diff --git a/src/hotspot/share/gc/shared/c1/barrierSetC1.cpp b/src/hotspot/share/gc/shared/c1/barrierSetC1.cpp new file mode 100644 index 0000000..92a7b82 --- /dev/null +++ b/src/hotspot/share/gc/shared/c1/barrierSetC1.cpp @@ -0,0 +1,326 @@ +/* + * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + * + */ + +#include "precompiled.hpp" +#include "c1/c1_Defs.hpp" +#include "c1/c1_LIRGenerator.hpp" +#include "gc/shared/c1/barrierSetC1.hpp" +#include "utilities/macros.hpp" + +#ifndef PATCHED_ADDR +#define PATCHED_ADDR (max_jint) +#endif + +#ifdef ASSERT +#define __ gen->lir(__FILE__, __LINE__)-> +#else +#define __ gen->lir()-> +#endif + +LIR_Opr BarrierSetC1::resolve_address(LIRAccess& access, bool resolve_in_register) { + DecoratorSet decorators = access.decorators(); + bool on_array = (decorators & IN_HEAP_ARRAY) != 0; + bool needs_patching = (decorators & C1_NEEDS_PATCHING) != 0; + + LIRItem& base = access.base().item(); + LIR_Opr offset = access.offset().opr(); + LIRGenerator *gen = access.gen(); + + LIR_Opr addr_opr; + if (on_array) { + addr_opr = LIR_OprFact::address(gen->emit_array_address(base.result(), offset, access.type())); + } else if (needs_patching) { + // we need to patch the offset in the instruction so don't allow + // generate_address to try to be smart about emitting the -1. + // Otherwise the patching code won't know how to find the + // instruction to patch. + addr_opr = LIR_OprFact::address(new LIR_Address(base.result(), PATCHED_ADDR, access.type())); + } else { + addr_opr = LIR_OprFact::address(gen->generate_address(base.result(), offset, 0, 0, access.type())); + } + + if (resolve_in_register) { + LIR_Opr resolved_addr = gen->new_pointer_register(); + __ leal(addr_opr, resolved_addr); + resolved_addr = LIR_OprFact::address(new LIR_Address(resolved_addr, access.type())); + return resolved_addr; + } else { + return addr_opr; + } +} + +void BarrierSetC1::store_at(LIRAccess& access,LIR_Opr value) { + DecoratorSet decorators = access.decorators(); + bool in_heap = (decorators & IN_HEAP) != 0; + assert(in_heap, "not supported yet"); + + LIR_Opr resolved = resolve_address(access, false); + access.set_resolved_addr(resolved); + store_at_resolved(access, value); +} + +void BarrierSetC1::load_at(LIRAccess& access, LIR_Opr result) { + DecoratorSet decorators = access.decorators(); + bool in_heap = (decorators & IN_HEAP) != 0; + assert(in_heap, "not supported yet"); + + LIR_Opr resolved = resolve_address(access, false); + access.set_resolved_addr(resolved); + load_at_resolved(access, result); +} + +LIR_Opr BarrierSetC1::atomic_cmpxchg_at(LIRAccess& access, LIRItem& cmp_value, LIRItem& new_value) { + DecoratorSet decorators = access.decorators(); + bool in_heap = (decorators & IN_HEAP) != 0; + assert(in_heap, "not supported yet"); + + access.load_address(); + + LIR_Opr resolved = resolve_address(access, true); + access.set_resolved_addr(resolved); + return atomic_cmpxchg_resolved(access, cmp_value, new_value); +} + +LIR_Opr BarrierSetC1::atomic_xchg(LIRAccess& access, LIRItem& value) { + DecoratorSet decorators = access.decorators(); + bool in_heap = (decorators & IN_HEAP) != 0; + assert(in_heap, "not supported yet"); + + access.load_address(); + + LIR_Opr resolved = resolve_address(access, true); + access.set_resolved_addr(resolved); + return atomic_xchg_resolved(access, value); +} + +LIR_Opr BarrierSetC1::atomic_add_at(LIRAccess& access, LIRItem& value) { + DecoratorSet decorators = access.decorators(); + bool in_heap = (decorators & IN_HEAP) != 0; + assert(in_heap, "not supported yet"); + + access.load_address(); + + LIR_Opr resolved = resolve_address(access, true); + access.set_resolved_addr(resolved); + return atomic_add_at_resolved(access, value); +} + +void BarrierSetC1::store_at_resolved(LIRAccess& access, LIR_Opr value) { + DecoratorSet decorators = access.decorators(); + bool is_volatile = (((decorators & MO_SEQ_CST) != 0) || AlwaysAtomicAccesses) && os::is_MP(); + bool needs_patching = (decorators & C1_NEEDS_PATCHING) != 0; + bool mask_boolean = (decorators & C1_MASK_BOOLEAN) != 0; + LIRGenerator* gen = access.gen(); + + if (mask_boolean) { + value = gen->mask_boolean(access.base().opr(), value, access.access_emit_info()); + } + + if (is_volatile && os::is_MP()) { + __ membar_release(); + } + + LIR_PatchCode patch_code = needs_patching ? lir_patch_normal : lir_patch_none; + if (is_volatile && !needs_patching) { + gen->volatile_field_store(value, access.resolved_addr()->as_address_ptr(), access.access_emit_info()); + } else { + __ store(value, access.resolved_addr()->as_address_ptr(), access.access_emit_info(), patch_code); + } + + if (is_volatile && !support_IRIW_for_not_multiple_copy_atomic_cpu) { + __ membar(); + } +} + +void BarrierSetC1::load_at_resolved(LIRAccess& access, LIR_Opr result) { + LIRGenerator *gen = access.gen(); + DecoratorSet decorators = access.decorators(); + bool is_volatile = (((decorators & MO_SEQ_CST) != 0) || AlwaysAtomicAccesses) && os::is_MP(); + bool needs_patching = (decorators & C1_NEEDS_PATCHING) != 0; + bool mask_boolean = (decorators & C1_MASK_BOOLEAN) != 0; + + if (support_IRIW_for_not_multiple_copy_atomic_cpu && is_volatile) { + __ membar(); + } + + LIR_PatchCode patch_code = needs_patching ? lir_patch_normal : lir_patch_none; + if (is_volatile && !needs_patching) { + gen->volatile_field_load(access.resolved_addr()->as_address_ptr(), result, access.access_emit_info()); + } else { + __ load(access.resolved_addr()->as_address_ptr(), result, access.access_emit_info(), patch_code); + } + + if (is_volatile && os::is_MP()) { + __ membar_acquire(); + } + + /* Normalize boolean value returned by unsafe operation, i.e., value != 0 ? value = true : value false. */ + if (mask_boolean) { + LabelObj* equalZeroLabel = new LabelObj(); + __ cmp(lir_cond_equal, result, 0); + __ branch(lir_cond_equal, T_BOOLEAN, equalZeroLabel->label()); + __ move(LIR_OprFact::intConst(1), result); + __ branch_destination(equalZeroLabel->label()); + } +} + +LIR_Opr BarrierSetC1::atomic_cmpxchg_resolved(LIRAccess& access, LIRItem& cmp_value, LIRItem& new_value) { + LIRGenerator *gen = access.gen(); + return gen->atomic_cmpxchg(access.type(), access.resolved_addr(), cmp_value, new_value); +} + +LIR_Opr BarrierSetC1::atomic_xchg_resolved(LIRAccess& access, LIRItem& value) { + LIRGenerator *gen = access.gen(); + return gen->atomic_xchg(access.type(), access.resolved_addr(), value); +} + +LIR_Opr BarrierSetC1::atomic_add_at_resolved(LIRAccess& access, LIRItem& value) { + LIRGenerator *gen = access.gen(); + return gen->atomic_add(access.type(), access.resolved_addr(), value); +} + +void BarrierSetC1::generate_referent_check(LIRAccess& access, LabelObj* cont) { + // We might be reading the value of the referent field of a + // Reference object in order to attach it back to the live + // object graph. If G1 is enabled then we need to record + // the value that is being returned in an SATB log buffer. + // + // We need to generate code similar to the following... + // + // if (offset == java_lang_ref_Reference::referent_offset) { + // if (src != NULL) { + // if (klass(src)->reference_type() != REF_NONE) { + // pre_barrier(..., value, ...); + // } + // } + // } + + bool gen_pre_barrier = true; // Assume we need to generate pre_barrier. + bool gen_offset_check = true; // Assume we need to generate the offset guard. + bool gen_source_check = true; // Assume we need to check the src object for null. + bool gen_type_check = true; // Assume we need to check the reference_type. + + LIRGenerator *gen = access.gen(); + + LIRItem& base = access.base().item(); + LIR_Opr offset = access.offset().opr(); + + if (offset->is_constant()) { + LIR_Const* constant = offset->as_constant_ptr(); + jlong off_con = (constant->type() == T_INT ? + (jlong)constant->as_jint() : + constant->as_jlong()); + + + if (off_con != (jlong) java_lang_ref_Reference::referent_offset) { + // The constant offset is something other than referent_offset. + // We can skip generating/checking the remaining guards and + // skip generation of the code stub. + gen_pre_barrier = false; + } else { + // The constant offset is the same as referent_offset - + // we do not need to generate a runtime offset check. + gen_offset_check = false; + } + } + + // We don't need to generate stub if the source object is an array + if (gen_pre_barrier && base.type()->is_array()) { + gen_pre_barrier = false; + } + + if (gen_pre_barrier) { + // We still need to continue with the checks. + if (base.is_constant()) { + ciObject* src_con = base.get_jobject_constant(); + guarantee(src_con != NULL, "no source constant"); + + if (src_con->is_null_object()) { + // The constant src object is null - We can skip + // generating the code stub. + gen_pre_barrier = false; + } else { + // Non-null constant source object. We still have to generate + // the slow stub - but we don't need to generate the runtime + // null object check. + gen_source_check = false; + } + } + } + if (gen_pre_barrier && !PatchALot) { + // Can the klass of object be statically determined to be + // a sub-class of Reference? + ciType* type = base.value()->declared_type(); + if ((type != NULL) && type->is_loaded()) { + if (type->is_subtype_of(gen->compilation()->env()->Reference_klass())) { + gen_type_check = false; + } else if (type->is_klass() && + !gen->compilation()->env()->Object_klass()->is_subtype_of(type->as_klass())) { + // Not Reference and not Object klass. + gen_pre_barrier = false; + } + } + } + + if (gen_pre_barrier) { + // We can have generate one runtime check here. Let's start with + // the offset check. + if (gen_offset_check) { + // if (offset != referent_offset) -> continue + // If offset is an int then we can do the comparison with the + // referent_offset constant; otherwise we need to move + // referent_offset into a temporary register and generate + // a reg-reg compare. + + LIR_Opr referent_off; + + if (offset->type() == T_INT) { + referent_off = LIR_OprFact::intConst(java_lang_ref_Reference::referent_offset); + } else { + assert(offset->type() == T_LONG, "what else?"); + referent_off = gen->new_register(T_LONG); + __ move(LIR_OprFact::longConst(java_lang_ref_Reference::referent_offset), referent_off); + } + __ cmp(lir_cond_notEqual, offset, referent_off); + __ branch(lir_cond_notEqual, offset->type(), cont->label()); + } + 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)); + __ branch(lir_cond_equal, T_OBJECT, cont->label()); + } + LIR_Opr src_klass = gen->new_register(T_OBJECT); + 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); + 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); + __ cmp(lir_cond_equal, reference_type, LIR_OprFact::intConst(REF_NONE)); + __ branch(lir_cond_equal, T_INT, cont->label()); + } + } +}