Mercurial > jdk8-mips64-public > hotspot / changeset

     1.1 --- a/src/share/vm/opto/subnode.cpp	Mon Aug 18 23:17:51 2008 -0700
     1.2 +++ b/src/share/vm/opto/subnode.cpp	Tue Aug 19 07:25:02 2008 -0700
     1.3 @@ -633,20 +633,31 @@
     1.4          kps != 1 &&             // both or neither are klass pointers
     1.5          !klass0->is_interface() && // do not trust interfaces
     1.6          !klass1->is_interface()) {
     1.7 +      bool unrelated_classes = false;
     1.8        // See if neither subclasses the other, or if the class on top
     1.9 -      // is precise.  In either of these cases, the compare must fail.
    1.10 +      // is precise.  In either of these cases, the compare is known
    1.11 +      // to fail if at least one of the pointers is provably not null.
    1.12        if (klass0->equals(klass1)   ||   // if types are unequal but klasses are
    1.13            !klass0->is_java_klass() ||   // types not part of Java language?
    1.14            !klass1->is_java_klass()) {   // types not part of Java language?
    1.15          // Do nothing; we know nothing for imprecise types
    1.16        } else if (klass0->is_subtype_of(klass1)) {
    1.17 -        // If klass1's type is PRECISE, then we can fail.
    1.18 -        if (xklass1)  return TypeInt::CC_GT;
    1.19 +        // If klass1's type is PRECISE, then classes are unrelated.
    1.20 +        unrelated_classes = xklass1;
    1.21        } else if (klass1->is_subtype_of(klass0)) {
    1.22 -        // If klass0's type is PRECISE, then we can fail.
    1.23 -        if (xklass0)  return TypeInt::CC_GT;
    1.24 +        // If klass0's type is PRECISE, then classes are unrelated.
    1.25 +        unrelated_classes = xklass0;
    1.26        } else {                  // Neither subtypes the other
    1.27 -        return TypeInt::CC_GT;  // ...so always fail
    1.28 +        unrelated_classes = true;
    1.29 +      }
    1.30 +      if (unrelated_classes) {
    1.31 +        // The oops classes are known to be unrelated. If the joined PTRs of
    1.32 +        // two oops is not Null and not Bottom, then we are sure that one
    1.33 +        // of the two oops is non-null, and the comparison will always fail.
    1.34 +        TypePtr::PTR jp = r0->join_ptr(r1->_ptr);
    1.35 +        if (jp != TypePtr::Null && jp != TypePtr::BotPTR) {
    1.36 +          return TypeInt::CC_GT;
    1.37 +        }
    1.38        }
    1.39      }
    1.40    }
    1.41 @@ -777,20 +788,31 @@
    1.42          kps != 1 &&             // both or neither are klass pointers
    1.43          !klass0->is_interface() && // do not trust interfaces
    1.44          !klass1->is_interface()) {
    1.45 +      bool unrelated_classes = false;
    1.46        // See if neither subclasses the other, or if the class on top
    1.47 -      // is precise.  In either of these cases, the compare must fail.
    1.48 +      // is precise.  In either of these cases, the compare is known
    1.49 +      // to fail if at least one of the pointers is provably not null.
    1.50        if (klass0->equals(klass1)   ||   // if types are unequal but klasses are
    1.51            !klass0->is_java_klass() ||   // types not part of Java language?
    1.52            !klass1->is_java_klass()) {   // types not part of Java language?
    1.53          // Do nothing; we know nothing for imprecise types
    1.54        } else if (klass0->is_subtype_of(klass1)) {
    1.55 -        // If klass1's type is PRECISE, then we can fail.
    1.56 -        if (xklass1)  return TypeInt::CC_GT;
    1.57 +        // If klass1's type is PRECISE, then classes are unrelated.
    1.58 +        unrelated_classes = xklass1;
    1.59        } else if (klass1->is_subtype_of(klass0)) {
    1.60 -        // If klass0's type is PRECISE, then we can fail.
    1.61 -        if (xklass0)  return TypeInt::CC_GT;
    1.62 +        // If klass0's type is PRECISE, then classes are unrelated.
    1.63 +        unrelated_classes = xklass0;
    1.64        } else {                  // Neither subtypes the other
    1.65 -        return TypeInt::CC_GT;  // ...so always fail
    1.66 +        unrelated_classes = true;
    1.67 +      }
    1.68 +      if (unrelated_classes) {
    1.69 +        // The oops classes are known to be unrelated. If the joined PTRs of
    1.70 +        // two oops is not Null and not Bottom, then we are sure that one
    1.71 +        // of the two oops is non-null, and the comparison will always fail.
    1.72 +        TypePtr::PTR jp = r0->join_ptr(r1->_ptr);
    1.73 +        if (jp != TypePtr::Null && jp != TypePtr::BotPTR) {
    1.74 +          return TypeInt::CC_GT;
    1.75 +        }
    1.76        }
    1.77      }
    1.78    }