Revert "Change hotness counting."

This reverts commit c86869ab894c05e3181e7d15eb1893fa8a3fcd47.

Reason for revert: App startup performance regression.

Bug: 203810169
Change-Id: Ie816969fffd7740fcdfa330aeb645399f5351865

4 files changed, 11 insertions, 14 deletions

diff --git a/compiler/optimizing/code_generator_arm64.cc b/compiler/optimizing/code_generator_arm64.cc
index f6d38fbaca..74efc9ea8d 100644
--- a/compiler/optimizing/code_generator_arm64.cc
+++ b/compiler/optimizing/code_generator_arm64.cc
@@ -1123,12 +1123,10 @@ void CodeGeneratorARM64::MaybeIncrementHotness(bool is_frame_entry) {
       __ Ldr(method, MemOperand(sp, 0));
     }
     __ Ldrh(counter, MemOperand(method, ArtMethod::HotnessCountOffset().Int32Value()));
-    vixl::aarch64::Label done;
-    DCHECK_EQ(0u, interpreter::kNterpHotnessValue);
-    __ Cbz(counter, &done);
-    __ Add(counter, counter, -1);
+    __ Add(counter, counter, 1);
+    // Subtract one if the counter would overflow.
+    __ Sub(counter, counter, Operand(counter, LSR, 16));
     __ Strh(counter, MemOperand(method, ArtMethod::HotnessCountOffset().Int32Value()));
-    __ Bind(&done);
   }
 
   if (GetGraph()->IsCompilingBaseline() && !Runtime::Current()->IsAotCompiler()) {
diff --git a/compiler/optimizing/code_generator_arm_vixl.cc b/compiler/optimizing/code_generator_arm_vixl.cc
index 29c72d8d07..700202ba20 100644
--- a/compiler/optimizing/code_generator_arm_vixl.cc
+++ b/compiler/optimizing/code_generator_arm_vixl.cc
@@ -2123,12 +2123,10 @@ void CodeGeneratorARMVIXL::MaybeIncrementHotness(bool is_frame_entry) {
     }
     // Load with zero extend to clear the high bits for integer overflow check.
     __ Ldrh(temp, MemOperand(kMethodRegister, ArtMethod::HotnessCountOffset().Int32Value()));
-    vixl::aarch32::Label done;
-    DCHECK_EQ(0u, interpreter::kNterpHotnessValue);
-    __ CompareAndBranchIfZero(temp, &done, /* is_far_target= */ false);
-    __ Add(temp, temp, -1);
+    __ Add(temp, temp, 1);
+    // Subtract one if the counter would overflow.
+    __ Sub(temp, temp, Operand(temp, ShiftType::LSR, 16));
     __ Strh(temp, MemOperand(kMethodRegister, ArtMethod::HotnessCountOffset().Int32Value()));
-    __ Bind(&done);
     if (!is_frame_entry) {
       __ Pop(vixl32::Register(kMethodRegister));
       GetAssembler()->cfi().AdjustCFAOffset(-static_cast<int>(kArmWordSize));
diff --git a/compiler/optimizing/code_generator_x86.cc b/compiler/optimizing/code_generator_x86.cc
index e6e22d3c4a..c49b08ba69 100644
--- a/compiler/optimizing/code_generator_x86.cc
+++ b/compiler/optimizing/code_generator_x86.cc
@@ -1109,9 +1109,10 @@ void CodeGeneratorX86::MaybeIncrementHotness(bool is_frame_entry) {
     }
     NearLabel overflow;
     __ cmpw(Address(reg, ArtMethod::HotnessCountOffset().Int32Value()),
-            Immediate(interpreter::kNterpHotnessValue));
+            Immediate(ArtMethod::MaxCounter()));
     __ j(kEqual, &overflow);
-    __ addw(Address(reg, ArtMethod::HotnessCountOffset().Int32Value()), Immediate(-1));
+    __ addw(Address(reg, ArtMethod::HotnessCountOffset().Int32Value()),
+            Immediate(1));
     __ Bind(&overflow);
     if (!is_frame_entry) {
       __ popl(EAX);
diff --git a/compiler/optimizing/code_generator_x86_64.cc b/compiler/optimizing/code_generator_x86_64.cc
index de78bf27ff..0584dc1365 100644
--- a/compiler/optimizing/code_generator_x86_64.cc
+++ b/compiler/optimizing/code_generator_x86_64.cc
@@ -1491,10 +1491,10 @@ void CodeGeneratorX86_64::MaybeIncrementHotness(bool is_frame_entry) {
       __ movq(CpuRegister(method), Address(CpuRegister(RSP), kCurrentMethodStackOffset));
     }
     __ cmpw(Address(CpuRegister(method), ArtMethod::HotnessCountOffset().Int32Value()),
-            Immediate(interpreter::kNterpHotnessValue));
+            Immediate(ArtMethod::MaxCounter()));
     __ j(kEqual, &overflow);
     __ addw(Address(CpuRegister(method), ArtMethod::HotnessCountOffset().Int32Value()),
-            Immediate(-1));
+            Immediate(1));
     __ Bind(&overflow);
   }