Revert "Reduce pauses for weak reference access"

This reverts commit 0ab5b6d2afbdd71a18f8fb9b1fcf39e54cfd55a5.

Reason for revert: Breaks CMS builds

Change-Id: Ib3dfcc90ac5b7259c7f718a0373b48acc2ba10b2

4 files changed, 7 insertions, 10 deletions

diff --git a/compiler/optimizing/intrinsics_arm64.cc b/compiler/optimizing/intrinsics_arm64.cc
index 0236f0d5a9..77b55e455e 100644
--- a/compiler/optimizing/intrinsics_arm64.cc
+++ b/compiler/optimizing/intrinsics_arm64.cc
@@ -3475,8 +3475,7 @@ void IntrinsicCodeGeneratorARM64::VisitReferenceGetReferent(HInvoke* invoke) {
     Register temp = temps.AcquireW();
     __ Ldr(temp,
            MemOperand(tr, Thread::WeakRefAccessEnabledOffset<kArm64PointerSize>().Uint32Value()));
-    static_assert(enum_cast<int32_t>(WeakRefAccessState::kVisiblyEnabled) == 0);
-    __ Cbnz(temp, slow_path->GetEntryLabel());
+    __ Cbz(temp, slow_path->GetEntryLabel());
   }
 
   {
diff --git a/compiler/optimizing/intrinsics_arm_vixl.cc b/compiler/optimizing/intrinsics_arm_vixl.cc
index 303ac171a7..a4a3457c37 100644
--- a/compiler/optimizing/intrinsics_arm_vixl.cc
+++ b/compiler/optimizing/intrinsics_arm_vixl.cc
@@ -2517,8 +2517,8 @@ void IntrinsicCodeGeneratorARMVIXL::VisitReferenceGetReferent(HInvoke* invoke) {
     vixl32::Register temp = temps.Acquire();
     __ Ldr(temp,
            MemOperand(tr, Thread::WeakRefAccessEnabledOffset<kArmPointerSize>().Uint32Value()));
-    __ Cmp(temp, enum_cast<int32_t>(WeakRefAccessState::kVisiblyEnabled));
-    __ B(ne, slow_path->GetEntryLabel());
+    __ Cmp(temp, 0);
+    __ B(eq, slow_path->GetEntryLabel());
   }
 
   {
diff --git a/compiler/optimizing/intrinsics_x86.cc b/compiler/optimizing/intrinsics_x86.cc
index 3a3886432a..7c2537495a 100644
--- a/compiler/optimizing/intrinsics_x86.cc
+++ b/compiler/optimizing/intrinsics_x86.cc
@@ -3346,9 +3346,8 @@ void IntrinsicCodeGeneratorX86::VisitReferenceGetReferent(HInvoke* invoke) {
   if (kEmitCompilerReadBarrier) {
     // Check self->GetWeakRefAccessEnabled().
     ThreadOffset32 offset = Thread::WeakRefAccessEnabledOffset<kX86PointerSize>();
-    __ fs()->cmpl(Address::Absolute(offset),
-                  Immediate(enum_cast<int32_t>(WeakRefAccessState::kVisiblyEnabled)));
-    __ j(kNotEqual, slow_path->GetEntryLabel());
+    __ fs()->cmpl(Address::Absolute(offset), Immediate(0));
+    __ j(kEqual, slow_path->GetEntryLabel());
   }
 
   // Load the java.lang.ref.Reference class, use the output register as a temporary.
diff --git a/compiler/optimizing/intrinsics_x86_64.cc b/compiler/optimizing/intrinsics_x86_64.cc
index e3be98732b..d5a7cb10e1 100644
--- a/compiler/optimizing/intrinsics_x86_64.cc
+++ b/compiler/optimizing/intrinsics_x86_64.cc
@@ -3098,9 +3098,8 @@ void IntrinsicCodeGeneratorX86_64::VisitReferenceGetReferent(HInvoke* invoke) {
   if (kEmitCompilerReadBarrier) {
     // Check self->GetWeakRefAccessEnabled().
     ThreadOffset64 offset = Thread::WeakRefAccessEnabledOffset<kX86_64PointerSize>();
-    __ gs()->cmpl(Address::Absolute(offset, /* no_rip= */ true),
-                  Immediate(enum_cast<int32_t>(WeakRefAccessState::kVisiblyEnabled)));
-    __ j(kNotEqual, slow_path->GetEntryLabel());
+    __ gs()->cmpl(Address::Absolute(offset, /* no_rip= */ true), Immediate(0));
+    __ j(kEqual, slow_path->GetEntryLabel());
   }
 
   // Load the java.lang.ref.Reference class, use the output register as a temporary.