# HG changeset patch
# User rkennke
# Date 1531254049 -7200
#      Tue Jul 10 22:20:49 2018 +0200
# Node ID 281a56a03a675087d5061b4984b7c37f6ce75371
# Parent  3bd1f65e748b4143dda7ce7a6a9a2f0b89d0c67d
[mq]: cleanup-c1.patch

diff --git a/src/hotspot/cpu/aarch64/c1_LIRAssembler_aarch64.cpp b/src/hotspot/cpu/aarch64/c1_LIRAssembler_aarch64.cpp
--- a/src/hotspot/cpu/aarch64/c1_LIRAssembler_aarch64.cpp
+++ b/src/hotspot/cpu/aarch64/c1_LIRAssembler_aarch64.cpp
@@ -2166,6 +2166,9 @@
   Register length  = op->length()->as_register();
   Register tmp = op->tmp()->as_register();
 
+  __ resolve_for_read(IN_HEAP, src);
+  __ resolve_for_write(IN_HEAP, dst);
+
   CodeStub* stub = op->stub();
   int flags = op->flags();
   BasicType basic_type = default_type != NULL ? default_type->element_type()->basic_type() : T_ILLEGAL;
@@ -2509,6 +2512,7 @@
       scratch = op->scratch_opr()->as_register();
     }
     assert(BasicLock::displaced_header_offset_in_bytes() == 0, "lock_reg must point to the displaced header");
+    __ resolve_for_write(IN_HEAP, obj);
     // add debug info for NullPointerException only if one is possible
     int null_check_offset = __ lock_object(hdr, obj, lock, scratch, *op->stub()->entry());
     if (op->info() != NULL) {
diff --git a/src/hotspot/cpu/aarch64/c1_LIRGenerator_aarch64.cpp b/src/hotspot/cpu/aarch64/c1_LIRGenerator_aarch64.cpp
--- a/src/hotspot/cpu/aarch64/c1_LIRGenerator_aarch64.cpp
+++ b/src/hotspot/cpu/aarch64/c1_LIRGenerator_aarch64.cpp
@@ -343,13 +343,7 @@
   // this CodeEmitInfo must not have the xhandlers because here the
   // object is already locked (xhandlers expect object to be unlocked)
   CodeEmitInfo* info = state_for(x, x->state(), true);
-  LIR_Opr obj_opr = obj.result();
-  DecoratorSet decorators = IN_HEAP;
-  if (!x->needs_null_check()) {
-    decorators |= IS_NOT_NULL;
-  }
-  obj_opr = access_resolve_for_write(decorators, obj_opr, state_for(x));
-  monitor_enter(obj_opr, lock, syncTempOpr(), scratch,
+  monitor_enter(obj.result(), lock, syncTempOpr(), scratch,
                         x->monitor_no(), info_for_exception, info);
 }
 
@@ -878,19 +872,6 @@
   LIRItem dst_pos(x->argument_at(3), this);
   LIRItem length(x->argument_at(4), this);
 
-  LIR_Opr dst_op = dst.result();
-  LIR_Opr src_op = src.result();
-  DecoratorSet decorators = IN_HEAP;
-  if (!x->arg_needs_null_check(2)) {
-    decorators |= IS_NOT_NULL;
-  }
-  dst_op = access_resolve_for_write(decorators, dst_op, info);
-  decorators = IN_HEAP;
-  if (!x->arg_needs_null_check(0)) {
-    decorators |= IS_NOT_NULL;
-  }
-  src_op = access_resolve_for_read(decorators, src_op, info);
-
   // operands for arraycopy must use fixed registers, otherwise
   // LinearScan will fail allocation (because arraycopy always needs a
   // call)
@@ -903,9 +884,9 @@
   // of the C convention we can process the java args trivially into C
   // args without worry of overwriting during the xfer
 
-  src_op = force_opr_to(src_op, FrameMap::as_oop_opr(j_rarg0));
+  src.load_item_force     (FrameMap::as_oop_opr(j_rarg0));
   src_pos.load_item_force (FrameMap::as_opr(j_rarg1));
-  dst_op = force_opr_to(dst_op, FrameMap::as_oop_opr(j_rarg2));
+  dst.load_item_force     (FrameMap::as_oop_opr(j_rarg2));
   dst_pos.load_item_force (FrameMap::as_opr(j_rarg3));
   length.load_item_force  (FrameMap::as_opr(j_rarg4));
 
@@ -917,7 +898,7 @@
   ciArrayKlass* expected_type;
   arraycopy_helper(x, &flags, &expected_type);
 
-  __ arraycopy(src_op, src_pos.result(), dst_op, dst_pos.result(), length.result(), tmp, expected_type, flags, info); // does add_safepoint
+  __ arraycopy(src.result(), src_pos.result(), dst.result(), dst_pos.result(), length.result(), tmp, expected_type, flags, info); // does add_safepoint
 }
 
 void LIRGenerator::do_update_CRC32(Intrinsic* x) {
diff --git a/src/hotspot/cpu/aarch64/gc/shenandoah/shenandoahBarrierSetAssembler_aarch64.cpp b/src/hotspot/cpu/aarch64/gc/shenandoah/shenandoahBarrierSetAssembler_aarch64.cpp
--- a/src/hotspot/cpu/aarch64/gc/shenandoah/shenandoahBarrierSetAssembler_aarch64.cpp
+++ b/src/hotspot/cpu/aarch64/gc/shenandoah/shenandoahBarrierSetAssembler_aarch64.cpp
@@ -465,7 +465,15 @@
 }
 
 void ShenandoahBarrierSetAssembler::resolve_for_write(MacroAssembler* masm, DecoratorSet decorators, Register obj) {
-  write_barrier(masm, obj);
+  bool oop_not_null = (decorators & IS_NOT_NULL) != 0;
+  if (oop_not_null) {
+    write_barrier(masm, obj);
+  } else {
+    Label is_null;
+    __ cbz(obj, is_null);
+    write_barrier(masm, obj);
+    __ bind(is_null);
+  }
 }
 
 void ShenandoahBarrierSetAssembler::cmpxchg_oop(MacroAssembler* masm, Register addr, Register expected, Register new_val,
diff --git a/src/hotspot/cpu/x86/c1_LIRAssembler_x86.cpp b/src/hotspot/cpu/x86/c1_LIRAssembler_x86.cpp
--- a/src/hotspot/cpu/x86/c1_LIRAssembler_x86.cpp
+++ b/src/hotspot/cpu/x86/c1_LIRAssembler_x86.cpp
@@ -3023,6 +3023,9 @@
   Register length  = op->length()->as_register();
   Register tmp = op->tmp()->as_register();
 
+  __ resolve_for_read(IN_HEAP, src);
+  __ resolve_for_write(IN_HEAP, dst);
+
   CodeStub* stub = op->stub();
   int flags = op->flags();
   BasicType basic_type = default_type != NULL ? default_type->element_type()->basic_type() : T_ILLEGAL;
@@ -3461,6 +3464,7 @@
       scratch = op->scratch_opr()->as_register();
     }
     assert(BasicLock::displaced_header_offset_in_bytes() == 0, "lock_reg must point to the displaced header");
+    __ resolve_for_write(IN_HEAP, obj);
     // add debug info for NullPointerException only if one is possible
     int null_check_offset = __ lock_object(hdr, obj, lock, scratch, *op->stub()->entry());
     if (op->info() != NULL) {
diff --git a/src/hotspot/cpu/x86/c1_LIRGenerator_x86.cpp b/src/hotspot/cpu/x86/c1_LIRGenerator_x86.cpp
--- a/src/hotspot/cpu/x86/c1_LIRGenerator_x86.cpp
+++ b/src/hotspot/cpu/x86/c1_LIRGenerator_x86.cpp
@@ -296,13 +296,7 @@
   // this CodeEmitInfo must not have the xhandlers because here the
   // object is already locked (xhandlers expect object to be unlocked)
   CodeEmitInfo* info = state_for(x, x->state(), true);
-  LIR_Opr obj_opr = obj.result();
-  DecoratorSet decorators = IN_HEAP;
-  if (!x->needs_null_check()) {
-    decorators |= IS_NOT_NULL;
-  }
-  obj_opr = access_resolve_for_write(decorators, obj_opr, state_for(x));
-  monitor_enter(obj_opr, lock, syncTempOpr(), scratch,
+  monitor_enter(obj.result(), lock, syncTempOpr(), scratch,
                         x->monitor_no(), info_for_exception, info);
 }
 
@@ -917,29 +911,14 @@
   LIRItem dst_pos(x->argument_at(3), this);
   LIRItem length(x->argument_at(4), this);
 
-  dst.load_item();
-  LIR_Opr dst_op = dst.result();
-  DecoratorSet decorators = IN_HEAP;
-  if (!x->arg_needs_null_check(2)) {
-    decorators |= IS_NOT_NULL;
-  }
-  dst_op = access_resolve_for_write(decorators, dst_op, info);
-  src.load_item();
-  LIR_Opr src_op = src.result();
-  decorators = IN_HEAP;
-  if (!x->arg_needs_null_check(0)) {
-    decorators |= IS_NOT_NULL;
-  }
-  src_op = access_resolve_for_read(decorators, src_op, info);
-
   // operands for arraycopy must use fixed registers, otherwise
   // LinearScan will fail allocation (because arraycopy always needs a
   // call)
 
 #ifndef _LP64
-  src_op = force_opr_to(src_op, FrameMap::rcx_oop_opr);
+  src.load_item_force     (FrameMap::rcx_oop_opr);
   src_pos.load_item_force (FrameMap::rdx_opr);
-  dst_op = force_opr_to(dst_op, FrameMap::rax_oop_opr);
+  dst.load_item_force     (FrameMap::rax_oop_opr);
   dst_pos.load_item_force (FrameMap::rbx_opr);
   length.load_item_force  (FrameMap::rdi_opr);
   LIR_Opr tmp =           (FrameMap::rsi_opr);
@@ -953,9 +932,9 @@
   // of the C convention we can process the java args trivially into C
   // args without worry of overwriting during the xfer
 
-  src_op = force_opr_to(src_op, FrameMap::as_oop_opr(j_rarg0));
+  src.load_item_force     (FrameMap::as_oop_opr(j_rarg0));
   src_pos.load_item_force (FrameMap::as_opr(j_rarg1));
-  dst_op = force_opr_to(dst_op, FrameMap::as_oop_opr(j_rarg2));
+  dst.load_item_force     (FrameMap::as_oop_opr(j_rarg2));
   dst_pos.load_item_force (FrameMap::as_opr(j_rarg3));
   length.load_item_force  (FrameMap::as_opr(j_rarg4));
 
@@ -968,7 +947,7 @@
   ciArrayKlass* expected_type;
   arraycopy_helper(x, &flags, &expected_type);
 
-  __ arraycopy(src_op, src_pos.result(), dst_op, dst_pos.result(), length.result(), tmp, expected_type, flags, info); // does add_safepoint
+  __ arraycopy(src.result(), src_pos.result(), dst.result(), dst_pos.result(), length.result(), tmp, expected_type, flags, info); // does add_safepoint
 }
 
 void LIRGenerator::do_update_CRC32(Intrinsic* x) {
@@ -1080,8 +1059,7 @@
     constant_aOffset = result_aOffset->as_jlong();
     result_aOffset = LIR_OprFact::illegalOpr;
   }
-  LIR_Opr result_a = a.result();
-  result_a = access_resolve_for_read(IN_HEAP, result_a, NULL);
+  LIR_Opr result_a = access_resolve_for_read(IN_HEAP, a.result(), NULL);
 
   long constant_bOffset = 0;
   LIR_Opr result_bOffset = bOffset.result();
@@ -1089,8 +1067,7 @@
     constant_bOffset = result_bOffset->as_jlong();
     result_bOffset = LIR_OprFact::illegalOpr;
   }
-  LIR_Opr result_b = b.result();
-  result_b = access_resolve_for_read(IN_HEAP, result_b, NULL);
+  LIR_Opr result_b = access_resolve_for_read(IN_HEAP, b.result(), NULL);
 
 #ifndef _LP64
   result_a = new_register(T_INT);
diff --git a/src/hotspot/cpu/x86/gc/shenandoah/shenandoahBarrierSetAssembler_x86.cpp b/src/hotspot/cpu/x86/gc/shenandoah/shenandoahBarrierSetAssembler_x86.cpp
--- a/src/hotspot/cpu/x86/gc/shenandoah/shenandoahBarrierSetAssembler_x86.cpp
+++ b/src/hotspot/cpu/x86/gc/shenandoah/shenandoahBarrierSetAssembler_x86.cpp
@@ -638,7 +638,16 @@
 }
 
 void ShenandoahBarrierSetAssembler::resolve_for_write(MacroAssembler* masm, DecoratorSet decorators, Register obj) {
-  write_barrier(masm, obj);
+  bool oop_not_null = (decorators & IS_NOT_NULL) != 0;
+  if (oop_not_null) {
+    write_barrier(masm, obj);
+  } else {
+    Label done;
+    __ testptr(obj, obj);
+    __ jcc(Assembler::zero, done);
+    write_barrier(masm, obj);
+    __ bind(done);
+  }
 }
 
 // Special Shenandoah CAS implementation that handles false negatives
diff --git a/src/hotspot/share/c1/c1_LIR.hpp b/src/hotspot/share/c1/c1_LIR.hpp
--- a/src/hotspot/share/c1/c1_LIR.hpp
+++ b/src/hotspot/share/c1/c1_LIR.hpp
@@ -923,7 +923,6 @@
       , lir_pack64
       , lir_unpack64
       , lir_unwind
-      , lir_shenandoah_wb
   , end_op1
   , begin_op2
       , lir_cmp
@@ -1450,6 +1449,7 @@
   virtual void print_instr(outputStream* out) const PRODUCT_RETURN;
 };
 
+
 class ConversionStub;
 
 class LIR_OpConvert: public LIR_Op1 {
diff --git a/src/hotspot/share/c1/c1_LIRGenerator.cpp b/src/hotspot/share/c1/c1_LIRGenerator.cpp
--- a/src/hotspot/share/c1/c1_LIRGenerator.cpp
+++ b/src/hotspot/share/c1/c1_LIRGenerator.cpp
@@ -246,22 +246,14 @@
 void LIRItem::load_item_force(LIR_Opr reg) {
   LIR_Opr r = result();
   if (r != reg) {
-    _result = _gen->force_opr_to(r, reg);
-  }
-}
-
-LIR_Opr LIRGenerator::force_opr_to(LIR_Opr op, LIR_Opr reg) {
-  if (op != reg) {
 #if !defined(ARM) && !defined(E500V2)
-    if (op->type() != reg->type()) {
+    if (r->type() != reg->type()) {
       // moves between different types need an intervening spill slot
-      op = force_to_spill(op, reg->type());
+      r = _gen->force_to_spill(r, reg->type());
     }
 #endif
-    __ move(op, reg);
-    return reg;
-  } else {
-    return op;
+    __ move(r, reg);
+    _result = reg;
   }
 }
 
@@ -1534,15 +1526,13 @@
   }
 #endif
 
-  LIR_Opr obj = object.result();
-
   if (x->needs_null_check() &&
       (needs_patching ||
        MacroAssembler::needs_explicit_null_check(x->offset()))) {
     // Emit an explicit null check because the offset is too large.
     // If the class is not loaded and the object is NULL, we need to deoptimize to throw a
     // NoClassDefFoundError in the interpreter instead of an implicit NPE from compiled code.
-    __ null_check(obj, new CodeEmitInfo(info), /* deoptimize */ needs_patching);
+    __ null_check(object.result(), new CodeEmitInfo(info), /* deoptimize */ needs_patching);
   }
 
   DecoratorSet decorators = IN_HEAP;
@@ -1652,7 +1642,6 @@
   decorators |= C1_WRITE_ACCESS;
   decorators |= ((decorators & MO_DECORATOR_MASK) != 0) ? MO_SEQ_CST : 0;
   LIRAccess access(this, decorators, base, offset, type);
-  new_value.load_item();
   if (access.is_raw()) {
     return _barrier_set->BarrierSetC1::atomic_cmpxchg_at(access, cmp_value, new_value);
   } else {
@@ -1729,12 +1718,12 @@
   }
 #endif
 
-  LIR_Opr obj = object.result();
   bool stress_deopt = StressLoopInvariantCodeMotion && info && info->deoptimize_on_exception();
   if (x->needs_null_check() &&
       (needs_patching ||
        MacroAssembler::needs_explicit_null_check(x->offset()) ||
        stress_deopt)) {
+    LIR_Opr obj = object.result();
     if (stress_deopt) {
       obj = new_register(T_OBJECT);
       __ move(LIR_OprFact::oopConst(NULL), obj);
@@ -2689,7 +2678,6 @@
       __ load_stack_address_monitor(0, lock);
 
       CodeEmitInfo* info = new CodeEmitInfo(scope()->start()->state()->copy(ValueStack::StateBefore, SynchronizationEntryBCI), NULL, x->check_flag(Instruction::DeoptimizeOnException));
-      obj = access_resolve_for_write(IN_HEAP | IS_NOT_NULL, obj, info);
       CodeStub* slow_path = new MonitorEnterStub(obj, lock, info);
 
       // receiver is guaranteed non-NULL so don't need CodeEmitInfo
diff --git a/src/hotspot/share/c1/c1_LIRGenerator.hpp b/src/hotspot/share/c1/c1_LIRGenerator.hpp
--- a/src/hotspot/share/c1/c1_LIRGenerator.hpp
+++ b/src/hotspot/share/c1/c1_LIRGenerator.hpp
@@ -235,8 +235,6 @@
   LIR_Opr round_item(LIR_Opr opr);
   LIR_Opr force_to_spill(LIR_Opr value, BasicType t);
 
-  LIR_Opr force_opr_to(LIR_Opr op, LIR_Opr reg);
-
   PhiResolverState& resolver_state() { return _resolver_state; }
 
   void  move_to_phi(PhiResolver* resolver, Value cur_val, Value sux_val);
diff --git a/test/hotspot/jtreg/gc/shenandoah/compiler/C1ArrayCopyNPE.java b/test/hotspot/jtreg/gc/shenandoah/compiler/C1ArrayCopyNPE.java
new file mode 100644
--- /dev/null
+++ b/test/hotspot/jtreg/gc/shenandoah/compiler/C1ArrayCopyNPE.java
@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2018 Red Hat, Inc. and/or its affiliates.
+ *
+ * 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.
+ *
+ */
+
+/* @test
+ * @summary test C1 arraycopy intrinsic
+ * @run main/othervm -XX:TieredStopAtLevel=1 -XX:+UseShenandoahGC -XX:+UnlockDiagnosticVMOptions -XX:ShenandoahGCHeuristics=aggressive C1ArrayCopyNPE
+ */
+
+public class C1ArrayCopyNPE {
+
+    private static final int NUM_RUNS = 10000;
+    private static final int ARRAY_SIZE=10000;
+    private static int[] a;
+    private static int[] b;
+
+    public static void main(String[] args) {
+        a = null;
+        b = new int[ARRAY_SIZE];
+        for (int i = 0; i < NUM_RUNS; i++) {
+            test();
+        }
+        a = new int[ARRAY_SIZE];
+        b = null;
+        for (int i = 0; i < NUM_RUNS; i++) {
+            test();
+        }
+    }
+
+    private static void test() {
+        try {
+            System.arraycopy(a, 0, b, 0, ARRAY_SIZE);
+            throw new RuntimeException("test failed");
+        } catch (NullPointerException ex) {
+            // Ok
+        }
+    }
+}