--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/shared/c1/barrierSetC1.cpp Thu Apr 26 20:42:43 2018 +0200
@@ -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_at_resolved(access, cmp_value, new_value);
+}
+
+LIR_Opr BarrierSetC1::atomic_xchg_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_xchg_at_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_at_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_at_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());
+ }
+ }
+}