Revert^5 "Disable write-barrier elimination pass"

This reverts commit 31b949bc4a76e5c6d00a8e18c346f123b5321a1c.

Reason for revert:
PS1 is reland as-is
PS2 has two fixes:
  * Missed poisoning heap references in a code path
  * Removed incorrect DCHECK

Change-Id: I81b317ddc704dbd8a173f5d5c624dbc69e2d9e60
Test: art/test/testrunner/testrunner.py --host --64 --optimizing -b
Test: art/test/testrunner/testrunner.py --target --64 --optimizing -b
      Both commnands with `export ART_HEAP_POISONING=true`
Bug: 301833859
Bug: 310755375
Bug: 260843353

1 files changed, 11 insertions, 11 deletions

diff --git a/compiler/optimizing/intrinsics_x86.cc b/compiler/optimizing/intrinsics_x86.cc
index 5986a2f3a0..b21f36cfcf 100644
--- a/compiler/optimizing/intrinsics_x86.cc
+++ b/compiler/optimizing/intrinsics_x86.cc
@@ -2023,11 +2023,11 @@ static void GenUnsafePut(LocationSummary* locations,
 
   if (type == DataType::Type::kReference) {
     bool value_can_be_null = true;  // TODO: Worth finding out this information?
-    codegen->MarkGCCard(locations->GetTemp(0).AsRegister<Register>(),
-                        locations->GetTemp(1).AsRegister<Register>(),
-                        base,
-                        value_loc.AsRegister<Register>(),
-                        value_can_be_null);
+    codegen->MaybeMarkGCCard(locations->GetTemp(0).AsRegister<Register>(),
+                             locations->GetTemp(1).AsRegister<Register>(),
+                             base,
+                             value_loc.AsRegister<Register>(),
+                             value_can_be_null);
   }
 }
 
@@ -2363,7 +2363,7 @@ static void GenReferenceCAS(HInvoke* invoke,
   bool value_can_be_null = true;  // TODO: Worth finding out this information?
   NearLabel skip_mark_gc_card;
   __ j(kNotZero, &skip_mark_gc_card);
-  codegen->MarkGCCard(temp, temp2, base, value, value_can_be_null);
+  codegen->MaybeMarkGCCard(temp, temp2, base, value, value_can_be_null);
   __ Bind(&skip_mark_gc_card);
 
   // If heap poisoning is enabled, we need to unpoison the values
@@ -2629,7 +2629,7 @@ static void GenUnsafeGetAndUpdate(HInvoke* invoke,
     // Mark card for object as a new value shall be stored.
     bool new_value_can_be_null = true;  // TODO: Worth finding out this information?
     DCHECK_EQ(temp2, ECX);  // Byte register for `MarkGCCard()`.
-    codegen->MarkGCCard(temp1, temp2, base, /*value=*/ out_reg, new_value_can_be_null);
+    codegen->MaybeMarkGCCard(temp1, temp2, base, /*value=*/out_reg, new_value_can_be_null);
 
     if (kPoisonHeapReferences) {
       // Use a temp to avoid poisoning base of the field address, which might happen if `out`
@@ -3357,7 +3357,7 @@ void IntrinsicCodeGeneratorX86::VisitSystemArrayCopy(HInvoke* invoke) {
     }
 
     // We only need one card marking on the destination array.
-    codegen_->MarkGCCard(temp1, temp3, dest, Register(kNoRegister), /* emit_null_check= */ false);
+    codegen_->MarkGCCard(temp1, temp3, dest);
 
     __ Bind(&skip_copy_and_write_barrier);
   }
@@ -4176,7 +4176,8 @@ static void GenerateVarHandleSet(HInvoke* invoke, CodeGeneratorX86* codegen) {
       is_volatile,
       /* value_can_be_null */ true,
       // Value can be null, and this write barrier is not being relied on for other sets.
-      WriteBarrierKind::kEmitWithNullCheck);
+      value_type == DataType::Type::kReference ? WriteBarrierKind::kEmitNotBeingReliedOn :
+                                                 WriteBarrierKind::kDontEmit);
 
   __ Bind(slow_path->GetExitLabel());
 }
@@ -4336,8 +4337,7 @@ static void GenerateVarHandleGetAndSet(HInvoke* invoke, CodeGeneratorX86* codege
             /* always_update_field= */ true,
             &temp2);
       }
-      codegen->MarkGCCard(
-          temp, temp2, reference, value.AsRegister<Register>(), /* emit_null_check= */ false);
+      codegen->MarkGCCard(temp, temp2, reference);
       if (kPoisonHeapReferences) {
         __ movl(temp, value.AsRegister<Register>());
         __ PoisonHeapReference(temp);