diff options
Diffstat (limited to 'src/share/vm/opto/subnode.cpp')
| -rw-r--r-- | src/share/vm/opto/subnode.cpp | 58 |
1 files changed, 44 insertions, 14 deletions
diff --git a/src/share/vm/opto/subnode.cpp b/src/share/vm/opto/subnode.cpp index 90ad08700..774aff9f4 100644 --- a/src/share/vm/opto/subnode.cpp +++ b/src/share/vm/opto/subnode.cpp @@ -633,20 +633,31 @@ const Type *CmpPNode::sub( const Type *t1, const Type *t2 ) const { kps != 1 && // both or neither are klass pointers !klass0->is_interface() && // do not trust interfaces !klass1->is_interface()) { + bool unrelated_classes = false; // See if neither subclasses the other, or if the class on top - // is precise. In either of these cases, the compare must fail. + // is precise. In either of these cases, the compare is known + // to fail if at least one of the pointers is provably not null. if (klass0->equals(klass1) || // if types are unequal but klasses are !klass0->is_java_klass() || // types not part of Java language? !klass1->is_java_klass()) { // types not part of Java language? // Do nothing; we know nothing for imprecise types } else if (klass0->is_subtype_of(klass1)) { - // If klass1's type is PRECISE, then we can fail. - if (xklass1) return TypeInt::CC_GT; + // If klass1's type is PRECISE, then classes are unrelated. + unrelated_classes = xklass1; } else if (klass1->is_subtype_of(klass0)) { - // If klass0's type is PRECISE, then we can fail. - if (xklass0) return TypeInt::CC_GT; + // If klass0's type is PRECISE, then classes are unrelated. + unrelated_classes = xklass0; } else { // Neither subtypes the other - return TypeInt::CC_GT; // ...so always fail + unrelated_classes = true; + } + if (unrelated_classes) { + // The oops classes are known to be unrelated. If the joined PTRs of + // two oops is not Null and not Bottom, then we are sure that one + // of the two oops is non-null, and the comparison will always fail. + TypePtr::PTR jp = r0->join_ptr(r1->_ptr); + if (jp != TypePtr::Null && jp != TypePtr::BotPTR) { + return TypeInt::CC_GT; + } } } } @@ -681,7 +692,11 @@ Node *CmpPNode::Ideal( PhaseGVN *phase, bool can_reshape ) { // Now check for LoadKlass on left. Node* ldk1 = in(1); - if (ldk1->Opcode() != Op_LoadKlass) + if (ldk1->is_DecodeN()) { + ldk1 = ldk1->in(1); + if (ldk1->Opcode() != Op_LoadNKlass ) + return NULL; + } else if (ldk1->Opcode() != Op_LoadKlass ) return NULL; // Take apart the address of the LoadKlass: Node* adr1 = ldk1->in(MemNode::Address); @@ -702,7 +717,11 @@ Node *CmpPNode::Ideal( PhaseGVN *phase, bool can_reshape ) { // Check for a LoadKlass from primary supertype array. // Any nested loadklass from loadklass+con must be from the p.s. array. - if (ldk2->Opcode() != Op_LoadKlass) + if (ldk2->is_DecodeN()) { + // Keep ldk2 as DecodeN since it could be used in CmpP below. + if (ldk2->in(1)->Opcode() != Op_LoadNKlass ) + return NULL; + } else if (ldk2->Opcode() != Op_LoadKlass) return NULL; // Verify that we understand the situation @@ -769,20 +788,31 @@ const Type *CmpNNode::sub( const Type *t1, const Type *t2 ) const { kps != 1 && // both or neither are klass pointers !klass0->is_interface() && // do not trust interfaces !klass1->is_interface()) { + bool unrelated_classes = false; // See if neither subclasses the other, or if the class on top - // is precise. In either of these cases, the compare must fail. + // is precise. In either of these cases, the compare is known + // to fail if at least one of the pointers is provably not null. if (klass0->equals(klass1) || // if types are unequal but klasses are !klass0->is_java_klass() || // types not part of Java language? !klass1->is_java_klass()) { // types not part of Java language? // Do nothing; we know nothing for imprecise types } else if (klass0->is_subtype_of(klass1)) { - // If klass1's type is PRECISE, then we can fail. - if (xklass1) return TypeInt::CC_GT; + // If klass1's type is PRECISE, then classes are unrelated. + unrelated_classes = xklass1; } else if (klass1->is_subtype_of(klass0)) { - // If klass0's type is PRECISE, then we can fail. - if (xklass0) return TypeInt::CC_GT; + // If klass0's type is PRECISE, then classes are unrelated. + unrelated_classes = xklass0; } else { // Neither subtypes the other - return TypeInt::CC_GT; // ...so always fail + unrelated_classes = true; + } + if (unrelated_classes) { + // The oops classes are known to be unrelated. If the joined PTRs of + // two oops is not Null and not Bottom, then we are sure that one + // of the two oops is non-null, and the comparison will always fail. + TypePtr::PTR jp = r0->join_ptr(r1->_ptr); + if (jp != TypePtr::Null && jp != TypePtr::BotPTR) { + return TypeInt::CC_GT; + } } } } |