Merge "ART: Fix Quick-style LR vs PC core spill mask bug"

3 files changed, 22 insertions, 21 deletions

diff --git a/compiler/dex/quick/arm/call_arm.cc b/compiler/dex/quick/arm/call_arm.cc
index eb8730cf4b..868d9a43e9 100644
--- a/compiler/dex/quick/arm/call_arm.cc
+++ b/compiler/dex/quick/arm/call_arm.cc
@@ -547,27 +547,28 @@ void ArmMir2Lir::GenExitSequence() {
     cfi_.RestoreMany(DwarfFpReg(0), fp_spill_mask_);
   }
   bool unspill_LR_to_PC = (core_spill_mask_ & (1 << rs_rARM_LR.GetRegNum())) != 0;
+  uint32_t core_unspill_mask = core_spill_mask_;
   if (unspill_LR_to_PC) {
-    core_spill_mask_ &= ~(1 << rs_rARM_LR.GetRegNum());
-    core_spill_mask_ |= (1 << rs_rARM_PC.GetRegNum());
+    core_unspill_mask &= ~(1 << rs_rARM_LR.GetRegNum());
+    core_unspill_mask |= (1 << rs_rARM_PC.GetRegNum());
   }
-  if (core_spill_mask_ != 0u) {
-    if ((core_spill_mask_ & ~(0xffu | (1u << rs_rARM_PC.GetRegNum()))) == 0u) {
+  if (core_unspill_mask != 0u) {
+    if ((core_unspill_mask & ~(0xffu | (1u << rs_rARM_PC.GetRegNum()))) == 0u) {
       // Unspilling only low regs and/or PC, use 16-bit POP.
       constexpr int pc_bit_shift = rs_rARM_PC.GetRegNum() - 8;
       NewLIR1(kThumbPop,
-              (core_spill_mask_ & ~(1u << rs_rARM_PC.GetRegNum())) |
-              ((core_spill_mask_ & (1u << rs_rARM_PC.GetRegNum())) >> pc_bit_shift));
-    } else if (IsPowerOfTwo(core_spill_mask_)) {
+              (core_unspill_mask & ~(1u << rs_rARM_PC.GetRegNum())) |
+              ((core_unspill_mask & (1u << rs_rARM_PC.GetRegNum())) >> pc_bit_shift));
+    } else if (IsPowerOfTwo(core_unspill_mask)) {
       // kThumb2Pop cannot be used to unspill a single register.
-      NewLIR1(kThumb2Pop1, CTZ(core_spill_mask_));
+      NewLIR1(kThumb2Pop1, CTZ(core_unspill_mask));
     } else {
-      NewLIR1(kThumb2Pop, core_spill_mask_);
+      NewLIR1(kThumb2Pop, core_unspill_mask);
     }
     // If we pop to PC, there is no further epilogue code.
     if (!unspill_LR_to_PC) {
       cfi_.AdjustCFAOffset(-num_core_spills_ * kArmPointerSize);
-      cfi_.RestoreMany(DwarfCoreReg(0), core_spill_mask_);
+      cfi_.RestoreMany(DwarfCoreReg(0), core_unspill_mask);
       DCHECK_EQ(cfi_.GetCurrentCFAOffset(), 0);  // empty stack.
     }
   }
diff --git a/compiler/optimizing/code_generator_arm.cc b/compiler/optimizing/code_generator_arm.cc
index 438ef694bf..a4c58b095a 100644
--- a/compiler/optimizing/code_generator_arm.cc
+++ b/compiler/optimizing/code_generator_arm.cc
@@ -48,7 +48,7 @@ static constexpr Register kMethodRegisterArgument = R0;
 // with baseline.
 static constexpr Register kCoreSavedRegisterForBaseline = R5;
 static constexpr Register kCoreCalleeSaves[] =
-    { R5, R6, R7, R8, R10, R11, PC };
+    { R5, R6, R7, R8, R10, R11, LR };
 static constexpr SRegister kFpuCalleeSaves[] =
     { S16, S17, S18, S19, S20, S21, S22, S23, S24, S25, S26, S27, S28, S29, S30, S31 };
 
@@ -409,8 +409,8 @@ CodeGeneratorARM::CodeGeneratorARM(HGraph* graph,
       method_patches_(MethodReferenceComparator(), graph->GetArena()->Adapter()),
       call_patches_(MethodReferenceComparator(), graph->GetArena()->Adapter()),
       relative_call_patches_(graph->GetArena()->Adapter()) {
-  // Save the PC register to mimic Quick.
-  AddAllocatedRegister(Location::RegisterLocation(PC));
+  // Always save the LR register to mimic Quick.
+  AddAllocatedRegister(Location::RegisterLocation(LR));
 }
 
 void CodeGeneratorARM::Finalize(CodeAllocator* allocator) {
@@ -599,12 +599,9 @@ void CodeGeneratorARM::GenerateFrameEntry() {
     RecordPcInfo(nullptr, 0);
   }
 
-  // PC is in the list of callee-save to mimic Quick, but we need to push
-  // LR at entry instead.
-  uint32_t push_mask = (core_spill_mask_ & (~(1 << PC))) | 1 << LR;
-  __ PushList(push_mask);
-  __ cfi().AdjustCFAOffset(kArmWordSize * POPCOUNT(push_mask));
-  __ cfi().RelOffsetForMany(DWARFReg(kMethodRegisterArgument), 0, push_mask, kArmWordSize);
+  __ PushList(core_spill_mask_);
+  __ cfi().AdjustCFAOffset(kArmWordSize * POPCOUNT(core_spill_mask_));
+  __ cfi().RelOffsetForMany(DWARFReg(kMethodRegisterArgument), 0, core_spill_mask_, kArmWordSize);
   if (fpu_spill_mask_ != 0) {
     SRegister start_register = SRegister(LeastSignificantBit(fpu_spill_mask_));
     __ vpushs(start_register, POPCOUNT(fpu_spill_mask_));
@@ -632,7 +629,10 @@ void CodeGeneratorARM::GenerateFrameExit() {
     __ cfi().AdjustCFAOffset(-kArmPointerSize * POPCOUNT(fpu_spill_mask_));
     __ cfi().RestoreMany(DWARFReg(SRegister(0)), fpu_spill_mask_);
   }
-  __ PopList(core_spill_mask_);
+  // Pop LR into PC to return.
+  DCHECK_NE(core_spill_mask_ & (1 << LR), 0U);
+  uint32_t pop_mask = (core_spill_mask_ & (~(1 << LR))) | 1 << PC;
+  __ PopList(pop_mask);
   __ cfi().RestoreState();
   __ cfi().DefCFAOffset(GetFrameSize());
 }
diff --git a/runtime/oat.h b/runtime/oat.h
index 1520a9bb02..b8b8d30f99 100644
--- a/runtime/oat.h
+++ b/runtime/oat.h
@@ -32,7 +32,7 @@ class InstructionSetFeatures;
 class PACKED(4) OatHeader {
  public:
   static constexpr uint8_t kOatMagic[] = { 'o', 'a', 't', '\n' };
-  static constexpr uint8_t kOatVersion[] = { '0', '6', '9', '\0' };
+  static constexpr uint8_t kOatVersion[] = { '0', '7', '0', '\0' };
 
   static constexpr const char* kImageLocationKey = "image-location";
   static constexpr const char* kDex2OatCmdLineKey = "dex2oat-cmdline";