A64: Synchronize with r16599.

src/a64/lithium-a64.cc

Index: src/a64/lithium-a64.cc
diff --git a/src/a64/lithium-a64.cc b/src/a64/lithium-a64.cc
index 66778d355f2c258c93865b758c4e667c04a054ae..2002835145838c538c6ad486c3370c82dbfb2765 100644
--- a/src/a64/lithium-a64.cc
+++ b/src/a64/lithium-a64.cc
@@ -30,6 +30,7 @@
 #include "lithium-allocator-inl.h"
 #include "a64/lithium-a64.h"
 #include "a64/lithium-codegen-a64.h"
+#include "hydrogen-osr.h"
 
 namespace v8 {
 namespace internal {
@@ -592,6 +593,17 @@ LPlatformChunk* LChunkBuilder::Build() {
   chunk_ = new(zone_) LPlatformChunk(info_, graph_);
   LPhase phase("L_Building chunk", chunk_);
   status_ = BUILDING;
+
+  // If compiling for OSR, reserve space for the unoptimized frame,
+  // which will be subsumed into this frame.
+  if (graph()->has_osr()) {
+    // TODO(all): GetNextSpillIndex just increments a field. It has no other
+    // side effects, so we should get rid of this loop.
+    for (int i = graph()->osr()->UnoptimizedFrameSlots(); i > 0; i--) {
+      chunk_->GetNextSpillIndex();
+    }
+  }
+
   const ZoneList<HBasicBlock*>* blocks = graph_->blocks();
   for (int i = 0; i < blocks->length(); i++) {
     DoBasicBlock(blocks->at(i));
@@ -2462,10 +2474,18 @@ LInstruction* LChunkBuilder::DoUnaryMathOperation(HUnaryMathOperation* instr) {
 
 
 LInstruction* LChunkBuilder::DoUnknownOSRValue(HUnknownOSRValue* instr) {
-  int spill_index = chunk_->GetNextSpillIndex();
-  if (spill_index > LUnallocated::kMaxFixedSlotIndex) {
-    Abort(kTooManySpillSlotsNeededForOSR);
-    spill_index = 0;
+  // Use an index that corresponds to the location in the unoptimized frame,
+  // which the optimized frame will subsume.
+  int env_index = instr->index();
+  int spill_index = 0;
+  if (instr->environment()->is_parameter_index(env_index)) {
+    spill_index = chunk_->GetParameterStackSlot(env_index);
+  } else {
+    spill_index = env_index - instr->environment()->first_local_index();
+    if (spill_index > LUnallocated::kMaxFixedSlotIndex) {
+      Abort(kTooManySpillSlotsNeededForOSR);
+      spill_index = 0;
+    }
   }
   return DefineAsSpilled(new(zone()) LUnknownOSRValue, spill_index);
 }