A64: Synchronize with r16599.

src/a64/builtins-a64.cc

Index: src/a64/builtins-a64.cc
diff --git a/src/a64/builtins-a64.cc b/src/a64/builtins-a64.cc
index 16e1ab4a3c6b6b98f604d38dde26133391a5271f..e64237dc83b6338213032e3313aaf8d15bb3b903 100644
--- a/src/a64/builtins-a64.cc
+++ b/src/a64/builtins-a64.cc
@@ -948,22 +948,29 @@ void Builtins::Generate_OnStackReplacement(MacroAssembler* masm) {
     __ CallRuntime(Runtime::kCompileForOnStackReplacement, 1);
   }
 
-  // If the result was -1 it means that we couldn't optimize the
-  // function. Just return and continue in the unoptimized version.
+  // If the code object is null, just return to the unoptimized code.
   Label skip;
-  __ Cmp(x0, Operand(Smi::FromInt(-1)));
-  __ B(ne, &skip);
+  __ CompareAndBranch(x0, Operand(Smi::FromInt(0)), ne, &skip);
   __ Ret();
 
   __ Bind(&skip);
-  // Untag the AST id and push it on the stack.
-  __ SmiUntag(x0);
-  __ Push(x0);
-
-  // Generate the code for doing the frame-to-frame translation using
-  // the deoptimizer infrastructure.
-  Deoptimizer::EntryGenerator generator(masm, Deoptimizer::OSR);
-  generator.Generate();
+
+  // Load deoptimization data from the code object.
+  // <deopt_data> = <code>[#deoptimization_data_offset]
+  __ Ldr(x1, MemOperand(x0, Code::kDeoptimizationDataOffset - kHeapObjectTag));
+
+  // Load the OSR entrypoint offset from the deoptimization data.
+  // <osr_offset> = <deopt_data>[#header_size + #osr_pc_offset]
+  __ Ldrsw(w1, UntagSmiFieldMemOperand(x1, FixedArray::OffsetOfElementAt(
+      DeoptimizationInputData::kOsrPcOffsetIndex)));
+
+  // Compute the target address = code_obj + header_size + osr_offset
+  // <entry_addr> = <code_obj> + #header_size + <osr_offset>
+  __ Add(x0, x0, x1);
+  __ Add(lr, x0, Code::kHeaderSize - kHeapObjectTag);
+
+  // And "return" to the OSR entry point of the function.
+  __ Ret();
 }