archive/jdk
1
0
Fork 0
mirror of https://github.com/openjdk/jdk.git synced 2025-09-21 11:34:38 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

8001107: @Stable annotation for constant folding of lazily evaluated variables

Browse source 
Co-authored-by: John Rose <john.r.rose@oracle.com>
Reviewed-by: rbackman, twisti, kvn
This commit is contained in:
Vladimir Ivanov 2013-09-10 14:51:48 -07:00
parent 19d50345e1
commit f0e77ac67f
25 changed files with 419 additions and 84 deletions
Download patch file Download diff file Expand all files Collapse all files

71
hotspot/src/share/vm/opto/parse3.cpp
View file

@ -147,7 +147,15 @@ void Parse::do_field_access(bool is_get, bool is_field) {
void Parse::do_get_xxx(Node* obj, ciField* field, bool is_field) {
// Does this field have a constant value? If so, just push the value.
if (field->is_constant()) {
// final field
// final or stable field
const Type* stable_type = NULL;
if (FoldStableValues && field->is_stable()) {
stable_type = Type::get_const_type(field->type());
if (field->type()->is_array_klass()) {
int stable_dimension = field->type()->as_array_klass()->dimension();
stable_type = stable_type->is_aryptr()->cast_to_stable(true, stable_dimension);
}
}
if (field->is_static()) {
// final static field
if (C->eliminate_boxing()) {
@ -167,11 +175,10 @@ void Parse::do_get_xxx(Node* obj, ciField* field, bool is_field) {
}
}
}
if (push_constant(field->constant_value()))
if (push_constant(field->constant_value(), false, false, stable_type))
return;
}
else {
// final non-static field
} else {
// final or stable non-static field
// Treat final non-static fields of trusted classes (classes in
// java.lang.invoke and sun.invoke packages and subpackages) as
// compile time constants.
@ -179,8 +186,12 @@ void Parse::do_get_xxx(Node* obj, ciField* field, bool is_field) {
const TypeOopPtr* oop_ptr = obj->bottom_type()->isa_oopptr();
ciObject* constant_oop = oop_ptr->const_oop();
ciConstant constant = field->constant_value_of(constant_oop);
if (push_constant(constant, true))
return;
if (FoldStableValues && field->is_stable() && constant.is_null_or_zero()) {
// fall through to field load; the field is not yet initialized
} else {
if (push_constant(constant, true, false, stable_type))
return;
}
}
}
}
@ -301,7 +312,8 @@ void Parse::do_put_xxx(Node* obj, ciField* field, bool is_field) {
// Note the presence of writes to final non-static fields, so that we
// can insert a memory barrier later on to keep the writes from floating
// out of the constructor.
if (is_field && field->is_final()) {
// Any method can write a @Stable field; insert memory barriers after those also.
if (is_field && (field->is_final() || field->is_stable())) {
set_wrote_final(true);
// Preserve allocation ptr to create precedent edge to it in membar
// generated on exit from constructor.
@ -314,35 +326,21 @@ void Parse::do_put_xxx(Node* obj, ciField* field, bool is_field) {
}
bool Parse::push_constant(ciConstant constant, bool require_constant, bool is_autobox_cache) {
bool Parse::push_constant(ciConstant constant, bool require_constant, bool is_autobox_cache, const Type* stable_type) {
const Type* con_type = Type::make_from_constant(constant, require_constant, is_autobox_cache);
switch (constant.basic_type()) {
case T_BOOLEAN: push( intcon(constant.as_boolean()) ); break;
case T_INT: push( intcon(constant.as_int()) ); break;
case T_CHAR: push( intcon(constant.as_char()) ); break;
case T_BYTE: push( intcon(constant.as_byte()) ); break;
case T_SHORT: push( intcon(constant.as_short()) ); break;
case T_FLOAT: push( makecon(TypeF::make(constant.as_float())) ); break;
case T_DOUBLE: push_pair( makecon(TypeD::make(constant.as_double())) ); break;
case T_LONG: push_pair( longcon(constant.as_long()) ); break;
case T_ARRAY:
case T_OBJECT: {
case T_OBJECT:
// cases:
// can_be_constant = (oop not scavengable || ScavengeRootsInCode != 0)
// should_be_constant = (oop not scavengable || ScavengeRootsInCode >= 2)
// An oop is not scavengable if it is in the perm gen.
ciObject* oop_constant = constant.as_object();
if (oop_constant->is_null_object()) {
push( zerocon(T_OBJECT) );
break;
} else if (require_constant || oop_constant->should_be_constant()) {
push( makecon(TypeOopPtr::make_from_constant(oop_constant, require_constant, is_autobox_cache)) );
break;
} else {
// we cannot inline the oop, but we can use it later to narrow a type
return false;
}
}
case T_ILLEGAL: {
if (stable_type != NULL && con_type != NULL && con_type->isa_oopptr())
con_type = con_type->join(stable_type);
break;
case T_ILLEGAL:
// Invalid ciConstant returned due to OutOfMemoryError in the CI
assert(C->env()->failing(), "otherwise should not see this");
// These always occur because of object types; we are going to
@ -350,17 +348,16 @@ bool Parse::push_constant(ciConstant constant, bool require_constant, bool is_au
push( zerocon(T_OBJECT) );
return false;
}
default:
ShouldNotReachHere();
return false;
}
// success
if (con_type == NULL)
// we cannot inline the oop, but we can use it later to narrow a type
return false;
push_node(constant.basic_type(), makecon(con_type));
return true;
}
//=============================================================================
void Parse::do_anewarray() {
bool will_link;