ARM64: Give LR to the allocator.

src/arm64/deoptimizer-arm64.cc

Index: src/arm64/deoptimizer-arm64.cc
diff --git a/src/arm64/deoptimizer-arm64.cc b/src/arm64/deoptimizer-arm64.cc
index 7ac5bd0d2d55b0eae80eba021f6e1159420592b0..0624a99917e3c127a353094411669909f785ad88 100644
--- a/src/arm64/deoptimizer-arm64.cc
+++ b/src/arm64/deoptimizer-arm64.cc
@@ -17,7 +17,7 @@ namespace internal {
 int Deoptimizer::patch_size() {
   // Size of the code used to patch lazy bailout points.
   // Patching is done by Deoptimizer::DeoptimizeFunction.
-  return 4 * kInstructionSize;
+  return 5 * kInstructionSize;
 }
 
 
@@ -48,6 +48,7 @@ void Deoptimizer::PatchCodeForDeoptimization(Isolate* isolate, Code* code) {
     Address deopt_entry = GetDeoptimizationEntry(isolate, i, LAZY);
 
     PatchingAssembler patcher(call_address, patch_size() / kInstructionSize);
+    patcher.adr(ip1, 0);
     patcher.ldr_pcrel(ip0, (2 * kInstructionSize) >> kLoadLiteralScaleLog2);
     patcher.blr(ip0);

[ulan, 2014/06/23 11:17:11]

Did you mean br(ip0) here?

[jbramley, 2014/06/23 17:22:05]

Yes! Thank you.

     patcher.dc64(reinterpret_cast<intptr_t>(deopt_entry));
@@ -150,6 +151,13 @@ static void CopyRegisterDumpToFrame(MacroAssembler* masm,
 #define __ masm()->
 
 void Deoptimizer::EntryGenerator::Generate() {
+  UseScratchRegisterScope temps(masm());
+
+  // The deopt entry jump must put the caller address in ip1. This can be done
+  // either in the level-one deopt table (GenerateDeoptJumpTable), or inline in
+  // the code (DeoptimizeBranch).
+  Register caller_address = temps.Acquire(ip1);
+
   GeneratePrologue();
 
   // TODO(all): This code needs to be revisited. We probably only need to save
@@ -161,9 +169,9 @@ void Deoptimizer::EntryGenerator::Generate() {
                                 FPRegister::kAllocatableFPRegisters);
   __ PushCPURegList(saved_fp_registers);
 
-  // We save all the registers expcept jssp, sp and lr.
-  CPURegList saved_registers(CPURegister::kRegister, kXRegSizeInBits, 0, 27);
-  saved_registers.Combine(fp);
+  // We save all allocatable registers plus fp.
+  CPURegList saved_registers(CPURegister::kRegister, kXRegSizeInBits,
+                             Register::kAllocatableRegisters | fp.Bit());
   __ PushCPURegList(saved_registers);
 
   const int kSavedRegistersAreaSize =
@@ -181,7 +189,7 @@ void Deoptimizer::EntryGenerator::Generate() {
   Register fp_to_sp = x4;
   // Get the address of the location in the code object. This is the return
   // address for lazy deoptimization.
-  __ Mov(code_object, lr);
+  __ Mov(code_object, caller_address);
   // Compute the fp-to-sp delta, and correct one word for bailout id.
   __ Add(fp_to_sp, masm()->StackPointer(),
          kSavedRegistersAreaSize + (1 * kPointerSize));
@@ -303,11 +311,8 @@ void Deoptimizer::EntryGenerator::Generate() {
   // registers (note that at least fp must be restored though).
 
   // Restore registers from the last output frame.
-  // Note that lr is not in the list of saved_registers and will be restored
-  // later. We can use it to hold the address of last output frame while
-  // reloading the other registers.
-  ASSERT(!saved_registers.IncludesAliasOf(lr));
-  Register last_output_frame = lr;
+  Register last_output_frame = temps.AcquireX();
+  ASSERT(!saved_registers.IncludesAliasOf(last_output_frame));
   __ Mov(last_output_frame, current_frame);
 
   // We don't need to restore x7 as it will be clobbered later to hold the