infernap12/jdk
1
0
Fork 0
mirror of https://github.com/openjdk/jdk.git synced 2026-03-20 04:43:32 +00:00
Code Issues Packages Projects Releases Wiki Activity

8211231: BarrierSetC1::generate_referent_check() confuses register allocator

Browse Source 
Reviewed-by: iveresov, kvn
This commit is contained in:
Roland Westrelin 2018-09-27 16:25:25 +02:00
parent bb0074a569
commit b00f4560cb
1 changed files with 6 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
src/hotspot/share/gc/shared/c1/barrierSetC1.cpp
View File

@ -296,6 +296,10 @@ void BarrierSetC1::generate_referent_check(LIRAccess& access, LabelObj* cont) {
if (gen_pre_barrier) {
// We can have generate one runtime check here. Let's start with
// the offset check.
// Allocate temp register to base and load it here, otherwise
// control flow below may confuse register allocator.
LIR_Opr base_reg = gen->new_register(T_OBJECT);
__ move(base.result(), base_reg);
if (gen_offset_check) {
// if (offset != referent_offset) -> continue
// If offset is an int then we can do the comparison with the
@ -318,14 +322,14 @@ void BarrierSetC1::generate_referent_check(LIRAccess& access, LabelObj* cont) {
if (gen_source_check) {
// offset is a const and equals referent offset
// if (source == null) -> continue
__ cmp(lir_cond_equal, base.result(), LIR_OprFact::oopConst(NULL));
__ cmp(lir_cond_equal, base_reg, LIR_OprFact::oopConst(NULL));
__ branch(lir_cond_equal, T_OBJECT, cont->label());
}
LIR_Opr src_klass = gen->new_register(T_METADATA);
if (gen_type_check) {
// We have determined that offset == referent_offset && src != null.
// if (src->_klass->_reference_type == REF_NONE) -> continue
__ move(new LIR_Address(base.result(), oopDesc::klass_offset_in_bytes(), T_ADDRESS), src_klass);
__ move(new LIR_Address(base_reg, oopDesc::klass_offset_in_bytes(), T_ADDRESS), src_klass);
LIR_Address* reference_type_addr = new LIR_Address(src_klass, in_bytes(InstanceKlass::reference_type_offset()), T_BYTE);
LIR_Opr reference_type = gen->new_register(T_INT);
__ move(reference_type_addr, reference_type);