub(t1, t2); // Local flavor of type subtraction
+}
+
bool CmpUNode::is_index_range_check() const {
// Check for the "(X ModI Y) CmpU Y" shape
return (in(1)->Opcode() == Op_ModI &&
--- a/hotspot/src/share/vm/opto/subnode.hpp Mon Jan 27 10:20:51 2014 -0800
+++ b/hotspot/src/share/vm/opto/subnode.hpp Fri May 16 12:05:14 2014 -0700
@@ -50,6 +50,7 @@
// Compute a new Type for this node. Basically we just do the pre-check,
// then call the virtual add() to set the type.
virtual const Type *Value( PhaseTransform *phase ) const;
+ const Type* Value_common( PhaseTransform *phase ) const;
// Supplied function returns the subtractend of the inputs.
// This also type-checks the inputs for sanity. Guaranteed never to
@@ -158,6 +159,7 @@
CmpUNode( Node *in1, Node *in2 ) : CmpNode(in1,in2) {}
virtual int Opcode() const;
virtual const Type *sub( const Type *, const Type * ) const;
+ const Type *Value( PhaseTransform *phase ) const;
bool is_index_range_check() const;
};