2 files changed, 9 insertions, 8 deletions
diff --git a/compiler/optimizing/code_generator_x86.cc b/compiler/optimizing/code_generator_x86.cc
index 08a752f1d2..8afc6bab89 100644
--- a/compiler/optimizing/code_generator_x86.cc
+++ b/compiler/optimizing/code_generator_x86.cc
@@ -7177,10 +7177,10 @@ void InstructionCodeGeneratorX86::GenerateGcRootFieldLoad(
           instruction, root, /* unpoison_ref_before_marking */ false);
       codegen_->AddSlowPath(slow_path);
 
-      // Test the entrypoint (`Thread::Current()->pReadBarrierMarkReg ## root.reg()`).
-      const int32_t entry_point_offset =
-          CodeGenerator::GetReadBarrierMarkEntryPointsOffset<kX86PointerSize>(root.reg());
-      __ fs()->cmpl(Address::Absolute(entry_point_offset), Immediate(0));
+      // Test if the GC is marking. Note that X86 and X86_64 don't switch the entrypoints when the
+      // GC is marking.
+      const int32_t is_marking_offset = Thread::IsGcMarkingOffset<kX86PointerSize>().Int32Value();
+      __ fs()->cmpl(Address::Absolute(is_marking_offset), Immediate(0));
       // The entrypoint is null when the GC is not marking.
       __ j(kNotEqual, slow_path->GetEntryLabel());
       __ Bind(slow_path->GetExitLabel());
diff --git a/compiler/optimizing/code_generator_x86_64.cc b/compiler/optimizing/code_generator_x86_64.cc
index ff6e099d12..c2b1a3190d 100644
--- a/compiler/optimizing/code_generator_x86_64.cc
+++ b/compiler/optimizing/code_generator_x86_64.cc
@@ -6542,10 +6542,11 @@ void InstructionCodeGeneratorX86_64::GenerateGcRootFieldLoad(
           instruction, root, /* unpoison_ref_before_marking */ false);
       codegen_->AddSlowPath(slow_path);
 
-      // Test the `Thread::Current()->pReadBarrierMarkReg ## root.reg()` entrypoint.
-      const int32_t entry_point_offset =
-          CodeGenerator::GetReadBarrierMarkEntryPointsOffset<kX86_64PointerSize>(root.reg());
-      __ gs()->cmpl(Address::Absolute(entry_point_offset, /* no_rip */ true), Immediate(0));
+      // Test if the GC is marking. Note that X86 and X86_64 don't switch the entrypoints when the
+      // GC is marking.
+      const int32_t is_marking_offset =
+          Thread::IsGcMarkingOffset<kX86_64PointerSize>().Int32Value();
+      __ gs()->cmpl(Address::Absolute(is_marking_offset, /* no_rip */ true), Immediate(0));
       // The entrypoint is null when the GC is not marking.
       __ j(kNotEqual, slow_path->GetEntryLabel());
       __ Bind(slow_path->GetExitLabel());