4 files changed, 33 insertions, 18 deletions
diff --git a/compiler/optimizing/code_generator_arm64.cc b/compiler/optimizing/code_generator_arm64.cc
index d9fefc1568..d530d08b98 100644
--- a/compiler/optimizing/code_generator_arm64.cc
+++ b/compiler/optimizing/code_generator_arm64.cc
@@ -1243,13 +1243,16 @@ void InstructionCodeGeneratorARM64::GenerateMethodEntryExitHook(HInstruction* in
   __ Str(index, MemOperand(tr, trace_buffer_index_addr));
 
   Register tmp = index;
-  // Record method pointer
+  // Record method pointer and trace action.
   __ Ldr(tmp, MemOperand(sp, 0));
+  // Use last two bits to encode trace method action. For MethodEntry it is 0
+  // so no need to set the bits since they are 0 already.
+  if (instruction->IsMethodExitHook()) {
+    DCHECK_GE(ArtMethod::Alignment(kRuntimePointerSize), static_cast<size_t>(4));
+    uint32_t trace_action = 1;
+    __ Orr(tmp, tmp, Operand(trace_action));
+  }
   __ Str(tmp, MemOperand(addr, kMethodOffsetInBytes));
-  // Record the method action
-  uint32_t trace_action = instruction->IsMethodExitHook() ? 1 : 0;
-  __ Mov(tmp, Operand(trace_action));
-  __ Str(tmp, MemOperand(addr, kTraceActionOffsetInBytes));
   // Record the timestamp.
   __ Mrs(tmp, (SystemRegister)SYS_CNTVCT_EL0);
   __ Str(tmp, MemOperand(addr, kTimestampOffsetInBytes));
diff --git a/compiler/optimizing/code_generator_arm_vixl.cc b/compiler/optimizing/code_generator_arm_vixl.cc
index 99e4bda73d..ecc7a68b94 100644
--- a/compiler/optimizing/code_generator_arm_vixl.cc
+++ b/compiler/optimizing/code_generator_arm_vixl.cc
@@ -2243,13 +2243,17 @@ void InstructionCodeGeneratorARMVIXL::GenerateMethodEntryExitHook(HInstruction*
   __ Sub(index, index, kNumEntriesForWallClock);
   __ Str(index, MemOperand(tr, trace_buffer_index_addr));
 
-  // Record method pointer
+  // Record method pointer and trace action.
   __ Ldr(tmp, MemOperand(sp, 0));
+  // Use last two bits to encode trace method action. For MethodEntry it is 0
+  // so no need to set the bits since they are 0 already.
+  if (instruction->IsMethodExitHook()) {
+    DCHECK_GE(ArtMethod::Alignment(kRuntimePointerSize), static_cast<size_t>(4));
+    uint32_t trace_action = 1;
+    __ Orr(tmp, tmp, Operand(trace_action));
+  }
   __ Str(tmp, MemOperand(addr, kMethodOffsetInBytes));
-  // Record the method action
-  uint32_t trace_action = instruction->IsMethodExitHook() ? 1 : 0;
-  __ Mov(tmp, Operand(trace_action));
-  __ Str(tmp, MemOperand(addr, kTraceActionOffsetInBytes));
+
   vixl32::Register tmp1 = index;
   // See Architecture Reference Manual ARMv7-A and ARMv7-R edition section B4.1.34.
   __ Mrrc(/* lower 32-bit */ tmp,
diff --git a/compiler/optimizing/code_generator_x86.cc b/compiler/optimizing/code_generator_x86.cc
index 16aa5c1cfa..bcf5ea0907 100644
--- a/compiler/optimizing/code_generator_x86.cc
+++ b/compiler/optimizing/code_generator_x86.cc
@@ -1277,13 +1277,17 @@ void InstructionCodeGeneratorX86::GenerateMethodEntryExitHook(HInstruction* inst
   __ subl(index, Immediate(kNumEntriesForWallClock));
   __ fs()->movl(Address::Absolute(trace_buffer_index_addr), index);
 
-  // Record method pointer
+  // Record method pointer and trace action.
   Register method = index;
   __ movl(method, Address(ESP, kCurrentMethodStackOffset));
+  // Use last two bits to encode trace method action. For MethodEntry it is 0
+  // so no need to set the bits since they are 0 already.
+  if (instruction->IsMethodExitHook()) {
+    DCHECK_GE(ArtMethod::Alignment(kRuntimePointerSize), static_cast<size_t>(4));
+    uint32_t trace_action = 1;
+    __ orl(method, Immediate(trace_action));
+  }
   __ movl(Address(entry_addr, kMethodOffsetInBytes), method);
-  // Record the method action
-  uint32_t trace_action = instruction->IsMethodExitHook() ? 1 : 0;
-  __ movl(Address(entry_addr, kTraceActionOffsetInBytes), Immediate(trace_action));
   // Get the timestamp. rdtsc returns timestamp in EAX + EDX.
   __ rdtsc();
   __ movl(Address(entry_addr, kTimestampOffsetInBytes), EDX);
diff --git a/compiler/optimizing/code_generator_x86_64.cc b/compiler/optimizing/code_generator_x86_64.cc
index 15893b1fec..2e03f1f3b4 100644
--- a/compiler/optimizing/code_generator_x86_64.cc
+++ b/compiler/optimizing/code_generator_x86_64.cc
@@ -1644,13 +1644,17 @@ void InstructionCodeGeneratorX86_64::GenerateMethodEntryExitHook(HInstruction* i
   __ subq(CpuRegister(index), Immediate(kNumEntriesForWallClock));
   __ gs()->movq(Address::Absolute(trace_buffer_index_addr, /* no_rip= */ true), CpuRegister(index));
 
-  // Record method pointer
+  // Record method pointer and action.
   CpuRegister method = index;
   __ movq(CpuRegister(method), Address(CpuRegister(RSP), kCurrentMethodStackOffset));
+  // Use last two bits to encode trace method action. For MethodEntry it is 0
+  // so no need to set the bits since they are 0 already.
+  if (instruction->IsMethodExitHook()) {
+    DCHECK_GE(ArtMethod::Alignment(kRuntimePointerSize), static_cast<size_t>(4));
+    uint32_t trace_action = 1;
+    __ orq(method, Immediate(trace_action));
+  }
   __ movq(Address(entry_addr, kMethodOffsetInBytes), CpuRegister(method));
-  // Record the method action
-  uint32_t trace_action = instruction->IsMethodExitHook() ? 1 : 0;
-  __ movq(Address(entry_addr, kTraceActionOffsetInBytes), Immediate(trace_action));
   // Get the timestamp. rdtsc returns timestamp in RAX + RDX even in 64-bit architectures.
   __ rdtsc();
   __ shlq(CpuRegister(RDX), Immediate(32));