Generate a custom OSR entrypoint for OSR compiles on all platforms, and transition to optimized cod…

src/ia32/builtins-ia32.cc

Index: src/ia32/builtins-ia32.cc
diff --git a/src/ia32/builtins-ia32.cc b/src/ia32/builtins-ia32.cc
index c02726b3ed2a55823edc82c508d8075da40ffbf1..a617da71d367745f58356b55dbcd6ccdc3b32d15 100644
--- a/src/ia32/builtins-ia32.cc
+++ b/src/ia32/builtins-ia32.cc
@@ -1337,22 +1337,30 @@ 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.
   Label skip;
-  __ cmp(eax, Immediate(Smi::FromInt(-1)));
+  // If the code object is null, just return to the unoptimized code.
+  __ cmp(eax, Immediate(0));
   __ j(not_equal, &skip, Label::kNear);
   __ ret(0);
 
   __ bind(&skip);
-  // Untag the AST id and push it on the stack.
-  __ SmiUntag(eax);
-  __ push(eax);
-
-  // 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.
+  __ mov(ebx, Operand(eax, Code::kDeoptimizationDataOffset - kHeapObjectTag));
+
+  // Load the OSR entrypoint offset from the deoptimization data.
+  __ mov(ebx, Operand(ebx, FixedArray::OffsetOfElementAt(
+      DeoptimizationInputData::kOsrPcOffsetIndex) - kHeapObjectTag));
+  __ SmiUntag(ebx);
+
+  // Compute the target address = code_obj + header_size + osr_offset
+  __ lea(eax, Operand(eax, ebx, times_1, Code::kHeaderSize - kHeapObjectTag));
+
+  // Overwrite the return address on the stack.
+  __ mov(Operand(esp, 0), eax);
+
+  // And "return" to the OSR entry point of the function.
+  __ ret(0);
 }