| /* |
| * Copyright (c) 2018, 2019, Red Hat, Inc. All rights reserved. |
| * |
| * 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 "gc/shenandoah/shenandoahBarrierSetAssembler.hpp" |
| #include "gc/shenandoah/shenandoahForwarding.hpp" |
| #include "gc/shenandoah/shenandoahHeap.hpp" |
| #include "gc/shenandoah/shenandoahHeapRegion.hpp" |
| #include "gc/shenandoah/shenandoahHeuristics.hpp" |
| #include "gc/shenandoah/shenandoahRuntime.hpp" |
| #include "gc/shenandoah/shenandoahThreadLocalData.hpp" |
| #include "interpreter/interpreter.hpp" |
| #include "interpreter/interp_masm.hpp" |
| #include "runtime/sharedRuntime.hpp" |
| #include "runtime/thread.hpp" |
| #ifdef COMPILER1 |
| #include "c1/c1_LIRAssembler.hpp" |
| #include "c1/c1_MacroAssembler.hpp" |
| #include "gc/shenandoah/c1/shenandoahBarrierSetC1.hpp" |
| #endif |
| |
| #define __ masm-> |
| |
| address ShenandoahBarrierSetAssembler::_shenandoah_lrb = NULL; |
| |
| void ShenandoahBarrierSetAssembler::arraycopy_prologue(MacroAssembler* masm, DecoratorSet decorators, bool is_oop, |
| Register src, Register dst, Register count, RegSet saved_regs) { |
| if (is_oop) { |
| bool dest_uninitialized = (decorators & IS_DEST_UNINITIALIZED) != 0; |
| if (ShenandoahSATBBarrier && !dest_uninitialized && !ShenandoahHeap::heap()->heuristics()->can_do_traversal_gc()) { |
| |
| Label done; |
| |
| // Avoid calling runtime if count == 0 |
| __ cbz(count, done); |
| |
| // Is marking active? |
| Address gc_state(rthread, in_bytes(ShenandoahThreadLocalData::gc_state_offset())); |
| __ ldrb(rscratch1, gc_state); |
| __ tbz(rscratch1, ShenandoahHeap::MARKING_BITPOS, done); |
| |
| __ push(saved_regs, sp); |
| if (count == c_rarg0) { |
| if (dst == c_rarg1) { |
| // exactly backwards!! |
| __ mov(rscratch1, c_rarg0); |
| __ mov(c_rarg0, c_rarg1); |
| __ mov(c_rarg1, rscratch1); |
| } else { |
| __ mov(c_rarg1, count); |
| __ mov(c_rarg0, dst); |
| } |
| } else { |
| __ mov(c_rarg0, dst); |
| __ mov(c_rarg1, count); |
| } |
| if (UseCompressedOops) { |
| __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_pre_narrow_oop_entry), 2); |
| } else { |
| __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_pre_oop_entry), 2); |
| } |
| __ pop(saved_regs, sp); |
| __ bind(done); |
| } |
| } |
| } |
| |
| void ShenandoahBarrierSetAssembler::arraycopy_epilogue(MacroAssembler* masm, DecoratorSet decorators, bool is_oop, |
| Register start, Register count, Register scratch, RegSet saved_regs) { |
| if (is_oop) { |
| Label done; |
| |
| // Avoid calling runtime if count == 0 |
| __ cbz(count, done); |
| |
| // Is updating references? |
| Address gc_state(rthread, in_bytes(ShenandoahThreadLocalData::gc_state_offset())); |
| __ ldrb(rscratch1, gc_state); |
| __ tbz(rscratch1, ShenandoahHeap::UPDATEREFS_BITPOS, done); |
| |
| __ push(saved_regs, sp); |
| assert_different_registers(start, count, scratch); |
| assert_different_registers(c_rarg0, count); |
| __ mov(c_rarg0, start); |
| __ mov(c_rarg1, count); |
| __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_post_entry), 2); |
| __ pop(saved_regs, sp); |
| |
| __ bind(done); |
| } |
| } |
| |
| void ShenandoahBarrierSetAssembler::shenandoah_write_barrier_pre(MacroAssembler* masm, |
| Register obj, |
| Register pre_val, |
| Register thread, |
| Register tmp, |
| bool tosca_live, |
| bool expand_call) { |
| if (ShenandoahSATBBarrier) { |
| satb_write_barrier_pre(masm, obj, pre_val, thread, tmp, tosca_live, expand_call); |
| } |
| } |
| |
| void ShenandoahBarrierSetAssembler::satb_write_barrier_pre(MacroAssembler* masm, |
| Register obj, |
| Register pre_val, |
| Register thread, |
| Register tmp, |
| bool tosca_live, |
| bool expand_call) { |
| // If expand_call is true then we expand the call_VM_leaf macro |
| // directly to skip generating the check by |
| // InterpreterMacroAssembler::call_VM_leaf_base that checks _last_sp. |
| |
| assert(thread == rthread, "must be"); |
| |
| Label done; |
| Label runtime; |
| |
| assert_different_registers(obj, pre_val, tmp, rscratch1); |
| assert(pre_val != noreg && tmp != noreg, "expecting a register"); |
| |
| Address in_progress(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_active_offset())); |
| Address index(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset())); |
| Address buffer(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset())); |
| |
| // Is marking active? |
| if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) { |
| __ ldrw(tmp, in_progress); |
| } else { |
| assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption"); |
| __ ldrb(tmp, in_progress); |
| } |
| __ cbzw(tmp, done); |
| |
| // Do we need to load the previous value? |
| if (obj != noreg) { |
| __ load_heap_oop(pre_val, Address(obj, 0), noreg, noreg, AS_RAW); |
| } |
| |
| // Is the previous value null? |
| __ cbz(pre_val, done); |
| |
| // Can we store original value in the thread's buffer? |
| // Is index == 0? |
| // (The index field is typed as size_t.) |
| |
| __ ldr(tmp, index); // tmp := *index_adr |
| __ cbz(tmp, runtime); // tmp == 0? |
| // If yes, goto runtime |
| |
| __ sub(tmp, tmp, wordSize); // tmp := tmp - wordSize |
| __ str(tmp, index); // *index_adr := tmp |
| __ ldr(rscratch1, buffer); |
| __ add(tmp, tmp, rscratch1); // tmp := tmp + *buffer_adr |
| |
| // Record the previous value |
| __ str(pre_val, Address(tmp, 0)); |
| __ b(done); |
| |
| __ bind(runtime); |
| // save the live input values |
| RegSet saved = RegSet::of(pre_val); |
| if (tosca_live) saved += RegSet::of(r0); |
| if (obj != noreg) saved += RegSet::of(obj); |
| |
| __ push(saved, sp); |
| |
| // Calling the runtime using the regular call_VM_leaf mechanism generates |
| // code (generated by InterpreterMacroAssember::call_VM_leaf_base) |
| // that checks that the *(rfp+frame::interpreter_frame_last_sp) == NULL. |
| // |
| // If we care generating the pre-barrier without a frame (e.g. in the |
| // intrinsified Reference.get() routine) then ebp might be pointing to |
| // the caller frame and so this check will most likely fail at runtime. |
| // |
| // Expanding the call directly bypasses the generation of the check. |
| // So when we do not have have a full interpreter frame on the stack |
| // expand_call should be passed true. |
| |
| if (expand_call) { |
| assert(pre_val != c_rarg1, "smashed arg"); |
| __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread); |
| } else { |
| __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread); |
| } |
| |
| __ pop(saved, sp); |
| |
| __ bind(done); |
| } |
| |
| void ShenandoahBarrierSetAssembler::resolve_forward_pointer(MacroAssembler* masm, Register dst, Register tmp) { |
| assert(ShenandoahLoadRefBarrier || ShenandoahCASBarrier, "Should be enabled"); |
| Label is_null; |
| __ cbz(dst, is_null); |
| resolve_forward_pointer_not_null(masm, dst, tmp); |
| __ bind(is_null); |
| } |
| |
| // IMPORTANT: This must preserve all registers, even rscratch1 and rscratch2, except those explicitely |
| // passed in. |
| void ShenandoahBarrierSetAssembler::resolve_forward_pointer_not_null(MacroAssembler* masm, Register dst, Register tmp) { |
| assert(ShenandoahLoadRefBarrier || ShenandoahCASBarrier, "Should be enabled"); |
| // The below loads the mark word, checks if the lowest two bits are |
| // set, and if so, clear the lowest two bits and copy the result |
| // to dst. Otherwise it leaves dst alone. |
| // Implementing this is surprisingly awkward. I do it here by: |
| // - Inverting the mark word |
| // - Test lowest two bits == 0 |
| // - If so, set the lowest two bits |
| // - Invert the result back, and copy to dst |
| |
| bool borrow_reg = (tmp == noreg); |
| if (borrow_reg) { |
| // No free registers available. Make one useful. |
| tmp = rscratch1; |
| __ push(RegSet::of(tmp), sp); |
| } |
| |
| Label done; |
| __ ldr(tmp, Address(dst, oopDesc::mark_offset_in_bytes())); |
| __ eon(tmp, tmp, zr); |
| __ ands(zr, tmp, markOopDesc::lock_mask_in_place); |
| __ br(Assembler::NE, done); |
| __ orr(tmp, tmp, markOopDesc::marked_value); |
| __ eon(dst, tmp, zr); |
| __ bind(done); |
| |
| if (borrow_reg) { |
| __ pop(RegSet::of(tmp), sp); |
| } |
| } |
| |
| void ShenandoahBarrierSetAssembler::load_reference_barrier_not_null(MacroAssembler* masm, Register dst, Register tmp) { |
| assert(ShenandoahLoadRefBarrier, "Should be enabled"); |
| assert(dst != rscratch2, "need rscratch2"); |
| |
| Label done; |
| __ enter(); |
| Address gc_state(rthread, in_bytes(ShenandoahThreadLocalData::gc_state_offset())); |
| __ ldrb(rscratch2, gc_state); |
| |
| // Check for heap stability |
| __ tbz(rscratch2, ShenandoahHeap::HAS_FORWARDED_BITPOS, done); |
| |
| RegSet to_save = RegSet::of(r0); |
| if (dst != r0) { |
| __ push(to_save, sp); |
| __ mov(r0, dst); |
| } |
| |
| __ far_call(RuntimeAddress(CAST_FROM_FN_PTR(address, ShenandoahBarrierSetAssembler::shenandoah_lrb()))); |
| |
| if (dst != r0) { |
| __ mov(dst, r0); |
| __ pop(to_save, sp); |
| } |
| |
| __ bind(done); |
| __ leave(); |
| } |
| |
| void ShenandoahBarrierSetAssembler::storeval_barrier(MacroAssembler* masm, Register dst, Register tmp) { |
| if (ShenandoahStoreValEnqueueBarrier) { |
| // Save possibly live regs. |
| RegSet live_regs = RegSet::range(r0, r4) - dst; |
| __ push(live_regs, sp); |
| __ strd(v0, __ pre(sp, 2 * -wordSize)); |
| |
| satb_write_barrier_pre(masm, noreg, dst, rthread, tmp, true, false); |
| |
| // Restore possibly live regs. |
| __ ldrd(v0, __ post(sp, 2 * wordSize)); |
| __ pop(live_regs, sp); |
| } |
| } |
| |
| void ShenandoahBarrierSetAssembler::load_reference_barrier(MacroAssembler* masm, Register dst, Register tmp) { |
| if (ShenandoahLoadRefBarrier) { |
| Label is_null; |
| __ cbz(dst, is_null); |
| load_reference_barrier_not_null(masm, dst, tmp); |
| __ bind(is_null); |
| } |
| } |
| |
| void ShenandoahBarrierSetAssembler::load_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type, |
| Register dst, Address src, Register tmp1, Register tmp_thread) { |
| bool on_oop = type == T_OBJECT || type == T_ARRAY; |
| bool on_weak = (decorators & ON_WEAK_OOP_REF) != 0; |
| bool on_phantom = (decorators & ON_PHANTOM_OOP_REF) != 0; |
| bool on_reference = on_weak || on_phantom; |
| |
| BarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1, tmp_thread); |
| if (on_oop) { |
| load_reference_barrier(masm, dst, tmp1); |
| |
| if (ShenandoahKeepAliveBarrier && on_reference) { |
| __ enter(); |
| satb_write_barrier_pre(masm /* masm */, |
| noreg /* obj */, |
| dst /* pre_val */, |
| rthread /* thread */, |
| tmp1 /* tmp */, |
| true /* tosca_live */, |
| true /* expand_call */); |
| __ leave(); |
| } |
| } |
| } |
| |
| void ShenandoahBarrierSetAssembler::store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type, |
| Address dst, Register val, Register tmp1, Register tmp2) { |
| bool on_oop = type == T_OBJECT || type == T_ARRAY; |
| if (!on_oop) { |
| BarrierSetAssembler::store_at(masm, decorators, type, dst, val, tmp1, tmp2); |
| return; |
| } |
| |
| // flatten object address if needed |
| if (dst.index() == noreg && dst.offset() == 0) { |
| if (dst.base() != r3) { |
| __ mov(r3, dst.base()); |
| } |
| } else { |
| __ lea(r3, dst); |
| } |
| |
| shenandoah_write_barrier_pre(masm, |
| r3 /* obj */, |
| tmp2 /* pre_val */, |
| rthread /* thread */, |
| tmp1 /* tmp */, |
| val != noreg /* tosca_live */, |
| false /* expand_call */); |
| |
| if (val == noreg) { |
| BarrierSetAssembler::store_at(masm, decorators, type, Address(r3, 0), noreg, noreg, noreg); |
| } else { |
| storeval_barrier(masm, val, tmp1); |
| // G1 barrier needs uncompressed oop for region cross check. |
| Register new_val = val; |
| if (UseCompressedOops) { |
| new_val = rscratch2; |
| __ mov(new_val, val); |
| } |
| BarrierSetAssembler::store_at(masm, decorators, type, Address(r3, 0), val, noreg, noreg); |
| } |
| |
| } |
| |
| void ShenandoahBarrierSetAssembler::cmpxchg_oop(MacroAssembler* masm, Register addr, Register expected, Register new_val, |
| bool acquire, bool release, bool weak, bool is_cae, |
| Register result) { |
| Register tmp1 = rscratch1; |
| Register tmp2 = rscratch2; |
| bool is_narrow = UseCompressedOops; |
| Assembler::operand_size size = is_narrow ? Assembler::word : Assembler::xword; |
| |
| assert_different_registers(addr, expected, new_val, tmp1, tmp2); |
| |
| Label retry, done, fail; |
| |
| // CAS, using LL/SC pair. |
| __ bind(retry); |
| __ load_exclusive(tmp1, addr, size, acquire); |
| if (is_narrow) { |
| __ cmpw(tmp1, expected); |
| } else { |
| __ cmp(tmp1, expected); |
| } |
| __ br(Assembler::NE, fail); |
| __ store_exclusive(tmp2, new_val, addr, size, release); |
| if (weak) { |
| __ cmpw(tmp2, 0u); // If the store fails, return NE to our caller |
| } else { |
| __ cbnzw(tmp2, retry); |
| } |
| __ b(done); |
| |
| __ bind(fail); |
| // Check if rb(expected)==rb(tmp1) |
| // Shuffle registers so that we have memory value ready for next expected. |
| __ mov(tmp2, expected); |
| __ mov(expected, tmp1); |
| if (is_narrow) { |
| __ decode_heap_oop(tmp1, tmp1); |
| __ decode_heap_oop(tmp2, tmp2); |
| } |
| resolve_forward_pointer(masm, tmp1); |
| resolve_forward_pointer(masm, tmp2); |
| __ cmp(tmp1, tmp2); |
| // Retry with expected now being the value we just loaded from addr. |
| __ br(Assembler::EQ, retry); |
| if (is_cae && is_narrow) { |
| // For cmp-and-exchange and narrow oops, we need to restore |
| // the compressed old-value. We moved it to 'expected' a few lines up. |
| __ mov(tmp1, expected); |
| } |
| __ bind(done); |
| |
| if (is_cae) { |
| __ mov(result, tmp1); |
| } else { |
| __ cset(result, Assembler::EQ); |
| } |
| } |
| |
| #undef __ |
| |
| #ifdef COMPILER1 |
| |
| #define __ ce->masm()-> |
| |
| void ShenandoahBarrierSetAssembler::gen_pre_barrier_stub(LIR_Assembler* ce, ShenandoahPreBarrierStub* stub) { |
| ShenandoahBarrierSetC1* bs = (ShenandoahBarrierSetC1*)BarrierSet::barrier_set()->barrier_set_c1(); |
| // At this point we know that marking is in progress. |
| // If do_load() is true then we have to emit the |
| // load of the previous value; otherwise it has already |
| // been loaded into _pre_val. |
| |
| __ bind(*stub->entry()); |
| |
| assert(stub->pre_val()->is_register(), "Precondition."); |
| |
| Register pre_val_reg = stub->pre_val()->as_register(); |
| |
| if (stub->do_load()) { |
| ce->mem2reg(stub->addr(), stub->pre_val(), T_OBJECT, stub->patch_code(), stub->info(), false /*wide*/, false /*unaligned*/); |
| } |
| __ cbz(pre_val_reg, *stub->continuation()); |
| ce->store_parameter(stub->pre_val()->as_register(), 0); |
| __ far_call(RuntimeAddress(bs->pre_barrier_c1_runtime_code_blob()->code_begin())); |
| __ b(*stub->continuation()); |
| } |
| |
| void ShenandoahBarrierSetAssembler::gen_load_reference_barrier_stub(LIR_Assembler* ce, ShenandoahLoadReferenceBarrierStub* stub) { |
| |
| Register obj = stub->obj()->as_register(); |
| Register res = stub->result()->as_register(); |
| |
| Label done; |
| |
| __ bind(*stub->entry()); |
| |
| if (res != obj) { |
| __ mov(res, obj); |
| } |
| // Check for null. |
| if (stub->needs_null_check()) { |
| __ cbz(res, done); |
| } |
| |
| load_reference_barrier_not_null(ce->masm(), res, rscratch1); |
| |
| __ bind(done); |
| __ b(*stub->continuation()); |
| } |
| |
| #undef __ |
| |
| #define __ sasm-> |
| |
| void ShenandoahBarrierSetAssembler::generate_c1_pre_barrier_runtime_stub(StubAssembler* sasm) { |
| __ prologue("shenandoah_pre_barrier", false); |
| |
| // arg0 : previous value of memory |
| |
| BarrierSet* bs = BarrierSet::barrier_set(); |
| |
| const Register pre_val = r0; |
| const Register thread = rthread; |
| const Register tmp = rscratch1; |
| |
| Address queue_index(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset())); |
| Address buffer(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset())); |
| |
| Label done; |
| Label runtime; |
| |
| // Is marking still active? |
| Address gc_state(thread, in_bytes(ShenandoahThreadLocalData::gc_state_offset())); |
| __ ldrb(tmp, gc_state); |
| __ mov(rscratch2, ShenandoahHeap::MARKING | ShenandoahHeap::TRAVERSAL); |
| __ tst(tmp, rscratch2); |
| __ br(Assembler::EQ, done); |
| |
| // Can we store original value in the thread's buffer? |
| __ ldr(tmp, queue_index); |
| __ cbz(tmp, runtime); |
| |
| __ sub(tmp, tmp, wordSize); |
| __ str(tmp, queue_index); |
| __ ldr(rscratch2, buffer); |
| __ add(tmp, tmp, rscratch2); |
| __ load_parameter(0, rscratch2); |
| __ str(rscratch2, Address(tmp, 0)); |
| __ b(done); |
| |
| __ bind(runtime); |
| __ push_call_clobbered_registers(); |
| __ load_parameter(0, pre_val); |
| __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread); |
| __ pop_call_clobbered_registers(); |
| __ bind(done); |
| |
| __ epilogue(); |
| } |
| |
| #undef __ |
| |
| #endif // COMPILER1 |
| |
| address ShenandoahBarrierSetAssembler::shenandoah_lrb() { |
| assert(_shenandoah_lrb != NULL, "need load reference barrier stub"); |
| return _shenandoah_lrb; |
| } |
| |
| #define __ cgen->assembler()-> |
| |
| // Shenandoah load reference barrier. |
| // |
| // Input: |
| // r0: OOP to evacuate. Not null. |
| // |
| // Output: |
| // r0: Pointer to evacuated OOP. |
| // |
| // Trash rscratch1, rscratch2. Preserve everything else. |
| address ShenandoahBarrierSetAssembler::generate_shenandoah_lrb(StubCodeGenerator* cgen) { |
| |
| __ align(6); |
| StubCodeMark mark(cgen, "StubRoutines", "shenandoah_lrb"); |
| address start = __ pc(); |
| |
| Label work, done; |
| __ mov(rscratch2, ShenandoahHeap::in_cset_fast_test_addr()); |
| __ lsr(rscratch1, r0, ShenandoahHeapRegion::region_size_bytes_shift_jint()); |
| __ ldrb(rscratch2, Address(rscratch2, rscratch1)); |
| __ tbnz(rscratch2, 0, work); |
| __ ret(lr); |
| __ bind(work); |
| |
| __ mov(rscratch2, r0); |
| resolve_forward_pointer_not_null(cgen->assembler(), r0, rscratch1); |
| __ cmp(rscratch2, r0); |
| __ br(Assembler::NE, done); |
| |
| __ enter(); // required for proper stackwalking of RuntimeStub frame |
| |
| __ push_call_clobbered_registers(); |
| |
| __ mov(lr, CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_JRT)); |
| __ blrt(lr, 1, 0, MacroAssembler::ret_type_integral); |
| __ mov(rscratch1, r0); |
| __ pop_call_clobbered_registers(); |
| __ mov(r0, rscratch1); |
| |
| __ leave(); // required for proper stackwalking of RuntimeStub frame |
| __ bind(done); |
| __ ret(lr); |
| |
| return start; |
| } |
| |
| #undef __ |
| |
| void ShenandoahBarrierSetAssembler::barrier_stubs_init() { |
| if (ShenandoahLoadRefBarrier) { |
| int stub_code_size = 2048; |
| ResourceMark rm; |
| BufferBlob* bb = BufferBlob::create("shenandoah_barrier_stubs", stub_code_size); |
| CodeBuffer buf(bb); |
| StubCodeGenerator cgen(&buf); |
| _shenandoah_lrb = generate_shenandoah_lrb(&cgen); |
| } |
| } |
