1 /*
   2  * Copyright (c) 2015, Red Hat, Inc. and/or its affiliates.
   3  *
   4  * This code is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This code is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  11  * version 2 for more details (a copy is included in the LICENSE file that
  12  * accompanied this code).
  13  *
  14  * You should have received a copy of the GNU General Public License version
  15  * 2 along with this work; if not, write to the Free Software Foundation,
  16  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  17  *
  18  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  19  * or visit www.oracle.com if you need additional information or have any
  20  * questions.
  21  *
  22  */
  23 
  24 #include "gc/shenandoah/brooksPointer.hpp"
  25 #include "gc/shenandoah/shenandoahBarrierSet.inline.hpp"
  26 
  27 #include "asm/macroAssembler.hpp"
  28 #include "interpreter/interpreter.hpp"
  29 
  30 #define __ masm->
  31 
  32 #ifndef CC_INTERP
  33 void ShenandoahBarrierSet::interpreter_read_barrier(MacroAssembler* masm, Register dst) {
  34   if (ShenandoahReadBarrier) {
  35     Label is_null;
  36     __ cbz(dst, is_null);
  37     interpreter_read_barrier_not_null(masm, dst);
  38     __ bind(is_null);
  39   }
  40 }
  41 
  42 void ShenandoahBarrierSet::interpreter_read_barrier_not_null(MacroAssembler* masm, Register dst) {
  43   if (ShenandoahReadBarrier) {
  44     __ ldr(dst, Address(dst, BrooksPointer::byte_offset()));
  45   }
  46 }
  47 
  48 void ShenandoahBarrierSet::interpreter_write_barrier(MacroAssembler* masm, Register dst) {
  49   if (ShenandoahWriteBarrier) {
  50   assert(dst != rscratch1, "different regs");
  51   assert(dst != rscratch2, "Need rscratch2");
  52 
  53   Label done;
  54 
  55   Address gc_phase_in_progress = Address(rthread, in_bytes(JavaThread::gc_phase_in_progress_offset()));
  56 
  57   __ ldrb(rscratch1, gc_phase_in_progress);
  58   __ membar(Assembler::LoadLoad);
  59 
  60   // Now check if evacuation is in progress.
  61   interpreter_read_barrier_not_null(masm, dst);
  62 
  63   __ tbz(rscratch1, ShenandoahHeap::EVACUATION_BITPOS, done);
  64 
  65   __ lsr(rscratch1, dst, ShenandoahHeapRegion::region_size_bytes_shift_jint());
  66   __ mov(rscratch2,  ShenandoahHeap::in_cset_fast_test_addr());
  67   __ ldrb(rscratch2, Address(rscratch2, rscratch1));
  68   __ tst(rscratch2, 0x1);
  69   __ br(Assembler::EQ, done);
  70 
  71   // Save possibly live regs.
  72   RegSet live_regs = RegSet::range(r0, r4) - dst;
  73   __ push(live_regs, sp);
  74   __ strd(v0, __ pre(sp, 2 * -wordSize));
  75 
  76   // Call into runtime
  77   __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahBarrierSet::write_barrier_IRT), dst);
  78 
  79   // Move result into dst reg.
  80   __ mov(dst, r0);
  81 
  82   // Restore possibly live regs.
  83   __ ldrd(v0, __ post(sp, 2 * wordSize));
  84   __ pop(live_regs, sp);
  85 
  86   __ bind(done);
  87   }
  88 }
  89 
  90 void ShenandoahHeap::compile_prepare_oop(MacroAssembler* masm, Register obj) {
  91   __ add(obj, obj, BrooksPointer::byte_size());
  92   __ str(obj, Address(obj, BrooksPointer::byte_offset()));
  93 }
  94 
  95 void ShenandoahBarrierSet::interpreter_storeval_barrier(MacroAssembler* masm, Register dst) {
  96   if (ShenandoahStoreValBarrier) {
  97     interpreter_read_barrier(masm, dst);
  98   }
  99 }
 100 
 101 void ShenandoahBarrierSet::asm_acmp_barrier(MacroAssembler* masm,
 102                                             Register op1, Register op2) {
 103   if (ShenandoahAcmpBarrier) {
 104     Label done;
 105     __ br(Assembler::EQ, done);
 106     // The object may have been evacuated, but we won't see it without a
 107     // membar here.
 108     __ membar(Assembler::LoadStore| Assembler::LoadLoad);
 109     interpreter_read_barrier(masm, op1);
 110     interpreter_read_barrier(masm, op2);
 111     __ cmp(op1, op2);
 112     __ bind(done);
 113   }
 114 }
 115 
 116 #endif